Stress analysis of self-tightness metal sealing against ultrahigh pressure medium

Stress is one of the most important factors in metal-to-metal sealing. In this paper, two methods (theoretical and empirical) were adopted to calculate the normal stress of the brass sealing surfaces against different ultrahigh pressure liquid. The theoretical formula was derived in terms of force balance, and the empirical formula was obtained by polynomial curve fitting, which the fitted data were from simulated results; besides, the results calculated using the empirical formula agree well with the results by theoretical formula. Meanwhile, the equivalent stresses of the brass seal, normal stress and contact stress on the brass seal surfaces were simulated by finite element method, and the simulated results indicated these stresses are increased with the increase of liquid pressure, and the maximum stresses always appear on the tip of the brass seal.

Periodontitis Exacerbates Benign Prostatic Hyperplasia through Regulation of Oxidative Stress and Inflammation

Epidemiological studies demonstrate that men with periodontitis are also susceptible to benign prostatic hyperplasia (BPH) and that periodontal treatment can improve the prostatic symptom. However, molecular links of this relationship are largely unknown. The goal of the current study was to elucidate the effects of experimental periodontitis on the hyperplasia of prostate and whether oxidative stress and inflammation participated in this process. For this purpose, ligature-induced periodontitis, testosterone-induced BPH, and the composite models in rats were established. Four weeks later, all the rats were sacrificed and the following items were measured: alveolar bone loss and histological examination of periodontal tissues were taken to assess the establishment of periodontitis model, prostate index and histological examination of prostate tissues were taken to test the establishment of the BPH model, inflammatory cytokines in plasma were assessed, and Bax/Bcl-2 proteins related to cell apoptosis were analyzed via western blot analysis. To further investigate whether oxidative stress participates in the aggravation of BPH, in vitro models were also conducted to measure the production of intracellular reactive oxygen species (ROS) and hydrogen peroxide (H2O2) concentration. We found that simultaneous periodontitis and BPH synergistically aggravated prostate histological changes, significantly increased Ki67 proliferation, and reduced apoptosis in rat prostate tissues. Also, our results showed that periodontal ligation induced increased Bcl-2 protein expression, whereas Bax expression was decreased in BPH rats than in normal rats. Compared with the control group, periodontitis and BPH both significantly enhanced inflammatory cytokine levels of TNF-α, IL-6, IL-1β, and CRP. Furthermore, Porphyromonas gingivalis lipopolysaccharide induced enhanced generation of intracellular expression of ROS and H2O2 in BPH-1 cells. Our experimental evidence demonstrated that periodontitis might promote BPH development through regulation of oxidative stress and inflammatory process, thus providing new strategies for prevention and treatment of BPH.

[Research progress on building of disease control and prevention system of the international experience]

Through literature search in regular database and official websites of relevant countries, this paper combs and summarizes the main characteristics of disease prevention and control systems in five countries, the United States, Germany, South Korea, Australia and Japan, and the European Union at key levels including legal construction, organizational structure, financing, personnel construction and international cooperation, in order to provide decision support for the construction of disease prevention and control system in China in the future.

Establishment and Validation of an ICP-MS Method for Simultaneous Measurement of 24 Elemental Impurities in Ubenimex APIs According to USP/ICH guidelines

Background:

To control the potential presence of heavy metals in pharmaceuticals, the United States Pharmacopeia (USP) and International Conference on Harmonization (ICH) have put forth new requirements and guidelines. USP <232> and ICH Q3D specify 24 elemental impurities and their concentration limits in consideration of the permitted daily exposure (PDE) of different drug categories (oral, parenteral and inhalation). while USP <233> describes more information about sample preparation and method validation procedure.

Objective:

To establish and verify an ICP-MS method for the determination of 24 elemental impurities (Cd, Pb, As, Hg, Co, V, Ni, Tl, Au, Pd, Ir, Os, Ph, Ru, Se, Ag, Pt, Li, Sb, Ba, Mo, Cu, Sn, Cr) in ubenimex APIs according to USP/ICH guidelines.

Method:

Samples were analyzed by ICP-MS after direct dissolution in diluted acid solution. All elements were detected in He/HEHe mode (except for Li, which was in No gas mode).

Results:

The spiked recoveries were within 80-120% except Hg (79.4% at 0.5J level in HEHe mode) and Cd (121.9% at 0.5J level in HE mode). The RSD of repeatability (N = 6) for all elements were < 7.0% and intermediate precision (N = 12) were < 9.0%. The correlation coefficients of linear (R) for 24 elements were all > 0.998. The limits of detection (LOD) were < 1 ng/mL except that Ni was 1.23 ng/mL in HEHe mode. The contents of 24 elements in 3 batches of samples were significantly lower than the actual target limit of ICH, while the highest content of Pd did not exceed 10 μg/g.

Conclusion:

The established method was proved to be simple, sensitive and accurate. It successfully applied to the elemental impurity determination in 3 batches of ubenimex APIs from different manufactories. This method also provided technical guidance for determination of multiple elements in pharmaceutical products.

Comparing clinical parameters of abnormal and normal fasting blood glucose in benign prostatic hyperplasia patients

OBJECTIVE

To investigate the correlation of clinical measurements on normal and abnormal fasting blood glucose (FBG) with benign prostatic hyperplasia (BPH).

METHODS

From September 2016 to January 2018, 771 BPH patients were enrolled for further selection. The eligible patients were divided into normal FBG, impaired fasting glucose (IFG), and high risk of type 2 diabetes mellitus (HR-T2DM) groups. Then, relevant parameters were compared among these three groups using Pearson's correlation coefficient.

RESULTS

Finally including 443 patients with normal FBG, 113 with IFG and 56 with HR-T2DM. Height, weight, body mass index, smoking status, hemoglobin, serum Na⁺, serum Cl^-, and serum Ca²⁺ were significantly different between normal and abnormal FBG groups. In IFG/HR-T2DM group, obviously connections were demonstrated for weight with prostate volume (PV), for serum Na⁺, PV, and serum Cl^- with total prostate-specific antigen (t-PSA), for FBG with international prostate symptom score (IPSS). In normal FBG group, significant correlations of age, weight, body mass index, hemoglobin, and serum Ca²⁺ with PV, of age, systolic blood pressure, PV, and serum Cl^- with t-PSA; and of FBG, hemoglobin, and serum Na⁺ with IPSS were also observed.

CONCLUSIONS

Our study suggests that FBG level probably plays an important role in BPH.

Chemoprophylaxis, diagnosis, treatments, and discharge management of COVID-19: An evidence-based clinical practice guideline (updated version)

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a rapidly spreading illness, coronavirus disease 2019 (COVID-19), affecting more than seventeen million people around the world. Diagnosis and treatment guidelines for clinicians caring for patients are needed. In the early stage, we have issued "A rapid advice guideline for the diagnosis and treatment of 2019 novel coronavirus (2019-nCoV) infected pneumonia (standard version)"; now there are many direct evidences emerged and may change some of previous recommendations and it is ripe for develop an evidence-based guideline. We formed a working group of clinical experts and methodologists. The steering group members proposed 29 questions that are relevant to the management of COVID-19 covering the following areas: chemoprophylaxis, diagnosis, treatments, and discharge management. We searched the literature for direct evidence on the management of COVID-19, and assessed its certainty generated recommendations using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Recommendations were either strong or weak, or in the form of ungraded consensus-based statement. Finally, we issued 34 statements. Among them, 6 were strong recommendations for, 14 were weak recommendations for, 3 were weak recommendations against and 11 were ungraded consensus-based statement. They covered topics of chemoprophylaxis (including agents and Traditional Chinese Medicine (TCM) agents), diagnosis (including clinical manifestations, reverse transcription-polymerase chain reaction (RT-PCR), respiratory tract specimens, IgM and IgG antibody tests, chest computed tomography, chest x-ray, and CT features of asymptomatic infections), treatments (including lopinavir-ritonavir, umifenovir, favipiravir, interferon, remdesivir, combination of antiviral drugs, hydroxychloroquine/chloroquine, interleukin-6 inhibitors, interleukin-1 inhibitors, glucocorticoid, qingfei paidu decoction, lianhua qingwen granules/capsules, convalescent plasma, lung transplantation, invasive or noninvasive ventilation, and extracorporeal membrane oxygenation (ECMO)), and discharge management (including discharge criteria and management plan in patients whose RT-PCR retesting shows SARS-CoV-2 positive after discharge). We also created two figures of these recommendations for the implementation purpose. We hope these recommendations can help support healthcare workers caring for COVID-19 patients.

Fasting blood glucose level and hypertension risk in aging benign prostatic hyperplasia patients

Evidence suggests there maybe an association among abnormal fasting blood glucose, hypertension and benign prostatic hyperplasia. In this study, we investigated whether abnormal fasting blood glucose correlates with hypertension in aging benign prostatic hyperplasia patients. Ultimately, 612 benign prostatic hyperplasia patients, including 230 hypertensive patients and 382 normotensive patients, were included. Univariate and multivariate logistic regression analyses were used to evaluate the associations. The results indicated that neither impaired fasting glucose/high risk of type 2 diabetes mellitus nor high risk of type 2 diabetes mellitus were associated with an increased risk of hypertension. When patients were stratified based on the severity of their hypertension, similar results were obtained (all P> 0.05). After adjusting for confounding factors, the nonsignificant tendencies for high risk of type 2 diabetes mellitus and impaired fasting glucose/high risk of type 2 diabetes mellitus to associate with hypertension persisted (all P> 0.05). Unlike earlier studies, the present study suggests that the level of fasting blood glucose may not be significantly related to hypertension in aging patients with benign prostatic hyperplasia.

Perceived infection transmission routes, infection control practices, psychosocial changes, and management of COVID-19 infected healthcare workers in a tertiary acute care hospital in Wuhan: a cross-sectional survey

BACKGROUND

Many healthcare workers were infected by coronavirus disease 2019 (COVID-19) early in the epidemic posing a big challenge for epidemic control. Hence, this study aims to explore perceived infection routes, influencing factors, psychosocial changes, and management procedures for COVID-19 infected healthcare workers.

METHODS

This is a cross-sectional, single hospital-based study. We recruited all 105 confirmed COVID-19 healthcare workers in the Zhongnan Hospital of Wuhan University from February 15 to 29, 2020. All participants completed a validated questionnaire. Electronic consent was obtained from all participants. Perceived causes of infection, infection prevention, control knowledge and behaviour, psychological changes, symptoms and treatment were measured.

RESULTS

Finally, 103 professional staff with COVID-19 finished the questionnaire and was included (response rate: 98.1%). Of them, 87 cases (84.5%) thought they were infected in working environment in hospital, one (1.0%) thought their infection was due to the laboratory environment, and 5 (4.9%) thought they were infected in daily life or community environment. Swab of throat collection and physical examination were the procedures perceived as most likely causing their infection by nurses and doctors respectively. Forty-three (41.8%) thought their infection was related to protective equipment, utilization of common equipment (masks and gloves). The top three first symptoms displayed before diagnosis were fever (41.8%), lethargy (33.0%) and muscle aches (30.1%). After diagnosis, 88.3% staff experienced psychological stress or emotional changes during their isolation period, only 11.7% had almost no emotional changes. Arbidol (Umifenovir; an anti-influza drug; 69.2%) was the drug most commonly used to target infection in mild and moderate symptoms.

CONCLUSION

The main perceived mode of transmission was not maintaining protection when working at a close distance and having intimate contact with infected cases. Positive psychological intervention is necessary.

The important effect of 5-HTTLPR polymorphism on the risk of depression in patients with coronary heart disease: a meta-analysis

Background

Depression has been recognized as an independent risk factor of coronary heart disease (CHD). Moreover, there is interrelationship of both depression and CHD. However, the potential pathophysiological mechanisms remain unknown. It might be influenced by genetic and environmental factors. According to recent researches, there is potential association between serotonin transporter gene-linked polymorphic region (5-HTTLPR) polymorphism and risk of depression in CHD patients, but the results are still inconclusive. Therefore, we performed this meta-analysis based on unadjusted and adjusted data to ascertain a more precise conclusion.

Methods

We searched relevant articles through PubMed, Embase, Web of Science, Chinese BioMedical Literature (CBM) and Chinese National Knowledge Infrastructure (CNKI) databases up to August 26, 2019. Study selection and data extraction were accomplished by two authors independently. The strength of the correlation was assessed via odds ratios (ORs) with their 95% confidence intervals (95%CIs).

Results

This meta-analysis enrolled six observational studies. Based on unadjusted data, there was significant relationship between 5-HTTLPR polymorphism and depression risk in CHD patients under all genetic models (S vs. L: OR = 1.31, 95%CI = 1.07–1.60; SS vs. LL: OR = 1.73, 95%CI = 1.12–2.67; LS vs. LL: OR = 1.47, 95%CI = 1.13–1.92; LS + SS vs. LL: OR = 1.62, 95%CI = 1.25–2.09; SS vs. LL + LS: OR = 1.33, 95%CI = 1.02–1.74). The results of adjusted data further strengthened this relationship (SS vs. LL: OR = 1.89, 95%CI = 1.28–2.80; LS vs. LL: OR = 1.69, 95%CI = 1.14–2.51; LS + SS vs. LL: OR = 1.80, 95%CI = 1.25–2.59). Subgroup analyses based on ethnicity and major depressive disorder revealed similar results to that of the overall analysis. No evidence of publication bias was observed.

Conclusions

Our results suggest that 5-HTTLPR polymorphism may have an important effect on the risk of depression among patients with CHD, and carriers of the S allele of 5-HTTLPR are more vulnerable to depression.

A rapid advice guideline for the diagnosis and treatment of 2019 novel coronavirus (2019-nCoV) infected pneumonia (standard version)

In December 2019, a new type viral pneumonia cases occurred in Wuhan, Hubei Province; and then named "2019 novel coronavirus (2019-nCoV)" by the World Health Organization (WHO) on 12 January 2020. For it is a never been experienced respiratory disease before and with infection ability widely and quickly, it attracted the world's attention but without treatment and control manual. For the request from frontline clinicians and public health professionals of 2019-nCoV infected pneumonia management, an evidence-based guideline urgently needs to be developed. Therefore, we drafted this guideline according to the rapid advice guidelines methodology and general rules of WHO guideline development; we also added the first-hand management data of Zhongnan Hospital of Wuhan University. This guideline includes the guideline methodology, epidemiological characteristics, disease screening and population prevention, diagnosis, treatment and control (including traditional Chinese Medicine), nosocomial infection prevention and control, and disease nursing of the 2019-nCoV. Moreover, we also provide a whole process of a successful treatment case of the severe 2019-nCoV infected pneumonia and experience and lessons of hospital rescue for 2019-nCoV infections. This rapid advice guideline is suitable for the first frontline doctors and nurses, managers of hospitals and healthcare sections, community residents, public health persons, relevant researchers, and all person who are interested in the 2019-nCoV.

A rapid advice guideline for the diagnosis and treatment of 2019 novel coronavirus (2019-nCoV) infected pneumonia (standard version)

In December 2019, a new type viral pneumonia cases occurred in Wuhan, Hubei Province; and then named "2019 novel coronavirus (2019-nCoV)" by the World Health Organization (WHO) on 12 January 2020. For it is a never been experienced respiratory disease before and with infection ability widely and quickly, it attracted the world's attention but without treatment and control manual. For the request from frontline clinicians and public health professionals of 2019-nCoV infected pneumonia management, an evidence-based guideline urgently needs to be developed. Therefore, we drafted this guideline according to the rapid advice guidelines methodology and general rules of WHO guideline development; we also added the first-hand management data of Zhongnan Hospital of Wuhan University. This guideline includes the guideline methodology, epidemiological characteristics, disease screening and population prevention, diagnosis, treatment and control (including traditional Chinese Medicine), nosocomial infection prevention and control, and disease nursing of the 2019-nCoV. Moreover, we also provide a whole process of a successful treatment case of the severe 2019-nCoV infected pneumonia and experience and lessons of hospital rescue for 2019-nCoV infections. This rapid advice guideline is suitable for the first frontline doctors and nurses, managers of hospitals and healthcare sections, community residents, public health persons, relevant researchers, and all person who are interested in the 2019-nCoV.

A rapid advice guideline for the diagnosis and treatment of 2019 novel coronavirus (2019-nCoV) infected pneumonia (standard version)

In December 2019, a new type viral pneumonia cases occurred in Wuhan, Hubei Province; and then named "2019 novel coronavirus (2019-nCoV)" by the World Health Organization (WHO) on 12 January 2020. For it is a never been experienced respiratory disease before and with infection ability widely and quickly, it attracted the world's attention but without treatment and control manual. For the request from frontline clinicians and public health professionals of 2019-nCoV infected pneumonia management, an evidence-based guideline urgently needs to be developed. Therefore, we drafted this guideline according to the rapid advice guidelines methodology and general rules of WHO guideline development; we also added the first-hand management data of Zhongnan Hospital of Wuhan University. This guideline includes the guideline methodology, epidemiological characteristics, disease screening and population prevention, diagnosis, treatment and control (including traditional Chinese Medicine), nosocomial infection prevention and control, and disease nursing of the 2019-nCoV. Moreover, we also provide a whole process of a successful treatment case of the severe 2019-nCoV infected pneumonia and experience and lessons of hospital rescue for 2019-nCoV infections. This rapid advice guideline is suitable for the first frontline doctors and nurses, managers of hospitals and healthcare sections, community residents, public health persons, relevant researchers, and all person who are interested in the 2019-nCoV.

Mn2O3/Al2O3 cathode material derived from a metal–organic framework with enhanced cycling performance for aqueous zinc-ion batteries

Rechargeable aqueous zinc-ion batteries (ZIBs) are considered to be potential candidates for large-scale energy storage due to their high capacity, low cost, high safety and environmental friendliness.

[Estimates of influenza-associated excess mortality by three regression models in Shanxi Province during 2013-2017]

Objective: Using three models too estimate excess mortality associated with influenza of Shanxi Province during 2013-2017. Methods: Mortality data and influenza surveillance data of 11 cities of Shanxi Province from the 2013-2014 through 2016-2017 were used to estimate influenza-associated all cause deaths, circulatory and respiratory deaths and respiratory deaths. Three models were used: (i) Serfling regression, (ii)Poisson regression, (iii)General line model. Results: The total reported death cases of all cause were 157 733, annual death cases of all cause were 39 433, among these cases, male cases 93 831 (59.50%), cases above 65 years old 123 931 (78.57%). Annual influenza-associated excess mortality, for all causes, circulatory and respiratory deaths, respiratory deaths were 8.62 deaths per 100 000, 6.33 deaths per 100 000 and 0.68 deaths per 100 000 estimated by Serfling model, respectively; and 21.30 deaths per 100 000, 16.89 deaths per 100 000 and 2.14 deaths per 100 000 estimated by General line model, respectively; and 21.76 deaths per 100 000, 17.03 deaths per 100 000 and 2.05 deaths per 100 000, estimated by Poisson model, respectively. Influenza-related excess mortality was higher in people over 75 years old; influenza-associated excess mortalityfor all causes, circulatory and respiratory deaths, respiratory deaths were 259.67 deaths per 100 000, 229.90 deaths per 100 000 and 32.63 deaths per 100 000, estimated by GLM model, respectively; and 269.49 deaths per 100 000, 233.69 deaths per 100 000 and 31.27 deaths per 100 000, estimated by Poisson model,respectively. Conclusion: Excess mortality associated with influenza mainly caused by A (H3N2), Influenza caused the most associated death amongold people.

Clinical Trial Registration and Reporting: Drug Therapy and Prevention of Cardiac-Related Infections

Objective: Clinical trials are the source of evidence. ClinicalTrials.gov is valuable for analyzing current conditions. Until now, the state of drug interventions for heart infections is unknown. The purpose of this study was to comprehensively assess the characteristics of trials on cardiac-related infections and the status of drug interventions.

Methods: The website ClinicalTrials.gov was used to obtain all registered clinical trials on drug interventions for cardiac-related infections as of February 16, 2019. All registration studies were collected, regardless of their recruitment status, research results, and research type. Registration information, results, and weblink-publications of those trials were analyzed.

Results: A total of 45 eligible trials were evaluated and 86.7% of them began from or after 2008 while 91.1% of them adopted interventional study design. Of all trials, 35.6% were completed and 15.6% terminated. Besides, 62.2% of interventional clinical trials recruited more than 100 subjects. Meanwhile, 86.7% of the eligible trials included adult subjects only. Of intervention trials, 65.8% were in the third or fourth phase; 78.1% adopted randomized parallel assignment, containing two groups; 53.6% were masking, and 61.0% described treatment. Moreover, 41.5% of the trials were conducted in North America while 29.3% in Europe. Sponsors for 40.0% of the studies were from the industry. Furthermore, 48.9% of the trials mentioned information on monitoring committees, 24.4% have been published online, and 13.3% have uploaded their results. Drugs for treatments mainly contained antibiotics, among which glycopeptides, β-lactams, and lipopeptides were the most commonly studied ones in experimental group, with the former ones more common. Additionally, 16.2% of the trials evaluated new antimicrobials.

Conclusions: Most clinical trials on cardiac-related infections registered at ClinicalTrials.gov were interventional randomized controlled trials (RCTs) for treatment. Most drugs focused in trials were old antibiotics, and few trials reported valid results. It is necessary to strengthen supervision over improvements in results, and to combine antibacterial activity with drug delivery regimens to achieve optimal clinical outcomes.

Periodontal Disease Is Associated With Increased Risk of Hypertension: A Cross-Sectional Study

Objective: Published evidence showed that periodontal disease is associated with hypertension. However, relevant findings remain controversial, with few evidences focusing on Chinese population. Therefore, the aim of this study was to investigate the association between periodontal disease and hypertension in Chinese population.

Methods: A total of 4,930 participants from an available health examination that was carried out in 2017 were selected for this retrospective study. The correlations between periodontal disease and hypertension were investigated using univariate and multiple logistic regression analyses and propensity score adjusted analysis. Interaction and subgroup analyses were also used to detect variable factors.

Results: Finally, a total of 3,952 participants aged 30–68 years were eligible for this study. The results showed that hypertension risk was statistically significant associated with periodontal disease either in unadjusted (OR = 1.28, 95%CI = 1.14–1.47) or in adjusted (OR = 1.34, 95%CI = 1.14–1.58) model. Result from propensity score adjusted analysis also demonstrated a similar association (OR = 1.23, 95%CI = 1.06–1.42).

Conclusion: Periodontal disease is significantly and positively correlated with increased risk of hypertension in Chinese population, and exact mechanisms of this association should be explored in future.

[Transurethral bipolar plasmakinetic prostatectomy for benign prostatic hyperplasia in high-risk and senior patients in China: a systematic review and meta-analysis]

Objective: To evaluate the effectiveness and safety of transurethral bipolar plasmakinetic prostatectomy in the treatment of benign prostatic hyperplasia in high-risk and senior patients in China. Methods: The PubMed, Cochrane Library, CBM, CNKI and WanFang databases were searched with computer for collecting relevant interventional case series from establishment dates to September 14, 2018. After quality evaluation and data extraction independently conducted by two authors, the Meta-analysis was performed using the Comprehensive Meta-analysis V2 software. Results: Eighteen studies involving 1 899 patients are included. Maximum flow rate increased to 12.28 ml/s (95%CI: 8.42-16.14), 12.88 ml/s (95%CI: 9.85-15.92) ,14.32 ml/s (95%CI: 10.47-18.18), 14.93 ml/s (95%CI: 10.19-19.67) and 20.00 ml/s (95%CI: 19.08-20.92) in 1, 3, 6, 12 and 24 months after surgery, respectively. International prostate symptom score decreased to -18.60 (95%CI: -23.20--14.00), -17.62 (95%CI: -20.21--15.03), -19.14 (95%CI: -20.70--17.59), -19.06 (95%CI: -21.53--16.60) and -22.90 (95%CI: -24.26--21.54), respectively. Quality of life decreased to -2.38 (95%CI: -4.26--0.50), -3.39 (95%CI: -4.57--2.21),-3.75 (95%CI: -4.14--3.36), -3.36(95%CI: -4.56--2.16), and -4.58(95%CI: -4.75--4.41). Post void residual decreased to -231.16 ml (95%CI: -288.30--174.01), -76.10 ml (95%CI: -116.71--35.50), -159.90 ml(95%CI: -207.21--112.59) and -87.70 ml (95%CI: -91.91--83.48). The event rate of postoperative adverse reactions all were not high. Conclusion: Transurethral bipolar plasmakinetic prostatectomy has better clinical efficacy and no obvious side effects in the treatment of benign prostatic hyperplasia in high-risk and senior patients in China.

[Technical guidelines for seasonal influenza vaccination in China, 2018-2019]

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and its complications. Currently, China has licensed trivalent (IIV3) and quadrivalent inactivated influenza vaccine (IIV4), including split-virus influenza vaccine and subunit vaccine. In most parts of China, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients need to pay for it. To strengthen the technical guidance for prevention and control of influenza and the operational research on influenza vaccination in China, the National Immunization Advisory Committee (NIAC), Influenza Vaccine Technical Working Group (TWG), updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)" , based on most recent existing scientific evidences. The main updates include: epidemiology and disease burden of influenza, types of influenza vaccines, northern hemisphere influenza vaccination composition for the 2018-2019 season, and, IIV3 and IIV4 vaccines'major immune responses, durability of immunity, immunogenicity, vaccine efficacy, effectiveness, safety, cost-effectiveness and cost-benefit. The recommendations include: Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications. No preferential recommendation is made for any influenza vaccine product for persons who can accept ≥1 licensed, recommended, and appropriate products. To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups, the recommendations prioritize seasonal influenza vaccination for children aged 6-60 months, adults ≥60 years of age, persons with specific chronic diseases, healthcare workers, the family members and caregivers of infants <6 months of age, and pregnant women or women who plan to pregnant during the influenza season. Children aged 6 months to 8 years old require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection. If they were vaccinated in previous influenza season, 1 dose is recommended. People ≥ 9 years old require 1 dose of influenza vaccine. It is recommended that people receive their influenza vaccination by the end of October. Influenza vaccination should be offered as soon as the vaccination is available. Influenza vaccination should continue to be available for those unable to be vaccinated before the end of October during the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for CDC members who are working on influenza control and prevention, PoVs members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and members of maternity and child care institutions at all levels.

The Top-100 Highly Cited Original Articles on Drug Therapy for Ventilator-Associated Pneumonia

Background: In recent decades, research on drug therapy for ventilator-associated pneumonia (VAP) remains one of the major hot-spots in the field of critical care medicine, but relevant data are not satisfactory. Our aim was to assess the status and trends of the most cited articles on drug therapy for VAP through bibliometric approaches. Methods: The Institute for Scientific Information (ISI) Web of Science core collection database was searched for the VAP-related articles. The time period for retrieval was from the beginning of the database to September 30, 2018. The top 100 most cited articles were selected to obtain their information on the authors, title, publication, number of citations, author's affiliations, country, etc. These general information and bibliometric data were collected for analysis. VOSviewer software was used to generate a term co-occurrence graph that visualized a reference pattern for different terms in the 100 articles. Results: The number of citations for the 100 selected articles ranged from 142 to 3,218. These articles were published in 31 different journals. The top three journals in terms of the number of our selected articles they published were "Critical Care Medicine" (17 articles), "American Journal of Respiratory and Critical Care Medicine" (11 articles) and "Clinical Infectious Diseases" (10 articles). The most frequently nominated author was Marin H. Kollef from the University of Washington, and of the top 100 articles, 16 listed his name. These top 100 articles were published after the year of 2000. The most common type of article in the top 100 was an original article (53%). The United States and France were the countries that contributed the most articles to the top 100. Gram-negative bacilli, pseudomonas aeruginosa, antibiotics, risk factors and other terms appeared more frequently, suggesting that attentions on this issue currently focused on the rational application and management of antibiotics. Conclusion: This study analyzed the 100 most cited articles on drug-treated VAP, and provided insights into the historical developments and characteristics of the most cited articles in the field of VAP.

[Technical guidelines for seasonal influenza vaccination in China (2018-2019)]

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and complications from infection. Currently, China has licensed trivalent inactivated influenza vaccine (IIV3) and quadrivalent inactivated influenza vaccine (IIV4), including split-virus influenza vaccine and subunit vaccine. Except for a few major cities, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients must pay for it. To strengthen the technical guidance for prevention and control of influenza and operational research on influenza vaccination in China, the National Immunization Advisory Committee (NIAC) Influenza Vaccine Technical Working Group (TWG), updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)" . The main updates in this version include: epidemiology, disease burden, types of influenza vaccines, northern hemisphere influenza vaccination composition for the 2018-2019 season, IIV3 and IIV4 immune response, durability of immunity, immunogenicity, vaccine efficacy, effectiveness, safety, cost-effectiveness and cost-benefit. The influenza vaccine TWG provided the recommendations for influenza vaccination for the 2018-2019 influenza season based on existing scientific evidence. The recommendations described in this report include the following: Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended, and appropriate product is available. To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups, the recommendations prioritize seasonal influenza vaccination for children aged 6-59 months, adults ≥60 years of age, persons with specific chronic diseases, healthcare workers, the family members and caregivers of infants <6 months of age, and pregnant women or women who plan to become pregnant during the influenza season. Children aged 6 months through 8 years require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection. If they were vaccinated in 2017-2018 influenza season or a prior season, 1 dose is recommended. People more than 8 years old require 1 dose of influenza vaccine. It is recommended that people receive their influenza vaccination by the end of October. Influenza vaccination should be offered as soon as the vaccination is available. For the people unable to be vaccinated before the end of October, influenza vaccination will continue to be offered for the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for use by staff members of the Centers for Disease Control and Prevention at all levels who work on influenza control and prevention, PoVs staff members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and staff members of maternity and child care institutions at all levels.

Up-Regulation of Phosphatase in Regenerating Liver-3 (PRL-3) Contributes to Malignant Progression of Hepatocellular Carcinoma by Activating Phosphatase and Tensin Homolog Deleted on Chromosome Ten (PTEN)/Phosphoinositide 3-Kinase (PI3K)/AKT Signaling Pathway

BACKGROUND The purpose of the study was to investigate the functional roles of phosphatase in regenerating liver-3 (PRL-3) in hepatocellular carcinoma (HCC), as well as the related molecular mechanisms. MATERIAL AND METHODS HCC tissues and adjacent normal tissues were collected from 124 HCC patients. The mRNA and protein levels of PRL-3 were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot assays, respectively. The relationship between PRL-3 expression and clinical characteristics of HCC patients was evaluated by chi-square test. MTT and Transwell assays were performed to estimate cell proliferation and motility, respectively. RESULTS The expression of PRL-3 was significantly increased in HCC tissues and cells at both protein and mRNA levels (P<0.01 for all). Furthermore, the up-regulation of PRL-3 was positively correlated with hepatic vascular invasion (P=0.019), lymph node metastasis (P=0.012), and TNM stage (P=0.001). The knockdown of PRL-3 suppressed HCC cell proliferation, migration, and invasion, and PR3K/AKT pathway activity was also obviously inhibited in HCC cells with PRL-3 deficiency. The levels of PTEN were negatively associated with PRL-3 expression. PRL-3 might inhibit the protein level of PTEN through enhancing its phosphorylation level. The transfection of si-PTEN can reverse the anti-tumor action caused by PRL-3 knockdown in HCC cells. CONCLUSIONS Up-regulation of PRL-3 may activate the PI3K/AKT signaling pathway and enhance malignant progression of HCC through targeting PTEN.

Efficacy, acceptability, and tolerability of antidepressant treatments for patients with post-stroke depression: a network meta-analysis

The aim of this study was to investigate the efficacy, acceptability, and tolerability of antidepressants in treating post-stroke depression (PSD) by performing a network meta-analysis of randomized controlled trials of the current literature. Eligible studies were retrieved from online databases, and relevant data were extracted. The primary outcome was efficacy as measured by the mean change in overall depressive symptoms. Secondary outcomes included discontinued treatment for any reason and specifically due to adverse events. Fourteen trials were eligible, which included 949 participants and 9 antidepressant treatments. Few significant differences were found for all outcomes. For the primary outcome, doxepin, paroxetine, and nortriptyline were significantly more effective than a placebo [standardized mean differences: −1.93 (95%CI=−3.56 to −0.29), −1.39 (95%CI=−2.59 to −0.21), and −1.25 (95%CI=−2.46 to −0.04), respectively]. Insufficient evidence exists to select a preferred antidepressant for treating patients with post-stroke depression, and our study provides little evidence that paroxetine may be the potential choice when starting treatment for PSD. Future studies with paroxetine and larger sample sizes, multiple medical centers, and sufficient intervention durations is needed for improving the current evidence.

[Association between ambient PM(l0)/PM(2.5) concentration and outpatient department visits due to respiratory disease in a hospital in Jinan, 2013-2015: a time series analysis]

Objective: To estimate the influence of the ambient PM(l0) and PM(2.5) pollution on the hospital outpatient department visit due to respiratory diseases in local residents in Jinan quantitatively. Methods: Time serial analysis using generalized addictive model (GAM) was conducted. After controlling the confounding factors, such as long term trend, weekly pattern and meteorological factors, considering lag effect and the influence of other air pollutants, the excess relative risks of daily hospital visits associated with increased ambient PM(10) and PM(2.5) levels were estimated by fitting a Poisson regression model. Results: A 10 μg/m(3) increase of PM(10) and PM(2.5) levels was associated with an increase of 0.36%(95%CI: 0.30%-0.43%) and 0.50%(95%CI: 0.30%-0.70%) respectively for hospital visits due to respiratory diseases. Lag effect of 6 days was strongest, the excess relative risks were 0.65% (95% CI: 0.58% -0.71% ) and 0.54% (95% CI: 0.42%-0.67%) respectively. When NO(2) concentration was introduced, the daily hospital visits due to respiratory disease increased by 0.83% as a 10 μg/m(3) increase of PM(10) concentration (95% CI: 0.76%-0.91%). Conclusion: The ambient PM(l0) and PM(2.5) pollution was positively associated with daily hospital visits due to respiratory disease in Jinan, and ambient NO(2) concentration would have the synergistic effect.

Reference of Temperature and Time during tempering process for non-stoichiometric FTO films

In order to enhance the mechanical strength of Low-E glass, Fluorine-doped tin oxide (FTO) films have to be tempered at high temperatures together with glass substrates. The effects of tempering temperature (600 °C ~ 720 °C) and time (150 s ~  300 s) on the structural and electrical properties of FTO films were investigated. The results show all the films consist of non-stoichiometric, polycrystalline SnO2 without detectable amounts of fluoride. 700 °C and 260 s may be the critical tempering temperature and time, respectively. FTO films tempered at 700 °C for 260 s possesses the resistivity of 7.54 × 10(-4) Ω • cm, the average transmittance in 400 ~ 800 nm of ~80%, and the calculated emissivity of 0.38. Hall mobility of FTO films tempered in this proper condition is mainly limited by the ionized impurity scattering. The value of [O]/[Sn] at the film surface is much higher than the stoichiometric value of 2.0 of pure crystalline SnO2.

QTL mapping analysis of plant height and ear height of maize (Zea mays L.)

Genetic map containing 103 microsatellite loci obtained on 200 F2 plants derived from the cross R15 x 478 was used for quantitative trait loci (QTL) mapping in maize. QTL were characterized in a population of 200 F2:4 lines, derived from selfing the F2 plants, and were evaluated with two replications in two environments. QTL determinations were made from the mean of these two environments. Plant height (PH) and ear height (EH) were measured. Using composite interval mapping (CIM) method, a total of 14 distinct QTLs were identified: nine for PH and five for EH. Additive, partial dominance, dominance, and overdominance actions existed among all detected QTL affecting plant height and ear height. The QTL explained 78.27% of the phenotypic variance of PH and 41.50% of EH. The 14 QTLs displayed mostly dominance or partial dominance gene action and mapped to chromosomes 2, 3, 4, 8 and 9.

The 70 kilodalton heat shock protein is an inhibitor of apoptosis in prostate cancer

The 70 kD heat shock protein (HSP70) plays essential cellular roles in mediating intracellular protein folding and protecting cells from proteotoxic stress. This study has examined the role of HSP70 in the expression of apoptosis in prostate carcinoma cells. Apoptosis was negatively correlated with HSP70 expression in PC-3 cells heat shocked in vivo. Further experiments carried out on an in vitro reconstituted system with isolated nuclei and cytoplasm from PC-3 cells showed that purified HSP70 directly inhibits apoptosis in a dose-dependant manner. Therefore, the potential role of depletion of intracellular HSP70 was examined as a means of inducing apoptosis in PC-3 cancer cells. Depletion of HSP70 by two independent strategies, either with anti-sense oligonucleotides directed against HSP70 mRNA or with the bioflavinoid drug quercetin, led to apoptosis in the absence of stress. In addition, quercetin pre-treatment synergistically enhanced apoptosis in combination with heat shock. Thus, HSP70 plays a physiological role in tumour cells as an inhibitor of apoptosis occurring both spontaneously and after stress and is a potential target for apoptosis-based cancer therapy.

Salicylic acid and aspirin inhibit the activity of RSK2 kinase and repress RSK2-dependent transcription of cyclic AMP response element binding protein- and NF-kappa B-responsive genes

Sodium salicylate (NaSal) and other nonsteroidal anti-inflammatory drugs (NSAIDs) coordinately inhibit the activity of NF-kappa B, activate heat shock transcription factor 1 and suppress cytokine gene expression in activated monocytes and macrophages. Because our preliminary studies indicated that these effects could be mimicked by inhibitors of signal transduction, we have studied the effects of NSAIDs on signaling molecules potentially downstream of LPS receptors in activated macrophages. Our findings indicate that ribosomal S6 kinase 2 (RSK2), a 90-kDa ribosomal S6 kinase with a critical role as an effector of the RAS-mitogen-activated protein kinase pathway and a regulator of immediate early gene transcription is a target for inhibition by the NSAIDs. NSAIDs inhibited the activity of purified RSK2 kinase in vitro and of RSK2 in mammalian cells and suppressed the phosphorylation of RSK2 substrates cAMP response element binding protein (CREB) and I-kappa B alpha in vivo. Additionally, NaSal inhibited the phosphorylation by RSK2 of CREB and I-kappa B alpha on residues crucial for their transcriptional activity in vivo and thus repressed CREB and NF-kappa B-dependent transcription. These experiments suggest that RSK2 is a target for NSAIDs in the inhibition of monocyte-specific gene expression and indicate the importance of RSK2 and related kinases in cell regulation, indicating a new area for anti-inflammatory drug discovery.

[Studies on the ganoderic acid, a new constituents from the fruiting body of Ganoderma lucidum (Fr.) Karst]

Three compounds have been isolated from the dichloromethane soluble fraction of the fruiting body of Ganoderma lucidum (Fr.) Karst. On basis of spectral analyses (UV, IR, MS, 1HNMR, 13CNMR and 2D-NMR), they were identified as 3, 7-dioxo-lanosta-8, 24(E)-dien-26-oic acid (I), 7 beta-15 alpha-dihydroxy-3, 11, 23-trioxo-5 alpha-lanost-8-en-26-oic acid (II) and 3 beta, 7 beta, 15 alpha-trihydroxy-11, 23-dioxo-5 alpha-lanosta-8-en-26-oic acid (III). Compound I is a new compound named ganoderic acid DM.

Kinetics of the competitive degradation of deoxyribose and other molecules by hydroxyl radicals produced by the Fenton reaction in the presence of ascorbic acid

The competition method in which the Fenton reaction is employed as an .OH radical generator and deoxyribose as a detecting molecule, has been used to determine the rate constants for reactions of the .OH radical with its scavengers. Nonlinear competition plots were obtained for those scavengers which reacted with the Fenton reagents (Fe2+ or H2O2). Ascorbic acid is believed to overcome this problem. We have investigated the kinetics of deoxyribose degradation by .OH radicals generated by the Fenton reaction in the presence of ascorbic acid, and observed that the inclusion of ascorbic acid in the Fenton system greatly increased the rate of .OH radical generation. As a result, the interaction between some scavengers and the Fenton reagents became negligeable and linear competition plots of A degree/A vs scavenger concentrations were obtained. The effects of experimental conditions such as, the concentrations of ascorbic acid, deoxyribose, H2O2 and Fe(2+)-EDTA, the EDTA/Fe2+ ratio as well as the incubation time, on the deoxyribose degradation and the determination of the rate constant for mercaptoethanol chosen as a reference compound were studied. The small standard error, (6.76 +/- 0.21) x 10(9) M-1s-1, observed for the rate constant values for mercaptoethanol determined under 13 different experimental conditions, indicates the latter did not influence the rate constant determination. This is in fact assured by introducing a term, kx, into the kinetic equation. This term represents the rate of .OH reactions with other reagents such as ascorbic acid, Fe(2+)-EDTA, H2O2 etc. The agreement of the rate constants obtained in this work with that determined by pulse radiolysis techniques for cysteine, thiourea and many other scavengers, suggests that this simple competition method is applicable to a wide range of compounds, including those which react with the Fenton reagents and those whose solubility in water is low.

Gas chromatographic-mass spectrometric determination of ibuprofen enantiomers in human plasma using R(-)-2,2,2-trifluoro-1-(9-anthryl)ethanol as derivatizing reagent

A relatively rapid, inexpensive, sensitive and stereospecific gas chromatographic-mass spectrometric method was developed for the quantification of S(+) and R(-)-ibuprofen in human plasma. This method uses a commercially available internal standard and has no interference from endogenous substances nor metabolites. The method involves derivatization of ibuprofen enantiomers with optically active R(-)-2,2,2-trifluoro-1-(9-anthryl)ethanol using oxalyl chloride as the coupling reagent. The subsequently formed diastereoisomers are separated by gas chromatography and analysed by mass spectrometry using selected-ion monitoring. The assay is successfully applied to a pharmacokinetic study. The simplicity, sensitivity and precision of the method make it convenient for the quantification of ibuprofen enantiomers in biological samples.

Transcriptional regulation by a point mutant of adenovirus-2 E1a product lacking DNA binding activity

The adenovirus E1a protein (E1A) regulates transcription through interaction with transcription factors bound to DNA, like cAMP response element BP1/ATF2, or through dissociating E2F transcription factor complex. However, it was also reported that E1A can bind to DNA (Chatterjee, P. K., Bruner, M., Flint, S. J., and Harter, M. L. (1988) EMBO J. 7, 835-841), and it is not clear whether DNA binding of E1A is involved in a part of the process of transcriptional regulation by E1A. In this paper, the small region of E1A that is responsible for DNA binding was identified and a point mutant lacking DNA binding activity was constructed. Analysis of deletion mutants of E1A proteins expressed in bacteria showed that a basic region between amino acids 201 and 216 of E1A is essential for DNA binding. Point mutation of arginines at amino acid numbers 205 and 206 to aspartic acids completely abolished the DNA binding activity of E1A. Using this mutant, the requirement of the E1A DNA binding for E1A-dependent transcriptional regulation was examined. trans-Activation of the adenovirus E4 promoter and trans-repression of the human c-erbB-2 promoter by this point mutant were examined by cotransfection experiments. Mutations of the E1A DNA-binding domain affected neither the E1A-induced trans-activation nor trans-repression at all. These results give complete proof that the DNA binding activity of E1A is not required for transcriptional regulation by E1A.

HIV-EP2, a new member of the gene family encoding the human immunodeficiency virus type 1 enhancer-binding protein. Comparison with HIV-EP1/PRDII-BF1/MBP-1

At least two different types of proteins, NF-kappa B/KBF1 and HIV-EP1/PRDII-BF1/MBP-1, which are members of a family of rel oncoproteins and metal-finger proteins, respectively, bind to the human immunodeficiency virus type (HIV-1) enhancer. As a new member of a HIV-EP1 family that is expressed at a high level in T cells, we have isolated cDNA clones of HIV-EP2 by cross-hybridization with HIV-EP1 cDNA. HIV-EP2 protein consists of 1,833 amino acids and has a molecular weight of 211,000. HIV-EP2 protein is highly homologous with HIV-EP1/PRDII-BF1/MBP-1 in three regions. These three regions contain the potential nuclear localization signal followed by a Ser/Thr-rich region, the DNA-binding domain consisting of a metal-finger structure, and a cluster of acidic amino acids. The DNA-binding property of HIV-EP2 was similar to that of HIV-EP1. Northern blot analysis of HIV-EP2 mRNA indicated relatively high expression in the T cell line Molt-4 and in some tumor cell lines. Furthermore, like HIV-EP1, expression of HIV-EP2 mRNA was greatly induced by mitogen and phorbol ester treatment of Jurkat T cells, suggesting that HIV-EP2 acts in HIV production from latently infected T cells.

Seasonal changes in cation transport in red blood cells of grey squirrel (Sciurus carolinensis) in relation to thermogenesis and cellular adaptation to cold

1. Unidirectional influx of 42K was measured in red cells of grey squirrels at seasonal intervals over two years. 2. Na/K pump-related (i.e. ouabain-sensitive) K influx at 37 degrees C was maximal in cells collected in January and was more than three times greater than cells collected in summer. Na/K pump activity, maximized by loading the cells with Na, exhibited a similar difference. 3. At 5 degrees C in fresh cells, ouabain-sensitive K influx, expressed as per cent of that at 37 degrees C, was highest in March. In Na-loaded cells it was lowest in summer. 4. Passive "leak" K influx (i.e., the residual influx remaining in presence of ouabain and bumetanide) was highest in October, and declined progressively to the summer months, when it was only 27% of that in October. 5. Cotransport (i.e., bumetanide-sensitive K influx) exhibited the same seasonal pattern as Na/K pump activity in fresh cells. 6. Net gain of Na in cells stored at 5 degrees C for three days in March was less than half of that in January or summer. 7. High transport activity in January may correlate with a requirement for increased non-shivering thermogenesis. However, red cells of grey squirrels exhibit maximum resistance to low temperature in March and at this time resemble the red cells of hibernating mammals.

Identical G+1 to A mutations in three different introns of the type III procollagen gene (COL3A1) produce different patterns of RNA splicing in three variants of Ehlers-Danlos syndrome. IV. An explanation for exon skipping some mutations and not others

Identical G+1 mutations in three different introns of the gene for type III procollagen (COL3A1) that cause aberrant splicing of RNA were found in three probands with life-threatening variants of Ehlers-Danlos syndrome. Because the three mutations were in a gene with multiple and homologous exons, they provided an interesting test for factors that influence aberrant splicing. The G+1 to A mutation in intron 16 caused extensive exon skipping, the G+1 to A mutation in intron 20 caused both use of a cryptic splice site and retention of all the intron sequences, and the G+1 to A mutation in intron 42 caused efficient use of a single cryptic splice site. The different patterns of RNA splicing were not explained by evaluation of potential cryptic splice sites in the introns by either their homology with 5'-splice sites from other genes or by their delta G(0)37 values for binding to U1 RNA. Instead, the results suggested that the patterns of aberrant RNA splicing were primarily determined by the relative rates at which adjacent introns were normally spliced.

The effects of acutely increased ventricular cavity pressure on intrinsic myocardial connective tissue

Studies of normal hearts have revealed a variety of intrinsic connective tissue structures that surround and interconnect myocytes and ventricular mural layers. Among these structures, springlike coiled perimysial fibers, arrayed parallel to myocytes in the interstitial space, have been described in papillary muscle and ventricle. To evaluate the role of the coiled perimysial fibers under perturbed conditions, rat ventricles were filled with barium-gelatin under different pressures and fixed, and then the myocardium was impregnated with silver to visualize the connective tissue. Ventricles were filled at 30, 70 and 100 to 120 mm Hg. The coiled perimysial fibers were studied for their orientation, stretch, integrity and relation to sarcomere length. The coils were noted to embed within the fibrous anulus and to knot into an umbilical-like mass at the apex, thus anchoring them at both ends of the ventricle. They underwent focal straightening even at 30 mm Hg, with generalized straightening and disruption at the highest pressure; changes were most pronounced in the midventricle. Sarcomeres were maintained below 2.2 micron at 30 and 70 mm Hg of cavity pressure in regions of coiled perimysial fiber stretch; only with fiber disruption at 100 to 120 mm Hg were sarcomeres significantly lengthened. Other findings included connective tissue disruption between ventricular wall layers that allowed slippage of myocytes and mural thinning. These observations suggest that coiled perimysial fibers may act as a buffer to protect myocytes from damage under the effects of high cavity pressure.

Reduced ion transport in erythrocytes of male Sprague-Dawley rats during starvation

Although several studies have suggested that the reduced activity of the Na+-K+ pump during starvation is a source of energy conservation, the hypothesis has not been tested in intact cells, nor has the contribution of passive permeability been considered in a controlled animal study. In this study three components of K+ influx (Na+-K+ pump = ouabain sensitive, cotransport = bumetanide sensitive and leak = both ouabain and bumetanide insensitive) and Na+ influx were measured with 42K+ and 24Na+ in intact red blood cells of adult male rats. During starvation rats lost an average of 28% of their body weight; pump K+ influx in cells stabilized for 2 h in incubation medium fell from 7.03 +/- 0.74 (SEM) to 4.82 +/- 0.25 mueq/(mL cells.h) with cell [Na+] of 6.4 +/- 0.9 and 4.4 +/- 0.2 mmol/L cells, respectively. Maximized Na+-K+ pump activity in Na+-loaded cells was also lower in cells of starved rats than in those of controls and was inversely correlated with extent of weight loss in the starved rats. Leak K+ influx was reduced from 0.73 +/- 0.08 to 0.47 +/- 0.03. Lower Na+ influx in cells of starved rats was not significant statistically, although alteration in passive Na+ transport was apparent. The results indicate decreases in both active and passive components of ion turnover of erythrocytes of rats during starvation.

Profound structural alterations of the extracellular collagen matrix in postischemic dysfunctional ("stunned") but viable myocardium

Ultrastructural studies of the extracellular collagen matrix were made on the "stunned" myocardium using scanning, conventional and high voltage transmission electron microscopy and light microscopy. Regional myocardial dysfunction was produced by 12 sequential 5 minute occlusions of the left anterior descending coronary artery, separated by 10 minute intervals of reperfusion. A final 90 minute reperfusion period documented persistent myocardial dysfunction. At the end of the final reperfusion period, the percent systolic shortening, measured by sonomicrometers, was depressed significantly to 35 +/- 9% of baseline. The heart was then perfusion fixed, and samples were taken from both control and stunned areas. No changes associated with irreversible cellular damage were noted in the stunned region. However, scanning electron microscopy of the stunned area showed that the extracellular collagen matrix underwent profound structural changes. Collagen cables were roughened, uncoiled and discontinuous. Linear grooves on the surface of the myocytes were frequently seen, indicating complete loss of collagen cables. The usual dense collagen weave surrounding myocytes became patchy or absent. Myocyte to myocyte struts were sparse and frequently absent, with remnant nodular or nublike structures indicative of breakage. High voltage electron microscopy of the stunned area showed that the collagen struts were discontinuous and vacuolated with rounded tips. Light microscopy of silver-stained sections of the stunned tissue demonstrated large patchy areas that were devoid of silver, indicating absence of the collagen matrix. There was a progressive increase in percent systolic bulging during each sequential coronary occlusion, suggesting increasing myocardial compliance. These results indicate that the myocardial collagen matrix is severely damaged from reversible ischemic cell injury. The greater myocardial compliance and less effective contractile effort in the stunned myocardium might be explained on a structural basis: disruption of the mechanical coupling function provided by the extracellular collagen matrix.