Sudden Unexpected Postnatal Collapse: Review and Management.

Sudden unexpected postnatal collapse (SUPC) of healthy newborns is a catastrophic event caused by cardiorespiratory collapse in a healthy newborn. The most common cause of SUPC is poor positioning of the newborn during skin-to-skin contact or breastfeeding when the newborn is not being observed by a health professional, attentive parent, or caretaker. Maternal/newborn health care professionals need to know about the essential information, definitions, incidence, risk factors, clinical presentation, outcomes, and prevention and management strategies to minimize the occurrence and impact of SUPC. A sample SUPC hospital policy is included in the manuscript.

Exposure to statin therapy decreases the incidence of venous thromboembolism after trauma.

INTRODUCTION: Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in trauma patients, despite chemoprophylaxis. Statins have been shown capable of acting upon the endothelium. We hypothesized that statin therapy in the pre- or in-hospital settings leads to a decreased incidence of VTE. METHODS: We conducted a retrospective cohort study of injured patients who received statin therapy pre- or in-hospital. Adult, highest-level trauma activation patients admitted January 2018 - June 2022 were included. Patients on prehospital anticoagulants, history of inherited bleeding disorder, and who died within the first 24 hours were excluded. Statin users were matched to non-users by statin use indications including age, current heart and cardiovascular conditions and history, hyperlipidemia, injury severity, and body mass index. Time to in-hospital statin initiation and occurrence of VTE and other complications within 60 days were collected. Differences between groups were determined by univariate, multivariable logistic regression, and Cox proportional hazard analyses. RESULTS: Of 3,062 eligible patients, 79 were statin users that were matched to 79 non-users. There were no differences in admissions demographics, vital signs, injury pattern, transfusion volumes, lengths of stay, or mortality between groups. The overall VTE incidence was 10.8% (17/158). Incidence of VTE in statin users was significantly lower (3%) than non-users (19%; P = 0.003). Differences between statin users and non-users were observed for rates of DVT (0% vs 9%), PE (3% vs 15%), and sepsis (0% vs 5%). Exposure to statins was associated with an 82% decreased risk of developing VTE (hazard ratio = 0.18, 95% CI 0.04 - 0.86; P = 0.033). CONCLUSIONS: Statin exposure was associated with decline in VTE and lower individual rates of DVT, PE, and sepsis. Our findings indicate that statins should be evaluated further as a possible adjunctive therapy for VTE chemoprophylaxis after traumatic injury. LEVEL OF EVIDENCE AND STUDY TYPE: Level III, Retrospective Cohort Study.

Treatment of Chronic Hypertrophic Burn Scars With a Fractional CO 2 Laser Is Well Tolerated in an Outpatient Clinic Setting.

INTRODUCTION: The necessity of treating hypertrophic burn scars has expanded significantly with increased burn survivorship. Ablative lasers, such as carbon dioxide (CO 2 ) lasers, have been the most common nonoperative option for improving functional outcomes in severe recalcitrant hypertrophic burn scars. However, the overwhelming majority of ablative lasers used for this indication require a combination of systemic analgesia, sedation, and/or general anesthesia due to the painful nature of the procedure. More recently, the technology of ablative lasers has advanced and is more tolerable than their first-generation counterparts. Herein, we hypothesized that refractory hypertrophic burn scars can be treated by a CO 2 laser in an outpatient clinic. METHODS: We enrolled 17 consecutive patients with chronic hypertrophic burn scars that were treated with a CO 2 laser. All patients were treated in the outpatient clinic with a combination of a topical solution (23% lidocaine and 7% tetracaine) applied to the scar 30 minutes before the procedure, Cryo 6 air chiller by Zimmer, and some patients received a mixture of N 2 O/O 2 . Laser treatments were repeated every 4 to 8 weeks until the patient's goals were met. Each patient completed a standardized questionnaire to assess tolerability and patient satisfaction of functional results. RESULTS: All patients tolerated the laser well in the outpatient clinic setting, with 0% indicating "not tolerable," 70.6% "tolerable," and 29.4% "very tolerable." Each patient received more than 1 laser treatment for the following complaints: decreased range of motion (n = 16, 94.1%), pain (n = 11, 64.7%), or pruritis (n = 12, 70.6%). Patients were also satisfied with the results of the laser treatments ("no improvement or worsened" = 0%, "improved" = 47.1%, and "significant improvement" = 52.9%). The age of patient, type of burn, location of burn, presence of skin graft, or age of scar did not significantly affect the tolerability of treatment or satisfaction of outcome. CONCLUSIONS: The treatment of chronic hypertrophic burn scars with a CO 2 laser is well tolerated in an outpatient clinic setting in select patients. Patients reported a high level of satisfaction with notable improvement in functional and cosmetic outcomes.

Sleep Latency and Post-Traumatic Stress Disorder Among Retired Career Florida Firefighters: Evidence From the Advancing Epidemiology of Retired Firefighters Aging Longitudinally Cohort.

OBJECTIVE: Our objective was to estimate the association of post-traumatic stress disorder (PTSD) and sleep latency among retired firefighters. METHODS: Baseline health survey data collected from retried career Florida firefighters participating in an ongoing prospective cohort study from 2017 to 2021 were analyzed. Risk for PTSD was assessed using a four-item primary care PTSD screening construct, and sleep onset latency was assessed by self-reported length of time to fall asleep. RESULTS: Among the 500 participants, 8.0% screened positive for PTSD risk and 37.6% had prolonged sleep onset latency (≥20 minutes to fall asleep). Retired firefighters with PTSD risk were 2.7 times more likely (adjusted odds ratio, 2.70; 95% confidence interval, 1.27-5.75) to have prolonged sleep latency compared with those without PTSD risk while controlling for covariates. CONCLUSIONS: Retired firefighters who screen positive for PTSD risk are three times more likely to report delayed sleep onset latency.

Histomorphometric and microarchitectural analysis of bone in metastatic breast cancer patients.

BACKGROUND: Despite widespread use of repeated doses of potent bone-targeting agents (BTA) in oncology patients, relatively little is known about their in vivo effects on bone homeostasis, bone quality, and bone architecture. Traditionally bone quality has been assessed using a trans-iliac bone biopsy with a 7 mm "Bordier" core needle. We examined the feasibility of using a 2 mm "Jamshidi™" core needle as a more practical and less invasive technique. METHODS: Patients with metastatic breast cancer on BTAs were divided according to the extent of bone metastases. They were given 2 courses of tetracycline labeling and then underwent a posterior trans-iliac trephine biopsy and bone marrow aspirate. Samples were analyzed for the extent of tumor invasion and parameters of bone turnover and bone formation by histomorphometry. RESULTS: Twelve patients were accrued, 1 had no bone metastases, 3 had limited bone metastases (LSM) (<3 lesions) and 7 had extensive bone metastases (ESM) (>3 lesions). Most of the primary tumors were estrogen receptor (ER)/progesterone receptor (PR) positive. The procedure was well tolerated. The sample quality was sufficient to analyze bone trabecular structure and bone turnover by histomorphometry in 11 out of 12 patients. There was a good correlation between imaging data and morphometric analysis of tumor invasion. Patients with no evidence or minimal bone metastases had no evidence of tumor invasion. Most had suppressed bone turnover and no detectable bone formation when treated with BTA. In contrast, 6 out of 7 patients with extensive bone invasion by imaging and evidence of tumor cells in the marrow had intense osteoclastic activity as measured by the number of osteoclasts. Of these 7 patients with ESM, 6 were treated with BTA with 5 showing resistance to BTA as demonstrated by the high number of osteoclasts present. 3 of these 6 patients had active bone formation. Based on osteoblast activity and bone formation, 3 out of 6 patients with ESM responded to BTA compared to all 3 with LSM. Compared to untreated patients, all patients treated with BTA showed a trend towards suppression of bone formation, as measured by tetracycline labelling. There was also a trend towards a significant difference between ESM and LSM treated with BTA, highly suggestive of resistance although limited by the small sample size. DISCUSSION: Our results indicate that trans-iliac bone biopsy using a 2 mm trephine shows excellent correlation between imaging assessment of tumor invasion and tumor burden by morphometric analysis of bone tissues. In addition, our approach provides additional mechanistic information on therapeutic response to BTA supporting the current clinical understanding that the majority of patients with extensive bone involvement eventually fail to suppress bone turnover (Petrut B, et al. 2008). This suggests that antiresorptive therapies become less effective as disease progresses.

Dissociating the effect of reward uncertainty and timing uncertainty on neural indices of reward prediction errors: A reward positivity (RewP) event-related potential (ERP) study.

Accurate reward predictions include forecasting both what a reward will be and when a reward will occur. We tested how variations in the certainty of reward outcome and certainty in timing of feedback presentation modulate neural indices of reward prediction errors using the reward positivity (RewP) component of the scalp-recorded brain event-related potential (ERP). In a within-subjects design, seventy-three healthy individuals completed two versions of a cued doors task; one cued the probability of a reward outcome while the other cued the probability of a delay before feedback. Replicating previous results, RewP amplitude was larger for uncertain feedback compared to certain feedback. Additionally, RewP amplitude was differentially associated with uncertainty of presence/absence of reward, but not uncertainty of feedback timing. Findings suggest a dissociation in that RewP amplitude is modulated by reward prediction certainty but is less affected by certainty surrounding timing of feedback.

Prevalence, predictors and outcomes of thyroid dysfunction in patients with acute myocardial infarction: the ThyrAMI-1 study.

PURPOSE: Thyroid dysfunction in patients with cardiac disease is associated with worse outcomes. This study aimed to evaluate the prevalence and analyse predictors and outcomes of thyroid dysfunction in patients presenting with an acute myocardial infarction (AMI). METHODS: A prospective multicentre observational study of patients recruited from six acute hospitals within the North of England. Consecutive patients without previous thyroid disease presenting with both ST-elevation AMI (STEMI) and non-ST-elevation AMI (NSTEMI) were recruited to the Thyroxine in Acute Myocardial Infarction 1 (ThyrAMI-1) cohort study between December 2014 and 2016. Thyroid profile, standard biochemistry measurements and demographic information were obtained within 12 h of admission to hospital. Multivariable logistic regression analyses were performed to assess the predictors of thyroid dysfunction and Cox proportional hazards analyses were utilised to compare all-cause mortality by categories of thyroid dysfunction up to June 2019. RESULTS: Of the 1802 participants analysed, 1440 (79.9%) were euthyroid, 312 (17.3%) had subclinical hypothyroidism (SCH), 22 (1.2%) had subclinical hyperthyroidism (SHyper) and 25 (1.3%) had low T3 syndrome (LT3S). Predictors for SCH were increasing age, female sex, higher thyroid peroxidase antibody (TPOAb) levels, higher serum creatinine levels and early morning sampling time (between 00:01-06:00 h). The predictors of SHyper were lower body mass index and afternoon sampling time (between 12:01 and 18:00 h). Predictors of LT3S were increasing age, higher creatinine levels and presence of previous ischaemic heart disease. Compared to the euthyroid group, patients with LT3S had higher all-cause mortality; adjusted hazard ratio (95% CI) of 2.02 (1.03-3.95), p = 0.04, whereas those with SCH and SHyper did not exhibit significantly increased mortality; adjusted hazard ratios (95% CI) of 1.05 (0.74-1.49), p = 0.79 and 0.27 (0.04-1.95), p = 0.19, respectively. CONCLUSIONS: Thyroid dysfunction is common in AMI patients on admission to hospital and our data provide an understanding regarding which factors might influence thyroid dysfunction in these patients. Furthermore, the negative association between LT3S and increased mortality post-AMI has once again been highlighted by this study. More research is required to assess if treatment of thyroid dysfunction improves clinical outcomes.

Validation of a simplified procedure for convenient and rapid quantification of reduced and oxidized glutathione in human plasma by liquid chromatography tandem mass spectrometry analysis.

Endogenous glutathione (GSH) and glutathione disulfide (GSSG) status is highly sensitive to oxidative conditions and have broad application as a surrogate indicator of redox status in vivo. Established methods for GSH and GSSG quantification in whole blood display limited utility in human plasma, where GSH and GSSG levels are ~3-4 orders of magnitude below those observed in whole blood. This study presents simplified sample processing and analytical LC-MS/MS approaches exhibiting the sensitivity and accuracy required to measure GSH and GSSG concentrations in human plasma samples, which after 5-fold dilution to suppress matrix interferences range from 200 to 500 nm (GSH) and 5-30 nm (GSSG). The utility of the methods reported herein is demonstrated by assay performance and validation parameters which indicate good sensitivity [lower limits of quantitation of 4.99 nm (GSH) and 3.65 nm (GSSG), and high assay precision (intra-assay CVs 3.6 and 1.9%, and inter-assay CVs of 7.0 and 2.8% for GSH and GSSG, respectively). These methods also exhibited exceptional recovery of analyte-spiked plasma samples (98.0 ± 7.64% for GSH and 98.5 ± 12.7% for GSSG). Good sample stability at -80°C was evident for GSH for up to 55 weeks and GSSG for up to 46 weeks, with average CVs <15 and <10%, respectively.

Safety and Efficacy of Using Nuts to Improve Bowel Health in Hemodialysis Patients.

OBJECTIVE: Constipation is common in patients with end-stage kidney disease. Nondrug strategies to manage constipation are challenging because of dietary potassium, phosphate, and fluid restrictions. Nuts are a high-fiber food but are excluded from the diet because of the high potassium and phosphate content. The aim of this study was to examine the safety and efficacy of using nuts to improve constipation in adults undertaking hemodialysis (HD). DESIGN AND METHODS: Adult patients undertaking HD were recruited to this nonrandomized, 10-week repeated measures, within-subject, pragmatic clinical trial, conducted in two HD units. The intervention consisted of consumption of 40g of raw almonds daily for four weeks, followed by a two-week washout and four-week control period. The primary safety outcome measures were change in predialysis serum potassium and phosphate levels. The primary efficacy outcome was reduction in constipation, measured using the Bristol Stool Form Scale and Palliative Care Outcome Scale (POS-S) renal symptom score. Secondary outcomes included quality of life, selected uremic toxins, cognition, gut microbiota profile, and symptom burden. RESULTS: Twenty patients completed the trial (median age: 67 [interquartile range: 57.5-77.8] years, 51% male). After controlling for dialysis adequacy, anuria, dietary intake, bicarbonate, and parathyroid hormone, there were no statistically significant changes in serum potassium (P = 0.21) or phosphate (P = 0.16) associated with daily consumption of almonds. However, statistically significant improvements in constipation were seen at weeks 2, 3, 4, and 10. There were statistically significant improvements in quality of life (P = 0.030), overall symptom burden (P = 0.002), vomiting (P = 0.020), itching (P = 0.006), and skin changes (P = 0.002). CONCLUSION: Daily consumption of almonds for four weeks was safe, effective, and well tolerated. Improvements in quality of life and symptom burden warrant further research to elucidate potential mechanisms. The findings support the potential reinclusion of foods such as nuts into the diet of patients who underwent HD.

Toward a mechanistic and physiological understanding of a ferredoxin:disulfide reductase from the domains Archaea and Bacteria.

Disulfide reductases reduce other proteins and are critically important for cellular redox signaling and homeostasis. Methanosarcina acetivorans is a methane-producing microbe from the domain Archaea that produces a ferredoxin:disulfide reductase (FDR) for which the crystal structure has been reported, yet its biochemical mechanism and physiological substrates are unknown. FDR and the extensively characterized plant-type ferredoxin:thioredoxin reductase (FTR) belong to a distinct class of disulfide reductases that contain a unique active-site [4Fe-4S] cluster. The results reported here support a mechanism for FDR similar to that reported for FTR with notable exceptions. Unlike FTR, FDR contains a rubredoxin [1Fe-0S] center postulated to mediate electron transfer from ferredoxin to the active-site [4Fe-4S] cluster. UV-visible, EPR, and Mössbauer spectroscopic data indicated that two-electron reduction of the active-site disulfide in FDR involves a one-electron-reduced [4Fe-4S]1+ intermediate previously hypothesized for FTR. Our results support a role for an active-site tyrosine in FDR that occupies the equivalent position of an essential histidine in the active site of FTR. Of note, one of seven Trxs encoded in the genome (Trx5) and methanoredoxin, a glutaredoxin-like enzyme from M. acetivorans, were reduced by FDR, advancing the physiological understanding of FDR's role in the redox metabolism of methanoarchaea. Finally, bioinformatics analyses show that FDR homologs are widespread in diverse microbes from the domain Bacteria.

Effects on bone resorption markers of continuing pamidronate or switching to zoledronic acid in patients with high risk bone metastases from breast cancer.

BACKGROUND: Switching patients who remain at high risk of skeletal related events (SREs) despite pamidronate to the more potent bisphosphonate zoledronate, may be an effective treatment strategy. As part of a previously reported clinic study in this setting, we evaluated whether biomarkers for bone resorption, such as Bone-Specific Alkaline Phosphatase (BSAP), bone sialoprotein (BSP), and N-terminal telopeptide (NTX) correlated with subsequent SRE risk. METHODS: Breast cancer patients who remained at high risk of SREs despite at least 3 months of q.3-4 weekly pamidronate were randomized to either continue on pamidronate or to switch to zoledronate (4 mg) once every 4 weeks for 12-weeks. High risk bone metastases were defined by either: occurrence of a prior SRE, bone pain, radiologic progression of bone metastases and/or serum C-terminal telopeptide (CTx) levels > 400 ng/L despite pamidronate use. Serum samples were collected at baseline and weeks 1, 4, 8 and 12 (CTx and BSAP) and baseline and week 12 (NTx and BSP), and all putative biomarkers were measured by ELISA. Follow up was extended to 2 years post trial entry for risk of subsequent SREs. The Kaplan-Meier method was used to estimate time-to-event outcomes. Generalized estimating equations (GEE) were used to evaluate if laboratory values over time or the change in laboratory values from baseline were associated with having a SRE within the time frame of this study. RESULTS: From March 2012 to May 2014, 76 patients were screened, with 73 eligible for enrolment. All 73 patients were available for biochemical analysis, with 35 patients receiving pamidronate and 38 patients receiving zoledronate. The GEE analysis found that no laboratory value was associated with having a subsequent SRE. Interaction between visit and laboratory values was also investigated, but no interaction effect was statistically significant. Only increased number of lines of prior hormonal treatment was associated with subsequent SRE risk. CONCLUSION: Our analysis failed to find any association between serum BSAP, BSP, CTx or NTx levels and subsequent SRE risk in this cohort of patients. This lack of correlation between serum biomarkers and clinical outcomes could be due to influences of prior bisphosphonate treatment or presence of extra-osseous metastases in a significant proportion of enrolled patients. As such, caution should be used in biomarker interpretation and use to direct decision making regarding SRE risk for high risk patients in this setting.

Methanosarcina acetivorans utilizes a single NADPH-dependent thioredoxin system and contains additional thioredoxin homologues with distinct functions.

The thioredoxin system plays a central role in the intracellular redox maintenance in the majority of cells. The canonical system consists of an NADPH-dependent thioredoxin reductase (TrxR) and thioredoxin (Trx), a disulfide reductase. Although Trx is encoded in almost all sequenced genomes of methanogens, its incorporation into their unique physiology is not well understood. Methanosarcina acetivorans contains a single TrxR (MaTrxR) and seven Trx (MaTrx1-MaTrx7) homologues. We previously showed that MaTrxR and at least MaTrx7 compose a functional NADPH-dependent thioredoxin system. Here, we report the characterization of all seven recombinant MaTrxs. MaTrx1, MaTrx3, MaTrx4 and MaTrx5 lack appreciable disulfide reductase activity, unlike previously characterized MaTrx2, MaTrx6 and MaTrx7. Enzyme assays demonstrated that, of the MaTrxs, only the reduction of disulfide-containing MaTrx7 is linked to the oxidation of reduced coenzymes. NADPH is shown to be supplied to the MaTrxR-MaTrx7 system through the oxidation of the primary methanogen electron carriers F420H2 and ferredoxin, indicating that it serves as a primary intracellular reducing system in M. acetivorans. Bioinformatic analyses also indicate that the majority of methanogens likely utilize an NADPH-dependent thioredoxin system. The remaining MaTrxs may have specialized functions. MaTrx1 and MaTrx3 exhibited thiol oxidase activity. MaTrx3 and MaTrx6 are targeted to the membrane of M. acetivorans and likely function in the formation and the reduction of disulfides in membrane and/or extracellular proteins, respectively. This work provides insight into the incorporation of Trx into the metabolism of methanogens, and this reveals that methanogens contain Trx homologues with alternative properties and activities.

A phase 2 trial exploring the clinical and correlative effects of combining doxycycline with bone-targeted therapy in patients with metastatic breast cancer.

BACKGROUND: Bone-targeting agents (BTAs), such as bisphosphonates and denosumab, have demonstrated no discernable effects on tumour response or disease free/overall survival in patients with bone metastases from breast cancer. Doxycycline is both osteotropic and has anti-cancer effects. When combined with zoledronate in animal models, doxycycline showed significantly increased inhibition of tumour burden and increased bone formation. We evaluated the effects of adding doxycycline to ongoing anti-cancer therapy in patients with metastatic breast cancer. METHODS: Breast cancer patients with bone metastases and ≥3 months of BTA use, entered this single-arm study. Patients received doxycycline 100 mg orally, twice a day for 12 weeks. The co-primary endpoints were; effect on validated pain scores (FACT-Bone pain and Brief Pain Inventory) and bone resorption markers (serum C-telopeptide, [sCTx]). All endpoints (pain scores, sCTx, bone-specific alkaline phosphatase, skeletal-related events, toxicity) were evaluated at baseline, 4, 8 and 12 weeks. Bone marrow was sampled at baseline and week 12 for exploratory biomarker analysis. RESULTS: Out of 37 enroled patients, 27 (73%) completed 12 weeks of therapy. No significant changes were seen in pain scores or bone turnover markers. Failure to complete treatment: drug toxicity (70%) and disease progression (30%). Sixteen (43%) patients had GI adverse events. CONCLUSIONS: Doxycycline 100 mg twice daily for 12 weeks had no significant effects on either bone pain or bone turnover markers. Its toxicity profile in this patient population would make further evaluation challenging.

Estrogen, progesterone, and HER2/neu receptor discordance between primary and metastatic breast tumours-a review.

Discordance in estrogen (ER), progesterone (PR), and HER2/neu status between primary breast tumours and metastatic disease is well recognized. In this review, we highlight how receptor discordance between primary tumours and paired metastasis can help elucidate the mechanism of metastasis but can also effect patient management and the design of future trials. Discordance rates and ranges were available from 47 studies (3384 matched primary and metastatic pairs) reporting ER, PR, and HER2/neu expression for both primary and metastatic sites. Median discordance rates for ER, PR, and HER2/neu were 14 % (range 0-67 %, IQR 9-25 %), 21 % (range 0-62 %, IQR 15-41 %), and 10 % (range 0-44 %, IQR 4-17 %), respectively. Loss of receptor expression was more common (9.17 %) than gain (4.51 %). Discordance rates varied amongst site of metastasis with ER discordance being highest in bone metastases suggesting that discordance is a true biological phenomenon. Discordance rates vary for both the biomarker and the metastatic site. Loss of expression is more common than gain. This can affect patient management as it can lead to a reduction in both the efficacy and availability of potential therapeutic agents. Future studies are recommended to explore both the mechanisms of discordance as well as its impact on patient outcome and management.

Mechanisms of Functional Hypoconnectivity in the Medial Prefrontal Cortex of Mecp2 Null Mice.

Frontal cortical dysfunction is thought to contribute to cognitive and behavioral features of autism spectrum disorders; however, underlying mechanisms are poorly understood. The present study sought to define how loss of Mecp2, the gene mutated in Rett syndrome (RTT), disrupts function in the murine medial prefrontal cortex (mPFC) using acute brain slices and behavioral testing. Compared with wildtype, pyramidal neurons in the Mecp2 null mPFC exhibit significant reductions in excitatory postsynaptic currents, the duration of excitatory UP-states, evoked population activity, and the ratio of NMDA:AMPA currents, as well as an increase in the relative fraction of NR2B currents. These functional changes are associated with reductions in the density of excitatory dendritic spines, the ratio of vesicular glutamate to GABA transporters and GluN1 expression. In contrast to recent reports on circuit defects in other brain regions, we observed no effect of Mecp2 loss on inhibitory synaptic currents or expression of the inhibitory marker parvalbumin. Consistent with mPFC hypofunction, Mecp2 nulls exhibit respiratory dysregulation in response to behavioral arousal. Our data highlight functional hypoconnectivity in the mPFC as a potential substrate for behavioral disruption in RTT and other disorders associated with reduced expression of Mecp2 in frontal cortical regions.

Jun N-terminal kinase activity is required for invagination but not differentiation of the sea urchin archenteron.

Although sea urchin gastrulation is well described at the cellular level, our understanding of the molecular changes that trigger the coordinated cell movements involved is not complete. Jun N-terminal kinase (JNK) is a component of the planar cell polarity pathway and is required for cell movements during embryonic development in several animal species. To study the role of JNK in sea urchin gastrulation, embryos were treated with JNK inhibitor SP600125 just prior to gastrulation. The inhibitor had a limited and specific effect, blocking invagination of the archenteron. Embryos treated with 2 µM SP600125 formed normal vegetal plates, but did not undergo invagination to form an archenteron. Other types of cell movements, specifically ingression of the skeletogenic mesenchyme, were not affected, although the development and pattern of the skeleton was abnormal in treated embryos. Pigment cells, derived from nonskeletogenic mesenchyme, were also present in SP600125-treated embryos. Despite the lack of a visible archenteron in treated embryos, cells at the original vegetal plate expressed several molecular markers for endoderm differentiation. These results demonstrate that JNK activity is required for invagination of the archenteron but not its differentiation, indicating that in this case, morphogenesis and differentiation are under separate regulation.

The Methanosarcina acetivorans thioredoxin system activates DNA binding of the redox-sensitive transcriptional regulator MsvR.

The production of biogas (methane) by an anaerobic digestion is an important facet to renewable energy, but is subject to instability due to the sensitivity of strictly anaerobic methanogenic archaea (methanogens) to environmental perturbations, such as oxygen. An understanding of the oxidant-sensing mechanisms used by methanogens may lead to the development of more oxidant tolerant (i.e., stable) methanogen strains. MsvR is a redox-sensitive transcriptional regulator that is found exclusively in methanogens. We show here that oxidation of MsvR from Methanosarcina acetivorans (MaMsvR) with hydrogen peroxide oxidizes cysteine thiols, which inactivates MaMsvR binding to its own promoter (P(msvR)). Incubation of oxidized MaMsvR with the M. acetivorans thioredoxin system (NADPH, MaTrxR, and MaTrx7) results in reduction of the cysteines back to thiols and activation of P msvR binding. These data confirm that cysteines are critical for the thiol-disulfide regulation of P(msvR) binding by MaMsvR and support a role for the M. acetivorans thioredoxin system in the in vivo activation of MaMsvR. The results support the feasibility of using MaMsvR and P(msvR), along with the Methanosarcina genetic system, to design methanogen strains with oxidant-regulated gene expression systems, which may aid in stabilizing anaerobic digestion.

Neoadjuvant endocrine therapy and window of opportunity trials: new standards in the treatment of breast cancer?

Until recently, the use of neoadjuvant endocrine therapy was mainly restricted to those patients whose general frailty or comorbidities were contraindications to surgery. There is now increased evidence that certain patient populations (i.e. older patients with hormone-receptor positive disease) can gain as good a pathologic response, with considerably less toxicity, from neoadjuvant endocrine therapy than from neoadjuvant chemotherapy. Optimization of neoadjuvant endocrine therapy is therefore an important therapeutic goal. However, possibly of greater importance in the overall management of breast cancer, is the increased interest in exploring the effects of brief periods of endocrine therapy on in vivo biomarkers, in so called window of opportunity trials. These trials can not only be used to identify the mechanisms of action of novel agents but also to predict optimal subsequent adjuvant therapy for individual patients. While this paper will briefly review the history of neoadjuvant endocrine therapy, more emphasis will be on the evaluation of pivotal window of opportunity trials that will likely lead to a long awaited paradigm shift in the management of breast cancer.

Molecular characterization of the thioredoxin system from Methanosarcina acetivorans.

The thioredoxin system, composed of thioredoxin reductase (TrxR) and thioredoxin (Trx), is widely distributed in nature, where it serves key roles in electron transfer and in the defense against oxidative stress. Although recent evidence reveals Trx homologues are almost universally present among the methane-producing archaea (methanogens), a complete thioredoxin system has not been characterized from any methanogen. We examined the phylogeny of Trx homologues among methanogens and characterized the thioredoxin system from Methanosarcina acetivorans. Phylogenetic analysis of Trx homologues from methanogens revealed eight clades, with one clade containing Trxs broadly distributed among methanogens. The Methanococci and Methanobacteria each contain one additional Trx from another clade, respectively, whereas the Methanomicrobia contain an additional five distinct Trxs. Methanosarcina acetivorans, a member of the Methanomicrobia, contains a single TrxR (MaTrxR) and seven Trx homologues (MaTrx1-7), with representatives from five of the methanogen Trx clades. Purified recombinant MaTrxR had 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) reductase and oxidase activities. The apparent Km value for NADPH was 115-fold lower than that for NADH, consistent with NADPH as the physiological electron donor to MaTrxR. Purified recombinant MaTrx2, MaTrx6 and MaTrx7 exhibited dithiothreitol- and lipoamide-dependent insulin disulfide reductase activities. However, only MaTrx7, which is encoded adjacent to MaTrxR, could serve as a redox partner to MaTrxR. These results reveal that M. acetivorans harbors at least three functional and distinct Trxs, and a complete thioredoxin system composed of NADPH, MaTrxR and at least MaTrx7. This is the first characterization of a complete thioredoxin system from a methanogen, which provides a foundation to understand the system in methanogens.

Incidence, consequences and treatment of bone metastases in breast cancer patients-Experience from a single cancer centre.

BACKGROUND: There is a paucity of literature about the benefits of bone-targeted agents for breast cancer patients with bone metastases treated in the non-trial setting. We explored the incidence, consequences, and treatment of bone metastases at a single cancer centre. METHODS: Electronic records of metastatic breast cancer patients were reviewed and pertinent information was extracted. RESULTS: Of 264 metastatic breast cancer patients, 195 (73%) developed bone metastases. Of these patients, 176 were eligible for analysis. Median age at bone metastases diagnosis was 56.9 years (IQR 48-67) and initial presentation of bone metastases included asymptomatic radiological findings (58%), bone pain (40%), or a SRE (12.5%). Most patients (88%) received a bone-targeted agent, starting a median of 1.5 months (IQR 0.8-3.30) after bone metastasis diagnosis. 62% of patients had ≥1 SRE. The median time from bone metastasis diagnosis to first SRE was 1.8 months (IQR 0.20-8.43 months). Median number of SREs per patient was 1.5 (IQR 0-3). Overall, 26.8% of all SREs were clinically asymptomatic. Within the entire cohort, 51% required opioids and 20% were hospitalized due to either an SRE or bone pain. CONCLUSIONS: Despite extensive use of bone-targeted agents, the incidence of SREs remains high. Nearly half of SREs occur prior to starting a bone-targeted agent. Use of opioids and hospitalizations secondary to bone metastases remain common. More effective treatment options are clearly needed.