Associative N fixation (ANF), the process by which dinitrogen gas is converted to ammonia by bacteria in casual association with plants, has not been well-studied in temperate ecosystems. We examined ...the ANF potential of switchgrass (Panicum virgatum L.), a North American prairie grass whose productivity is often unresponsive to N fertilizer addition, via separate short-term 15N2 incubations of rhizosphere soils and excised roots four times during the growing season. Measurements occurred along N fertilization gradients at two sites with contrasting soil fertility (Wisconsin, USA Mollisols and Michigan, USA Alfisols). In general, we found that ANF potentials declined with long-term N addition, corresponding with increased soil N availability. Although we hypothesized that ANF potential would track plant N demand through the growing season, the highest root fixation rates occurred after plants senesced, suggesting that root diazotrophs exploit carbon (C) released during senescence, as C is translocated from aboveground tissues to roots for wintertime storage. Measured ANF potentials, coupled with mass balance calculations, suggest that ANF appears to be an important source of N to unfertilized switchgrass, and, by extension, to temperate grasslands in general.
Transgender persons face many barriers to health care that may delay cancer diagnosis and treatment, possibly resulting in decreased survival. Yet, data on cancer in this population are limited. We ...examined cancer stage at diagnosis, treatment, and survival among transgender patients compared with cisgender patients in the National Cancer Database (NCDB).
Gender (male, female, or transgender) was extracted from medical records from patients diagnosed with cancer between 2003 and 2016. Logistic regression estimated odds ratios (ORs) for the associations between gender and stage at diagnosis and treatment receipt. Cox proportional hazards regression estimated hazard ratios (HRs) for associations between gender and all-cause survival.
Among 11 776 699 persons with cancer in NCDB, 589 were transgender. Compared with cisgender patients, transgender patients may be more likely to be diagnosed with advanced stage lung cancer (OR = 1.76, 95% confidence interval CI = 0.95 to 3.28); be less likely to receive treatment for kidney (OR = 0.19, 95% CI = 0.08 to 0.47) and pancreas (OR = 0.33, 95% CI = 0.11 to 0.95) cancers; and have poorer survival after diagnosis with non-Hodgkin lymphoma (HR = 2.34, 95% CI = 1.51 to 3.63), prostate (HR = 1.91, 95% CI = 1.06 to 3.45), and bladder cancers (HR = 2.86, 95% CI = 1.36 to 6.00). Similar associations were found for other cancer sites, although not statistically significant.
Transgender patients may be diagnosed at later stages, be less likely to receive treatment, and have worse survival for many cancer types. Small sample size hampered our ability to detect statistically significant differences for some cancer sites. There is a need for transgender-focused cancer research as the population ages and grows.
Gender identity is not collected in the census, cancer registries, or most population-based cohort studies. ...research on cancer in this population has been limited to a few case reports. ...it is ...important that clinicians be aware of the cancer risks in transgender populations, but systems level changes may also be needed to ensure that transgender people are invited for routine screening, and that cervical samples from individuals with a male personal identification number are processed similarly to samples collected from cis women. In summary, the prevalence of individuals reporting and seeking treatment for gender incongruence is growing globally. ...there is an urgent need to explore cancer risk and cancer mortality in transgender persons as the incidence of certain cancers may be altered from that of cisgender persons. ...documenting transphobia and discrimination in healthcare is needed to provide interventions to clinicians in order to improve access to cancer prevention and care for all transgender individuals.
15% of US adults have gallstones, most of which are clinically "silent". Several studies show that menopausal hormone therapy (MHT) increases symptomatic gallstones and cholecystectomy risk. MHT use ...may be contraindicated in women with gallstones and population studies may be biased by "confounding by contraindication" while the true association between MHT and gallstones remains underestimated. We sought to examine whether MHT use was associated with asymptomatic gallstones using instrumental variable (IV) analysis to account for confounding by contraindication. We used 2018 postmenopausal women from the Third National Health and Nutrition Examination Survey to estimate associations of MHT use with asymptomatic gallstones. A traditional logistic regression analysis was compared to instrumental variable (IV) analysis to account for confounding by contraindication. 12% of women with asymptomatic gallstones and 25% of women without gallstones were current MHT users (P < 0.001). The traditional analysis suggested a decreased odds of asymptomatic gallstones in current versus never users (OR 0.58, 95% CI 0.37, 0.89), but increased odds (OR 1.51, 95% CI 0.44, 5.16) in the IV analysis. The traditional analysis consistently underestimated the odds of asymptomatic gallstones with MHT use compared to the IV analysis. Accounting for confounding by contraindication, we found a suggestive, though imprecise, positive association between MHT use and asymptomatic gallstones among postmenopausal women. Failure to consider contraindication can produce incorrect results.
Background and Aims
Gallbladder cancer (GBC) has a female predominance, whereas the other biliary tract cancers (BTCs) have a male predominance, suggesting that sex hormones may be involved in ...carcinogenesis. We sought to evaluate the association between menopausal hormone therapy (MHT) and the risk of BTC in women.
Approach and Results
This nested case‐control study was conducted in the UK Clinical Practice Research Datalink. Cases diagnosed between 1990 and 2017 with incident primary cancers of the gallbladder (GBC), cholangiocarcinoma (CCA), ampulla of Vater (AVC), and mixed type were matched to 5 controls on birth year, diagnosis year, and years in the general practice using incidence density sampling. Conditional logistic regression was used to calculate ORs and 95% CIs for associations between MHT use and BTC type. The sample consisted of 1,682 BTC cases (483 GBC, 870 CCA, 105 AVC, and 224 mixed) and 8,419 matched controls with a mean age of 73 (SD, 11) years. Combined formulations (estrogen‐progesterone) were associated with an increased GBC risk (OR, 1.97; 95% CI, 1.08, 3.59). Orally administered MHT was associated with an increased GBC risk (OR, 2.28; 95% CI, 1.24, 4.17). Estrogen‐only formulations (OR, 0.59; 95% CI, 0.34, 0.93) and cream or suppository administrations (OR, 0.57; 95% CI, 0.34, 0.95) were associated with decreased CCA risk. The number of prescriptions, dose, duration of use, and time since last use were not associated with GBC or CCA risk. MHT use was not associated with risk of AVC or mixed cancer.
Conclusions
Combination MHT formulations and oral administrations were associated with increased GBC risk, whereas estrogen‐only formulations were associated with a lower CCA risk. MHT formulation and administration should be carefully considered when prescribing.
Pulmonary exposure to multi-walled carbon nanotubes (MWCNTs) has been linked to an increased risk of developing cardiovascular disease in addition to the well-documented physicochemical-dependent ...adverse lung effects. A proposed mechanism is through a strong and sustained pulmonary secretion of acute phase proteins to the blood. We identified physicochemical determinants of MWCNT-induced systemic acute phase response by analyzing effects of pulmonary exposure to 14 commercial, well-characterized MWCNTs in female C57BL/6J mice pulmonary exposed to 0, 6, 18 or 54 μg MWCNT/mouse. Plasma levels of acute phase response proteins serum amyloid A1/2 (SAA1/2) and SAA3 were determined on day 1, 28 or 92. Expression levels of hepatic Saa1 and pulmonary Saa3 mRNA levels were assessed to determine the origin of the acute phase response proteins. Pulmonary Saa3 mRNA expression levels were greater and lasted longer than hepatic Saa1 mRNA expression. Plasma SAA1/2 and SAA3 protein levels were related to time and physicochemical properties using adjusted, multiple regression analyses. SAA3 and SAA1/2 plasma protein levels were increased after exposure to almost all of the MWCNTs on day 1, whereas limited changes were observed on day 28 and 92. SAA1/2 and SAA3 protein levels did not correlate and only SAA3 protein levels correlated with neutrophil influx. The multiple regression analyses revealed a protective effect of MWCNT length on SAA1/2 protein level on day 1, such that a longer length resulted in lowered SAA1/2 plasma levels. Increased SAA3 protein levels were positively related to dose and content of Mn, Mg and Co on day 1, whereas oxidation and diameter of the MWCNTs were protective on day 28 and 92, respectively. The results of this study reveal very differently controlled pulmonary and hepatic acute phase responses after MWCNT exposure. As the responses were influenced by the physicochemical properties of the MWCNTs, this study provides the first step towards designing MWCNT that induce less SAA.
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