Mismatched hemagglutinin and neuraminidase specificities in recent human H3N2 influenza viruses

The hemagglutinin (HA) of influenza viruses initiates infection by binding to sialic acid on the cell surface via alpha2,6 (human) or alpha2,3 (avian) linkage. The influenza neuraminidase (NA) can cleave both alpha2,3- and alpha2,6-linked sialic acids, but all influenza NAs have a marked preference for the non-human alpha2,3 linkage. Recent H3N2 influenza viruses have lost the ability to agglutinate chicken red blood cells. To determine if changes in HA specificity or affinity correlate with NA specificity or activity, we examined red cell binding and elution of a series of H3N2 viruses. We found that the NA activity of many influenza viruses does not release binding by their HA. In some egg-adapted strains, lack of elution correlates with low levels of viral NA activity, and these elute rapidly when bacterial NA is added. However, a Fujian-like virus, A/Oklahoma/323/03, does not elute by its own NA or with Vibrio cholerae sialidase, and it binds to red cells pre-treated with V. cholerae sialidase. It elutes after addition of the broad specificity Micromonospora viridifaciens sialidase. Human glycophorin inhibits A/Oklahoma/323/03 hemagglutination 6-fold better than fetuin. We conclude that specific forms of sialic acid are used as receptor by recent human H3N2 influenza viruses, perhaps involving branched alpha2,6 sialic acid or alpha2,8 sialic acid structures on O-linked carbohydrates. The virus itself has no O-linked glycans, so even though the NA is not able to cleave receptors on cells, the viruses will not self-aggregate. It will be important to monitor efficacy of neuraminidase inhibitors in case there are NA-resistant receptors in the human respiratory tract that allow the viruses to be less dependent on NA activity.     

Endotoxin-induced gamma interferon production: contributing cell types and key regulatory factors

Gamma interferon (IFN-gamma) is an important mediator of endotoxin (lipopolysaccharide [LPS])-induced immune responses. However, the specific cell types that produce IFN-gamma in response to LPS and the cellular factors that regulate LPS-induced IFN-gamma production have not been fully determined. The present studies were undertaken to characterize the cell populations that produce IFN-gamma after LPS challenge in the spleens of mice and to determine the regulatory factors that modulate LPS-induced production of IFN-gamma. Our studies show that the levels of splenic IFN-gamma mRNA and protein production peak at 6 and 8 h, respectively, after systemic LPS challenge. Approximately 60% of IFN-gamma-producing cells are natural killer (NK) cells (CD3(-)DX5(+)) and 25% are NKT cells (CD3(+)DX5(+)). Most of the remaining IFN-gamma-producing cells are T cells (CD3(+)DX5(-)), macrophages, and dendritic cells. Functionally, interleukin-12 (IL-12) is the major IFN-gamma-stimulating factor after LPS challenge, with costimulation provided by IL-15, IL-18, and B7 proteins. IL-10 is a major inhibitor of LPS-induced IFN-gamma production. Unlike intact heat-killed gram-negative and gram-positive bacteria, the class II major histocompatibility complex did not play a functional role in LPS-induced IFN-gamma production. LPS is a potent stimulus for splenic IL-10, IL-12 p40, and IL-15 mRNA expression, whereas IL-12 p35 and IL-18 mRNAs, as well as B7 proteins, are constitutively expressed in the mouse spleen. Of the factors studied, IL-18 serves as the most potent costimulus with IL-12 for IFN-gamma production, followed by IL-15 and B7 proteins. These data demonstrate that NK cells and NKT cells are the most abundant IFN-gamma-producing cells in the mouse spleen after LPS challenge and that IL-10 and IL-12 are key functional regulators of LPS-induced IFN-gamma production.     

巯甲丙脯酸对实验性冠状动脉痉挛致左室功能不全的作用

犬２１只，经左冠脉内注射麦角新硷诱发冠脉痉挛后随机静滴生理盐水（对照组）或等量盐水溶的巯甲丙脯酸（治疗组），观察１小时。心电图显示治疗组的异常ＳＴ段下降和严重室性心律失常明显少于对照组；冠脉造影显示治疗组痉挛血管支数及狭窄程度均少于和轻于对照组；左室造影和超声心电图显示治疗组的左室收缩末和舒张末容积小于对照组，ＥＦ值或△Ｄ大于对照组，ＡＡ／ＥＡ小于对照组；血流动力学参数表明治疗组左室收缩压，平均肺     

Evaluation of the Coulter three-part differential screen

An evaluation of the Coulter Electronics, Inc. (Hialeah, FL) three-part differential screen (3PD) was undertaken to determine the performance characteristics of this system. The 3PD measures white blood cell (WBC) volumes and, by automatic analysis of the resultant WBC histogram, produces a determination of the number and percent of lymphocytes, mononuclear cells, and granulocytes. A group of 984 random patient blood samples was tested. The overall review rate (samples requiring some further analysis or review) was 42%. The main source of false negatives on the 3PD was eosinophilia: 5 out of 22 instances of eosinophilia greater than 750/microL were not flagged. The precision of the three parameters, measured as percent coefficient of variation, was 3.3% for lymphocytes, 14.2% for mononuclear cells, 3.1% for granulocytes, and 2.4% for the total WBC. The stability of blood samples was acceptable for up to eight hours at room temperature (less at 4 degrees C).     

Factors affecting the detection of enteroviruses in cerebrospinal fluid with coxsackievirus B3 and poliovirus 1 cDNA probes.

Enteroviruses are common pathogens of meningitis and encephalitis, and infections are often difficult to distinguish clinically from bacterial and herpetic infections of the central nervous system. An array of enteroviruses added to cerebrospinal fluid in reconstruction experiments were detected by a dot hybridization assay. Optimal handling and processing conditions for infected cerebrospinal fluid were established, and the effect on the hybridization reaction of humoral and cellular components of the inflammatory response was determined. Six hybridization probes, derived from poliovirus 1 and coxsackievirus B3, were then tested, singly and in combinations, to optimize the sensitivity and spectrum of the assay. Implications for enteroviral taxonomy based on these experiments are discussed.     

An evaluation of three methods of typing organisms of the genus Proteus

An assessment of three simple methods of typing Proteus strains is described. The methods chosen were biochemical typing, bacteriocine typing, and typing by means of the Dienes phenomenon. Dienes typing was deemed to be superior to biochemical typing and bacteriocine typing.A brief discussion on the relationship between the Dienes phenomenon and bacteriocine production is appended.     

Effects of Advertising: A Qualitative Analysis of Young Adults’ Engagement with Social Media About Food

Young adults are constantly exposed to energy-dense, nutrient-poor food and beverages, particularly through advertising. Exposure can influence poor food choices and negatively impact health. This study aimed to understand young adults’ attitudes and experiences associated with food-related advertisements, particularly on social media. This qualitative analysis involved n = 166 Australian 18 to 24-year-olds who were involved in a four-week online conversation on different areas relating to health, social media, and eating. Inductive thematic analysis was utilised on two forums on the recall and perceptions of food-related advertisements. Young adults commonly mentioned aspects of the marketing mix (promotion, product, price, and place) in food advertisements. Participants were more readily able to recall energy-dense, nutrient-poor food advertisements compared to healthy food-related advertisements. Digital advertisements were often discussed alongside the use of ad-blockers and algorithms which tailored their social media viewing to what they like. Participants felt constant exposure to unhealthy food advertisements hindered their ability to realise healthy eating behaviours and created feelings of guilt. This current analysis highlights the need to provide an advertising environment that appropriately motivates healthy eating and a food environment that allows healthy food to be the affordable and convenient option.     

Psycho-Behavioural Segmentation in Food and Nutrition: A Systematic Scoping Review of the Literature

Inadequate dietary intakes are a key modifiable risk factor to reduce the risk of developing non-communicable diseases. To encourage healthy eating and behaviour change, innovative public health interventions are required. Social marketing, in particular segmentation, can be used to understand and target specific population groups. However, segmentation often uses demographic factors, ignoring the reasons behind why people behave the way they do. This review aims to explore the food and nutrition related research that has utilised psycho-behavioural segmentation. Six databases from were searched in June 2020. Inclusion criteria were: published 2010 onwards, segmentation by psycho-behavioural variables, outcome related to food or nutrition, and healthy adult population over 18 years. 30 studies were included; most were quantitative (n = 28) and all studies used post-hoc segmentation methods, with the tools used to segment the population varying. None of the segments generated were targeted in future research. Psycho-behavioural factors are key in understanding people’s behaviour. However, when used in post-hoc segmentation, do not allow for effective targeting as there is no prior understanding of behaviours that need to change within each segment. In future, we should move towards hybrid segmentation to assist with the design of interventions that target behaviours such as healthy eating.     

Correction to: Middle School Effects of the Dating Matters® Comprehensive Teen Dating Violence Prevention Model on Physical Violence,Bullying, and Cyberbullying: A Cluster-Randomized Controlled Trial

Prevention Science - The article “Middle School Effects of the Dating Matters® Comprehensive Teen Dating Violence Prevention Model on Physical Violence, Bullying, and Cyberbullying: a...     

A Group Randomized Trial Evaluating High School FLASH,a Comprehensive Sexual Health Curriculum

PurposeTo evaluate the effectiveness of a school-based comprehensive sexual health curriculum (FLASH) on high-school students’ sexual behavior and related outcomes.MethodsA cohort of 1,597 9th and 10th grade students representing 20 schools from two regions in the U.S. (Midwest and South) were enrolled and completed the baseline survey. Following baseline, the 20 schools were randomly assigned to receive FLASH (n = 10 schools, five per region) or a knowledge-based sexual health curriculum (n = 10 schools, five per region). Follow-up surveys were administered at 3 months and 12 months after the instruction period.ResultsThere were no statistically significant differences between conditions for the overall sample on rates of vaginal sex in the past 3 months or the rates of vaginal sex without a condom or other birth control. In supplementary subgroup analyses of students who were not sexually experienced at baseline, FLASH showed a statistically significant protective impact at the 3-month follow-up on vaginal sex without a condom or birth control (p = .04). FLASH also showed statistically significant gains in psychosocial outcomes, such as refusal and condom use self-efficacy, attitudes toward birth control and condoms, and perceived norms.ConclusionsFLASH demonstrated consistent short-term and long-term impacts on key behavioral determinants. It also showed a significant impact on vaginal sex without a condom or other birth control for the subgroup of students who were not sexually experienced at baseline. Behavioral impacts were not evident for the entire study population.