A Social Media Quality Review of Popular Sinusitis Videos on TikTok

OBJECTIVE

Social media may inform health care decisions among younger patient populations. TikTok is a social media platform that allows users to post short-form videos. This study aimed to assess the quality of sinusitis-related videos on TikTok.

STUDY DESIGN

We searched TikTok on January 29, 2023, for sinusitis-related hashtags: #sinusitis, #sinus, #sinusinfection.

SETTING

Internet.

METHODS

The number of views/shares per day, uploader type (nonmedical influencer, lay individual, and medical professional) content categories (medical advice, marketing, comedy, and lifestyle/acceptability), and content type (educational vs factual) were collected. The Patient Education Materials Assessment Tool for Audiovisual Material and Journal of the American Medical Association criteria score was used to measure understandability, actionability, and reliability. The Global Quality Scale (GQS) was used to evaluate the quality of videos; the harm/benefit score was used to evaluate causative effects. Analyses were performed using analysis of variance (α = .05).

RESULTS

There were 221 videos identified, which garnered over 300 million views and 1 million shares. Almost half of the videos were published by nonmedical influencers. When controlling for covariates, nonmedical influencers and lay uploaders were more likely to have harmful harm/benefit scores, less understandable videos, and lower GQS scores compared to medical professionals. Less than half of videos posted by nonmedical influencers categorized as educational were factual (46.7%); lay individuals and medical professionals had higher rates of factual educational content (79.9% and 83.7%, respectively).

CONCLUSION

Most nonmedical influencer-posted TikTok videos about sinusitis are inaccurate, despite being portrayed as medical advice/educational. Rhinologists must find modern ways to disseminate true disease-related content via social media to combat medical misinformation.

Clinical Significance of Pheochromocytoma Size on the Timing and Extent of Surgery

INTRODUCTION

Elevated metanephrine and catecholamine levels 3-fold upper limit of normal (ULN) are diagnostic for pheochromocytoma. We sought to determine whether size correlates with biochemical activity or symptoms which could guide timing of surgery.

METHODS

Data from consecutive patients undergoing adrenalectomy for pheochromocytoma at our institution over a 10-year period were retrospectively collected. These included maximal lesion diameter on preoperative imaging, plasma/urine metanephrine and/or catecholamine levels, demographic variables and presence of typical paroxysmal symptoms. Receiver operating characteristic curves were used to assess predictive accuracy.

RESULTS

Sixty-three patients were included in the analysis (41 females and 22 males). Median age was 56 (43, 69) years. Due to various referring practices, 31 patients had documented 24-h urine metanephrine, 26 had 24-h urine catecholamine, and 52 had fractionated plasma metanephrine levels available for review. Values were converted to fold change compared to ULN and the maximum of all measured values was used for logistic regression. Median tumor size was 3.40 (2.25, 4.55) cm in greatest dimension. Tumor size at which pheochromocytoma produced > 3-fold ULN was ≥2.3 cm (AUC of 0.84). Biochemical activity increased with doubling tumor size (odds ratio = 8, P = 0.0004) or ≥ 1 cm increase in tumor size (odds ratio = 3.03, P = 0.001). 40 patients had paroxysmal symptoms, but there was no significant correlation between tumor size/biochemical activity and symptoms.

CONCLUSIONS

In our study, tumor size directly correlated with the degree of biochemical activity and pheochromocytomas ≥2.3 cm produced levels 3 times ULN. These findings may allow clinicians to adjust timing of operative intervention.

Single center outcomes from parenchymal-sparing resections and microwave ablations for neuroendocrine tumor liver metastases

BACKGROUND

Reported outcomes after surgical debulking in patients with advanced neuroendocrine tumor liver metastases (NETLM) are sparse.

METHODS

NETLM patients that underwent surgical debulking from 2019 to 2021 were reviewed. Trends in perioperative liver function, complications, symptom response, and progression-free survival were examined.

RESULTS

1069 liver lesions were debulked from 53 patients using a combination of parenchymal-sparing resections (PSR) and ultrasound-guided microwave ablations (MWA). Post-operative transaminitis and thrombocytopenia were common, and severity correlated with increasing number of lesions. Laboratory markers for synthetic liver function did not differ according to the number of lesions debulked. 13% of patients sustained a Clavien-Dindo grade 3 or 4 complication which was not associated with the number of lesions targeted. All patients with preoperative symptoms had improvement after surgery. Median time to progression was 10.9 months.

CONCLUSIONS

PSR with MWA for large numbers of NETLM is safe and effective for symptom control and does not affect synthetic liver function.

Socioeconomic status is associated with pediatric adenotonsillectomy outcomes: A single institution study

OBJECTIVE

Our institution serves a diverse patient population across a large metropolitan city. Literature has shown pediatric otolaryngology patients with lower socioeconomic status (SES) have higher rates of sleep-disordered breathing, delays in treatment time, and greater risks of complications post-tonsillectomy. This study aims to examine the effects of SES on adenotonsillectomy outcomes performed at our institution.

STUDY DESIGN

A retrospective chart review including 1560 pediatric patients (ages 0-18) who underwent adenotonsillectomy between January 2015 and December 2020.

SETTING

Large metropolitan hospital, level 1 trauma center.

METHODS

Outcome variables included postoperative hospital admission, phone calls, 30-day follow-up, and persistent obstructive sleep apnea (OSA). Descriptive statistics using Wilcoxon Signed Rank Tests and univariate and multivariate logistic regression modeling were used to determine statistically significant covariates at α = 0.05.

RESULTS

The cohort included Non-Hispanic White (n = 488, 31 %), Non-Hispanic Black (n = 801, 51 %), Hispanic (n = 210, 13 %), and other (n = 61, 4 %) groups. Using multivariate regression, privately insured patients were less likely to have moderate-to-severe OSA before surgery (0.65 95 % CI 0.45, 0.93 p = 0.017) and be admitted postoperatively (0.73, 0.55-0.96, p < 0.01), while more likely to have postoperative follow-up phone calls (1.57, 1.19-2.09, p < 0.01) and visits (1.53, 1.22-1.92, p < 0.01). Increased income was associated with decreased rehospitalizations within three months of surgery (0.98, 0.97-1.00, p < 0.01).

CONCLUSION

This study suggests SES significantly affects adenotonsillectomy outcomes. Further studies are warranted to provide better care for all pediatric patients.

Racial differences in phenotypic frailty assessment among general thoracic surgery patients

Objectives

The American Association for Thoracic Surgery recommends using frailty assessments to identify patients at higher risk of perioperative morbidity and mortality. We evaluated what patient factors are associated with frailty in a thoracic surgery patient population.

Methods

New patients aged more than 50 years who were evaluated in a thoracic surgery clinic underwent routine frailty screening with a modified Fried's Frailty Phenotype. Differences in demographics and comorbid conditions among frailty status groups were assessed with chi-square and Student t tests. Logistic regressions performed with binomial distribution assessed the association of demographic and clinical characteristics with nonfrail, frail, prefrail, and any frailty (prefrail/frail) status.

Results

The study population included 317 patients screened over 19 months. Of patients screened, 198 (62.5%) were frail or prefrail. Frail patients undergoing thoracic surgery were older, were more likely single or never married, had lower median income, and had lower percent predicted diffusion capacity of the lungs for carbon monoxide and forced expiratory volume during 1 second (all P < .05). More non-Hispanic Black patients were frail and prefrail compared with non-Hispanic White patients (P = .003) and were more likely to score at least 1 point on Fried's Frailty Phenotype (adjusted odds ratio, 3.77; P = .02) when controlling for age, sex, number of comorbidities, median income, diffusion capacity of the lungs for carbon monoxide, and forced expiratory volume during 1 second. Non-Hispanic Black patients were more likely than non-Hispanic White patients to score points for slow gait and low activity (both P < .05).

Conclusions

Non-Hispanic Black patients undergoing thoracic surgery are more likely to score as frail or prefrail than non-Hispanic White patients. This disparity stems from differences in activity and gait speed. Frailty tools should be examined for factors contributing to this disparity, including bias.

Assessment of Demographic Changes of Workforce Diversity in Otolaryngology, 2013 to 2022

Importance

Given the growth of minoritized groups in the US and the widening racial and ethnic health disparities, improving diversity remains a proposed solution in the field of otolaryngology. Evaluating current trends in workforce diversity may highlight potential areas for improvement.

Objective

To understand the changes in gender, racial, and ethnic diversity in the otolaryngology workforce in comparison with changes in the general surgery and neurosurgery workforces from 2013 to 2022.

Design, Setting, and Participants

This cross-sectional study used publicly available data from the Accreditation Council for Graduate Medical Education and the Association of American Medical Colleges for 2013 to 2022, and included medical students and trainees in all US medical residency programs and allopathic medical schools.

Main Outcomes and Measures

Average percentages of women, Black, and Latino trainees during 2 intervals of 5 years (2013-2017 and 2018-2022). Pearson χ2 tests compared demographic information. Normalized ratios were calculated for each demographic group in medical school and residency. Piecewise linear regression assessed linear fit for representation across time periods and compared rates of change.

Results

The study population comprised 59 865 medical residents (43 931 [73.4%] women; 6203 [10.4%] Black and 9731 [16.2%] Latino individuals; age was not reported). The comparison between the 2 study intervals showed that the proportions of women, Black, and Latino trainees increased in otolaryngology (2.9%, 0.7%, and 1.6%, respectively), and decreased for Black trainees in both general surgery and neurosurgery (-0.4% and -1.0%, respectively). In comparison with their proportions in medical school, Latino trainees were well represented in general surgery, neurosurgery, and otolaryngology (normalized ratios [NRs]: 1.25, 1.06, and 0.96, respectively); however, women and Black trainees remained underrepresented in general surgery, neurosurgery, and otolaryngology (women NRs, 0.76, 0.33, and 0.68; Black NRs, 0.63, 0.61, and 0.29, respectively). The percentage of women, Black, and Latino trainees in otolaryngology all increased from 2020 to 2022 (2.5%, 1.1%, and 1.1%, respectively). Piecewise regression showed positive trends across all 3 specialties.

Conclusions and Relevance

The findings of this cross-sectional study indicate a positive direction but only a modest increase of diversity in otolaryngology, particularly in the context of national demographic data. Novel strategies should be pursued to supplement existing efforts to increase diversity in otolaryngology.

Factors Associated with Health-Related Quality of Life in Lung Transplant Candidates and Recipients

OBJECTIVES

Health-related quality of life has been well studied across transplantation fields, but factors associated with lung transplant preoperative and postoperative quality of life remain unknown. Here, we determine factors associated with health-related quality of life in lung transplant candidates and recipients to identify patients at risk of lower health-related quality of life.

MATERIALS AND METHODS

From January 2021 to May 2022, health-related quality of life was measured in candidates and recipients using the RAND 36-Item Short Form Health Survey questionnaire. We reviewed demographic parameters and clinical information and scored frailty according to the modified 5-item frailty index. We performed Fisher exact test and the Pearson chi-square test and used linear regression models to determine covariate associations on physical component summary, mental component summary, and self-reported health scores (α = 0.05).

RESULTS

Eleven candidates and 17 recipients comp-leted the survey. Compared with candidates, transplant recipients reported significantly higher scores in 4 of the 8 health domains and in the physical component summary (P < .01), mental component summary (P = .05), and self-reported health score (P < .01). In candidates, higher body mass index and higher modified 5-item frailty index scores were negatively associated with the physical component summary and mental component summary, respec-tively (P < .05). In recipients, higher body mass index and higher lung allocation scores were associated with lower values for the physical component summary (-2.29; P < .05) and self-reported health score (-0.33; P < .05), respectively.

CONCLUSIONS

Body mass index, the modified 5-item frailty index, and the lung allocation score were significantly associated with health-related quality of life in lung transplant recipients. Future interventions should target these modifiable associations to maximize candidate and recipient health-related quality of life.

Embolization in Juvenile Nasopharyngeal Angiofibroma Surgery: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare outcomes of juvenile nasopharyngeal angiofibroma (JNA) resection between embolized and non-embolized cohorts, and between transarterial embolization (TAE) and direct puncture embolization (DPE).

DATA SOURCES

Per PRISMA guidelines, PubMed, Embase, Web of Science, Scopus, and Cochrane databases were searched for publications prior to or in 2021.

MATERIALS AND METHODS

Original English manuscripts investigating the resection of JNA with and without preoperative embolization were included. Embolization type, recurrence rate, complication rates, blood loss, and transfusions were extracted. Risk of bias was assessed by the Risk of Bias in Non-randomized Studies-of Interventions method.

RESULTS

There were 61 studies with 917 patients included. Preoperative embolization was performed in 79.3% of patients. Of those embolized, 75.8% (N = 551) underwent TAE and 15.8% (N = 115) underwent DPE. JNA recurrence in embolized patients was lower than in non-embolized patients (9.3% vs. 14.4%; odds ratio [OR]: 0.61, 95% confidence interval [CI]: 0.35, 1.06). DPE resulted in lower rates of disease recurrence (0% vs. 9.5%; OR: 0.066, 95% CI: 0.016, 0.272) and complications (1.8% vs. 21.9%; OR: 0.07, 95% CI: 0.02, 0.3) than TAE. A random effects Bayesian model was performed to analyze the difference in mean blood loss in 6 studies that included both embolized and non-embolized patients. This analysis showed a mean reduction in blood loss of 798 mL in the embolized group.

CONCLUSIONS

We found embolization decreases blood loss in JNA resection. DPE led to improved recurrence and complication rates when compared to TAE, but future prospective studies are needed to further evaluate which embolization technique can optimize outcomes in JNA.

LEVEL OF EVIDENCE

NA Laryngoscope, 2023.

Histotripsy induces apoptosis and reduces hypoxia in a neuroblastoma xenograft model

BACKGROUND

Neuroblastoma (NB) is the most common extracranial solid tumor of childhood, and high-risk disease is resistant to intensive treatment. Histotripsy is a focused ultrasound therapy under development for tissue ablation via bubble activity. The goal of this study was to assess outcomes of histotripsy ablation in a xenograft model of high-risk NB.

METHODS

Female NCr nude mice received NGP-luciferase cells intrarenally. Under ultrasound image guidance, histotripsy pulses were applied over a distance of 4-6 mm within the tumors. Bioluminescence indicative of tumor viability was quantified before, immediately after, and 24 h after histotripsy exposure. Tumors were immunostained to assess apoptosis (TUNEL), endothelium (endomucin), pericytes (αSMA), hypoxia (pimonidazole), vascular endothelial growth factor A (VEGFA), and platelet-derived growth factor-B (PDGF-B). The apoptotic cytokine TNFα and its downstream effector cleaved caspase-3 (c-casp-3) were assessed with SDS-PAGE.

RESULTS

Histotripsy induced a 50% reduction in bioluminescence compared to untreated controls, with an absence of nuclei in the treatment core surrounded by a dense rim of TUNEL-positive cells. Tumor regions not targeted by histotripsy also showed an increase in TUNEL staining density. Increased apoptosis in histotripsy samples was consistent with increases in TNFα and c-casp-3 relative to controls. Treated tumors exhibited a decrease in hypoxia, VEGF, PDGF-B, and pericyte coverage of vasculature compared to control samples. Further, increases in vasodilation were found in histotripsy-treated specimens.

CONCLUSIONS

In addition to ablative effects, histotripsy was found to drive tumor apoptosis through intrinsic pathways, altering blood vessel architecture, and reducing hypoxia.

Oral community health worker-led interventions in households with average levels of psychosocial factors

Introduction

Household-level psychosocial stress levels have been linked to child tooth brushing behaviors. Community health worker (CHW) interventions that target psychosocial factors in high-risk communities have been associated with changes in health behaviors.

Aim

Observe changes in psychosocial factors over time and an association between psychosocial factors and CHW intervention dose amongst urban Chicago families.

Patients and methods

Participants (N = 420 families) were recruited from 10 community clinics and 10 Women, Infants, or Children (WIC) centers in Cook County, Illinois to participate in a clinical trial. Research staff collected participant-reported psychosocial factors (family functioning and caregiver reports of depression, anxiety, support, and social functioning) and characteristics of CHW-led oral health intervention visits (number, content, child engagement) at 0, 6, and 12 months. CHWs recorded field observations after home visits on household environment, social circumstances, stressors, and supports.

Results

Participants across the cohort reported levels of psychosocial factors consistent with average levels for the general population for nearly all measures. Psychosocial factors did not vary over time. Social functioning was the only measure reported at low levels [32.0 (6.9); 32.1 (6.7); 32.7 (6.9); mean = 50 (standard deviation)] at 0, 6, and 12 months. We did not observe a meaningful difference in social functioning scores over time by exposure to CHW-led intervention visits (control arm, 0, 1, 2, 3, and 4 visits). Field observations made by CHWs described a range of psychosocial stress related to poverty, language barriers, and immigration status.

Conclusion

The unexpectedly average and unchanging psychosocial factors over time, in the context of field observations of stress related to poverty, lack of support, immigration status, and language barriers, suggests that our study did not adequately capture the social determinants of health related to oral health behaviors or that measurement biases precluded accurate assessment. Future studies will assess psychosocial factors using a variety of instruments in an attempt to better measure psychosocial factors including social support, depression, anxiety, functioning, trauma and resilience within our urban population. We will also look at neighborhood-level factors of community distress and resilience to better apply the social ecologic model to child oral health behaviors.

Community health worker intervention to improve tooth brushing in young children: Results from a cluster randomized controlled trial

OBJECTIVES

Coordinated Oral health Promotion (CO-OP) Chicago is a cluster randomized controlled trial testing the efficacy of a community health worker (CHW) intervention to improve tooth brushing in low-income children.

METHODS

Four hundred twenty children under 3 years old (mean 21.5 months) were recruited from 20 sites in or near Chicago, IL. Children were identified mainly as Black race (41.9%) or Hispanic ethnicity (53.8%) and most (85.2%) had Medicaid. Intervention families were offered four CHW home visits over 1 year. Brushing frequency was self-reported. Plaque score was determined from images collected in homes using disclosing solution. Analyses used GEE logistic models with variable selection at p < .05.

RESULTS

At enrolment, 45.0% of families reported twice a day or more child brushing frequency, and child plaque scores were poor (mean of 1.9, SD: 0.6). Data were obtained from 87.1% of children at 6 months and 86.2% at 12 months. In the CHW intervention arm (10 sites, N = 211), 23.7% received 4 visits, 12.8% 3 visits, 21.3% 2 visits, 23.2% 1 visit and 19% no visits from CHWs. No intervention effect was seen for brushing frequency or plaque score. Child brushing frequency improvement over time was associated with a range of child and caregiver factors. The only factor associated with a change in plaque score over time was parent involvement in brushing.

CONCLUSIONS

Oral-health-specific CHW services were not associated with improved brushing behaviours in these young children. However, caregiver involvement with brushing supported more quality brushing. More robust interventions are needed to support families during this critical developmental period.

An empirical example of analysis using a two-stage modeling approach: within-subject association of outdoor context and physical activity predicts future daily physical activity levels

People differ from each other to the extent to which momentary factors, such as context, mood, and cognitions, influence momentary health behaviors. However, statistical models to date are limited in their ability to test whether the association between two momentary variables (i.e., subject-level slopes) predicts a subject-level outcome. This study demonstrates a novel two-stage statistical modeling strategy that is capable of testing whether subject-level slopes between two momentary variables predict subject-level outcomes. An empirical case study application is presented to examine whether there are differences in momentary moderate-to-vigorous physical activity (MVPA) levels between the outdoor and indoor context in adults and whether these momentary differences predict mean daily MVPA levels 6 months later. One hundred and eight adults from a multiwave longitudinal study provided 4 days of ecological momentary assessment (during baseline) and accelerometry data (both at baseline and 6 month follow-up). Multilevel data were analyzed using an open-source program (MixWILD) to test whether momentary strength between outdoor context and MVPA during baseline was associated with average daily MVPA levels measured 6 months later. During baseline, momentary MVPA levels were higher in outdoor contexts as compared to indoor contexts (b = 0.07, p < .001). Participants who had more momentary MVPA when outdoors (vs. indoors) during baseline (i.e., a greater subject-level slope) had higher daily MVPA at the 6 month follow-up (b = 0.09, p < .05). This empirical example shows that the subject-level momentary association between specific context (i.e., outdoors) and health behavior (i.e., physical activity) may contribute to overall engagement in that behavior in the future. The demonstrated two-stage modeling approach has extensive applications in behavioral medicine to analyze intensive longitudinal data collected from wearable sensors and mobile devices.

Extending the mixed‐effects model to consider within‐subject variance for Ecological Momentary Assessment data

Ecological Momentary Assessment data present some new modeling opportunities. Typically, there are sufficient data to explicitly model the within-subject (WS) variance, and in many applications, it is of interest to allow the WS variance to depend on covariates as well as random subject effects. We describe a model that allows multiple random effects per subject in the mean model (eg, random location intercept and slopes), as well as random scale in the error variance model. We present an example of the use of this model on a real dataset and a simulation study that shows the benefit of this model, relative to simpler approaches.

Do fluctuations in positive affective and physical feeling states predict physical activity and sedentary time?

OBJECTIVES

Higher levels of positive affect and feelings of energy and vitality are associated with greater physical activity (PA) and lower sedentary time (ST). However, whether fluctuations in these feelings contribute to the regulation of these behaviors is unclear. This study examined the extent to which within-person variability in positive affect and feeling energetic predicted participants' overall levels of PA and ST.

DESIGN

This analysis combined data from four ecological momentary assessment (EMA) studies (age_range: 8-73 years) with ambulatory monitoring via waist-worn accelerometry (N=661).

METHODS

Positive affect and energy were assessed through EMA several times per day across 4-7 days. Accelerometer data was used to create the following behavioral outcomes: (1) meeting MVPA guidelines (children: 60 minutes/day, adults: 30 minutes/day) and (2) minutes of ST per hour of accelerometer wear. A two-stage analytic approach was used to test the study aim. In the first stage, Mixed-Effects Location Scale Modeling decomposed mean levels and variability in positive affect and energy. In the second stage, a linear or logistic regression (depending on whether the outcome was continuous or dichotomous, respectively) was tested to investigate associations between subject-level mean and variability in EMA ratings and the behavioral outcome.

RESULTS

Greater subject-level variability but not subject-level mean of feeling energetic was associated with lower odds of meeting MVPA guidelines (β=-0.43, p<0.05).

CONCLUSIONS

Fluctuations in physical feeling states may deplete self-regulatory resources involved in planning and implementing PA behavior. Alternatively, being more physically active may stabilize one's perceived energy levels.

A Mixed-Effects Model for Detecting Disrupted Connectivities in Heterogeneous Data

The human brain is an amazingly complex network. Aberrant activities in this network can lead to various neurological disorders such as multiple sclerosis, Parkinson's disease, Alzheimer's disease, and autism. functional magnetic resonance imaging has emerged as an important tool to delineate the neural networks affected by such diseases, particularly autism. In this paper, we propose a special type of mixed-effects model together with an appropriate procedure for controlling false discoveries to detect disrupted connectivities for developing a neural network in whole brain studies. Results are illustrated with a large data set known as autism brain imaging data exchange which includes 361 subjects from eight medical centers.

Pharmacometrics Markup Language (PharmML): Opening New Perspectives for Model Exchange in Drug Development

The lack of a common exchange format for mathematical models in pharmacometrics has been a long-standing problem. Such a format has the potential to increase productivity and analysis quality, simplify the handling of complex workflows, ensure reproducibility of research, and facilitate the reuse of existing model resources. Pharmacometrics Markup Language (PharmML), currently under development by the Drug Disease Model Resources (DDMoRe) consortium, is intended to become an exchange standard in pharmacometrics by providing means to encode models, trial designs, and modeling steps.

MIXREGLS: A Program for Mixed-Effects Location Scale Analysis

MIXREGLS is a program which provides estimates for a mixed-effects location scale model assuming a (conditionally) normally-distributed dependent variable. This model can be used for analysis of data in which subjects may be measured at many observations and interest is in modeling the mean and variance structure. In terms of the variance structure, covariates can by specified to have effects on both the between-subject and within-subject variances. Another use is for clustered data in which subjects are nested within clusters (e.g., clinics, hospitals, schools, etc.) and interest is in modeling the between-cluster and within-cluster variances in terms of covariates. MIXREGLS was written in Fortran and uses maximum likelihood estimation, utilizing both the EM algorithm and a Newton-Raphson solution. Estimation of the random effects is accomplished using empirical Bayes methods. Examples illustrating stand-alone usage and features of MIXREGLS are provided, as well as use via the SAS and R software packages.

Recombinant canarypox vectored West Nile virus (WNV) vaccine protects dogs and cats against a mosquito WNV challenge

The safety and efficacy of a canarypox vector expressing PrM and E genes of West Nile virus (WNV) (ALVAC-WNV) was evaluated in dogs and cats. One group of 17 dogs (vaccinated with 10(5.6) TCID(50)) and two groups of cats (groups 1 [n=14] vaccinated with 10(7.5) TCID(50) and 2 [n=8] 10(5.6) TCID(50)) were vaccinated twice at 28-day intervals. Fifteen dogs and eleven cats served as negative controls. The cats and dogs were challenged 120 and 135 days after the second immunization, respectively via the bites of Aedes albopictus mosquitoes infected with WNV. The first dose of vaccine induced a detectable antibody response in four dogs and five cats (one immunized with low and four with high doses). After the second dose, all the vaccinated dogs and all of the cats, immunized with high dose had detectable antibody titers, whereas only four of eight cats in the low dose group were seropositive. None of the vaccinated dogs and one vaccinated cat developed viremia following the WNV mosquito-challenge. In contrast, 14 of the 15 control dogs and 9 of the 11 control cats developed viremia. The experimental vaccine described in this study may be of value in the prevention of WNV infection in dogs and cats.

Nitric oxide production by chicken macrophages activated by Acemannan, a complex carbohydrate extracted from Aloe vera

Cultures of normal chicken spleen cells and HD11 line cells produce nitric oxide (NO) in response to Acemannan, a complex carbohydrate derived from the Aloe vera plant. Neither cell type produced detectable amounts of NO in response to similar concentrations of yeast mannan, another complex carbohydrate. Nitric oxide production was dose dependent and inhibitable by the nitric oxide synthase inhibitor NG-methyl-L-arginine. In addition, the production of NO was inhibited by preincubation of ACM with concanavalin A in a dose-dependent manner. These results suggest that ACM-induced NO synthesis may be mediated through macrophage mannose receptors, and macrophage activation may be accountable for some of the immunomodulatory effects of ACM in chickens.