Elevated C-Reactive Protein in Older Men With Chronic Pain: Association With Plasma Amyloid Levels and Hippocampal Volume.

BACKGROUND: Chronic pain leads to tau accumulation and hippocampal atrophy, which may be moderated through inflammation. In older men, we examined associations of chronic pain with Alzheimer's disease (AD)-related plasma biomarkers and hippocampal volume as moderated by systemic inflammation. METHODS: Participants were men without dementia. Chronic pain was defined as moderate-to-severe pain in 2+ study waves at average ages 56, 62, and 68. At age 68, we measured plasma amyloid-beta (Aß42, n = 871), Aß40 (n = 887), total tau (t-tau, n = 841), and neurofilament light chain (NfL, n = 915), and serum high-sensitivity C-reactive protein (hs-CRP, n = 968), a marker of systemic inflammation. A subgroup underwent structural MRI to measure hippocampal volume (n = 385). Analyses adjusted for medical morbidities, depressive symptoms, and opioid use. RESULTS: Chronic pain was related to higher Aß40 (ß = 0.25, p = .009), but hs-CRP was unrelated to AD-related biomarkers (ps > .05). There was a significant interaction such that older men with both chronic pain and higher levels of hs-CRP had higher levels of Aß42 (ß = 0.36, p = .001) and Aß40 (ß = 0.29, p = .003). Chronic pain and hs-CRP did not interact to predict levels of Aß42/Aß40, t-tau, or NfL. Furthermore, there were significant interactions such that Aß42 and Aß40 were associated with lower hippocampal volume, particularly when levels of hs-CRP were elevated (hs-CRP × Aß42: ß = -0.19, p = .002; hs-CRP × Aß40: ß = -0.21, p = .001), regardless of chronic pain status. CONCLUSIONS: Chronic pain was associated with higher plasma Aß, especially when hs-CRP was also elevated. Higher hs-CRP and Aß levels were both related to smaller hippocampal volumes. Chronic pain, when accompanied by systemic inflammation, may elevate the risk of neurodegeneration in AD-vulnerable regions.

Associations between depression and cardiometabolic health: A 27-year longitudinal study.

BACKGROUND: Clarifying the relationship between depression symptoms and cardiometabolic and related health could clarify risk factors and treatment targets. The objective of this study was to assess whether depression symptoms in midlife are associated with the subsequent onset of cardiometabolic health problems. METHODS: The study sample comprised 787 male twin veterans with polygenic risk score data who participated in the Harvard Twin Study of Substance Abuse ('baseline') and the longitudinal Vietnam Era Twin Study of Aging ('follow-up'). Depression symptoms were assessed at baseline [mean age 41.42 years (s.d. = 2.34)] using the Diagnostic Interview Schedule, Version III, Revised. The onset of eight cardiometabolic conditions (atrial fibrillation, diabetes, erectile dysfunction, hypercholesterolemia, hypertension, myocardial infarction, sleep apnea, and stroke) was assessed via self-reported doctor diagnosis at follow-up [mean age 67.59 years (s.d. = 2.41)]. RESULTS: Total depression symptoms were longitudinally associated with incident diabetes (OR 1.29, 95% CI 1.07-1.57), erectile dysfunction (OR 1.32, 95% CI 1.10-1.59), hypercholesterolemia (OR 1.26, 95% CI 1.04-1.53), and sleep apnea (OR 1.40, 95% CI 1.13-1.74) over 27 years after controlling for age, alcohol consumption, smoking, body mass index, C-reactive protein, and polygenic risk for specific health conditions. In sensitivity analyses that excluded somatic depression symptoms, only the association with sleep apnea remained significant (OR 1.32, 95% CI 1.09-1.60). CONCLUSIONS: A history of depression symptoms by early midlife is associated with an elevated risk for subsequent development of several self-reported health conditions. When isolated, non-somatic depression symptoms are associated with incident self-reported sleep apnea. Depression symptom history may be a predictor or marker of cardiometabolic risk over decades.

Assessing Molecular Docking Tools to Guide Targeted Drug Discovery of CD38 Inhibitors.

A promising protein target for computational drug development, the human cluster of differentiation 38 (CD38), plays a crucial role in many physiological and pathological processes, primarily through the upstream regulation of factors that control cytoplasmic Ca2+ concentrations. Recently, a small-molecule inhibitor of CD38 was shown to slow down pathways relating to aging and DNA damage. We examined the performance of seven docking programs for their ability to model protein-ligand interactions with CD38. A test set of twelve CD38 crystal structures, containing crystallized biologically relevant substrates, were used to assess pose prediction. The rankings for each program based on the median RMSD between the native and predicted were Vina, AD4 > PLANTS, Gold, Glide, Molegro > rDock. Forty-two compounds with known affinities were docked to assess the accuracy of the programs at affinity/ranking predictions. The rankings based on scoring power were: Vina, PLANTS > Glide, Gold > Molegro >> AutoDock 4 >> rDock. Out of the top four performing programs, Glide had the only scoring function that did not appear to show bias towards overpredicting the affinity of the ligand-based on its size. Factors that affect the reliability of pose prediction and scoring are discussed. General limitations and known biases of scoring functions are examined, aided in part by using molecular fingerprints and Random Forest classifiers. This machine learning approach may be used to systematically diagnose molecular features that are correlated with poor scoring accuracy.

Recall and Recognition Discriminability in Parkinson's Disease and Huntington's Disease.

BACKGROUND: Parkinson's disease (PD) and Huntington's disease (HD) are two neurodegenerative diseases affecting frontal-striatal function and memory ability. Studies using the original California Verbal Learning Test (CVLT) to examine recall and recognition abilities between these groups have produced mixed findings. Some found that individuals with HD demonstrate worse recall and recognition than those with PD, whereas others reported comparable performance. OBJECTIVE: We utilized multiple indices of recall and recognition discriminability, provided by the second and third editions of the CVLT (CVLT-II and CVLT-3, respectively), that allow for a more thorough assessment of more nuanced aspects of verbal memory function. METHODS: We examined differences between individuals with PD (n = 72) and those with HD (n = 77) on CVLT-II indices of recall discriminability (immediate, short delay free and cued, long delay free and cued) and recognition discriminability (total, source, semantic, and novel) using standardized scores while controlling for education and Dementia Rating Scale-2 scores. RESULTS: The HD group performed significantly worse than the PD group on all measures of recall and recognition discriminability (ps < 0.05), and group differences were associated with large Cohen's d effect sizes. CONCLUSIONS: Our findings suggest that individuals with HD are more impaired than individuals with PD in more nuanced aspects of recall and recognition memory function. These CVLT indices yield more thorough assessments of recall and recognition memory function and have the potential to improve efforts to characterize and distinguish profiles of memory loss in different neurodegenerative populations, including PD and HD.

Incidence, course, and management of toxicities associated with cobimetinib in combination with vemurafenib in the coBRIM study.

Background: In the coBRIM phase III trial, the addition of cobimetinib, an MEK inhibitor, to vemurafenib, a BRAF inhibitor, significantly improved progression-free survival [hazard ratio (HR), 0.58; P < 0.0001] and overall survival (HR, 0.70; P = 0.005) in advanced BRAF-mutated melanoma. Here, we report on the incidence, course, and management of key adverse events (AEs) in the coBRIM study. Patients and methods: Patients were randomly assigned 1:1 to receive vemurafenib (960 mg twice a day) and either cobimetinib (60 mg once a day, 21 days on/7 days off) or placebo. In addition to standard safety evaluations, patients underwent regular ophthalmic, cardiac, and dermatologic surveillance examinations. Results: Of 495 patients recruited to the study, 493 patients received treatment and constituted the safety population (cobimetinib combined with vemurafenib, 247; vemurafenib, 246). At data cut-off (30 September 2015), median follow-up was 18.5 months. Nearly every patient experienced an AE. In patients who received cobimetinib combined with vemurafenib, the frequency of grade ≥3 AEs was higher than in patients who received vemurafenib alone (75% versus 61%). Most AEs, including grade ≥3 AEs, occurred within the first treatment cycle. After the first cycle (28 days), the incidence of common AEs (rash, diarrhoea, photosensitivity, elevated creatine phosphokinase, serous retinopathy, pyrexia, and liver laboratory abnormalities) decreased substantially over time. Most AEs were managed conservatively by supportive care measures, dose modifications of study treatment, and, occasionally, permanent treatment discontinuation. Conclusions: These data indicate that most AEs arising from treatment with cobimetinib combined with vemurafenib generally occur early in the treatment course, are mild or moderate and are manageable by patient monitoring, dose modification and supportive care. ClinicalTrials.gov: NCT01689519.

Impact of age and medical comorbidity on adjuvant treatment outcomes for stage III colon cancer: a pooled analysis of individual patient data from four randomized, controlled trials.

BACKGROUND: Adjuvant oxaliplatin plus capecitabine or leucovorin/5-fluorouracil (LV/5-FU) (XELOX/FOLFOX) is the standard of care for stage III colon cancer (CC); however, there is disagreement regarding oxaliplatin benefit in patients aged >70. In most analyses, the impact of medical comorbidity (MC) has not been assessed. Efficacy and safety of adjuvant XELOX/FOLFOX versus LV/5-FU were compared with respect to age and MC using pooled data from four randomized, controlled trials, selected for access to patient-level MC data and including commonly endorsed and utilized regimens. PATIENTS AND METHODS: Individual data from patients with stage III CC in NSABP C-08, XELOXA, X-ACT, and AVANT were pooled, excluding bevacizumab-treated patients. Patients were grouped by treatment, MC (low versus high), or age (<70 versus ≥70), and compared for disease-free survival (DFS), overall survival (OS), and adverse events (AEs). Multivariable Cox proportional hazards regression controlled for gender, T stage, and N stage. RESULTS: DFS benefits were shown for XELOX/FOLFOX versus LV/5-FU regardless of age or MC, although benefits were modestly attenuated for patients aged ≥70. Hazard ratios were 0.68 (P < 0.0001) and 0.77 (P < 0.014) for <70 and ≥70 age groups; 0.69 (P < 0.0001) and 0.59 (P < 0.0001) for Charlson Comorbidity Index ≤1 and >1 groups; and 0.70 (P < 0.0001) and 0.58 (P < 0.0001) for National Cancer Institute Combined Index ≤1 and >1 groups. OS was also significantly improved in all groups. Grade 3/4 serious AE rates were comparable across cohorts and MC scores and higher in patients aged ≥70. Oxaliplatin-relevant grade 3/4 AEs, including neuropathy, were comparable across ages and MC scores. CONCLUSIONS: Results further support consideration of XELOX or FOLFOX as standard treatment options for the adjuvant management of stage III CC in all age groups and in patients with comorbidities, consistent with those who were eligible for these clinical trials.

Epidemiology and natural history of central venous access device use and infusion pump function in the NO16966 trial.

BACKGROUND: Central venous access devices in fluoropyrimidine therapy are associated with complications; however, reliable data are lacking regarding their natural history, associated complications and infusion pump performance in patients with metastatic colorectal cancer. METHODS: We assessed device placement, use during treatment, associated clinical outcomes and infusion pump performance in the NO16966 trial. RESULTS: Device replacement was more common with FOLFOX-4 (5-fluorouracil (5-FU)+oxaliplatin) than XELOX (capecitabine+oxaliplatin) (14.1% vs 5.1%). Baseline device-associated events and post-baseline removal-/placement-related events occurred more frequently with FOLFOX-4 than XELOX (11.5% vs 2.4% and 8.5% vs 2.1%). Pump malfunctions, primarily infusion accelerations in 16% of patients, occurred within 1.6-4.3% of cycles. Fluoropyrimidine-associated grade 3/4 toxicity was increased in FOLFOX-4-treated patients experiencing a malfunction compared with those who did not (97 out of 155 vs 452 out of 825 patients), predominantly with increased grade 3/4 neutropenia (53.5% vs 39.8%). Febrile neutropenia rates were comparable between patient cohorts±malfunction. Efficacy outcomes were similar in patient cohorts±malfunction. CONCLUSIONS: Central venous access device removal or replacement was common and more frequent in patients receiving FOLFOX-4. Pump malfunctions were also common and were associated with increased rates of grade 3/4 haematological adverse events. Oral fluoropyrimidine-based regimens may be preferable to infusional 5-FU based on these findings.

Treatment effect of capecitabine and docetaxel or docetaxel alone by oestrogen receptor status in patients with metastatic breast cancer: results of an exploratory analysis.

We investigated treatment effects by oestrogen receptor (ER) status among women with metastatic breast cancer (MBC) receiving capecitabine (C) plus docetaxel (D) or D alone in a randomised phase III trial. Data were retrospectively analysed from patients whose disease had recurred following (neo)adjuvant anthracyclines. ER status was identified in 356/506 patients. In patients with ER-positive tumours, median overall survival from enrolment was 17.7 months with CD versus 12.5 months with D (hazard ratio [HR] 0.65, 95% confidence interval [CI]: 0.47-0.89; P = 0.007) and median time to progression (TTP) was 6.8 and 5.4 months, respectively (HR 0.62, 95% CI: 0.46-0.84; P = 0.002). For patients with ER-negative tumours, significantly longer TTP was seen with CD (5.2 versus 3.5 months; HR 0.73, 95% CI: 0.53-0.98; P = 0.038). Whether there is an additional C to D treatment benefit in ER-positive versus ER-negative MBC requires further evaluation.

Pemetrexed for the maintenance treatment of locally advanced or metastatic non-small cell lung cancer.

This paper presents a summary of the evidence review group (ERG) report into the clinical effectiveness and cost-effectiveness of pemetrexed for the maintenance treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC), in accordance with the licensed indication, based upon the evidence submission from the manufacturer (Eli Lilly) to the National Institute for Health and Clinical Excellence (NICE) as part of the single technology appraisal (STA) process. The primary clinical outcome measure was progression free survival (PFS). Secondary outcomes included overall survival (OS), time to worsening of symptoms, objective tumour response rate, adverse events and changes in lung cancer symptom scale. Data for two populations were presented: patients with non-squamous NSCLC histology and patients with adenocarcinoma histology. The clinical evidence was derived from a double-blind, placebo-controlled randomised controlled trial (RCT), the JMEN trial. The trial compared the use of pemetrexed + best supportive care (BSC ) as maintenance therapy, with placebo + BSC in patients with NSCLC (n = 663) who had received four cycles of platinum-based chemotherapy (CTX) and whose disease had not progressed. In the licensed population (patients with non-squamous histology), the trial demonstrated greater median PFS for patients treated with pemetrexed than for patients in the placebo arm [4.5 vs 2.6 months; hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.36 to 0.55, p < 0.00001]. Median OS was also greater for the pemetrexed- treated patients (15.5 vs 10.3 months; HR 0.70; 95% CI 0.56 to 0.88, p = 0.002). In addition, tumour response and disease control rates were statistically significantly greater for patients who received pemetrexed. Patient survival rates at 1 year and 2 years were higher in the pemetrexed arm. The incremental cost-effectiveness ratios (ICERs) estimated by the manufacturer's model were 33,732 pounds per quality adjusted life-year (QALY) for the licensed nonsquamous population, and 39,364 pounds per QALY for the adenocarcinoma subgroup. Both of these ICERs were above the standard NICE willingness-to-pay range (20,000 pounds-30,000 pounds per QALY). The manufacturer also presented a case for pemetrexed to be considered as an end of life treatment. The ERG identified a number of problems in the economic model presented by the manufacturer; after correction, the base case ICER was re-estimated as 51,192 pounds per QALY gained and likely to exceed NICE's willingness-to-pay thresholds. Following a revised economic analysis submitted by the manufacturer, the AC accepted that an ICER of 47,000 pounds per QALY gained was most plausible. The AC also considered that maintenance treatment with pemetrexed fulfilled the end of life criteria.The guidance issued by NICE, on 20 June 20 2010, in TA190 as a result of the STA states that: People who have received pemetrexed in combination with cisplatin as first-line chemotherapy cannot receive pemetrexed maintenance treatment. 1.1 Pemetrexed is recommended as an option for the maintenance treatment of people with locally advanced or metastatic non-small-cell lung cancer other than predominantly squamous cell histology if disease has not progressed immediately following platinum-based chemotherapy in combination with gemcitabine, paclitaxel or docetaxel.

Endoscopically assisted minimally invasive surgery for gallstones.

BACKGROUND: We present a case report of Bouveret syndrome followed by a review of the recent literature regarding the management of this condition. Bouveret syndrome is a form of gastric outlet obstruction secondary to a gallstone which has eroded through the gallbladder into the duodenum. It is an uncommon variant of gallstone ileus. Endoscopic methods have been described to extract the stone from the duodenum. METHODS: This is a case of an 85-year-old female patient who presented with a 1-week history of nausea, intermittent bilious vomiting and anorexia. Imaging confirmed the diagnosis of Bouveret syndrome caused by two large gallstones. Conventional endoscopic methods successfully extracted the impacted stones from the duodenum into the stomach but were unable to extract the stones from the stomach. A mini-transverse laparotomy and gastrotomy were performed to finally extract the stones.

Patient, carer and health service outcomes of nurse-led early discharge after breast cancer surgery: a randomised controlled trial.

Patients with breast cancer who require axillary clearance traditionally remain in hospital until their wound drains are removed. Early discharge has been shown to improve clinical outcomes, but there has been little assessment of the psychosocial and financial impact of early discharge on patients, carers and the health service. This study aimed to evaluate the effectiveness of a nurse-led model of early discharge from hospital. Main outcome measures were quality of life and carer burden. Secondary outcomes included patient satisfaction, arm morbidity, impact on community nurses, health service costs, surgical cancellations and in-patient nursing dependency. A total of 108 patients undergoing axillary clearance with mastectomy or wide local excision for breast cancer were randomised to nurse-led early discharge or conventional stay. Nurse-led early discharge had no adverse effects on quality of life or patient satisfaction, had little effect on carer burden, improved communication between primary and secondary care, reduced cancellations and was safely implemented in a mixed rural/urban setting. In total, 40% of eligible patients agreed to take part. Nonparticipants were significantly older, more likely to live alone and had lower emotional well being before surgery. This study provides further evidence of the benefits of early discharge from hospital following axillary clearance for breast cancer. However, if given the choice, most patients prefer to stay in hospital until their wound drains are removed.

Vaccination of pediatric solid tumor patients with tumor lysate-pulsed dendritic cells can expand specific T cells and mediate tumor regression.

Dendritic cells (DCs) have been shown to be a promising adjuvant for inducing immunity to cancer. We evaluated tumor lysate-pulsed DC in a Phase I trial of pediatric patients with solid tumors. Children with relapsed solid malignancies who had failed standard therapies were eligible. The vaccine used immature DC (CD14-, CD80+, CD86+, CD83-, and HLA-DR+) generated from peripheral blood monocytes in the presence of granulocyte/monocyte colony-stimulating factor and interleukin-4. These DC were then pulsed separately with tumor cell lysates and the immunogenic protein keyhole limpet hemocyanin (KLH) for 24 h and then combined. A total of 1 x 10(6) to 1 x 10(7) DC are administered intradermally every 2 weeks for a total of three vaccinations. Fifteen patients (ages 3-17 years) were enrolled with 10 patients completing all vaccinations. Leukapheresis yields averaged 2.8 x 10(8) peripheral blood mononuclear cells (PBMC)/kg, and DC yields averaged 10.9% of starting PBMC. Patients with neuroblastoma, sarcoma, and renal malignancies were treated without obvious toxicity. Delayed-type hypersensitivity (DTH) response was detected in 7 of 10 patients for KLH and 3 of 6 patients for tumor lysates. Priming of T cells to KLH was seen in 6 of 10 patients and to tumor in 3 of 7 patients as demonstrated by specific IFN-gamma-secreting T cells in unstimulated PBMCs. Significant regression of multiple metastatic sites was seen in 1 patient. Five patients showed stable disease, including 3 who had minimal disease at time of vaccine therapy and remain free of tumor with 16-30 months follow-up. Our results demonstrate that it is feasible to generate large numbers of functional DC from pediatric patients even in those highly pretreated and with a large tumor burden. The DC can be administered in an outpatient setting without any observable toxicity. Most importantly, we have demonstrated the ability of the tumor lysate/KLH-pulsed DC to generate specific T-cell responses and to elicit regression of metastatic disease.

Treatment of solid tumours in children with tumour-lysate-pulsed dendritic cells.

Dendritic cells are potent stimulators of antigen-specific immune responses, including antitumour responses. We explored the use of tumour-lysate-pulsed dendritic cells in children with relapsed solid tumours. Dendritic cell treatment in children was feasible and apparently not toxic. The treatment was able to produce significant tumour regression in a child with metastatic fibrosarcoma.

Physical interactions between phospholamban and sarco(endo)plasmic reticulum Ca2+-ATPases are dissociated by elevated Ca2+, but not by phospholamban phosphorylation, vanadate, or thapsigargin, and are enhanced by ATP.

Previous co-immunoprecipitation studies (Asahi, M., Kimura, Y., Kurzydlowski, K., Tada, M., and MacLennan, D. H. (1999) J. Biol. Chem. 274, 32855-32862) revealed that physical interactions between phospholamban (PLN) and the fast-twitch skeletal muscle sarco(endo)plasmic reticulum Ca(2+) ATPase (SERCA1a) were retained, even with PLN monoclonal antibody 1D11 bound to an epitope lying between PLN residues 7 and 17. Because the 1D11 antibody relieves inhibitory interaction between the two proteins, it was of interest to determine whether PLN phosphorylation or elevation of Ca(2+), which also relieves inhibitory interactions between PLN and SERCA, would disrupt physical interactions. Co-immunoprecipitation was measured in the presence of increasing concentrations of Ca(2+) or after phosphorylation of PLN by protein kinase A. Physical interactions were dissociated by elevated Ca(2+) but not by PLN phosphorylation. The addition of ATP enhanced interactions between PLN and SERCA. The further addition of vanadate and thapsigargin, both of which stabilize the E(2) conformation, did not diminish binding of PLN to SERCA. These data suggest that physical interactions between PLN and SERCA are stable when SERCA is in the Ca(2+)-free E(2) conformation but not when it is in the E(1) conformation and that phosphorylation of PLN does not dissociate physical interactions between PLN and SERCA.

Characterization and quantitation of phospholamban and its phosphorylation state using antibodies.

Quantitative immunoassays to discriminate and quantitate phospholamban and its phosphorylation states in heart homogenates were developed using known amounts of protein determined by amino acid analysis. Synthetic 1-52 phospholamban, the hydrophilic 1-25 peptide, and 1-25 phosphopeptides containing P-Ser(16), P-Thr(17), and dually phosphorylated (P-Ser(16), P-Thr(17)) were used to calibrate immunoblot systems. In addition, synthetic 1-52 peptide was phosphorylated using cAMP-dependent protein kinase (P-Ser(16)) or Ca(2+)-calmodulin protein kinase (P-Thr(17)) and then separated from unphosphorylated 1-52 by HPLC prior to quantitation. Further, canine cardiac sarcoplasmic reticulum was phosphorylated in vitro using [gamma-(32)P]-ATP with cAMP-dependent protein kinase and/or Ca(2+)-calmodulin-dependent protein kinase as well as sequential phosphorylation in both orders to assess the veracity of antibody recognition of phosphorylated forms. Western blots proved useful in characterizing the reactivity of the different antibodies to phospholamban and phosphorylated phospholamban, but were inefficient for accurate quantitation and problems with antibody recognition of dually phosphorylated phospholamban were found. mAb 1D11 recognized all forms of phospholamban, polyclonal antibodies 285 and PS-16 were highly selective for P-Ser(16) phospholamban but had diminished reactivity to diphosphorylated (P-Ser(16), P-Thr(17)) phospholamban, and polyclonal antibody PT-17, although selective for P-Thr(17) phospholamban, generated very weak signals on Western blots and reacted poorly with diphosphorylated phospholamban. Results in quantitative immunodot blot experiments were even more compelling. None of the phosphorylation specific antibodies reacted with the diphospho 1-25 phospholamban peptide. Transgenic mouse hearts expressing varying levels of PLB and ferret heart biopsy samples taken before and after isoproterenol perfusion were analyzed. In all samples containing phospholamban, a basal level of Ser(16) phosphorylation (about 4% of the total PLB population) and a lesser amount of Thr(17) phosphorylation was observed. Upon isoproterenol perfusion, Ser(16) phosphorylation increased only to 17% of the total phospholamban population with a similar change in Thr(17) phosphorylation. This suggests that phospholamban phosphorylation may serve as an electrostatic switch that dissociates inactive calcium pump complexes into catalytically active units. Thus, direct correlations between phospholamban phosphorylation state and contractile parameters may not be valid.

A review of the comparative mammalian toxicity of ethylene glycol and propylene glycol.

The purpose of this article is to review and interpret the scientific literature on the mammalian toxicity of ethylene glycol (EG) and propylene glycol (PG), with the goal of comparing the toxicity of the two chemicals. This type of review may serve as the basis for risk management decision-making. Because EG is not a GRAS (generally recognized as safe) chemical, its uses are restricted when compared with PG; thus, certain routes of exposure are not relevant here for toxicological comparison (e.g., subcutaneous, intramuscular, and intravenous). Therefore, this review is focused on the oral, inhalation, and dermal routes of exposure. However, where toxicological data derived from an alternative route of exposure serve to eludicate mechanisms of toxicity, data from these routes are considered. Based on the review provided herein, the following conclusions can be drawn. From the standpoint of lethality, acute effects, and reproductive, developmental, and kidney toxicity, the toxicity of EG exceeds that of PG. Further, localized dermal effects from EG and PG are both mild, with data suggesting that PG may have a skin contact sensitization potential. Finally, PG exposure in laboratory animals has been associated with reversible hematological changes; no data were located for EG from which to draw a toxicological comparison.

Relationship between phospholamban and nucleotide activation of cardiac sarcoplasmic reticulum Ca2+ adenosinetriphosphatase.

A strong connection with nucleotide activation of Ca2+ATPase and phospholamban inhibition has been found. Phospholamban decreases the number of activatable Ca2+ATPase without affecting substrate affinity or the ability of nucleotide to serve its dual modulatory roles, i.e., catalytic and regulatory. Low concentrations of certain nucleotide mimetics, quercetin, tannin, and ellagic acid, with structural similarity to adenine can unmask phospholamban's inhibitory effect while concurrently acting as competitive inhibitors of nucleotide binding. Micromolar concentrations of tannin (EC50 approximately 0.3 microM) and ellagic acid (EC50 approximately 3 microM) stimulated Ca2+ uptake and calcium-activated ATP hydrolysis at submicromolar Ca2+ in isolated cardiac sarcoplasmic reticulum (SR). Stimulation of Ca2+ATPase was followed by pronounced inhibiton at only slightly higher tannin concentrations (IC50 approximately 3 microM), whereas inhibitory effects by ellagic acid were observed at much greater concentrations (IC50 > 300 microM) than the EC50. A complex relationship between compound, SR protein, and MgATP concentration is a major determining factor in the observed effects. Stimulation was only observed under conditions of phospholamban regulation, while the inhibitory effects were observed in cardiac SR at micromolar Ca2+ and in skeletal muscle SR, which lacks phospholamban. Maximal stimulation of Ca2+ATPase was identical to that observed with the anti-phospholamban monoclonal antibody 1D11. Both compounds appear to relieve the Ca2+ATPase from phospholamban inhibition, thereby increasing the calcium sensitivity of the Ca2+ATPase like that observed with phosphorylation of phospholamban or treatment with monoclonal antibody 1D11. Tannin, even under stimulatory conditions, is a competitive inhibitor of MgATP with a linear Dixon plot. The subsequent inhibitory action of higher tannin concentrations results from competition of tannin with the nucleotide binding site of the Ca2+ATPase. In contrast, ellagic acid produced a curvilinear Dixon plot suggesting partial inhibition of nucleotide activation. The data suggest that nucleotide activation of Ca2+ATPase is functionally coupled to the phospholamban interaction site. These compounds through their interaction with the adenine binding domain of the nucleotide binding site prevent or dissociate phospholamban regulation. Clearly, this portion of Ca2+ATPase needs further study to elucidate its role in phospholamban inhibition.

Increased apoptosis during papilloma development in mice susceptible to tumor progression.

Programmed cell death (apoptosis) is known to occur not only during normal development and tissue remodeling but also during neoplasia. Despite the suggested role of apoptosis in preventing the proliferation of malignant cells, a positive correlation between tumor progression and the presence of apoptotic cells has been found in different types of cancer, including epithelial tumors. In normal mouse skin, the role of apoptosis is not completely understood, and it has been suggested that terminal differentiation may be a special case of apoptosis. In the work reported here, we counted apoptotic cells in mouse skin tumors generated with a two-stage chemical carcinogenesis protocol. We analyzed papillomas from outbred SENCAR mice at different times during promotion, and to better determine the correlation between apoptosis and tumor progression, we compared papillomas generated from two inbred strains derived from the SENCAR stock that differ in their susceptibility to tumor progression. Our results showed that in mouse skin chemical carcinogenesis, the number of apoptotic cells was greater in papillomas that may have been in the process of progressing to squamous cell carcinomas. This conclusion is also supported by the fact that papillomas from SENCAR P/Bt. mice, a tumor progression-susceptible strain derived from outbred SENCAR mice, had more apoptotic cells than papillomas from progression-resistant SSIN mice.

Dissociation of phospholamban regulation of cardiac sarcoplasmic reticulum Ca2+ATPase by quercetin.

Quercetin had a biphasic effect on Ca2+ uptake and calcium-stimulated ATP hydrolysis in isolated cardiac sarcoplasmic reticulum (SR). Stimulation of Ca2+ATPase was observed at low quercetin concentrations (<25 microM) followed by inhibition at higher concentrations. The effects were dependent upon the SR protein concentration, the MgATP concentration, and intact phospholamban regulation of cardiac Ca2+ATPase. Only the inhibitory effects at higher quercetin concentrations were observed in skeletal muscle SR which lacks phospholamban and in cardiac SR treated to remove phospholamban regulation. Stimulation was additive with monoclonal antibody 1D11 (directed against phospholamban) at submaximal antibody concentrations; however, the maximal antibody and quercetin stimulation were identical. Quercetin increased the calcium sensitivity of the Ca2+ATPase like that observed with phosphorylation of phospholamban or treatment with monoclonal antibody 1D11. In addition, low concentrations of quercetin increased the steady-state formation of phosphoenzyme from ATP or Pi, but higher quercetin decreased phosphoenzyme levels. Quercetin, even under stimulatory conditions, was a competitive inhibitor of ATP, but appears to relieve the Ca2+ATPase from phospholamban inhibition, thereby, producing an activation. The subsequent inhibitory action of higher quercetin concentrations results from competition of quercetin with the nucleotide binding site of the Ca2+ATPase. The data suggest that quercetin interacts with the nucleotide binding site to mask phospholamban's inhibition of the SR Ca2+ATPase and suggests that phospholamban may interact at or near the nucleotide binding site.