Scenarios for modeling solar radiation modification.

Making informed future decisions about solar radiation modification (SRM; also known as solar geoengineering)-approaches such as stratospheric aerosol injection (SAI) that would cool the climate by reflecting sunlight-requires projections of the climate response and associated human and ecosystem impacts. These projections, in turn, will rely on simulations with global climate models. As with climate-change projections, these simulations need to adequately span a range of possible futures, describing different choices, such as start date and temperature target, as well as risks, such as termination or interruptions. SRM modeling simulations to date typically consider only a single scenario, often with some unrealistic or arbitrarily chosen elements (such as starting deployment in 2020), and have often been chosen based on scientific rather than policy-relevant considerations (e.g., choosing quite substantial cooling specifically to achieve a bigger response). This limits the ability to compare risks both between SRM and non-SRM scenarios and between different SRM scenarios. To address this gap, we begin by outlining some general considerations on scenario design for SRM. We then describe a specific set of scenarios to capture a range of possible policy choices and uncertainties and present corresponding SAI simulations intended for broad community use.

Use of deep laryngeal oxygen insufflation during laryngoscopy in children: a randomized clinical trial.

BACKGROUND: Brief periods of haemoglobin oxygen desaturation are common in children during induction of general anaesthesia. We tested the hypothesis that oxygen insufflation during intubation slows desaturation. METHODS: Patients 1-17 yr old undergoing nasotracheal intubation were enrolled and randomly assigned to one of three groups: standard direct laryngoscopy (DL); laryngoscopy with Truview PCD videolaryngoscope (VLO2); or laryngoscopy with an oxygen cannula attached to the side of a standard laryngoscope (DLO2). The co-primary outcomes were time to 1% reduction in [Formula: see text] from baseline, and the slope of overall desaturation vs time. All three groups were compared against each other. RESULTS: Data from 457 patients were available for the final analysis: 159 (35%) DL; 145 (32%) DLO2; and 153 (33%) VLO2. Both VLO2 and DLO2 were superior to DL in both time to a 1% reduction in [Formula: see text] from baseline and the overall rate of desaturation (all P<0.001). The 25th percentile (95% confidence interval) of time to a 1% saturation decrease was 30 (24, 39) s for DL, 67 (35, 149) s for DLO2 and 75 (37, 122) s for VLO2. Mean desaturation slope was 0.13 (0.11, 0.15)% s(-1) for DL, 0.04 (0.02, 0.06)% s(-1) for DLO2 and 0.03 (0.004, 0.05)% s(-1) for VLO2. We did not find a correlation between decrease in [Formula: see text] percentage and BMI or age. CONCLUSIONS: Laryngeal oxygen insufflation increases the time to 1% desaturation and reduces the overall rate of desaturation during laryngoscopy in children. CLINICAL TRIAL REGISTRATION: NCT01886807.

Elevated C-reactive protein levels are associated with prevalent dementia in the oldest-old.

BACKGROUND: C-reactive protein (CRP) is a nonspecific marker of inflammation that is increased in the brain and serum of patients with Alzheimer's disease (AD), and has been associated with increased risk of developing dementia. Inflammation increases with age, and the number of people reaching age 90 years and older is growing, making the association between inflammation and dementia increasingly relevant. Using a cross-sectional design, we examined whether high levels of serum CRP are associated with increased odds of prevalent dementia in the oldest-old. METHODS: Serum CRP levels of 305 participants (mean age +/- standard deviation, 94.3 +/- 2.9 years) from the 90+ Study, a longitudinal cohort study of people aged 90 years and older, were evaluated with respect to all-cause dementia. Levels of CRP were divided into three categories: undetectable (<0.5 mg/dL), detectable (0.5-0.7 mg/dL), and elevated (> or =0.8 mg/dL). Odds ratios (ORs) were calculated using logistic regression, and were adjusted for covariates. RESULTS: Relative to participants with undetectable CRP levels, participants with detectable or elevated CRP levels had increased odds of all-cause dementia (detectable: OR, 3.0; 95% confidence interval, 1.2-7.3; elevated: OR, 5.0; 95% confidence interval, 1.9-12.9). When participants were subdivided by gender, significantly increased ORs were seen only in women. CONCLUSIONS: In the oldest-old, high CRP levels are associated with increased odds of all-cause dementia, particularly in women. Prospective studies are necessary to confirm whether increased CRP levels are associated with an increased risk of developing dementia in this age group.

High levels of serum C-reactive protein are associated with greater risk of all-cause mortality, but not dementia, in the oldest-old: results from The 90+ Study.

OBJECTIVES: To evaluate whether high levels of C-reactive protein (CRP) in serum are associated with greater risk of all-cause dementia or mortality in the oldest-old. DESIGN: Prospective. SETTING: Research clinic and in-home visits. PARTICIPANTS: Population-based sample of adults (N=227; aged 93.9+/-2.8) from The 90+ Study, a longitudinal cohort study of people aged 90 and older. MEASUREMENTS: CRP levels were divided into three groups according to the assay detection limit: undetectable (<0.5 mg/dL), detectable (0.5-0.7 mg/dL), and elevated (> or =0.8 mg/dL). Neurological examination was used to determine dementia diagnosis (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria). Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were computed using Cox regression, and results were stratified according to and apolipoprotein E4 (APOE4) genotype. RESULTS: Subjects with detectable CRP levels had significantly greater risk of mortality (HR=1.7, 95% CI=1.0-2.9), but not dementia (HR=1.2, 95% CI=0.6-2.1), 0.4 to 4.5 years later than subjects with undetectable CRP. The highest relative risk for dementia and mortality was in APOE4 carriers with detectable CRP (dementia HR=4.5, 95% CI=0.9-23.3; mortality HR=5.6, 95% CI=1.0-30.7). CONCLUSION: High levels of CRP are associated with greater risk of mortality in people aged 90 and older, particularly in APOE4 carriers. There was a trend toward greater risk of dementia in APOE4 carriers with high CRP levels, although this relationship did not reach significance. High levels of CRP in the oldest-old represent a risk factor for negative outcomes.

A Diabetes Outcome Progression Trial (ADOPT): baseline characteristics of Type 2 diabetic patients in North America and Europe.

AIMS: To examine baseline characteristics of patients recruited into ADOPT, a multinational trial comparing three oral glucose-lowering monotherapies. METHODS: Between April 2000 and June 2002, 4360 patients aged 30-75 years with Type 2 diabetes diagnosed for < 3 years and remaining on diet therapy alone with fasting plasma glucose levels (FPG) between 7.0 and 10.0 mmol/l were enrolled by 488 North American and European centres. Medical histories, anthropometric data and laboratory measurements were determined using common methodologies. RESULTS: The mean (SD) age of the patients was 57 (10) years, body mass index 32.2 (6.4) kg/m(2), HbA(1c) 7.4 (0.9)%; 58% were male, 88% Caucasian and 15% smoked. North American Caucasians (NAC) were younger, more obese, and more insulin resistant than European Caucasians (EUC), but had better pancreatic B-cell function. NAC had lower total, low-density lipoprotein- and high-density liporpotein-cholesterol concentrations with higher triglyceride concentrations and were more often on lipid-lowering treatment. They had lower blood pressure levels but were equally likely to be on antihypertensive treatment. Metabolic syndrome was more frequent and microalbuminuria less frequent in NAC. Within North America, NAC had lower HbA(1c) concentrations than Blacks, Hispanics and Asians despite similar or higher FPG and 30-min postchallenge glucose concentrations. CONCLUSIONS: Caucasian North American and European ADOPT patients differ with respect to adiposity, insulin resistance and metabolic syndrome prevalence. North American Blacks, Hispanics and Asians had lower HbA(1c) concentrations than NAC despite similar or higher glucose concentrations. These phenotypic differences may influence the progression of Type 2 diabetes and the response to initial oral glucose-lowering monotherapy.

Effect of early addition of rosiglitazone to sulphonylurea therapy in older type 2 diabetes patients (>60 years): the Rosiglitazone Early vs. SULphonylurea Titration (RESULT) study.

AIM: To compare the efficacy, safety and tolerability of adding rosiglitazone (RSG) vs. sulphonylurea (SU) dose escalation in older type 2 diabetes mellitus (T2DM) patients inadequately controlled on SU therapy. METHODS: A total of 227 T2DM patients from 48 centres in the USA and Canada, aged > or =60 years, were randomized to receive RSG (4 mg) or placebo once daily in combination with glipizide 10 mg twice daily for 2 years in a double-blind, parallel-group study. Previous SU monotherapy was (1/4) to (1/2) maximum recommended dose for > or =2 months prior to screening with fasting plasma glucose (FPG) > or =7.0 and < or =13.9 mmol/l. Treatment options were individualized, and escalation of study medication was specifically defined. RESULTS: Disease progression (time to reach confirmed FPG > or =10 mmol/l while on maximum doses of both glipizide and study medication or placebo) was reported in 28.7% of patients uptitrating SU plus placebo compared with only 2.0% taking RSG and SU combination (p < 0.0001). RSG + SU significantly decreased HbA(1c), FPG, insulin resistance, plasma free fatty acids and medical care utilization and improved treatment satisfaction compared with uptitrated SU. CONCLUSIONS: Addition of RSG to SU in older T2DM patients significantly improved glycaemic control and reduced disease progression compared with uptitrated SU alone but without increasing hypoglycaemia. These benefits were associated with increased patient treatment satisfaction and reduced medical care utilization with regards to emergency room visits and length of hospitalization. Early addition of RSG is an effective treatment option for older T2DM patients inadequately controlled on submaximal SU monotherapy.

Stimulation of cortical acetylcholine release following blockade of ionotropic glutamate receptors in nucleus accumbens.

In vivo microdialysis techniques were used to determine the ability of glutamate receptors within the nucleus accumbens to trans-synaptically modulate the basal forebrain cortical cholinergic system. Rats were implanted with a dialysis probe in the medial prefrontal cortex to measure changes in cortical acetylcholine efflux and in the ipsilateral nucleus accumbens to locally manipulate glutamate receptor activity. Intra-accumbens perfusion of the broad spectrum ionotropic glutamate receptor antagonist kynurentate (1.0, 5.0 mm) led to a dose-dependent increase (maximum of 200%) in cortical acetylcholine efflux. This stimulated efflux was reproduced with the intra-accumbens perfusion of the AMPA/kainate antagonist DNQX (0.1, 0.25, 2.5 mm; maximum increase of 200%) or the NMDA antagonist D-CPP (10.0, 100.0, 200 micro M; maximum increase of 400%). These results reveal a significant glutamatergic tone within the accumbens of awake rats and support the hypothesis that accumbens efferents to basal forebrain modulate the excitability of the basal forebrain cortical cholinergic system.

An assessment of the value of ultrasonographic screening for endometrial disease in postmenopausal women without symptoms.

OBJECTIVE: Our purpose was to evaluate the use of transvaginal ultrasonography for the detection of endometrial disease in a population of postmenopausal women who were without symptoms. STUDY DESIGN: Postmenopausal women were screened for potential inclusion in 2 multicenter, double-blind, placebo-controlled studies of 2 years' duration to evaluate the safety and efficacy of idoxifene in the prevention of osteoporosis. Baseline endometrial evaluation was performed by transvaginal ultrasonography and aspiration biopsy of the endometrium. RESULTS: A total of 1926 women were screened by transvaginal ultrasonography, and 1833 of them had endometrial thickness < or =6 mm. Five cases of endometrial abnormality (adenocarcinoma [n = 1] and atypical hyperplasia [n = 4]) were detected in the 1750 women from this cohort who underwent biopsy. The negative predictive value was >99%. One case of adenocarcinoma was detected in the 42 women who had endometrial thickness >6 mm and underwent biopsy. However, the sampling rate (45%) of women with endometrial thickness >6 mm was too low for confidence in the positive predictive value of 2%. CONCLUSIONS: Despite a high negative predictive value, transvaginal ultrasonography may not be an effective screening procedure for detection of endometrial abnormality in untreated postmenopausal women who are without symptoms.

Sonographic assessment of the endometrium in osteopenic postmenopausal women treated with idoxifene.

Idoxifene is a novel selective estrogen receptor modulator that has shown beneficial effects on bone turnover and lipid metabolism in clinical studies. Preclinical studies have demonstrated that idoxifene has estrogen antagonist activities on the endometrium. This paper describes the results of a double-blind, placebo-controlled, and dose ranging study involving 331 osteopenic postmenopausal women who were treated with either placebo or idoxifene (2.5, 5, or 10 mg/day) for 12 weeks. In these women, endometrial assessment was carried out by transvaginal sonography and endometrial biopsy on selected patients at baseline and on all women at the end of treatment. Women with an endometrial thickness greater than 10 mm were excluded from the study. Aspiration endometrial biopsy was performed on women with an endometrial thickness between 6 and 10 mm at baseline and on all women after treatment. Of the 298 biopsies performed in the subjects at the end of treatment, 99% of the women were reported to have either a benign or atrophic endometrium (85%) or insufficient tissue for diagnosis (14%). Proliferative histologic features were reported in two cases (1%) (2.5 mg idoxifene) and atypical hyperplasia in one placebo patient. Even though idoxifene use was associated with a dose related increase in endometrial thickness as evaluated by transvaginal sonography, no relationship was established between endometrial histologic features and change in endometrial thickness. On histologic analysis, the increase in endometrial thickness seen on transvaginal sonography was not associated with proliferative or hyperplastic change in the epithelial (glandular) endometrial tissue. In 48 patients (16% of total) transvaginal sonography showed endometrial thickening of 5 mm or more over the study period. The endometrial histologic features were benign in all these patients. Nineteen percent of women developed intraluminal fluid, even though endometrial thickness was normal and unchanged and histologic features were normal. Our data show that after 3 months of treatment, no significant pathologic changes of the endometrium were observed. Our data indicate that measurements of endometrial thickness by transvaginal sonography may falsely suggest the presence of endometrial pathologic changes in some postmenopausal women treated with idoxifene. Additional testing using saline infusion sonohysterography is an important part of the transvaginal sonography protocol in equivocal or abnormal cases to exclude focal lesions such as polyps. In addition, our data indicate that pathologic changes of the endometrium are extremely rare in the treated group, indicative of its short term safety. Continued investigation such as this will be needed to establish long term safety.

A novel method for selection of invasive tumor cells: derivation and characterization of highly metastatic K1735 melanoma cell lines based on in vitro and in vivo invasive capacity.

Tumor cell invasion of basement membranes is required at several steps in the process of metastasis. To study the genetic and biochemical events mediating invasion, a variant cell line (TK) was selected from the metastatic M2 K1735 murine melanoma cell line. A novel selection procedure was used, based on in vitro and in vivo invasion and growth upon basement membrane and stroma. Additionally, two extrapulmonary metastases of the TK cell line, TK-Eve and TK-Liver, were established as cell lines and characterized. The TK cell line demonstrates greater metastatic potential in vivo and invasive ability in vitro than the parent M2 cell line, confirming the validity of the selection procedure. In addition, the M2 and TK cell lines were examined for other cell functions involved in the metastatic process. Cellular growth rates and sensitivity to T lymphocyte and natural killer cell lysis were not determining factors in the metastatic potentials of the M2 and selected cell lines; possible macrophage contribution to metastatic behavior was noted. [35S]methionine pulse labeling of protein synthesis and karyotypic analysis confirm the close relationship of parental and selected cell lines.