Impact of prior SARS-CoV-2 infection on college students' hesitancy to receive additional COVID-19 vaccine booster doses: A study from Taizhou, China

Purpose

This study aimed to examine the impact of a history of SARS-CoV-2 infection on the hesitancy of college students to receive additional COVID-19 vaccine booster doses.

Methods

A population-based self-administered online survey was conducted in July 2024 in Taizhou, China. A total of 792 respondents were included in this study. Logistic regression was conducted to identify factors associated with college students' hesitation to receive booster doses of the COVID-19 vaccine.

Results

Of 792 respondents, 32.2 % hesitated to receive additional doses of the COVID-19 vaccine booster. Furthermore, 23.5 % of the respondents reported an increase in hesitancy to receiving additional COVID-19 vaccine booster doses compared to before they were infected with SARS-CoV-2. In the regression analyses, college students who had a secondary infection were more hesitant to receive additional COVID-19 vaccine booster doses (OR = 0.481, 95 % CI: (0.299-0.774), P = 0.003). Moreover, students with secondary infections who were male (OR = 0.417, 95 % CI: 0.221-0.784, P = 0.007), with lower than a bachelor's degree (OR = 0.471, 95 % CI: 0.272-0.815, P = 0.007), in non-medical majors (OR = 0.460, 95 % CI: 0.248-0.856, P = 0.014), and sophomores or below (OR = 0.483, 95 % CI: 0.286-0.817, P = 0.007) were more hesitant to receive additional COVID-19 vaccine booster doses.

Conclusion

A history of SARS-CoV-2 infection affects college students' hesitation to receive additional COVID-19 vaccine booster doses, which was higher in those who experienced secondary infections.

Parents' willingness to pay for their children's COVID-19 vaccine in Taiwan, China: A cross-sectional study

Most COVID-19 studies aim to assess factors influencing willingness to pay for vaccines between the public and medical staff. However, few studies focus on parents' willingness to pay for their children's COVID-19 vaccine. The current study aimed to assess parents' willingness to pay for their children's vaccination against COVID-19 and its influencing factors. This population-based cross-sectional study used a self-administered questionnaire. The inclusion criterion was parents with at least one child younger than 18 years. The final analysis included 384 valid data points. A total of 89.1% of the parents indicated that they are willing to pay for their children's vaccination against COVID-19. Among them, both fathers' and mothers' willingness to pay for their children's COVID-19 vaccine was 89.6%. The mean and median willingness to pay were% would pay for their children. Excluding other confounding factors, willingness to pay for the COVID-19 vaccine for themselves and hesitation to vaccinate their children were significantly associated with parents' willingness to pay for their children's COVID-19 vaccine. We found that 89.1% of the parents in Taiwan would pay for their children's COVID-19 vaccine. Parents' willingness to pay for themselves and hesitation to vaccinate their children were associated with willingness to pay. Reducing hesitation about vaccines and developing policies for vaccine payment may have a positive impact on willingness to pay for vaccines and promoting COVID-19 vaccination.

Willingness of college students to receive COVID-19 heterologous vaccination in Taizhou, China

This study aimed to determine the willingness of college students to choose COVID-19 heterologous vaccination and its associated influencing factors in Taizhou, China. A population-based, self-administered online questionnaire was conducted from March 15 to 17, 2022. Of the 2,463 participants who had received the invitation, 1,821 responded to the survey (response rate = 73.9%). Only 14% (86/614) of those willing to receive a booster would chose a heterologous vaccination; the perception of better effectiveness of a COVID-19 heterologous vaccination booster was the significant factor (X2 = 22.671, p < .001). Additionally, female college students'older age (χ2 = 7.523, P = .023), major of medical (χ2 = 6.294, P = .012), and better perceived effectiveness of COVID-19 heterologous vaccination booster (χ2 = 22.659, P < .001), were more willing to receive heterologous booster doses. Chinese college students have a strong willingness to receive booster shots, but the percentage of those willing to receive a heterologous vaccine is only 14.0%, and the lack of understanding of its effectiveness is an important factor in the low proportion of heterologous vaccine selection. Health education, public health awareness, and the disclosure of heterologous vaccine information can help improve the public's understanding of heterologous vaccines and provide them with more choices.

Relationship between COVID-19 vaccine hesitancy and willingness to pay for the booster dose of COVID-19 vaccine of oncology patients in Taizhou, China

OBJECTIVE

This population-based study aimed to determine the hesitancy and willingness to pay (WTP) for the booster dose of a coronavirus disease (COVID-19) vaccine among patients with cancer in Taizhou, China.

PATIENTS AND METHODS

A self-administered online questionnaire was administered to patients with cancer in Taizhou, China. The chi-square test, binary logistic regression model were used to evaluate the WTP for the booster dose of a COVID-19 vaccine. The minimum sample size was 218, determined by G*Power software (latest ver. 3.1.9.7). A total of 354 patients received the survey, and 256 (72.3%) patients responded.

RESULTS

Overall, 69.9% (179/256) of respondents were willing to pay for the booster dose, and 78.8% (141/179) of these patients were willing to pay 1-99 CNY. Furthermore, 50.4% (129/256) of respondents were hesitant to receive a COVID-19 vaccine. Being unhesitant was significantly associated with WTP for the booster dose (aOR: 3.040; 95% CI: 1.669-5.540).

CONCLUSION

Hesitant patients with cancer had a lower WTP for the booster dose against COVID-19 than non-hesitant participants. These results imply that further health education programmes are essential to decrease the hesitancy of patients with cancer and enhance booster dose vaccination rates for public health improvements.KEY MESSAGESOur research showed that 70% of patients with cancer are willing to pay for the booster dose of the COVID-19 vaccine, and most are willing to pay less than 100 CNY, and this result reflects the economic value and affordability of the third dose of vaccination.COVID-19 vaccine-hesitant patients with cancer had a lower willingness to pay for a booster dose against COVID-19 than non-hesitant participants and few patients are still unwilling to pay among patients do not hesitate to receive the third dose.Therefore, promoting willingness to pay among oncology patients and addressing vaccine hesitancy remains key.

Impact of household decision makers' hesitancy to vaccinate children against COVID-19 on other household members: A family-based study in Taizhou, China

Background

Vaccination is the most effective means of preventing outbreaks of infectious diseases, and family ;decision makers play an important role in decision-making regarding family matters and may influence other family members to take an active role in vaccinating children against COVID-19.

Purpose

This study examined the influence of family decision makers on the hesitation of other family members to vaccinate their children against COVID-19.

Methods

A population-based, self-administered online questionnaire was administered in Taizhou, China, from September 1, 2021, to September 15, 2021. The questionnaire included demographic information, knowledge, attitudes, and perceptions about the COVID-19 vaccine as well as hesitation regarding the use of the COVID-19 vaccination in children. In total, 490 respondents were included in this study. Logistic regression was used to assess the factors associated with vaccine hesitancy.

Results

In total, 490 respondents from 190 households were interviewed. Of the 190 family decision makers, 43.7% (83/190) were hesitant to vaccinate their children against COVID-19. When family decision makers were hesitant to vaccinate children against COVID-19, 65.1% (82/126) of the other family members expressed similar hesitancy regarding vaccination. When family decision makers were not hesitant to vaccinate children, only 21.3% (37/174) of other family members were hesitant to do so. In the regression analysis, family decision makers' hesitation to vaccinate their children was associated with other family members' hesitation (OR=6.264, 95% CI:3.132-12.526). In addition, decision makers' perceptions of the safety of the vaccine (OR=0.422, 95% CI:0.215-0.826) and hesitation to vaccinate themselves (OR=8.967, 95% CI:4.745-16.948) influenced their hesitation to vaccinate their children.

Conclusion

The present study found that family decision makers' hesitation to vaccinate children against COVID-19 influenced other family members' hesitation to vaccinate children. In addition, family decision makers' perceptions of the safety of the vaccine and their hesitation to vaccinate themselves influenced other family members' hesitation to vaccinate their children.

Parental hesitancy against COVID-19 vaccination for children and associated factors in Taiwan

Background

Since July 2021, some countries and regions have initiated the vaccination of minors against coronavirus disease (COVID-19), and parental COVID-19 vaccine hesitancy will affect the vaccination of minors. We aimed to identify the level of parental hesitancy to vaccinate their children against COVID-19 in Taiwan and the factors associated with vaccine hesitancy.

Methods

We conducted a population-based, self-administered online questionnaire in Taiwan to assess parental hesitancy and the factors influencing their children’s vaccination against COVID-19.

Results

Among 384 respondents, 64.1% were hesitant to have their children vaccinated against COVID-19. Mothers were more likely to hesitate to vaccinate their teens than their fathers (67.5% vs. 50%, P < 0.005). Multiple regression results showed that parents who were hesitant to vaccinate themselves (OR = 3.81, 95% CI:2.07–7.02) and those who scored lower on their perception of their children’s vaccination (OR = 9.73, 95% CI:5.62–16.84) were more hesitant to vaccinate their children with COVID-19 vaccine.

Conclusions

According to the study findings, 64.1% of Taiwanese parents were hesitant to vaccinate their children against COVID-19. Parents who were hesitant to receive the COVID-19 vaccine for themselves and had negative views of the vaccine for their children were more likely to be hesitant to vaccinate their children. An in-depth discussion of the factors affecting vaccine hesitancy and targeted health education is conducive to promoting vaccination in children with COVID-19.

[The mediating effect of perceived social support in the relationship between maternal personality traits and pregnancy-related anxiety]

Objective: Exploring the mediating effect of perceived social support between the maternal personality traits and pregnancy-related anxiety. Methods: Singleton pregnant women who underwent antenatal checkups in the obstetrics department of general hospital affiliated to Ningxia Medical University from July to December 2021 were enrolled in this study to investigate perceived social support, pregnancy-related anxiety and conscious personality traits. Pearson correlation analysis was used to analyze the association between the maternal personality traits, perceived social support, and pregnancy-related anxiety, and the mediating effect of perceived social support was analyzed using Bootstrap method. Results: A total of 1 259 subjects were included in the study, of which 170 (13.50%) pregnant women felt introverted. The total score of perceived social support was (46.37±8.38), and 31.45% of pregnant women had high perceived social support. The total score of pregnancy-related anxiety was (21.48±5.53). The score of worry about fetal health was (10.09±3.24), and 368 (29.23%) of pregnant women had pregnancy-related anxiety. Maternal personality traits and pregnancy-related anxiety were negatively correlated (r=-0.076, P<0.05) and positively correlated with perceived social support during pregnancy (r= 0.127, P<0.05). Perceived social support during pregnancy and pregnancy-related anxiety were negatively correlated (r=-0.236, P<0.05). Perceived social support partially mediated the relationship between the maternal personality traits and pregnancy-related anxiety, with a relative effect value of 37.50%. Conclusion: The maternal personality traits, level of perceived social support and pregnancy-related anxiety are all related. Perceived social support could mediate the relationship between the maternal personality traits and pregnancy-related anxiety.

The main decision-making competence for willingness-to-pay towards COVID-19 vaccination: a family-based study in Taizhou, China

PURPOSE

This research aimed to explore individuals' willingness to pay (WTP) and studied the role of family decision makers in WTP for COVID-19 vaccines.

METHODS

A self-administered online questionnaire evaluating the willingness of community residents to pay for booster vaccination of COVID-19 vaccine was conducted among families in a community in Taizhou, China. The logistic regression model was performed to identify the factors associated with WTP for the COVID-19 vaccines, and all data were analysed by R software, version 4.1.0.

RESULTS

44.2% and 43.7% of 824 community residents were willing to pay for the first two doses and the booster dose of the COVID-19 vaccine, respectively. Decision-makers were more willing to pay for both the first two doses and the boost dose of the COVID-19 vaccines, with OR (95%CI) being 1.75 (1.25-2.47) and 1.89 (1.34-2.67), respectively. Besides, participants' WTP for COVID-19 vaccines were also associated with their occupation and monthly household income.

CONCLUSION

This study found that family decision-makers were more willing to pay for both the first two doses and the booster dose of COVID-19 vaccines in Taizhou, China. To improve the WTP for COVID-19 vaccines, public policy programs need to conduct a comprehensive cost-benefit analysis and focus on the role of family decision makers in vaccination.Key MessagesA study evaluating the willingness of community residents to pay for booster vaccination of COVID-19 vaccine was conducted among families in a community in Taizhou, China.Family decision-makers were more willing to pay for both the first two doses and the booster dose of COVID-19 vaccines.To improve the WTP for COVID-19 vaccines, public policy programs need to conduct a comprehensive cost-benefit analysis and focus on the role of family decision-makers in vaccination.

Adverse reactions to inactivated COVID-19 vaccination in patients with chronic liver disease: The effect of anxiety

Studies have shown that patients with chronic liver disease are at a higher risk of contracting novel coronavirus pneumonia than healthy individuals, and many guidelines state that patients with chronic liver disease should be prioritized for COVID-19 vaccination, but there are a few studies on its safety in CLD patients. We aimed to evaluate the safety of the inactivated COVID-19 vaccine in patients with chronic liver disease, and the effect of anxiety on adverse reactions. A questionnaire survey for self-administered post-vaccination adverse reaction monitoring was conducted from June 17, 2021, to August 11, 2021, in patients with chronic liver disease attending a tertiary care hospital in Taizhou, China. We analyzed the data from of a total of 160 participants who scanned the QR code on social media to respond to the questionnaire. The overall incidence of adverse reactions after COVID-19 vaccination in patients with chronic liver disease was 44.4% (71/160), and the most common adverse reaction was local injection site reaction, accounting for 80.3% of adverse reactions (57/71). No serious adverse reactions were reported. Approximately 53.1% of the patients had anxiety about vaccination, and 51.8% of those who felt anxious reported adverse reactions. The safety of COVID-19 vaccination in patients with chronic liver disease is good, and there is a strong association between adverse reactions and vaccine anxiety. Pre-vaccination education for patients with vaccine anxiety and psychological counseling may reduce reports of adverse reactions and improve patients' confidence in the vaccine.

Willingness-to-pay for a booster dose of inactivated SARS-CoV-2 vaccine in Taizhou, China

This study was conducted to ascertain whether people in China would be willing to pay for an inactivated COVID-19 vaccine booster dose. An online survey estimating participants' willingness to pay (WTP) for a booster dose of COVID-19 vaccine was conducted in Taizhou, China. The participants received ane-mail or e-poster on WeChat. A total of 1576 subjects participated the survey. A total of 66.4% (1046/1576) of the respondents were willing to pay for a booster dose of COVID-19 vaccine for themselves. Using binary logistic regression analysis, the following factors were significantly related to a WTP for a booster dose of COVID-19 vaccine: 1) confidence in the safety of the COVID-19 vaccines (high vs. low, OR: 4.30, 95%CI: 1.61-11.43), 2) confidence in the preventive effectiveness of the COVID-19 vaccines against SARS-CoV-2 virus (moderate vs. little, OR: 1.76, 95%CI: 1.30-2.38; great vs. little, OR: 2.244, 95%CI: 1.62-3.12), and 3) COVID-19 vaccine hesitancy (unhesitant vs. very unhesitant, OR: 0.67, 95%CI: 0.45-1.02; hesitant vs. very unhesitant, OR: 0.29, 95%CI: 0.19-0.44; very hesitant vs. very unhesitant, OR: 0.09, 95%CI: 0.03-0.27). This study revealed that a moderate proportion of participants responded that they would be willing to pay for a booster dose of COVID-19 vaccine. These findings suggest the importance of a detailed assessment and a health education plan that better understands the population's risk perception as well as the potential health risks in China.

Willingness of Older Adults with Chronic Diseases to Receive a Booster Dose of Inactivated Coronavirus Disease 2019 Vaccine: A Cross-Sectional Study in Taizhou, China

Vaccination is an important measure to control the spread of COVID-19 among elderly high-risk groups; however, the propensity to receive COVID-19 vaccine boosters has not been evaluated in these populations. Here, we aimed to investigate the willingness to receive a COVID-19 vaccine booster among the elderly chronic disease population in Taizhou, China. A cross-sectional, hospital-based survey was conducted in the outpatient department of a tertiary care hospital between 6 July and 11 August 2021 in Taizhou, China, and the data were uploaded to Wen-Juan-Xing, one of the largest online platforms used to collect survey data in China. The targeted population was non-oncology chronic disease patients aged 60 years and above. The minimum sample size was 229, determined by the G*Power software (v3.1.9.2, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany). A total of 254 patients with valid data were enrolled in this study, with a response rate of 82.5% (254/308). Chi-square tests and one-way binary regression were used to compare the proportions and the degree of influence of categorical factors. The magnitude of the effect for the comparisons was measured by Gramer’s V. A multivariate binary logistic regression model was used to correct for confounders and to identify factors. All data were analyzed using SPSS v24.0 (IBM Corporation, Armonk, NY, USA). A total of 198 respondents (77.9%) were willing to receive a COVID-19 vaccine booster dose, and 77.6% of respondents were willing to receive the primary dose. Age < 70 years (OR 2.82), stable disease control (OR 2.79), confidence in the effectiveness of the COVID-19 vaccine (OR 3.11), and vaccine recipient (OR 5.02) were significantly associated with the willingness to receive a COVID-19 vaccine booster dose. Promoting primary dose vaccination is essential for advancing booster vaccination, and it is important to focus on elderly patients’ confidence in the vaccine, in addition to strengthening health management and promoting disease stability. Follow-up studies should focus on elderly patients who belong to specific disease groups.

Intentions of Patients with Hypertension to Receive a Booster Dose of the COVID-19 Vaccine: A Cross-Sectional Survey in Taizhou, China

COVID-19 patients with hypertension have increased hospital complications and mortality rates. Moreover, these patients also have lower antibody titers after receiving the coronavirus disease (COVID-19) vaccine. Therefore, patients with hypertension should receive a COVID-19 vaccine booster. To promote the uptake of COVID-19 vaccine booster among hypertensive patients, this study investigated patients’ willingness and factors that influence patients with hypertension to receive the COVID-19 vaccine booster. From July 2021 to August, 410 patients with hypertension were surveyed. Overall, 76.8% of patients were willing to receive the COVID-19 vaccine booster, as 82.7% of patients without comorbidities and 72.7% of patients with comorbidities were willing to receive the vaccine booster. The main factors that influenced the willingness of patients with hypertension to receive a booster dose were the preventive effect of the vaccine (χ2 = 52.827, p < 0.05), vaccine safety (χ2 = 42.423, p < 0.05), vaccine knowledge (χ2 = 7.831, p < 0.05), presence of comorbidities (χ2 = 4.862, p < 0.05), disease control (χ2 = 5.039, p < 0.05), and antihypertensive treatments (χ2 = 12.565, p < 0.05). This study’s findings highlight the need to promote knowledge about booster vaccination among patients and health management. These measures would improve patients’ willingness and knowledge about the vaccine and their health status, which are the main factors that influence patients’ intention to receive booster vaccines.

Relationship between knowledge, attitudes, and practices and COVID-19 vaccine hesitancy: A cross-sectional study in Taizhou, China

Objective

This study aimed to explore COVID-19 vaccine hesitancy in Chinese adults and analyzed the relationship between knowledge, attitudes, practices (KAP), and COVID-19 vaccine hesitancy.

Methods

A population-based self-administered online survey was conducted in Taizhou, China to evaluate the population's hesitancy to receive COVID-19 vaccination. A total of 2.463 adults received the invitation for the survey through WeChat (A Chinese app that is used for chat, social media, and mobile payment), and 1.788 interviewees answered the structured questionnaire. The overall response rate was 72.6%.

Results

Total 45.2% of people were hesitant about the COVID-19 vaccination. Using binary logistic regression analysis, we found low perception of safety (Model 3: Odds ratio = 2.977, Confidence interval: 2.237–3.963) and efficacy (Model 3: OR = 1.904, 95%CI: 1.462–2.479) of the COVID-19 vaccine in adults is the most important risk factor for COVID-19 vaccine hesitation. People who know more about COVID-19 vaccination are less hesitant (Model 2: OR = 0.967, 95% CI: 0.951–0.983). People who did not seek information independently about the COVID-19 vaccine are more likely to be skeptical (Model 4: OR = 1.300, 95% CI: 1.058–1.598, P = 0.013).

Conclusion

In China, the population had higher levels of COVID-19 vaccine hesitation, and their knowledge of the COVID-19 vaccine, perceptions of safety and efficacy, and physical health status were significantly associated with vaccine hesitation. These results provide ideas for promoting COVID-19 vaccination and intervention and have far-reaching implications for further strengthening research on vaccine hesitancy in COVID-19 and exploring strategies for COVID-19 vaccine promotion.

COVID-19 vaccine hesitancy between teachers and students in a college, a cross-sectional study in China

Studies have identified teacher effects on students’ attitudes. This study explored the differences in and associations between teachers’ and students’ COVID-19 vaccine hesitancy, and the factors that affect it. A population-based self-administered online survey was conducted to evaluate the COVID-19 vaccine hesitancy of teachers and students in a college in Taizhou, China. A total of 835 valid questionnaires were obtained. All data were analyzed using IBM SPSS statistics 26.0 software. The proportions of COVID-19 vaccine hesitancy for teachers and students were 31.7%, and 23.8%, respectively. In the binary logistic regression analysis, teachers who perceived the safety of the COVID-19 vaccine as low (OR = 6.794 , 95%CI: 1.701–27.143), did not pay continuous attention to the vaccine news (OR = 3.498, 95%CI: 1.150–10.640), and suffered chronic diseases (OR = 2.659, 95%CI: 1.135–6.227) were more likely to hesitate to get vaccinated against COVID-19. The group of students who perceived the COVID-19 vaccine safety as being low (OR = 1.805, 95%CI: 1.094–2.979) were more hesitant to get the COVID-19 vaccine. While both teachers and students were hesitant about the COVID-19 vaccine, teachers were found to be more so. Perceptions regarding the safety of COVID-19 vaccines, attention to and awareness of vaccine news, and chronic medical conditions were the main factors that influenced the hesitation regarding COVID-19 vaccines. Therefore, students’ vaccine hesitancy may depend largely on the perceptions of the vaccine’s safety rather than teachers’ vaccine hesitancy.

The impact of the Omicron epidemic on the health behavior in Cape Town, South Africa

Background

South Africa was the first country with a case of Omicron variant infection diagnosed; therefore, this study aimed to elucidate the impact of the Omicron mutant strain outbreak on the health behavior of the South African population and encourage the population to adopt timely protective behaviors against Omicron mutant strain infection.

Study design and methods

This was a population-based, cross-sectional study conducted in Cape Town, South Africa, in December 2021. We distributed 300 questionnaires to adults aged >18 years, and they were all returned.

Results

Of the South African population, 60.3% expressed a high level of concern regarding Omicron; 89.3% improved on at least one of the following three health behaviors: mask-wearing, washing hands, and reducing socialization; and only 10.7% exhibited no improvement in health behaviors. Of these, 71.3% and 57.0% increased the length of time they wore a mask and washed their hands, respectively, and 47% decreased the number of times they socialized. Age, residence, education level, chronic disease, and whether they had received the COVID-19 vaccine were significantly different (p < 0.05) between the presence and absence of enhanced health behaviors. The levels of concern and knowledge regarding the Omicron virus significantly influenced health-behavior change (all P < 0.05).

Conclusion

There has been a positive change in the South African population toward adopting mask-wearing, hand washing, and reducing socialization in response to the Omicron virus strain epidemic. Based on one health approach, it is important to focus on populations with chronic diseases, those who have not yet received the COVID-19 vaccine, and other populations with low rates of health behavior change.

Willingness to receive a booster dose of inactivated coronavirus disease 2019 vaccine in Taizhou, China

PURPOSE

This population-based study aimed to determine the willingness to receive a booster dose of vaccine against coronavirus disease (COVID-19) in Taizhou, China.

METHODS

An online questionnaire investigation addressing participants' willingness to receive a booster dose of the COVID-19 vaccine was organized in Taizhou, China. Of the 2318 interviewees who received the invitation, 1576 finished a qualifying questionnaire, corresponding to a response rate of 68.0%.

RESULTS

The majority of respondents (n = 1435 [91.1%]) were willing to accept a booster vaccination against COVID-19. History of allergic reaction to other vaccines (OR = 0.30), confidence in the safety of the COVID-19 vaccines (OR = 3.20), confidence in the effectiveness of the COVID-19 vaccines against SARS-CoV-2 (OR = 2.25) and its variants (useful versus [vs.] useless, OR = 2.33), and vaccine recipients (OR = 3.09) remained significantly associated with willingness to accept a booster dose of COVID-19 vaccines.

CONCLUSION

A moderate proportion of the participants who responded were willing to receive a booster dose of the COVID-19 vaccine. These results are valuable for starting health education and interventions to accelerate vaccine uptake and improve public health outcomes during the COVID-19 pandemic in China.

Sex Differences in Adverse Reactions to an Inactivated SARS-CoV-2 Vaccine Among Medical Staff in China

Objective: We investigated whether there were sex differences in adverse reactions to an inactivated SARS-CoV-2 vaccine among medical staff in China. Methods: From 24 February to 7 March 2021 an online cross-sectional survey was conducted with a self-administered COVID-19 vaccine questionnaire among medical staff in Taizhou, China. In total, 1397 interviewees (1,107 women and 290 men) participated in the survey. Results: In our study, 178 (16.1%) women and 23 (7.9%) men reported adverse reactions following their first vaccination, and 169 (15.3%) women and 35 (12.1%) men reported adverse reactions following their second vaccination. After adjusting for confounding factors, adverse reactions to other vaccines, worry about adverse reactions, knowledge of the inactivated vaccine being used in the hospital, taking the vaccine for one's family proactively and receiving an influenza vaccination were significantly related to adverse reactions to both injections in women. In contrast, in men, concerns about adverse reactions independently increased the risk of adverse reactions following either vaccination, and a history of adverse reactions to other vaccines also increased the risk of adverse reactions to both injections. Conclusions: Sex differences in the frequency of reported adverse reactions to an inactivated SARS-CoV-2 vaccine and potential factors were demonstrated in a sample of medical staff.

Determinants of parental hesitancy to vaccinate their children against COVID-19 in China

Vaccine hesitancy seriously hinders herd immunity. We explored the determinants of parental hesitancy to vaccinate children against Coronavirus Disease 2019 (COVID-19) in China.A population-based self-administered online questionnaire evaluating parental hesitancy in vaccinating their children against COVID-19 was conducted in Taizhou, China. Of the 2463 parents who received the invitation, 1788 (72.6%) responded to the survey.Of the repondents, 52.5% were hesitant. Mothers exhibited a greater proportion of vaccine hesitancy than fathers did (57.5% vs. 41.7%, P < 0.001). Multiple logistic regression analysis indicated that parents with children under 18 years of age (OR = 0.94, 95%CI: 0.90-0.99), lower knowledge scores about COVID-19 vaccination (Q1: OR = 1.92, 95%CI: 1.37-2.69; Q2: OR = 1.51, 95%CI: 1.10-2.08), lower awareness of the permission of vaccinating children (OR = 1.74, 95%CI: 1.36-2.23) and hesitancy to inoculate themselves (OR = 8.18, 95%CI: 6.48-10.33) were associated with parental hesitancy to inoculate their children. Results also revealed the disparity between fathers and mothers regarding associated factors.This study found that a substantial proportion of parents reported being hesitant to vaccinate children against COVID-19, implying the necessity of comprehensive assessment and health education programs for vaccination systems in China.

Hydroxytyrosol and Oleuropein Inhibit Migration and Invasion of MDA-MB-231 Triple-Negative Breast Cancer Cell via Induction of Autophagy

BACKGROUND

Breast Cancer (BC) is the leading cause of cancer-related deaths among women. As such, novel chemotherapeutic agents are urgently needed, especially for Triple-Negative Breast Cancer (TNBC). Hydroxytyrosol (HT) and Oleuropein (OL) are rich in olive oil, which is associated with a low occurrence of BC. However, the effects and mechanisms of action of HT and OL in BC cells are still unclear. This study aimed to explore the molecular mechanisms underlying the antitumor effect of HT and OL in TNBC.

METHODS

TNBC MDA-MB-231 cells were treated with HT and OL in combination with Hepatocyte Growth Factor (HGF), rapamycin (Rapa, an inducer of autophagy) or 3-methyladenine (3-MA, an inhibitor of autophagy). Cell viability, migration, invasion, and autophagy signaling were analyzed by scratch assays, transwell migration assays, and Western blot analysis.

RESULTS

Treatment with HT or OL reduced MDA-MB-231 cell viability in a dose-dependent manner. MDAMB- 231 cells were more sensitive to HT treatment than OL treatment. Rapa treatment could significantly block HGF-induced MDA-MB-231 cell migration and invasion, suggesting that inhibition of autophagy could promote migration and invasion. Moreover, HT or OL treatment significantly suppressed HGF or 3-MA induced cell migration and invasion by reversing LC3-II/LC3-I and Beclin-1 downregulation and reversing p62 upregulation.

CONCLUSION

These data indicated that HT and OL may inhibit migration and invasion of TNBC cells by activating autophagy. These findings provide potential therapeutic strategies that target autophagy to limit the pathogenesis and progression of BC.

Hydroxytyrosol and Oleuropein Inhibit Migration and Invasion via Induction of Autophagy in ER-Positive Breast Cancer Cell Lines (MCF7 and T47D)

Hydroxytyrosol (HT) and oleuropein (OL), the most abundant of the phenolic compounds in olives, have anticancer properties against breast cancer (BC). However, little attention has been paid to the mechanism of HT or OL in BC cells. The objective of this study was to identify the underlying molecular mechanisms of these compounds. ER-positive BC MCF7 and T47D cells were treated with HT and OL in combination with hepatocyte growth factor (HGF), rapamycin (Rapa, an agonist of autophagy) or 3-methyladenine (3-MA, an inhibitor of autophagy). Cell viability, metastasis capability and autophagy-related proteins were evaluated by wound healing assays, Transwell assays and Western blot. HT and OL reduced the cell viability of MCF-7 and T47D cells in a dose-dependent manner. Both cells were more sensitive to HT than OL. In addition, Rapa significantly inhibited HGF-induced migration and invasion, indicating that metastases of both BC cells could be inhibited by suppression of autophagy. Moreover, HT and OL significantly blocked HGF- or 3-MA-induced cell migration and invasion by reversing LC3II/LC3I and Beclin-1 downregulation and p62 upregulation. These findings revealed that HT and OL could suppress migration and invasion by activating autophagy in ER-positive BC cells, which might be a promising therapeutic strategy.

[Clinical features and advanced progress of secondary BPPV]

BPPV is a disease provoked by abrupt head movements, results in short paroxysmal vertigo or nystagmus. These patients often can accurately describe the dizziness happened when they head move suddenly, especially when looking upward, turning over in bed, lying down, or bending over. BPPV is divided into idiopathic BPPV and secondary BPPV, in most cases. The underlying cause cannot be determined, which is called idiopathic; however, in 30% patients, BPPV may be attributed to a specific cause and is termed secondary BPPV. We reviewed the pathogenesis, mechanisms, clinical features, treatment and the latest progress of secondary BPPV.

A Gene Selection Method for Microarray Data Based on Binary PSO Encoding Gene-to-Class Sensitivity Information

Traditional gene selection methods for microarray data mainly considered the features' relevance by evaluating their utility for achieving accurate predication or exploiting data variance and distribution, and the selected genes were usually poorly explicable. To improve the interpretability of the selected genes as well as prediction accuracy, an improved gene selection method based on binary particle swarm optimization (BPSO) and prior information is proposed in this paper. In the proposed method, BPSO encoding gene-to-class sensitivity (GCS) information is used to perform gene selection. The gene-to-class sensitivity information, extracted from the samples by extreme learning machine (ELM), is encoded into the selection process in four aspects: initializing particles, updating the particles, modifying maximum velocity, and adopting mutation operation adaptively. Constrained by the gene-to-class sensitivity information, the new method can select functional gene subsets which are significantly sensitive to the samples' classes. With the few discriminative genes selected by the proposed method, ELM, K-nearest neighbor and support vector machine classifiers achieve much high prediction accuracy on five public microarray data, which in turn verifies the efficiency and effectiveness of the proposed gene selection method.

Computed tomography findings of hepatic veno-occlusive disease caused by Sedum aizoon with histopathological correlation

This study investigated the value of computed tomography (CT) in the diagnosis and treatment of hepatic veno-occlusive disease (HVOD) caused by Sedum aizoon (SA). The clinical manifestations, treatment results, imaging findings, and histological findings of the liver were analyzed in 39 patients with HVOD caused by SA. Hepatomegaly, liver dysfunction, abdominal effusion, and geographic density changes on liver CT scans were found in all 39 patients. The pathological findings of histological liver examination included swelling and point-like necrosis of liver cells, significant expansion and congestion of the sinuses, endothelial swelling, and wall thickening with incomplete lumen occlusion of small liver vessels. CT geographic density changes were confirmed by histological examination of the liver in 18 patients. Sixteen patients with small amounts of ascites that started within 4 weeks of treatment recovered completely or significantly improved after symptomatic and supportive treatment. However, only 43.75% of the patients with larger amounts of ascites improved following symptomatic and supportive treatment. In conclusion, liver CT examination is a valuable, safe, and noninvasive tool for the diagnosis of HVOD caused by SA. In selected cases, liver CT examination may replace liver biopsy and histological analysis.

Oxymatrine and cancer therapy

Oxymatrine is a kind of alkaloid extracted from traditional Chinese herb Sophora flavescens Ait. It has been proved to exert various biological activities such as anti-angiogenesis, proliferation-inhibiting, apoptosis-promoting, analgesic-strengthening, and anti-metastasis. The biological activities are related with inhibition of angiogenesis-associated factors, regulation of related signaling pathway and protein expression, synergistic effects with chemotherapy drug, cell cycle arrest and inhibition of voltage-activated K+ channel. In this review, we summarize the recent investigations of oxymatrine in cancer therapy so as to provide references for further study and clinical therapy.

Link of obesity and gastrointestinal cancer: crossroad of inflammation and oxidative stress

Obesity incidence has reached pandemic levels, and is accompanied by high incidence and poor prognosis of various types of cancers including gastrointestinal ones. Underlying mechanisms include elevated levels of insulin, IGF-I, and altered adipokine concentration, mainly towards leptin and adiponectin levels. However, it is not yet thoroughly understood. It is now widely known that obesity is associated with chronic low-grade inflammation, characteristic of altered immune cell infiltration in adipose tissue, and changed inflammatory cytokines and chemokines: tumor necrosis factor alpha (TNF-a), IL-6, and the chemoattractant monocyte chemoattractant protein 1 (MCP-1) and others, all together eventually promoting caner pathogenesis. Moreover, accumulating reports have shown that excess adipose tissue in obese individuals resulted in elevated levels of systematic oxidative stress, another way of promoting cancer development and progression. In general, altered immunological milieu and oxidative stress in obesity are important determinants for tumorigenesis.

Magnetism-Driven Ferroelectricity in Double Perovskite Y₂NiMnO₆

We report the discovery of multiferroic behavior in double perovskite Y2NiMnO6. X-ray diffraction shows that the material has a centrosymmetric crystal structure of space group P2(1)/n with Ni(2+)/Mn(4+) ordering. This result is further confirmed by aberration-corrected scanning transmission electron microscopy combined with atomic resolution electron energy loss spectroscopy. The appearance of ferroelectric polarization coincides with the magnetic phase transition (∼67 K), which indicates that the ferroelectricity is driven by magnetism, and this is further confirmed by its strong magnetoelectric (ME) effect. We proposed the origin of the ferroelectricity is associated with the combination of Ni(2+)/Mn(4+) charge ordering and the ↑↑↓↓ spin ordering. When compared with other known magnetic multiferroics, Y2NiMnO6 displays several attractive multiferroic properties, including high polarization (∼145 μC/m(2)), a high multiferroic transition temperature (∼67 K), and strong ME coupling (∼21%).

Clinical significance of hmgb1 expression in human gastric cancer

High mobility group box 1 (HMGB1) has been proved to be implicated in a variety of cell physiological and pathological behaviors including immune response, inflammation and cancer. Accumulating evidence suggests that HMGB1 plays a critical role in the development and progression of multiple malignancies. However, the clinical significance and prognosis of HMGB1 expression in some cancers remain controversial. The present study aimed to investigate whether overexpression of HMGB1 is an independent prognostic factor in patients with gastric cancer. The correlation of HMGB1 expression with clinicopathologic characteristics and prognosis was assessed by immunohistochemical assay through tissue microarray procedure in 50 primary gastric cancer cases. Our results indicated that the positive expression of HMGB1 was significantly increased in the nucleus of gastric cancer tissues compared with the adjacent non-cancerous tissues (ANCT) (64.0&#x0025; vs 44.0&#x0025;, P=0.025), but was not linked to the clinicopathologic features, including the TNM stage (P=0.533) and metastatic lymph node (P=0.771), in patients with gastric cancer. Kapalan-Meier and log-rank analysis demonstrated that overexpression of HMGB1 did not exert significant impact on the overall survival of patients with gastric cancer (P=0.805). Furthermore, Cox regression analysis showed that high HMGB1 protein expression did not represent an independent risk factor for patients with gastric cancer (P=0.677). Taken together, our findings suggest that high expression of HMGB1 is not correlated with the clinicopathologic characteristics of gastric cancer, and cannot serve as an independent prognostic biomarker for patients with gastric cancer.

The Jahn-Teller effect in the electron momentum spectroscopy of ammonia

The 1e and 3a(1) bands of the ammonia molecule have been studied using the high-resolution electron momentum spectroscopy at impact energies of 1200 and 600 eV. Several slices of 1e and 3a(1) bands in the different binding energy ranges were selected, and their electron-momentum distributions were carefully compared. The discernable difference among the distributions of the selected slices of the 1e band shows that the Jahn-Teller effect indeed influences the electron momentum distribution of the 1e orbital of ammonia.

Significance of the serum level of transforming growth factor β1 and its difference in patients with chronic hepatitis B and HBV-induced hepatic cirrhosis

AIM: To investigate the relationship between the levels of transforming growth factor (TGF) β1 in serum and inflammation, as well as fibrous degeneration of the liver, and the difference in the levels of TGFβ1 in patients between with chronic hepatitis B and HBV-induced hepatic cirrhosis.

METHODS: Four markers of hepatic fibrosis (HA, LN, CIV, PCⅢ) were measured by radioimmunoassay and the serum levels of TGFβ1 were measured by enzyme linked immunosorbent assay (ELISA) in 65 patients with chronic hepatitis B (chronic hepatitis group), 56 patients with HBV-induced hepatic cirrhosis (hepatic cirrhosis group) and 50 health personnel who were negative for HBV markers (control group).

RESULTS: The serum level of TGFβ1 in the chronic hepatitis group was significantly higher than that in the hepatic cirrhosis and control groups (22 ± 13 μg/L vs 10 ± 9 μg/L, 11 ± 9 μg/L, P < 0.01). The level of TGFβ1 in the hepatic cirrhosis group was similar to that in the control group. There was no correlation between the serum level of TGFβ1 and hepatic function, as well as markers of hepatic fibrosis. However, PCⅢ was excluded, and the coefficient of correlation between PCⅢ and serum level of TGFβ1 in the hepatic cirrhosis group (r = 0.269, P = 0.045).

CONCLUSION: TGFβ1 may play an important role in the onset of hepatic cirrhosis, and it may aid diagnosis of hepatic cirrhosis. However, there is no evidence to show that it can help establish the degree of inflammation and fibrous degeneration in the liver.

CordyMax Cs-4 improves steady-state bioenergy status in mouse liver

OBJECTIVE

To evaluate effects of CordyMax Cs-4, a mycelial fermentation product of Cordyceps sinensis, on energy metabolism.

DESIGN

An in vivo pharmacology study using 31P nuclear magnetic resonance (NMR) spectroscopy. SUBJECTS AND STUDY INTERVENTIONS: Adult male C57-BL/6 mice were given an aqueous extract of CordyMax, 200 or 400 mg/kg per day or placebo for 7 days.

OUTCOME MEASUREMENTS

Using 31P-NMR spectroscopy to measure cellular triphosphates and inorganic phosphate, expressed as a ratio to a reference peak, and calculate tissue pH.

RESULTS

Steady-state beta adenosine triphosphate (ATP) increased in the liver of mice that received CordyMax (200 or 400 mg/kg per day) for 7 days, by 12.3% +/- 0.8% and 18.4% +/- 0.9%, respectively, compared to placebo controls (both p < 0.001), suggesting a higher hepatic bioenergy status in CordyMax-treated animals. Hepatic inorganic phosphate (Pi) decreased by 24.5% +/- 0.9% and 17.6% +/- 1.7% in the two treatment groups, respectively, compared to placebo controls (p < 0.001). The ratio of beta-ATP:Pi increased by 47.7% +/- 1.6% and 41.4% +/- 2.4%, respectively, in the treatment groups (both p < 0.001 compared to placebo). After discontinuation of CordyMax for 7 days, beta-ATP and Pi returned towards baseline.

CONCLUSION

CordyMax is effective in improving bioenergy status in the murine liver, suggesting a mechanism underlying the known clinical effectiveness of CordyMax in alleviating fatigue and improving physical endurance, especially in elderly subjects.

Mice with gene disruption of both endothelial and neuronal nitric oxide synthase exhibit insulin resistance

Studies from our laboratory using acute pharmacologic blockade of nitric oxide synthase (NOS) activity have suggested that nitric oxide (NO) has an important role in regulating carbohydrate metabolism. We now report on insulin sensitivity in mice with targeted disruptions in endothelial NOS (eNOS) and neuronal NOS (nNOS) genes compared with their wild-type (WT) counterparts. Mice underwent hyperinsulinemic-euglycemic clamp studies after a 24-h fast, during an insulin infusion of 20 mU x kg(-1) x min(-1). Glucose levels were measured at baseline and every 10 min during the clamp. Insulin levels were measured at baseline and at the end of the clamp study. Glucose infusion rates (GIRs) during the last 30 min of the clamp study were in a steady state. Tritiated glucose infusion was used to measure rates of endogenous glucose output (EGO) both at baseline and during steady-state euglycemia. Glucose disposal rates (GDRs) were computed from the GIR and EGO. Fasting and steady-state glucose and insulin levels were comparable in the 3 groups of mice. No differences in fasting EGO were noted between the groups. GIR was significantly reduced (37%, P = 0.001) in the eNOS knockout (KO) mice compared with the WT mice, with values for the nNOS mice being intermediate. EGO was completely suppressed in the nNOS and WT mice during insulin infusion, but not in the eNOS mice. Even so, the eNOS mice displayed significantly reduced whole-body GDRs compared with those of the WT mice (82.67+/-10.77 vs. 103.67+/-3.47 mg x kg(-1) x min(-1), P = 0.03). eNOS KO mice are insulin resistant at the level of the liver and peripheral tissues, whereas the nNOS KO mice are insulin resistant only in the latter. These data indicate that NO plays a role in modulating insulin sensitivity and carbohydrate metabolism and that the eNOS isoform may play a dominant role relative to nNOS.

Dose-response relationship of insulin to glucose fluxes in the awake and unrestrained mouse

The purpose of the study was to use the hyperinsulinemic-euglycemic clamp technique to generate insulin dose-response curves for insulin suppression of endogenous glucose output (EGO) and stimulation of the glucose disposal rate (GDR) in conscious unstressed mice. Five groups of male ICR (Institute for Cancer Research) mice were studied (N = 43). The animals underwent surgery for implantation of a jugular vein catheter 2 to 3 days before the clamp and were fasted 6 hours before the study. Each group was clamped at a different insulin infusion rate of 0, 2.5, 10, or 20 mU/kg/min. 3H-3-glucose was infused for measurement of the glucose turnover rate (rate of appearance [Ra]). Blood samples were collected by milking a severed tail-tip. EGO was calculated as the difference between the Ra and glucose infusion rate (GIR), and the glucose clearance rate (GCR) as the GDR divided by the plasma glucose concentration. From the curves generated, half-maximal EGO and GCR were obtained at a plasma insulin concentration of 20 to 30 microU/mL, which was achieved at an insulin infusion rate of about 4 to 5 mU/kg/min. Maximal suppression of EGO and stimulation of the GCR occurred at an insulin infusion rate of 10 mU/kg/min. The establishment of normative curves for insulin-stimulated glucose metabolism in conscious mice facilitates the evaluation of glucose metabolism in a variety of mouse models of insulin resistance.

Glucosamine infusion in rats rapidly impairs insulin stimulation of phosphoinositide 3-kinase but does not alter activation of Akt/protein kinase B in skeletal muscle

Glucosamine, a metabolite of glucose via the hexosamine biosynthetic pathway, potently induces insulin resistance in skeletal muscle by impairing insulin-induced GLUT4 translocation to the plasma membrane. Activation of phosphoinositide (PI) 3-kinase is necessary for insulin-stimulated GLUT4 translocation, and the serine/threonine kinase Akt/protein kinase B (PKB) is a downstream mediator of some actions of PI 3-kinase. To determine whether glucosamine-induced insulin resistance could be due to impaired signaling, we measured insulin receptor substrate (IRS)-1 and insulin receptor tyrosine phosphorylation; PI 3-kinase activity associated with IRS-1, IRS-2, and phosphotyrosine; and Akt activity and phosphorylation in skeletal muscle of rats infused for 2 h with glucosamine (6.0 mg x kg(-1) x min(-1)) or saline. Euglycemic-hyperinsulinemic clamp studies (12 mU x kg(-1) x min(-1) insulin) in awake rats showed that glucosamine infusion resulted in rapid induction of insulin resistance, with a 33% decrease in glucose infusion rate (P < 0.01). Tissues were harvested after saline alone (basal), 1 min after an insulin bolus (10 U/kg), or after 2 h of insulin clamp in saline- and glucosamine-infused rats. After 1 min of insulin stimulation, phosphorylation of IRS-1 and insulin receptor increased 6- to 8-fold in saline-infused rats and 7- to 10-fold in glucosamine-infused rats. In saline-infused rats, 1 min of insulin stimulation increased PI 3-kinase activity associated with IRS-1, IRS-2, or phosphotyrosine 7.6-, 6.4-, and 10-fold, respectively. In glucosamine-infused rats treated for 1 min with insulin, PI 3-kinase activity associated with IRS-1 was reduced 28% (P < 0.01) and that associated with phosphotyrosine was reduced 43% (P < 0.01). Insulin for 1 min stimulated Akt/PKB activity approximately 5-fold in both saline- and glucosamine-infused rats; insulin-induced hyperphosphorylation of Akt/PKB was not different between groups. Glucosamine infusion alone had no effect on tyrosine phosphorylation of the insulin receptor or IRS-1 or on stimulation of PI 3-kinase or Akt/PKB activity. However, 2 h of insulin clamp reduced PI 3-kinase activity associated with IRS-1, IRS-2, or phosphotyrosine to <30% of that seen with 1 min of insulin. No effect of glucosamine was seen on these signaling events when compared with 2 h of insulin clamp without glucosamine. Our data show that 1) glucosamine infusion in rats is associated with an impairment in the early activation of PI 3-kinase by insulin in skeletal muscle, 2) this insulin-resistant state does not involve alterations in the activation of Akt/PKB, and 3) prolonged insulin infusion under clamp conditions results in a blunting of the PI 3-kinase response to insulin.

The scientific rediscovery of a precious ancient Chinese herbal regimen: Cordyceps sinensis: part II

Cordyceps sinensis (Berk.) Sacc. is a time-honored tonic food and herbal medicine in China, where recent research has shown that many of its traditional uses may be viewed from the basis of pharmacological activities. The ongoing exploration of C. sinensis in its wild form and cultured, fermented mycelial products derived from it, are reviewed from English and Chinese literature. Part II concludes the series with a review of C. sinensis in preclinical in vitro and in vivo studies, and open-label and double-blinded clinical trials on the respiratory, renal, hepatic, cardiovascular, immunologic, and nervous systems, and its effects on cancer, glucose metabolism, inflammatory conditions, and toxicological studies. In Part I, which appeared in the Fall 1998 issue of this journal (4(3):289-303), we discussed the effects of C. sinensis on antisenescence, endocrine and sexual functions, atherosclerosis, hyperlipidemia, and free radicals.

A technique for assessing the effects of olfaction on feed preference in lactating Holstein cows

Our objective was to develop a method for assessing the effects of olfaction on feed preference. Two multiparous lactating Holstein cows were offered a totally mixed ration consisting of corn silage, alfalfa haylage, and a ground corn and soybean meal-based concentrate mixture (25:25:50 on a DM basis) for their ad libitum consumption in four consecutive 2.5-h periods daily for 5 d. An apparatus was developed that allowed odorants to be distributed at a set rate over two feeding containers with limited possibility of odor carryover. Four odorants and a control (no odorant) were compared against each other. All possible comparisons were conducted on the left and right feeding sides to avoid potential lateral-preference effects. Rank values of 0 or .5 were assigned to each odorant based on the percentage of total feed consumed in a period. A test of overall equality based on the sums of squares of ranks was used to determine whether odors affected preference. The limited results indicated that inhalation of odorants did not affect preference. Rank values were doubled for several odorants when compared with others, which suggested that the sample size limited experimental sensitivity. To attain reasonable power, we estimated that at least six cows were needed per study. Large effects of odorants on feed preference would have been required to reach statistical significance in this trial; however, the method provides a practical technique for testing the effects of olfaction on feed preference in cattle when the suggested number of cows is used.

The scientific rediscovery of an ancient Chinese herbal medicine: Cordyceps sinensis: part I

This review presents Cordyceps sinensis (Berk.) Sacc., a fungus highly valued in China as a tonic food and herbal medicine. The extant records show the continued use of C. sinensis is now centuries old. The major chemical, pharmacological, and toxicological studies on C. sinensis and the various derived, cultured, fermented mycelial products currently in use are reviewed from the English and Chinese literature. Preclinical in vitro and in vivo studies and clinical blinded or open-label trials in to date over 2000 patients are reviewed. These studies show the main activities of the fungus in oxygen-free radical scavenging, antisenescence, endocrine, hypolipidemic, antiatherosclerotic, and sexual function-restorative activities. The safety of the fungus, its effects on the nervous system, glucose metabolism, the respiratory, hepatic, cardiovascular, and immune systems, immunologic disease, inflammatory conditions, cancer, and diseases of the kidney will be reviewed in the second part of this article to be published in the winter issue of this journal.

Central nervous system nitric oxide synthase activity regulates insulin secretion and insulin action

Systemic inhibition of nitric oxide synthase (NOS) with NG-monomethyl-L-arginine (L-NMMA) causes acute insulin resistance (IR), but the mechanism is unknown. We tested whether L-NMMA-induced IR occurs via NOS blockade in the central nervous system (CNS). Six groups of Sprague-Dawley rats were studied after chronic implantation of an intracerebroventricular (ICV) catheter into the lateral ventricle and catheters into the carotid artery and jugular vein. Animals were studied after overnight food deprivation, awake, unrestrained, and unstressed; all ICV infusion of L-NMMA or D-NMMA (control) were performed with artificial cerebrospinal fluid. ICV administration of L-NMMA resulted in a 30% rise in the basal glucose level after 2 h, while ICV D-NMMA had no effect on glucose levels. Insulin, epinephrine, and norepinephrine levels were unchanged from baseline in both groups. Tracer (3H-3-glucose)-determined glucose disposal rates during 2 h euglycemic hyperinsulinemic (300 microU/ml) clamps performed after ICV administration of L-NMMA were reduced by 22% compared with D-NMMA. Insulin secretory responses to a hyperglycemic clamp and to a superimposed arginine bolus were reduced by 28% in L-NMMA-infused rats compared with D-NMMA. In conclusion, ICV administration of L-NMMA causes hyperglycemia via the induction of defects in insulin secretion and insulin action, thus recapitulating abnormalities observed in type 2 diabetes. The data suggest the novel concept that central NOS-dependent pathways may control peripheral insulin action and secretion. This control is not likely to be mediated via adrenergic mechanisms and could occur via nonadrenergic, noncholinergic nitrergic neural and/or endocrine pathways. These data support previously published data suggesting that CNS mechanisms may be involved in the pathogenesis of some forms of insulin resistance and type 2 diabetes independent of adiposity.

Glucosamine infusion in rats mimics the beta-cell dysfunction of non-insulin-dependent diabetes mellitus

Sustained hyperglycemia can cause peripheral insulin resistance and pancreatic beta-cell dysfunction and has been termed glucose toxicity or glucose-induced desensitization. Glucosamine, a product of glucose flux through the hexosamine biosynthetic pathway (HBP), causes insulin resistance in peripheral tissues and has been shown to cause abnormal glucose-insulin secretion coupling, and thus has been implicated in the pathogenesis of glucose toxicity. Here, we investigate whether glucosamine-induced insulin secretory dysfunction is specific to glucose or also extends to nonglucose secretagogues such as arginine. Two groups of 12 weight-matched Sprague-Dawley rats underwent hyperglycemic clamp studies (steady-state blood glucose, approximately 220 mg x dL(-1)) during infusion of normal saline or glucosamine 3.5 mg x kg(-1) x min(-1) over a 100-minute period. Insulin levels were measured at baseline and between 90 and 100 minutes. One hundred minutes into the hyperglycemic clamp, subgroups of seven rats each (saline- and glucosamine-infused rats) received a bolus of arginine (100 mg x kg(-1)) while the glucose infusion rate was unaltered. Glucose and insulin levels were measured at 1, 3, 5, 10, 15, and 30 minutes after the arginine bolus. Both groups had similar fasting glucose and insulin levels. At steady state (60 to 100 minutes), glucose levels were almost identical in both groups (223.58+/-3.94 v 224.58+/-4.34 mg x dL(-1)), but the glucose infusion rate (26.55+/-1.60 v 8.83+/-1.35 mg x kg(-1) x min(-1), P < .0001) and insulin level (41.36+/-6.47 v 18.04+/-2.95 mU x mL(-1), P < .0001) were markedly reduced in animals receiving glucosamine. Peak insulin levels 1 minute after the arginine bolus were lower in rats infused with glucosamine versus saline (274.00+/-30.38 v 176.25+/-20.12 microU x ml(-1), P=.0319). Total insulin secretion in response to arginine was significantly lower in the glucosamine group as determined by the area under the curve (1,268.09+/-142.27 v 706.77+/-84.79 microU x mL(-1) x min, P=.0054). In conclusion, glucosamine causes severe impairment in glucose-induced insulin secretion. Further, glucosamine-induced beta-cell secretory dysfunction extends to nonglycemic stimuli like arginine. This pattern of insulin secretory dysfunction is similar to that observed in patients with non-insulin-dependent diabetes mellitus (NIDDM). These data suggest that glucosamine may participate in the pathogenesis of glucose toxicity at the level of the beta cell in NIDDM patients.

Substitution of neutral detergent fiber from forage with neutral detergent fiber from by-products in the diets of lactating cows

Four lactating dairy cows that were ruminally and duodenally cannulated were used in an experiment with a 4 x 4 Latin square design to determine the effects of the substitution of neutral detergent fiber (NDF) from forage with NDF from wheat middlings, corn gluten feed, or a blend of distillers dried grains and hominy. Dietary crude protein and NDF averaged 18 and 31%, respectively, for the diet with 71.2% of the NDF from forage (control diet) and for diets with 55% of the NDF from forage (by-product diets). The substitution of NDF from these by-products for forage NDF did not affect dry matter intake (20.1 kg/d) or digestibility of organic matter. Total tract digestibility of acid detergent fiber was lower for cows fed the diet containing a blend of distillers dried grains and hominy than for cows fed the diet containing corn gluten feed. Microbial crude protein synthesis, milk production (23.9 kg/d), and milk fat percentage were similar for all cows, regardless of diet. Cows fed the diets containing wheat middlings or a blend of distillers dried grains and hominy had reduced ruminal pH compared with that of cows fed the diet containing corn gluten feed or the control diet. Diets containing 55% of total NDF from forage with 31% of total NDF from corn gluten feed, wheat middlings, or a blend of distillers dried grains and hominy can supply sufficient effective fiber to maintain normal ruminal function.

Overexpression of glutamine:fructose-6-phosphate amidotransferase in transgenic mice leads to insulin resistance

The hexosamine biosynthetic pathway has been hypothesized to be involved in mediating some of the toxic effects of hyperglycemia. Glutamine:fructose-6-phosphate amidotransferase (GFA), the first and rate limiting enzyme of the hexosamine biosynthetic pathway, was overexpressed in skeletal muscle and adipose tissue of transgenic mice. A 2.4-fold increase of GFA activity in muscle of the transgenic mice led to weight-dependent hyperinsulinemia in random-fed mice. The hyperinsulinemic-euglycemic clamp technique confirmed that transgenic mice develop insulin resistance, with a glucose disposal rate of 68.5 +/- 3.5 compared with 129.4 +/- 9.4 mg/kg per min (P < 0.001) for littermate controls. The decrease in the glucose disposal rate of the transgenic mice is accompanied by decreased protein but not mRNA levels of the insulin-stimulated glucose transporter (GLUT4). These data support the hypothesis that excessive flux through the hexosamine biosynthesis pathway mediates adverse regulatory and metabolic effects of hyperglycemia, specifically insulin resistance of glucose disposal. These mice can serve as a model system to study the mechanism for the regulation of glucose homeostasis by hexosamines.

Glucosamine induces insulin resistance in vivo by affecting GLUT 4 translocation in skeletal muscle. Implications for glucose toxicity

Glucosamine (Glmn), a product of glucose metabolism via the hexosamine pathway, causes insulin resistance in isolated adipocytes by impairing insulin-induced GLUT 4 glucose transporter translocation to the plasma membrane. We hypothesized that Glmn causes insulin resistance in vivo by a similar mechanism in skeletal muscle. We performed euglycemic hyperinsulinemic clamps (12 mU/kg/min + 3H-3-glucose) in awake male Sprague-Dawley rats with and without Glmn infusion at rates ranging from 0.1 to 6.5 mg/kg/min. After 4h of euglycemic clamping, hindquarter muscles were quick-frozen and homogenized, and membranes were subfractionated by differential centrifugation and separated on a discontinuous sucrose gradient (25, 30, and 35% sucrose). Membrane proteins were solubilized and immunoblotted for GLUT 4. With Glmn, glucose uptake (GU) was maximally reduced by 33 +/- 1%, P < 0.001. The apparent Glmn dose to reduce maximal GU by 50% was 0.1 mg/kg/min or 1/70th the rate of GU on a molar basis. Control galactosamine and mannosamine infusions had no effect on GU. Relative to baseline, insulin caused a 2.6-fold increase in GLUT 4 in the 25% membrane fraction (f), P < 0.01, and a 40% reduction in the 35%f, P < 0.05, but had no effect on GLUT 4 in the 30% f, P= NS. Addition of Glmn to insulin caused a 41% reduction of GLUT 4 in the 25%f, P < 0.05, a 29% fall in the 30%f, and prevented the reduction of GLUT 4 in the 35% f. The 30%f membranes were subjected to a second separation with a 27 and 30% sucrose gradient. Insulin mobilized GLUT 4 away from the 30%f, P < 0.05, but not the 27% f. In contrast, Glmn reduced GLUT 4 in the 27%f, P < 0.05, but not the 30%f. Thus Glmn appears to alter translocation of an insulin-insensitive GLUT 4 pool. Coinfusion of Glmn did not alter enrichment of the sarcolemmal markers 5'-nucleotidase, Na+/K+ATPase, and phospholemman in either 25, 30, or 35% f. Thus Glmn completely blocked movement of Glut 4 induced by insulin. Glmn is a potent inducer of insulin resistance in vivo by causing (at least in part) a defect intrinsic to GLUT 4 translocation and/or trafficking. These data support a potential role for Glmn to cause glucose-induced insulin resistance (glucose toxicity).

Insulin resistance after hypertension induced by the nitric oxide synthesis inhibitor L-NMMA in rats

To explore the relationship between insulin resistance and hypertension, we examined whether acute induction of hypertension can engender insulin resistance. For this purpose we measured rates of insulin-mediated glucose uptake in awake unstressed rats with the euglycemic hyperinsulinemic (12 microns.kg-1.min-1) clamp technique during infusions of saline alone or after induction of hypertension by bolus administration of NG-monomethyl-L-arginine (L-NMMA, 30 and 15 mg/kg), a competitive inhibitor of nitric oxide synthase. Arterial pressure was approximately 20% greater with L-NMMA bolus than with saline alone. Isotopically determined steady-state rates of glucose uptake were 36 +/- 1 mg.kg-1.min-1 during saline alone and 26 +/- 2 and 19 +/- 1 mg.kg-1.min-1 with low- and high-dose L-NMMA (P < 0.001 vs. saline), respectively. To rule out that insulin resistance induced by L-NMMA was adrenergically mediated, clamp studies were repeated with alpha- and beta-blockade. Rates of glucose uptake remained approximately 20% below those observed with saline alone (P < 0.001). A significant inverse correlation was observed between the height of the blood pressure and the rate of glucose uptake (r = 0.32, P = 0.04). In conclusion, acute induction of hypertension with L-NMMA can cause marked insulin resistance. We postulate that reduced skeletal muscle perfusion and/or sympathetic nervous system activation may contribute to insulin resistance induced by L-NMMA.

Purification, characterization and developmental expression of indole-3-ethanol oxidase from seeds of Phaseolus vulgaris

Purification of indole-3-ethanol (IEt) oxidase was carried out from extracts of the seeds of two bean cultivars. The IEt oxidase from the Labrador cultivar was purified more than 1000-fold and had a molecular weight of about 56 kD. The enzyme reaction required oxygen and produced hydrogen peroxide, was not stimulated by either NADP or FAD, and was inhibited by EDTA and iodoacetate. Physiologically-relevant inhibitors included gibberellic acid, indoleacetic acid and indoleacetaldehyde, through at higher than physiological concentrations. IEt oxidase from the Farden Losa cultivar differed in some properties, but an antiserum prepared against this enzyme detected corresponding proteins from the Labrador and Tendergreen cultivars. In developing Tendergreen bean seeds, the IEt oxidase activity was temporally correlated with IEt levels. Parallel immunochemical measurement of IEt was obscured by non-specific reactions.

[Activation and free radical formation of leukocytes in patients with acute ischemic stroke]

The leukocyte count, leukocyte activation, lipoperoxidant (Lpo) of leukocytes and C3 in the peripheral blood were determined in 44 patients with acute ischemic stroke and the results were compared with those in age-matched healthy controls. No significant difference in mean leukocyte counts was observed between the patients and controls. The levels of leukocyte activation in the patients were significantly higher than those in the controls (137.94 +/- 38.86 U/L vs 92.22 +/- 20.29 U/L, P < 0.01), while the levels of Lpo of leukocytes and C3 were significantly lower than those in the controls (0.90 +/- 0.87 mumol/L and 0.96 +/- 0.72 g/L vs 1.57 +/- 1.29 mumol/L and 1.69 +/- 0.70 g/L, P < 0.01). The changes of these levels were in correlation with the extent of cerebral infarction. It is suggested that leukocytes might be involved in the pathophysiological process of acute ischemic brain damage. Its mechanisms and route of activation were discussed briefly.

Intestinal lactase: maturational excess expression of mRNA over enzyme protein

The mechanism of decline of intestinal lactase during mammalian development remains uncertain. Despite a major loss of catalytic activity, lactase mRNA appears to persist at detectable concentrations in adult rats. We quantified lactase activity, total lactase protein, and lactase mRNA in rats aged 7, 11, 15, 18, 22, 30, and 60 days using the 7S ribosomal RNA as the developmental control. The active lactase fraction was 0.81 of total lactase for all age groups except 60-day-old animals, in which it declined to 0.60 (P = 0.004), indicating that conversion of active lactase to inactive species contributed to the lower activity in the adult. Northern blots revealed a single discrete 6.8-kb message at all ages. Although lactase activity and immunoprotein decreased coordinately to a minimum by day 30 (20% of the 7-day value), lactase mRNA doubled to a maximum at day 22 and was maintained at 7-day concentrations even in 60-day adults. The lactase mRNA-to-protein ratio was low at 7 days (0.19) but more than doubled (0.50) by 22 days, achieved a fivefold increase (1.0) by 30 days, and persisted at 0.77 in adults. The relative excess of lactase message during maturation suggests that translational or post-translational events may be paramount in the developmental regulation of lactase gene expression.