Birth Outcomes Associated With E-Cigarette and Non-E-Cigarette Tobacco Product Use During Pregnancy: An Examination of PATH Data Waves 1-5.

OBJECTIVES: To examine associations of prenatal e-cigarette use to pregnancy and birth outcomes. METHODS: Currently pregnant women (n = 1 037) from Waves 1 through 4 of the Population Assessment of Tobacco and Health Study who had pregnancy or live birth outcome data in a subsequent wave (Waves 2-5; 2013 to 2019). Weighted bivariate and multivariable models\ examined associations between past 30-day tobacco use assessed during pregnancy (any past 30-day e-cigarette use, any past 30-day non-e-cigarette tobacco use, or no past 30-day tobacco use) with adverse pregnancy (miscarriage, abortion, ectopic or tubal pregnancy, stillbirth) and birth outcomes (preterm birth, low birth weight, birth defect, placenta previa, placental abruption, pre-eclampsia) reported in the subsequent wave. RESULTS: Approximately 1% of pregnant women reported past 30-day exclusive e-cigarette use and 3.2% used e-cigarettes and one other tobacco product. Compared to no tobacco use, past 30-day e-cigarette use (exclusive or use with another tobacco product) during pregnancy was not associated with increased odds of an adverse pregnancy or birth outcome in bivariate or multivariable models. Past 30-day non-e-cigarette tobacco use was associated with increased odds of an adverse pregnancy outcome in multivariable models, but not an adverse live birth outcome. Compared to past 30-day cigarette use, past 30-day e-cigarette use during pregnancy was not associated with lowered odds of a birth or pregnancy outcome. CONCLUSIONS: E-cigarette use during pregnancy is rare. Understanding the positive and negative impacts of pre-natal e-cigarette use on women's health may guide public health messaging campaigns. IMPLICATIONS: Results showed that past 30-day e-cigarette use during pregnancy was low, with cigarette smoking remaining the most prevalent form of tobacco use during pregnancy. Current e-cigarette use during pregnancy used either exclusively or with another tobacco product, was not associated with increased risk of an adverse pregnancy, or birth outcome. A small sample size of e-cigarette users and limited information on quantity and frequency of e-cigarette use before and during pregnancy may limit conclusions. Healthcare providers may use this information when discussing the harms and consequences associated with e-cigarette and tobacco use during pregnancy.

Subcutaneous choriocarcinomas in captive Amargosa voles (Microtus californicus scirpensis).

Spontaneous choriocarcinomas are rare, highly vascular, malignant trophoblastic tumors that occur in humans and animals. This report describes the unusual spontaneous presentation of 4 choriocarcinomas within the subcutaneous tissues of 4, multiparous but nongravid, Amargosa voles (Microtus californicus scirpensis) from a captive breeding colony. Two subcutaneous neoplasms were composed of multifocal discohesive and infiltrative aggregates of medium to large trophoblasts and cytotrophoblasts within a fibrovascular stroma. Neoplastic cells were associated with variably sized thrombi and cavitary areas of hemorrhage and necrosis. Two subcutaneous tumors were predominantly composed of expansile, blood-filled, cystic spaces lined by neoplastic cytotrophoblasts and occasionally contained medium to large trophoblasts. Trophoblasts and cytotrophoblasts were positive for pancytokeratin and cytokeratin 8/18, negative for alpha-fetoprotein, and contained intracytoplasmic Periodic acid-Schiff (PAS)-positive glycogen in all 4 tumors. In species with hemochorial placentation, migration of trophoblasts into maternal circulation with embolization to distant nonreproductive tissues occurs and may explain the unusual subcutaneous distribution of these 4 tumors. The 2 multiloculated paucicellular tumors may represent an early stage of neoplastic transformation. To the authors' knowledge, this is the first report characterizing choriocarcinomas in extrareproductive sites in rodents.

Common and Not-So-Common Pathologic Findings of the Gastrointestinal Tract of Rhesus and Cynomolgus Macaques.

Rhesus and cynomolgus macaques are the most frequently used nonhuman primate (NHP) species for biomedical research and toxicology studies of novel therapeutics. In recent years, there has been a shortage of laboratory macaques due to a variety of competing factors. This was most recently exacerbated by the surge in NHP research required to address the severe acute respiratory syndrome (SARS)-coronavirus 2 pandemic. Continued support of these important studies has required the use of more varied cohorts of macaques, including animals with different origins, increased exposure to naturally occurring pathogens, and a wider age range. Diarrhea and diseases of the gastrointestinal tract are the most frequently occurring spontaneous findings in macaques of all origins and ages. The purpose of this review is to alert pathologists and scientists involved in NHP research to these findings and their impact on animal health and study endpoints, which may otherwise confound the interpretation of data generated using macaques.

A novel non-human primate model of Pelizaeus-Merzbacher disease.

Pelizaeus-Merzbacher disease (PMD) is a severe hypomyelinating disorder of the central nervous system (CNS) linked to mutations in the proteolipid protein-1 (PLP1) gene. Although there are multiple animal models of PMD, few of them fully mimic the human disease. Here, we report three spontaneous cases of male neonatal rhesus macaques with the clinical symptoms of hypomyelinating disease, including intention tremors, progressively worsening motor dysfunction, and nystagmus. These animals demonstrated a paucity of CNS myelination accompanied by reactive astrogliosis, and a lack of PLP1 expression throughout white matter. Genetic analysis revealed that these animals were related to one another and that their parents carried a rare, hemizygous missense variant in exon 5 of the PLP1 gene. These animals therefore represent the first reported non-human primate model of PMD, providing a novel and valuable opportunity for preclinical studies that aim to promote myelination in pediatric hypomyelinating diseases.

Two cases of cryptococcus gattii infection in the rhesus macaque (Macaca Mulatta).

Cryptococcus gattii was diagnosed in two female indoor-housed rhesus macaques. Gross and histopathologic findings included an isolated pulmonary cryptococcoma in a non-SIV-infected macaque and disseminated disease centered on the lungs of an SIV-infected macaque. Fungal yeast were positive with special stains, and the diagnoses were confirmed with a lateral flow assay and PCR.

Urothelial carcinoma in the urinary bladder of a Japanese macaque (Macaca fuscata).

Tumors of urinary origin are infrequently reported in non-human primates. Urothelial carcinoma involving the urinary bladder was diagnosed in an adult female Japanese macaque that extended transmurally to the uterus and cervix. To our knowledge, this is the first report of a primary cystic urothelial carcinoma in a Japanese macaque.

Colon volvulus in rhesus macaques (Macaca mulatta) at the Oregon National Primate Research Center-Retrospective analysis.

Colonic volvulus is an uncommon, often life-threatening condition, in non-human primates. Twenty-six cases of colonic volvulus in rhesus macaques (Macaca mulatta) were identified in necropsy records spanning 38 years at the Oregon National Primate Research Center (ONPRC). This report represents the largest collection of colonic volvuli in rhesus macaques.

Youth Vaping and Tobacco Use in Context in the United States: Results From the 2018 National Youth Tobacco Survey.

INTRODUCTION: According to the National Youth Tobacco Survey (NYTS), youth e-cigarette use (vaping) rose between 2017 and 2018. Frequency of vaping and concurrent past 30-day (p30d) use of e-cigarettes and tobacco products have not been reported. METHODS: We analyzed the 2018 NYTS (N = 20 189) for vaping among all students (middle and high school; 6-12th grades; 9-19 years old) by frequency of vaping, exclusive vaping, p30d poly-product use (vaping and use of one or more tobacco product), and any past tobacco product use. RESULTS: In 2018, 81.4% of students had not used any tobacco or vapor product in the p30d, and 86.2% had not vaped in the p30d. Among all students, of the 13.8% vaped in the p30d, just over half vaped on ≤5 days (7.0%), and roughly a quarter each vaped on 6-19 days (3.2%) and on 20+ days (3.6%). Almost three quarters of p30d vapers (9.9%) reported past or concurrent tobacco use and the remainder (3.9%) were tobacco naïve. 2.8% of students were tobacco naïve and vaped on ≤5 days; 0.7% were tobacco-naïve and vaped on 6-19 days, and 0.4% were tobacco-naïve and vaped on 20+ days. CONCLUSIONS: Vaping increased among US youth in 2018 over 2017. The increases are characterized by patterns of low p30d vaping frequency and high poly-product use, and a low prevalence of vaping among more frequent but tobacco naïve vapers. IMPLICATIONS: Results underscore the importance of including the full context of use patterns. The majority of vapers (60.0%-88.9% by use frequency) were concurrent p30d or ever tobacco users. About 4% of students were tobacco naïve and vaped in the p30d, but few (0.4%) vaped regularly on 20 or more days. Reporting youth vaping data with frequency and tobacco product co-use will give public health decision-makers the best possible information to protect public health.

Menthol and Mint Cigarettes and Cigars: Initiation and Progression in Youth, Young Adults and Adults in Waves 1-4 of the PATH Study, 2013-2017.

INTRODUCTION: This study examined in youth (12-17 years), young adults (18-24 years), and adults (25+ years): (1) the prevalence of the first menthol cigarette and menthol/mint cigar use among new tobacco users; (2) association between the first menthol/mint use, subsequent tobacco use, and nicotine dependence ~1 year later compared with the first non-menthol/mint use. AIMS AND METHODS: Longitudinal analysis of data from Waves 1 to 4 of the Population Assessment of Tobacco and Health (PATH) Study (2013-2017; 10 086 youth and 21 281 adults). Main outcome measures were past 12-month and past 30-day cigarette and cigar use, and nicotine dependence. RESULTS: Youth and young adult new cigarette users are more likely to smoke a menthol cigarette or indicate that they do not know the flavor compared with adults aged 25+. A greater proportion of adults aged 25+ first used menthol/mint-flavored cigars (13.4%) compared with youth (8.5%) and young adults (7.4%). Among young adults, first use of a menthol cigarette is associated with past 12-month use of cigarettes at the subsequent wave and first use of any menthol/mint-flavored cigars is associated with past 30-day use of these products at the subsequent wave in both youth and young adults. In youth and adults, there were no significant relationships between first use of a menthol/mint cigarette or cigar and nicotine dependence scores at a subsequent wave in multivariable analyses. CONCLUSIONS: The first use of menthol/mint cigarettes and cigars is associated with subsequent cigarette and cigar use in young people aged 12-24. IMPLICATIONS: This study examined the relationship between initiation with menthol cigarettes and menthol/mint cigars, subsequent tobacco use, and nicotine dependence in US youth, young adults, and adults who participated in Waves 1-4 of the Population Assessment of Tobacco and Health study. New use of menthol cigarettes was associated with greater past 12-month cigarette use in young adults and new use of menthol/mint-flavored cigars was associated with greater past 30-day cigar use in youth and young adults compared with non-menthol use. Initiation with menthol/mint cigarette and cigar products may lead to subsequent use of those products.

Heterologous Expression and Functional Characterization of Novel CYP2C9 Variants Identified in the Alaska Native People.

CYP2C9 is a major form of human liver cytochrome P450 that is responsible for the oxidative metabolism of several widely used low-therapeutic index drugs, including (S)-warfarin and phenytoin. In a cohort of Alaska Native people, ultrarare or novel CYP2C9 protein variants, M1L (rs114071557), N218I (rs780801862), and P279T (rs182132442, CYP2C9*29), are expressed with higher frequencies than the well characterized CYP2C9*2 and CYP2C9*3 alleles. We report here on their relative expression in lentivirus-infected HepG2 cells and the functional characterization of purified reconstituted enzyme variants expressed in Escherichia coli toward (S)-warfarin, phenytoin, flurbiprofen, and (S)-naproxen. In the infected HepG2 cells, robust mRNA and protein expression were obtained for wild-type, N218I, and P279T variants, but as expected, the M1L variant protein was not translated in this liver-derived cell line. His-tagged wild-type protein and the N218I and P279T variants, but not M1L, expressed well in E. coli and were highly purified after affinity chromatography. Upon reconstitution with cytochrome P450 oxidoreductase and cytochrome b5, the N218I and P279T protein variants metabolized (S)-warfarin, phenytoin, flurbiprofen, and (S)-naproxen to the expected monohydroxylated or O-demethylated metabolites. Steady-state kinetic analyses revealed that the relative catalytic efficiency ratios of (S)-warfarin metabolism by the P279T and N218I variants were 87% and 24%, respectively, of wild-type CYP2C9 protein. A similar rank ordering was observed for metabolism of phenytoin, flurbiprofen, and (S)-naproxen. We conclude that carriers of the variant N218I and, especially, the M1L alleles would be at risk of exacerbated therapeutic effects from drugs that rely on CYP2C9 for their metabolic clearance. SIGNIFICANCE STATEMENT: Novel gene variants of CYP2C9-M1L, and N218I, along with P279T (CYP2C9*29)-are expressed in Alaska Native people at relatively high frequencies. In vitro characterization of their functional effects revealed that each variant confers reduced catalytic efficiency toward several substrates, including the low-therapeutic index drugs (S)-warfarin and phenytoin. These data provide the first functional information for new, common CYP2C9 variants in this understudied population. The data may help guide dose adjustments in allele carriers, thus mitigating potential healthcare disparities.

Pulmonary amniotic fluid embolism in a rhesus macaque (Macaca mulatta).

A pregnant female rhesus macaque died spontaneously during stage two labor. Gross and histopathologic findings included severe pulmonary edema, with low numbers of blood vessels containing pale basophilic mucinous material (Alcian Blue positive and PTAH negative), consistent with intravascular amniotic fluid-derived mucin resulting in pulmonary amniotic fluid embolism.

Young Adult Tobacco and E-cigarette Use Transitions: Examining Stability Using Multistate Modeling.

INTRODUCTION: The objective of this study was to describe tobacco and nicotine product use state transition probabilities among youth and young adults over time. METHODS: A national sample of young adult tobacco product users and nonusers between the ages of 18 and 34 years at baseline was surveyed at 6-month intervals for 3 years. Use and nonuse states were defined as mutually exclusive categories based on self-reported, past 30-day use of the various products. Never use, noncurrent use, and current use of combustible, noncombustible tobacco, and electronic cigarette (e-cigarette) products was assessed at each interval. A multistate model was fit to estimate transition probabilities between states and length of stay within each state. RESULTS: After 6 months, same-state transition probabilities were high for all use states (0.76-0.96), except for dual product use (0.48). After 3 years, transition probabilities were smaller and tended to converge toward combustible product use for baseline e-cigarette (0.42), combustible (0.51), and dual product users (0.52). Age was inversely associated with transition risk from never or noncurrent use to use of combustible or e-cigarette products. CONCLUSIONS: Never and noncurrent users, followed by combustible product users, were most likely to remain in those states throughout the 3-year observation interval. Users of any tobacco or e-cigarette product at baseline were most likely to transition to combustible product use or noncurrent use by the final follow-up. IMPLICATIONS: This study describes the probability of transitioning between various states of tobacco product use, including never and no current use, over a span of 3 years in a sample of young adults. This type of longitudinal description, which includes all tobacco product use states, is lacking in most studies that tend to focus on one or only a few products. The results suggest that it is important to assess outcomes over a sufficiently long period to capture true variability in patterns of product use.

Impact of flavors and humectants on waterpipe tobacco smoking topography, subjective effects, toxicant exposure and intentions for continued use.

INTRODUCTION: The present study examined how the lack of characterising flavours and low levels of humectants may affect users' waterpipe tobacco (WT) smoking topography, subjective effects, toxicant exposure and intentions for continued use. METHODS: 89 WT smokers completed four ad libitum smoking sessions (characterising flavor/high humectant (+F+H); characterising flavor/low humectant (+F-H); no characterising flavor/high humectant (-F+H); no characterising flavor/low humectant (-F-H)) in a randomised cross-over design. WT was commercially available; same brand but nicotine levels were not held constant. A subsample (n=50) completed a standardised, 10-puff session preceding ad libitum smoking. Participants completed questionnaires, exhaled carbon monoxide (eCO) testing and provided blood samples for plasma nicotine. Smoking topography was measured throughout the session. Post hoc analyses showed that -F+H and -F-H did not differ significantly in humectant levels. Therefore, these groups were collapsed in analyses (-F-H). RESULTS: WT smokers reported significantly greater satisfaction, liking, enjoyment and greater intentions for continued use when smoking +F+H compared with other WT products, with -F-H receiving the lowest ratings. Significant differences in topography were observed during standardised and ad libitum sessions, with the -F-H preparation leading to greater total inhaled volume and eCO boost, but lower nicotine boost compared with +F+H (all p<0.05). DISCUSSION: The findings demonstrate the importance of flavours and humectants on improving WT smoking experience and increasing the likelihood that users will want to initiate and continue smoking. Moreover, it demonstrates that flavours and humectants influence smoking behaviour and toxicant exposure in some unexpected ways that are important for regulatory efforts.

Flavour types used by youth and adult tobacco users in wave 2 of the Population Assessment of Tobacco and Health (PATH) Study 2014-2015.

BACKGROUND: Most youth and young adult (YA) tobacco users use flavoured products; however, little is known about specific flavours used. METHODS: We report flavour types among US tobacco users from the Population Assessment of Tobacco and Health Study, wave 2, 2014-2015. At wave 2, we examined (1) flavour use and type at past 30-day use; (2) new flavoured tobacco product use and type; (3) product-specific flavour patterns across youth (ages 12-17) (n=920), YA (18-24) (n=3726) and adult (25+) (n=10 346) past 30-day and new tobacco users and (4) concordance between self-coded and expert-coded brand flavour type among all adults (18+). RESULTS: Prevalence of flavoured tobacco product use was highest among youth, followed by YA and adult 25+ any tobacco users. Within each age group, flavoured use was greatest among hookah, e-cigarette and snus users. Overall, menthol/mint, fruit and candy/sweet were the most prevalent flavour types at first and past 30-day use across age groups. For past 30-day use, all flavour types except menthol/mint exhibited an inverse age gradient, with more prevalent use among youth and YAs, followed by adults 25+. Prevalence of menthol/mint use was high (over 50% youth, YAs; 76% adults 25+) and exhibited a positive age gradient overall, though the reverse for cigarettes. Brand-categorised and self-reported flavour use measures among adults 18+ were moderately to substantially concordant across most products. CONCLUSIONS: Common flavours like menthol/mint, fruit and candy/sweet enhance appeal to young tobacco users. Information on flavour types used by product and age can inform tobacco flavour regulations to addess flavour appeal especially among youth.

Spontaneous KRT5 Gene Mutation in Rhesus Macaques (Macaca mulatta): A Novel Nonhuman Primate Model of Epidermolysis Bullosa Simplex.

Epidermolysis bullosa simplex (EBS) is an inherited skin disorder characterized by increased skin and mucous membrane fragility. Most cases are caused by mutations in keratin 5 (KRT5) and keratin 14 (KRT14). Mutations of these genes result in cytoskeletal disruption of the basal keratinocytes. Gross and histopathologic findings of 2 clinically affected homozygous rhesus macaques with an insertion variant mutation in KRT5 are described and compared with 6 deceased phenotypically normal animals that were heterozygous for the KRT5 insertion variant. Animals that were homozygous for the KRT5 insertion variant were stillborn and had widespread loss of the epidermis. Microscopic examination confirmed severe ulceration and basal cell vacuolation with basilar vesicle formation in the remaining intact epidermis. Immunohistochemistry for cytokeratin 5 demonstrated lack of epidermal immunoreactivity in homozygotes. DNA sequencing identified a 34-base pair insertion variant in exon 5 of the KRT5 gene. To our knowledge, this is the first report of epidermolysis bullosa in rhesus macaques.

Challenges Associated With Cervical Cancer Screening and Management in Obese Women: A Provider Perspective.

OBJECTIVES: Obese women are at increased risk of cervical cancer, partly due to missed detection of cervical precancers during routine cervical cancer screening. We administered a clinician survey to better understand specific challenges and identify potential solutions to performing cervical cancer screening and management in obese women. MATERIALS AND METHODS: We administered a web-based survey to 2,319 members of the American Society of Colposcopy and Cervical Pathology including questions related to challenges associated with cervical sampling and visualization in obese compared with normal weight women and potential strategies for improvement. We summarized providers' responses using descriptive statistics and used Fisher exact tests to evaluate associations between provider characteristics and challenges with cervical sampling, visualization, and biopsy. RESULTS: Of the 240 providers that completed the survey, 89% and 93% reported that cervical sampling and visualization are more challenging in obese women, respectively, whereas 80% reported that taking a biopsy was more challenging. Commonly reported barriers included vaginal prolapse, difficulty visualizing and accessing the cervix, and lack of long enough sampling devices and large enough speculums. Frequently used techniques to improve sampling and visualization included use of a condom or examination glove finger to sheath a speculum and using a tenaculum. Most providers identified training for cervical sampling and colposcopy in obese women as a learning gap, and only 8% reported receiving such training. CONCLUSIONS: Cervical cancer screening and management are more challenging in obese compared with normal weight women. Major barriers to cervical sampling and visualization included lack of adequately sized equipment and lack of education and training.

A new LC-MS assay for the quantitative analysis of vitamin K metabolites in human urine.

Vitamin K (VK), in both its phylloquinone and menaquinone forms, has been hypothesized to undergo ω- and ß-oxidation on its hydrophobic side chain in order to generate the observed urinary metabolites, K acid I and K acid II, which are excreted primarily as glucuronide conjugates. Synthetic standards of K acid I, K acid II, and a putative intermediate metabolite, menaquinone (MK)1 ω-COOH, were used to develop and optimize a new atmospheric pressure negative chemical ionization LC-MS/MS assay for the quantitation of these compounds in urine from untreated individuals and subjects treated with a high dose VK supplement. VK catabolites were extracted from urine, deconjugated, and converted to their methyl ester derivatives using previously reported methodology. The assay showed a high degree of sensitivity, with limits of detection below 10-50 fmol of metabolite per milliliter of urine, as well as an inter-assay precision of 8-12%. Metabolite standards provided unambiguous evidence for MK1 ω-COOH as a new human urinary metabolite of VK. This assay provides a minimally invasive, highly sensitive, and specific alternative for monitoring VK status in humans.

Impact of Question Type and Question Order on Tobacco Prevalence Estimates in US Young Adults: A Randomized Experiment.

The purpose of this study was to identify the effects of question type, order, and inclusion of product images on tobacco use estimates in a national sample of young adults. Participants aged 18-34 years (N = 4,100) in the Truth Initiative Young Adult Cohort Study (2016) were randomized to one of five question types assessing ever and past 30-day use of tobacco products: (1) "select all that apply" list (checklist, CL); (2) breakout items for each product (B); (3) breakout + images (B + I); (4) CL and B; and (5) CL and B + I. The order of question type was randomly assigned in groups 4 and 5. Bivariate analyses estimated product-specific prevalence by question type/order. Ever cigarette and cigar use prevalence was higher and ever e-cigarette use was lower in B and B + I than in CL. Ever hookah use was higher in B + I than in CL. Past 30-day e-cigarette use was 8.3% higher and past 30-day smokeless use was 13.0% higher in B + I than in CL. In groups 4 and 5, higher prevalence of ever cigarette, cigar, hookah, and past 30-day smokeless use was observed when B was presented first. Question type, order, and inclusion of images affect prevalence estimates of tobacco use. IMPLICATIONS: This study identifies the effects of question type, order, and inclusion of product images on tobacco use estimates in a national sample of young adults. Ever use and past 30-day use prevalence estimates of specific products were affected by respondents answering breakout items or breakout items with images compared with respondents answering a checklist of items in the survey. Current surveys that include a "select all that apply" list format may be underestimating ever and past 30-day prevalence estimates of tobacco products.

Proliferative Typhlocolitis With Multinucleated Giant Cells: A Nonspecific Enteropathy in Immunodeficient Sentinel Mice.

Beginning in 2015, athymic nude sentinel mice from conventional, medium-, and high-security facilities presented to the Comparative Pathology Laboratory (CPL) with weight loss, diarrhea, and/or rectal prolapse. Regardless of whether clinical signs were present or absent, the gross observation of ceco-colonic thickening corresponded histologically to pleocellular typhlocolitis with mucosal hyperplasia and lamina proprial multinucleated cells. A subset of affected sentinels exhibited granulomatous serositis and hepatosplenic necrosis with multinucleated cells. Initial suspicion of mouse hepatitis virus infection was excluded by polymerase chain reaction, electron microscopy, and serology. Multinucleated giant cells were confirmed as macrophages by positive immunoreactivity to Mac-3 and Iba-1 and negative immunoreactivity to pancytokeratin. From conventional and medium-security facilities, Helicobacter species were identified in 40 of 143 (27.9%) mice, with H. hepaticus accounting for 72.5% of identified Helicobacter species. Other agents included opportunistic bacterial infection (41/145, 28.3%), murine norovirus (16/106, 15.1%), and pinworms (2/146, 1.4%). From high-security facilities, only Enterobacter cloacae was identified (2/13, 15.4%), and no evidence of Helicobacter sp., murine norovirus, or pinworms was present. No potentially infectious disease agent(s) was identified in 71 of 146 (48.6%) affected nude sentinels from conventional and medium-security facilities and 11 of 13 (84.6%) affected nude sentinels from high-security facilities. No statistically significant differences in histologic lesion scores were identified between Helicobacter-positive and Helicobacter-negative mice. Thus, proliferative typhlocolitis with multinucleated giant cells was considered a nonspecific histologic pattern associated with a variety of primary and opportunistic pathogens in athymic nude mice.

Patterns of Nicotine and Tobacco Product Use in Youth and Young Adults in the United States, 2011-2015.

Introduction: As cigarette smoking has decreased among youth and young adults (YAs) in the United States, the prevalence of other tobacco and nicotine product use has increased. Methods: This study identified common past 30-day patterns of tobacco and nicotine product use in youth (grades 6-12) and YAs (aged 18-24). Using data from the 2011-2015 National Youth Tobacco Survey (NYTS) and corresponding years of the Truth Initiative Young Adult Cohort Study (TIYAC), past 30-day use of the following products was assessed: cigarettes, e-cigarettes, any type of cigar, smokeless tobacco, hookah, and other tobacco products (pipe, bidis, kreteks, dissolvable tobacco, and snus). A user-generated program in R was used to assess all possible combinations of product-specific and polytobacco use. Results: The top five patterns of past 30-day use in youth were exclusive cigarette use (12.0%), exclusive cigar use (10.3%), exclusive e-cigarette use (10.0%), dual use of cigarettes and cigars (6.1%), and exclusive hookah use (5.2%). In YAs, the top five patterns were exclusive cigarette use (46.5%), exclusive cigar use (10.0%), dual use of cigarettes and cigars (6.4%), exclusive hookah use (5.9%), and dual use of cigarettes and e-cigarettes (3.9%). Conclusions: As noncigarette tobacco and nicotine products become increasingly popular among tobacco users, further research is needed to identify predictors and correlates of specific tobacco use patterns in youth and YAs. This analysis can inform tobacco prevention efforts focusing on emerging tobacco products such as e-cigarettes and hookah. Educational and other intervention efforts should focus on the diversity of products and use patterns in these age groups. Implications: This study uses population-based data to provide new information on the most prevalent patterns of past 30-day nicotine and tobacco use over a 5-year period among youth and young adults. Study findings demonstrate that youth and young adults report using tobacco and nicotine products in different combinations, with varying popularity over time. Additionally, by examining young adults as a separate group, this study highlights the unique patterns of use not previously discussed in the adult literature.