Improving Enforcement Measures And Establishing Clear Criteria: A Content Analysis Of Tobacco-Brand-Owned Instagram Accounts

INTRODUCTION

This study examines limitations of the current regulatory framework for tobacco advertising on Instagram. We first investigate compliance with FDA warning label requirements for posts by tobacco-owned accounts. Next, we examine the prevalence of content that has been restricted in broadcast or print for its youth appeal, followed by content meeting more expansive criteria for youth appeal set forth in the FDA's guidance document.

METHODS

Posts by tobacco-brand-owned accounts between January 1, 2021, and February 14, 2022, were sampled from Mintel's Comperemedia Omni database. Instagram posts from 15 accounts were examined for violations of FDA warning label requirements and content that has been restricted on other mediums, including cartoons, sports branding, unauthorized claims, and young models (N=1243). Finally, a subsample of n=453 unambiguously branded posts was coded for themes that met the FDA's criteria of resonating with younger audiences, particularly that "adolescents rely on external information as they seek to shape their own identities".

RESULTS

Only 12.8% of posts had fully compliant warning labels. Content that has been in some way regulated on other mediums, such as cartoons (1.6%), unauthorized health claims (<1%), sports branding (<1%), and young models (4.4%) were infrequent. However, a conservative analysis focusing only on branded posts found that posts frequently highlighted tech elements (45%), device customizability (24.5%), vaper identity (17.7%), stylized product photography (33.6%), social media engagement (32.2%) and memes (5.7%).

CONCLUSIONS

Enforcement of existing regulations on Instagram is minimal. Explicit content restrictions applying evidence-based guidance on youth-appealing advertising are needed.

IMPLICATIONS

This research has important implications for enforcing and expanding advertising regulations on social media. First, Instagram's self-imposed regulations are ineffective, permitting tobacco companies to post ads from brand-owned accounts despite claiming to restrict tobacco promotion on the platform. Second, policymakers should seek to apply FDA guidance on youth-appealing advertising informed by decades of research to create explicit enforceable content restrictions that extend beyond cartoons, sports figures, and young models to include content likely to situate tobacco use within the developing self-concept of vulnerable youth such as presenting e-cigarettes as hi-tech devices, highlighting vaper identity, or infiltrating online social media culture. Finally, greater resources for enforcement are needed given the only applicable regulation, warning labels, remains largely ignored.

Objective Characteristics and Subjective Responses of 18-24-Year-Olds to U.S. nationally Televised Tobacco Advertisements

Background: Restrictions on televised tobacco ads do not apply to vaping and oral nicotine products. Several campaigns are currently active on U.S. national television. This research examines the extent to which objective ad features are associated with ad, brand, and product appeal and use intentions among 18-24-year-olds. Methods: We identified seven unique campaigns for Vuse, Velo, and JUUL from the Mintel Comperemedia database, coded for youth-appealing content, and then randomly assigned among N = 1450 18-24-year-olds. Following exposure to one 15-second ad, participants completed a survey assessing their subjective responses. Results: Youth-appealing content was prevalent across these ads to varying degrees. Mixed effects regression analyses showed a positive association between features from the Content Appealing to Youth (CAY) index and pro-social brand perceptions, positive attitudes, reactions, and perceived effectiveness of the ad, and positive use perceptions. Moreover, themes related to customization of the device and environmental sustainability were associated with similar positive perceptions, including that using the product would be cool, as well as behavioral intentions to try, use occasionally, and use daily. Conclusions: Regulators need to update tobacco advertising restrictions to accurately reflect the current tobacco product landscape. This study contributes to the research on tobacco promotion strategies by examining the current marketing landscape for newer tobacco products and their appeal to youth. Findings from this study inform comprehensive tobacco marketing regulations, recommending the FDA update its guidelines and apply current marketing restrictions to e-cigarettes and oral nicotine products.

Relationship between clinical measures of hearing and clinical measures of vestibular function

PURPOSE

Patients often have basic audiometry (BA) but not objective diagnostic tests of the vestibular system (VNG) when complaining of symptoms of a vestibular disorder. The relationship of BA results to VNG results is unknown. This study sought to determine if BA scores are related to impaired VNG scores.

MATERIALS AND METHODS

We reviewed electronic medical records at a tertiary care center, for patients seen between 2015 and 2021 who had had both a BA and a VNG (n = 651). BA subtests were pure tone averages, word recognition, and tympanogram. VNG subtests were cervical vestibular evoked myogenic potentials, Dix-Hallpike maneuvers, and bi-thermal caloric tests. All tests were summarized as normal/abnormal.

RESULTS

More subjects had abnormal BA than abnormal VNG scores. Age but not sex was significantly related to abnormal scores. High BP was a significant comorbidity in 15 % of the sample, more in patients with abnormal than normal VNG scores. Although the abnormal BA and abnormal VNG were significantly related, pure tone averages and tympanogram scores were not related to VNG subtests. Abnormal word recognition with both ears combined was significantly related to normal and abnormal bi-thermal caloric tests.

CONCLUSIONS

If the clinician needs to know of any VNG impairment, in general, then performing a BA without a VNG might suffice. If the clinician needs information about the details of possible vestibular impairment, then a VNG should be performed.

Oral Cavity Squamous Cell Carcinomas in Patients with a History of Oral Lichen Planus: Frequency and Outcomes

PURPOSE/OBJECTIVE(S)

Oral lichen planus (OLP) is an inflammatory condition which affects the mucous membranes of the oral cavity. While previous studies have described the association between OLP and development of oral cavity cancer, there is currently a paucity of literature examining the impact of this disease on treatment response and prognosis. As such, we present a retrospective cohort study of Oral cavity squamous cell carcinoma (OCSCC) patients with a history of OLP to explore the course of their disease.

MATERIALS/METHODS

Using an IRB approved tertiary care registry of head and neck cancer patients, we identified patients with OCSCC who had a prior diagnosis of OLP. The number of new primary tumors, rates of local (LF), regional (RF) and distant failure (DF), as well as overall survival (OS) were assessed using Cox proportional hazards and Kaplan Meier analysis for actuarial survival estimates.

RESULTS

Fifty-four patients with OCSCC and OLP were identified with 109 individual OCSCC diagnoses. Patients had a median age of 67 years, were predominantly female (n = 42, 77.8%) and never smokers (n = 29, 53.7%) with a median follow up after diagnosis of OCSCC of 46.5 months. Nine patients (16.7%) had a history of immunosuppression of whom 6 (11.1%) had chronic steroid use for treatment of OLP. Within the cohort, 33 (61.1%) of OLP patients had a single OCSCC, 11 (20.4%) had 2, and 10 (18.5%) had >3 separate tumors develop. The most common oral cavity subsites were oral tongue (n = 42, 38.5%), followed by alveolar ridge (n = 14, 12.8%) and gingiva (n = 13, 11.9%). Papillary SCC subtype was identified in 10.1%. 92.7% of tumors (n = 101) were treated with primary surgery, with 23 (21.1%) receiving adjuvant RT and 10 of those patients receiving concurrent chemotherapy. Among resected patients, pathologic stages were predominantly T1-2 (84.1%) and N0 (50% vs N1 15.6% and N2a-3 34.4%). The mean RT dose was 62 Gy in 32 fractions. Locoregional failure occurred in 24.8% of cancers (n = 27), with local and regional failure occurring in 13.8% (n = 15) and 11% (n = 12) of lesions, respectively. Recurrence free survival at 3 and 5 years was 75% and 70.3%, respectively, with overall survival at 3 and 5 years of 71.1% and 67%, respectively.

CONCLUSION

Patients with OCSCC and a history of OLP are predominantly female and never smokers. The tumors that develop in such patients are often early stage but a proportion of patients appear to be at higher risk of developing multiple malignancies and surveillance of this patient population to identify new tumors is crucial.

Definitive Radiotherapy for the Treatment of Gross Disease in Unresected Differentiated Thyroid Cancer

PURPOSE/OBJECTIVE(S)

While surgery (with or without radioactive iodine (RAI)) is the mainstay of locoregional control in differentiated thyroid cancer (DTC), patients with unresectable disease present a clinical challenge. Uncontrolled disease in the neck can lead to substantial morbidity and mortality in DTC and obtaining locoregional control is vital to preserving quality of life and longevity. High dose definitive radiotherapy (RT) for gross disease in DTC is understudied. This study examines the efficacy of definitive RT in this setting.

MATERIALS/METHODS

From an IRB-approved registry of head and neck cancer cases treated at a tertiary care center over a period of 8 years (2014-2022), patients with incompletely resected or unresectable DTC including papillary, follicular, mixed, medullary, and poorly differentiated types were identified. All patients were treated to the neck and/or thyroid regions with visible gross disease to a definitive dose of radiation. The primary endpoint was local control within the radiated portal with a secondary endpoint of locoregional control within the neck.

RESULTS

A total of 31 patients were identified, of whom 74.2% were Caucasian. Fourteen were female (45.2%), and 17 (54.8%) were male. The median age was 68 years (range 26-90) and the median follow-up was 31 months. Histologically, 19 (61.3%) cases were papillary, 4 (12.9%) were follicular, 2 (6.5%) were mixed, 3 (9.7%) were medullary, and 3 (9.7%) were poorly differentiated. Among patients with non-medullary DTC 18 (69.2%) received prior RAI. Twelve patients were treated with radiation at initial diagnosis, while 19 patients were treated at the time of recurrence; two patients received concurrent chemotherapy. Twenty-eight patients (90.3%) were treated with IMRT and 3 (9.7%) were treated with SBRT. The median dose to the gross disease was 66 Gy (range 30-70.4) in 32 fractions (range 5-35). Overall, 5 patients (16.1%) experienced a locoregional failure after RT and all experienced failure in the RT portal. The actuarial infield control/locoregional control of radiation therapy at 3 and 5 years was 84.8% and 74.2%, respectively. Overall survival at 3 and 5 years was 68.5% and 47.4%, respectively. Among patients who had a locoregional failure after RT, 2 patients were salvaged with systemic therapy, 2 patients with surgery, and 1 patient with SBRT re-irradiation (40 Gy/5 fractions). The patient salvaged with SBRT remains without disease 8 months post-RT.

CONCLUSION

Definitive radiotherapy is a highly effective strategy to obtain durable control of unresected DTC. It should be standard for unresected disease and considered as a viable alternative for patients with borderline resectable disease for whom resection would be highly morbid.

Belief and Recall of Nicotine as Therapeutic for COVID-19 May Undermine E-Cigarette Quitting Behavior

We examine the proposition that misinformation about the therapeutic potential of nicotine to prevent or treat COVID-19 may lead to relapse among attempted e-cigarette quitters. A sample of N = 507 e-cigarette ever-users who reported at least one quit attempt in the past year were surveyed in June of 2021 for recall and belief in several claims about COVID-19 and nicotine. Participants who recalled and believed at least one misinformation claim were significantly more likely to have relapsed than those who did not recall or believe such claims. These differences remained robust to regression analysis adding demographic covariates and accounting for continuous measurement of recall and belief. Misinformation about e-cigarette use is reaching young adult e-cigarette users who are trying to quit. The implications of these findings merit further research to characterize potential barriers to successful e-cigarette cessation.

The influence of pro-vaping “gatewatchers” on the dissemination of COVID-19 misinformation on Twitter (Preprint)

Background

Objective

Methods

Results

Conclusions

Screening for balance in children and adults in a community science education setting: Normative data, influence of age, sex, and body mass index, and feasibility

BACKGROUND

Screening standing and walking balance is useful for people suspected of having vestibular disorders, a variety of neurologic and musculoskeletal disorders, and for screening astronauts returning after exposure to microgravity. Visitors to a community science education center children and adults, aged 4 to 85, were tested on tandem walking with eyes closed and the modified Romberg test on compliant foam. They were then asked about their experience participating in research, many people for the first time.

METHODS

Subjects performed 10 steps of tandem walking with eyes closed, and three trials of the modified Romberg, or Clinical Test of Sensory Integration and Balance, with eyes closed, standing on compliant memory foam, with a) head still, b) head shaking in yaw, and c) head nodding in pitch. Afterward, staff queried subjects about the experience of participating in science.

RESULTS

Age-related changes across the life span occurred in both sets of tests. Therefore, look-up tables by age are provided. Body mass index significantly affected tandem walking. Some sex differences were found. The tests were easy to administer in a community setting. Most participants enjoyed the experience and reported that they learned about the process of scientific research.

DISCUSSION

These data support and extend the evidence for age-related changes in balance performance across the lifespan and for an influence of body mass index on some balance skills. Clinicians and sports educators should be cognizant of these differences when they use these tests for screening. The community science education environment provided a useful laboratory in which to collect valid and reliable data, while simultaneously educating participants about the process of science.

A content analysis of promotional features in US direct-mail from ads across tobacco products from 2018-2020

INTRODUCTION

Direct-mail advertising is a crucial channel through which tobacco companies deliver price incentives that lower the barrier to tobacco use while promoting tobacco products via thematic appeals not legally permitted on other marketing channels. We examine the prevalence of price incentives and ad characteristics used in tobacco product ads mailed directly to US consumers.

METHODS

We analyzed the content of direct-mail tobacco advertisements (N= 1047) in circulation between January 2018 and December 2020 as captured by Mintel Comperemedia Direct. These ads were coded for product type, manufacturer/brand type, model characteristics, price incentives, and themes known to appeal to vulnerable subgroups.

RESULTS

Ads across all tobacco products included price incentives (96%) and contained themes that appealed to rural white (40%) and black audiences (15%). Themes known to appeal to youth and young adults were present in 40% of ads across all products, including 78% of ads promoting electronic nicotine delivery systems (ENDS). Moreover, among the ENDS ads featuring youth appealing themes (51%), also featured young models.

DISCUSSION

Expanding on previous research which focused on combustible and smokeless tobacco products, this analysis examines direct-mail ads across the full range of tobacco products. Our findings highlight the need for regulations to address 1) the high prevalence of price incentives which undermine the effectiveness of excise taxes on tobacco use, and 2) ad themes and characteristics that appeal to groups vulnerable to tobacco use, both of which have the potential to further exacerbate tobacco related health disparities.

IMPLICATIONS

This study reinforces the importance of examining direct-mail as the dominant medium for tobacco advertising, particularly by including coupons and discount codes that reduce product price and thus circumventing the effect of tobacco-related tax legislation.Direct-mail encourages continued product loyalty and use and engages new consumers using price incentives and advertising strategies likely to appeal to price-sensitive consumers and other vulnerable populations.Substantial use of youth-appealing elements in ENDS ads contradict the tobacco industry's mandate to not appeal to youth, warranting highlighting the gaps in current regulations that allows them to continue appealing to this population.

How did beliefs and perceptions about e-cigarettes change after national news coverage of the EVALI outbreak?

Introduction

Exposure to media content can shape public opinions about tobacco. In early September 2019, the outbreak of e-cigarette, or vaping, product use–associated lung injury (EVALI) became headline news in the United States.

Methods

In August and September 2019, we conducted two cross-sectional online surveys with current and former smokers assessing attitudes and beliefs about e-cigarettes. Study one (n = 865) was collected before the EVALI outbreak was widely covered and study two (n = 344) was collected after the outbreak had become nation-wide news. We examined differences in perceptions and beliefs between time points.

Results

E-cigarette harm perceptions increased between study one (mean = 2.67) and study two (mean = 2.90, p < .05). Ever-users of e-cigarettes largely account for this change. Endorsement of the belief that e-cigarettes were risky and more likely to cause lung damage compared to cigarettes increased between studies (p < .05). Seventy eight percent of participants at study two were aware of the vaping illness story. Being aware of the story was associated with more endorsement of the belief that e-cigarettes were risky to use, but not that using e-cigarettes would make the participant more likely to get damaged lungs.

Discussion

When the stories about the health and safety of tobacco products dominate the public information environment, it presents an opportunity to change beliefs that are frequently targeted by paid health campaigns. Changes in participant’s perceptions of e-cigarettes were associated with coverage of this large news story, underscoring the importance of working to ensure that coverage is a scientifically accurate as possible.

"Consent is sexy": A poster campaign using sex-positive images and messages to increase dyadic sexual communication

Objective: "Consent is Sexy" (CIS) is a poster campaign incorporating sex-positive messages to promote consent and increase sexual communication among college students. We assess reactions to the campaign and associations between campaign recall and communication attitudes and behaviors. Participants: Male and female undergraduates at a Midwestern university were recruited (N = 284). Methods: A cross-sectional survey was conducted. t-Tests, logistic and multiple linear regressions were used to analyze the data. Results: Over half (56%) of participants recalled the campaign and reactions were positive. Students who recalled CIS had more positive attitudes towards sexual communication (p = .04) and greater perceived behavioral control (PBC; p < .01). Conclusions: Results show many students paid attention and reacted positively to CIS posters and results offer dissemination insights. Consent campaigns should continue to cultivate positive attitudes and PBC in regards to sexual communication.

Visual Cancer Communication on Social Media: An Examination of Content and Effects of #Melanomasucks

Background

Instagram is increasingly becoming a platform on which visual communication of cancer takes place, but few studies have investigated the content and effects. In particular, a paucity of research has evaluated the effects of visual communication of cancer on participative engagement outcomes.

Objective

The objective of our study was to investigate cancer-related beliefs and emotions shared on Instagram and to examine their effects on participative engagement outcomes including likes, comments, and social support.

Methods

This study analyzed the content of 441 posts of #melanomasucks on Instagram and assessed the effects of the content characteristics on outcomes, including the number of likes and comments and types of social support using group least absolute shrinkage and selection operator logistic regression.

Results

Posts about controlling melanoma were most frequent (271/441, 61.5%), followed by 240 (54.4%) posts about outcomes of having melanoma. Ninety posts (20.4%) were about the causes of melanoma. A greater number of posts expressed positive (159/441, 36.1%) than negative emotions (100/441, 22.7%). Eighty posts (18.1%) expressed hope, making it the most frequently expressed emotion; 49 posts expressed fear (11.1%), 46 were humorous (10.4%), and 46 showed sadness (10.4%). Posts about self behavior as a cause of melanoma decreased likes (P<.001) and social support comments (P=.048). Posts about physical consequences of melanoma decreased likes (P=.02) but increased comments (P<.001) and emotional social support (P<.001); posts about melanoma treatment experience increased comments (P=.03) and emotional social support (P<.001). None of the expressions of positive emotions increased likes, comments, or social support. Expression of anger increased the number of likes (P<.001) but those about fear (P<.001) and joy (P=.006) decreased the number of likes. Posts about fear (P=.003) and sadness (P=.003) increased emotional social support. Posts showing images of melanoma or its treatment on the face or body parts made up 21.8% (96/441) of total posts. Inclusion of images increased the number of comments (P=.001).

Conclusions

To our knowledge, this is the first investigation of the content and effects of user-generated visual cancer communication on social media. The findings show where the self-expressive and social engagement functions of #melanomasucks converge and diverge, providing implications for extending research on the commonsense model of illness and for developing conceptual frameworks explaining participative engagement on social media.

A Schema of Denial: The Influence of Rape Myth Acceptance on Beliefs, Attitudes, and Processing of Affirmative Consent Campaign Messages

This study aims to examine the influence of rape myth acceptance (RMA) and the perceived salience of sexual violence on the cognitive processing of an affirmative consent campaign active on the campus where research was conducted. As part of a midcourse evaluation of the Consent is Sexy (CIS) campaign (N = 285), a subsample of participants who reported prior exposure to campaign posters (N = 182) was asked to review four campaign posters and indicate the extent to which they processed the message in the posters systematically. Robust gender differences in perceived salience of sexual violence, supportive attitudes, and perceived behavioral control (PBC) toward establishing consent were mediated by RMA. Moreover, robust gender differences in the systematic processing of the campaign were mediated by RMA and perceived salience in serial. Implications of the influence of rape myths and perceived salience on the cognitive processing of affirmed consent campaigns are discussed with respect to both campaign message design and implementation.

Disability in multiple sclerosis is related to normal appearing brain tissue MTR histogram abnormalities

Background: Magnetization transfer ratio (MTR) histogram analysis provides a global measure of disease burden in multiple sclerosis (MS). MTR abnormalities in normal appearing brain tissue (NABT) provide quantitative information on the extent of tissue damage undetected by conventional T2-weighted (T2W) magnetic resonance imaging (MRI). A ims: 1) To compare the MTR histograms from NABT across a broad spectrum of relapse onset MS patients, including relapsing-remitting (RR) MS (including newly diagnosed and benign subgroups) and secondary progressive (SP) MS. 2) To determine the relationship between clinical disability and NA BT MTR histograms. Methods: 2D spin echo magnetization transfer imaging was performed on 70 RRMS and 25 SPMS patients and compared with 63 controls. MTR histograms were acquired for NA BT after extracting lesions and cerebrospinal fluid (C SF). T2W images were used to measure the brain parenchymal fraction (BPF) and T2 lesion load. Results: MS patients had a disease duration ranging from 0.5 to 37 years and an Expanded Disability Status Scale (EDSS) score ranging from 0 to 8.5. There was a significant decrease in NA BT mean MTR (± standard deviation) compared with controls (33.07 pu± 1.06 versus 34.26 pu± 0.47; P < 0.001) with an effect size of 2.56. The reductio n in NA BT mean MTR varied among patient groups from 4.9% for SPMS, 3% for all RRMS, 2.7% for early RRMS and 2.5% for benign MS, compared with controls. NA BT mean MTR correlated significantly with T2 lesion load (r = -0.82) and BPF (r =0.58). EDSS score correlated with NA BT mean MTR (r = -0.43), BPF (r = -0.33) and with T2 lesion load (r =0.59). Multivariate analysis using NA BT MTR peak height, T2 lesion load and BPF combined only accounted for 38% of the variance in the EDSS (r =0.62; P <0.001). Disease duration accounted for an additional 14% of variance in the EDSS (r =0.72; P <0.001). Conclusions: There is evidence of diffuse abnormalities in NA BT in addition to global brain atrophy in relapse onset MS patients, including those with recently diagnosed RRMS and benign MS. The abnormalities are greatest in patients with the more disabling SPMS. A trophy, NA BT and lesion abnormalities are all partly correlated; the processes marked by these MR measures all contribute to disability in MS, providing complementary information relevant to the complex pathological processes that occur in MS.

Randomised clinical trial: the safety and tolerability of Trichuris suis ova in patients with Crohn's disease

BACKGROUND

Recent evidence suggests that embryonated eggs of the porcine whipworm Trichuris suis ova (TSO) may be an effective treatment for inflammatory bowel disease (IBD).

AIM

To assess the safety and tolerability of TSO following a single dose in patients with Crohn's disease.

METHODS

This was a sequential dose-escalation (500, 2500 and 7500 viable embryonated TSO), randomised, double-blind, placebo-controlled study to evaluate the safety of a single dose of oral suspension TSO in patients with Crohn's disease. Twelve patients were randomised into each of three cohorts. Patients were assessed 1, 3, 5, 7, 9, 11 and 14 days following dosing (via a telephone call and diary symptom collection through 14 days postdose) for adverse events, changes to concomitant medications and gastrointestinal (GI) signs and symptoms. Patients were again assessed at Months 1, 2 and 6.

RESULTS

Eighteen males and 18 females were enrolled, ages 20 to 54 years. All patients were dosed and completed the initial 2-month follow-up period (five patients did not attend their 6-month study visit). GI disorders were reported with the highest frequency; 7 (25.9%) TSO-treated patients and 3 (33.3%) placebo-treated patients. No dose-dependent relationship was observed, with 3 (33.3%) placebo, 4 (44.4%) TSO 500, 0 (0.0%) TSO 2500 and 3 (33.3%) TSO 7500 patients experiencing at least one GI event, and no clinically meaningful changes in GI signs and symptoms.

CONCLUSIONS

A single dose of Trichuris suis ova up to 7500 ova was well tolerated and did not result in short- or long-term treatment-related side effects. Clinicaltrials.gov NCT01576461.

Activation of mTOR coincides with autophagy during ligation-induced atrophy in the rat submandibular gland

Salivary gland atrophy is a common consequence of pathology, including Sjögren's syndrome, irradiation therapy and obstructive sialadenitis. During severe atrophy of the rat submandibular gland caused by excretory duct ligation, the majority of acinar cells disappear through apoptosis, whereas ductal cells proliferate and dedifferentiate; yet, the gland can survive in the atrophic state almost indefinitely, with an ability to fully recover if deligated. The control mechanisms governing these observations are not well understood. We report that ~10% of acinar cells survive in ligation-induced atrophy. Microarray and quantitative real-time PCR analysis of ligated glands indicated sustained transcription of acinar cell-specific genes, whereas ductal-specific genes were reduced to background levels. After 3 days of ligation, activation of the mammalian target of rapamycin (mTOR) pathway and autophagy occurred as shown by phosphorylation of 4E-BP1 and expression of autophagy-related proteins. These results suggest that activation of mTOR and the autophagosomal pathway are important mechanisms that may help to preserve acinar cells during atrophy of salivary glands after injury.

Gonadotropin-releasing hormone receptor system: modulatory role in aging and neurodegeneration

Receptors for hormones of the hypothalamic-pituitary-gonadal axis are expressed throughout the brain. Age-related decline in gonadal reproductive hormones cause imbalances of this axis and many hormones in this axis have been functionally linked to neurodegenerative pathophysiology. Gonadotropin-releasing hormone (GnRH) plays a vital role in both central and peripheral reproductive regulation. GnRH has historically been known as a pituitary hormone; however, in the past few years, interest has been raised in GnRH actions at non-pituitary peripheral targets. GnRH ligands and receptors are found throughout the brain where they may act to control multiple higher functions such as learning and memory function and feeding behavior. The actions of GnRH in mammals are mediated by the activation of a unique rhodopsin-like G protein-coupled receptor that does not possess a cytoplasmic carboxyl terminal sequence. Activation of this receptor appears to mediate a wide variety of signaling mechanisms that show diversity in different tissues. Epidemiological support for a role of GnRH in central functions is evidenced by a reduction in neurodegenerative disease after GnRH agonist therapy. It has previously been considered that these effects were not via direct GnRH action in the brain, however recent data has pointed to a direct central action of these ligands outside the pituitary. We have therefore summarized the evidence supporting a central direct role of GnRH ligands and receptors in controlling central nervous physiology and pathophysiology.

Interaction between two quantitative trait loci affects fetal haemoglobin expression

The biological mechanisms controlling complex quantitative traits are likely to be affected by interactions between genetic factors, sometimes referred to as epistasis. The identification of interacting loci through genetic analyse faces many challenges, and few examples of replicated findings of interaction exist for humans and model system organisms. The replication of an interaction, or the non-independence, of two quantitative trait loci (QTL) affecting the developmental switch from the expression of fetal to adult haemoglobin is reported here. Fetal haemoglobin expression in adults is a highly heritable, yet complex, phenotype. Using a sample of 874 dizygotic twin pairs of European descent, we found linkage to a QTL on chromosome 8 to be conditional on the twin pairs' genotypes at a polymorphism in the beta-globin complex; an interaction originally identified in a large Asian Indian kindred. The beta-globin polymorphism has been previously shown to be associated with fetal haemoglobin levels in adults. This study reports the first known replication of a genetic interaction between QTLs influencing a complex human trait.

Chlamydophila pneumoniae infection of the central nervous system in patients with multiple sclerosis

BACKGROUND

Chlamydophila pneumoniae has been postulated as an aetiological agent in the pathophysiology of multiple sclerosis. Previous studies show conflicting results.

OBJECTIVE

To investigate patients with multiple sclerosis and other neurological diseases for evidence of past or present infection with C pneumoniae.

METHODS

19 patients with multiple sclerosis and 29 with other neurological diseases were studied. Evidence was sought for past or present infection with C pneumoniae using polymerase chain reaction (PCR) and cell culture of cerebrospinal fluid (CSF), and enzyme linked immunosorbent assay and microimmunofluorescence of serum.

RESULTS

C pneumoniae was grown from the CSF of one patient with multiple sclerosis. PCR was negative in all cases. Anti-chlamydial antibodies were detected in the same proportion in each group.

CONCLUSIONS

This study does not support the theory of an association between C pneumoniae and multiple sclerosis.

Spatial mapping of T2 and gadolinium-enhancing T1 lesion volumes in multiple sclerosis: evidence for distinct mechanisms of lesion genesis?

It is generally believed that most T2-weighted (T2) lesions in the central white matter of patients with multiple sclerosis begin with a variable period of T1-weighted (T1) gadolinium (Gd) enhancement and that T1 Gd-enhancing and T2 lesions represent stages of a single pathological process. Lesion probability maps can be used to test this hypothesis by providing a quantitative description of the spatial distribution of these two types of lesions across a patient population. The simplest prediction of this hypothesis would be that the spatial distributions of T1 Gd-enhancing and T2 lesions are identical. We generated T1 Gd-enhancing and T2 lesion probability maps from 19 patients with relapsing-remitting multiple sclerosis. There was a significantly higher probability (P = 0.001) for T2 lesions to be found in the central relative to the peripheral white matter (risk ratio 4.5), although the relative distribution of T1 Gd-enhancing lesions was not significantly different (P = 0.7) between central and peripheral white matter regions (risk ratio 0.6). Longitudinal data on the same population were used to demonstrate a similar distribution asymmetry between new T1 Gd-enhancing and new T2 lesions that developed over the course of 1 year. Alternative hypotheses to explain this observation were tested. We found no spatial difference in the likelihood of development of persistent T2 lesions following T1 Gd enhancement. The relative distribution of T1 Gd-enhancing lesions was shown to be independent of the dose of Gd contrast agent and the frequency of scanning. Our findings suggest that a proportion of the periventricular T2 lesion volume may arise from mechanisms other than those associated with early breakdown of the blood-brain barrier leading to T1 Gd enhancement.

Single-dose gadolinium with magnetization transfer versus triple-dose gadolinium in the MR detection of multiple sclerosis lesions

PURPOSE

To compare the efficacy of single-dose gadolinium with magnetization transfer contrast (MTC) with that of triple-dose gadolinium in detecting enhancing multiple sclerosis lesions.

METHODS

Twenty-one patients with multiple sclerosis were examined with MR imaging first with 0.1 mmol/kg gadolinium (single dose) and then, after 24 to 72 hours, with 0.3 mmol/kg gadolinium (triple dose). T2-weighted fast spin-echo and T1-weighted spin-echo MR images with and without MTC were obtained before contrast administration followed by either T1-weighted spin-echo images with MTC (single dose) or conventional T1-weighted spin-echo images (triple dose), starting 5, 17, and 29 minutes after contrast administration. All images were evaluated in a blinded fashion and scored in random order by two readers. Outcome parameters included number of enhancing lesions, number of active MR examinations (those containing at least one enhancing lesion), contrast ratio (signal intensity of enhancing lesion divided by signal intensity of normal-appearing white matter), and size of enhancing lesions.

RESULTS

Eighty-one percent more enhancing lesions and 49% more active MR examinations were detected when a triple dose of gadolinium was used as compared with a single dose. The level of agreement between readers as to the number of enhancing lesions was significantly higher for triple-dose than for single-dose gadolinium. With triple-dose gadolinium, contrast ratios and areas of enhancement increased by 10% and 33%, respectively. Delayed imaging increased the size of the lesion by 11% on single-dose MTC images and by 18% on triple-dose images.

CONCLUSION

Triple-dose gadolinium is more effective (higher sensitivity and interobserver agreement) than single-dose gadolinium in combination with MTC in detecting enhancing multiple sclerosis lesions.