Reducing the carbon footprint of general anaesthesia: a comparison of total intravenous anaesthesia vs. a mixed anaesthetic strategy in 47,157 adult patients.

Global warming is a major public health concern. Volatile anaesthetics are greenhouse gases that increase the carbon footprint of healthcare. Modelling studies indicate that total intravenous anaesthesia is less carbon intensive than volatile anaesthesia, with equivalent quality of care. In this observational study, we aimed to apply the findings of previous modelling studies to compare the carbon footprint per general anaesthetic of an exclusive TIVA strategy vs. a mixed TIVA-volatile strategy. This comparative retrospective study was conducted over 2 years in two French hospitals, one using total intravenous anaesthesia only and one using a mixed strategy including both intravenous and inhalation anaesthetic techniques. Based on pharmacy procurement records, the quantity of anaesthetic sedative drugs was converted to carbon dioxide equivalents. The primary outcome was the difference in carbon footprint of hypnotic drugs per intervention between the two strategies. From 1 January 2021 to 31 December 2022, 25,137 patients received general anaesthesia in the hospital using the total intravenous anaesthesia strategy and 22,020 in the hospital using the mixed strategy. The carbon dioxide equivalent footprint of hypnotic drugs per intervention in the hospital using the total intravenous anaesthesia strategy was 20 times lower than in the hospital using the mixed strategy (emissions of 2.42 kg vs. 48.85 kg carbon dioxide equivalent per intervention, respectively). The total intravenous anaesthesia strategy significantly reduces the carbon footprint of hypnotic drugs in general anaesthesia in adult patients compared with a mixed strategy. Further research is warranted to assess the risk-benefit ratio of the widespread adoption of total intravenous anaesthesia.

[Association between the violence in the community and the aggressive behaviors of psychotics during their hospitalizations]. / Relation entre la violence intra-hospitalière des patients avec psychoses et la violence dans la communauté.

BACKGROUND: Violence is a common issue in psychiatry and has multiple determiners. The aim of this study is to assess the psychotic inpatients' violence in association with the violence of the neighborhood from which the patients are drawn and to estimate the impact of this environmental factor with regard to other factors. METHOD: A prospective multicenter study was led in nine French cities. Eligible patients were psychotic involuntary patients hospitalized in the cities' psychiatric wards. During their treatments, any kind of aggressive behavior by the patients has been reported by the Overt Aggression Scale (OAS). RESULTS: From June 2010 to May 2011, 95 patients have been included. Seventy-nine per cent of the patients were violent during their hospitalizations. In a bivariate analysis, inpatient violence was significantly associated with different factors: male gender, patient violence history, substance abuse, manic or mixed disorder, the symptoms severity measured by the BPRS, the insight degree and the city crime rate. In a multivariate analysis, the only significant factors associated with the patients' violence were substance abuse, the symptoms severity and the crime rates from the different patients' cities. CONCLUSION: These results suggest that violence within the psychotic patients' neighborhood could represent a risk of violence during their treatments.

Ultrasonographic measurement of antral area for estimating gastric fluid volume in parturients.

BACKGROUND: The aim of this prospective observational study was to assess the performance of ultrasonographic gastric antral area (GAA) to predict gastric fluid volumes of >0.4, >0.8 and >1.5 ml kg(-1), in fasted women in established labour. METHODS: A first ultrasound examination of the antrum was performed, in order to confirm gastric vacuity by using a qualitative score. Baselines GAA measurements were obtained in both supine and right lateral decubitus positions. Thereafter, parturients were allowed to drink clear fluids only. Measurement of GAA was repeated 15 min after last fluid intake, in both supine and right lateral positions. Receiver operating characteristics (ROC) curves were constructed to determine the accuracy of GAA to diagnose ingested volumes of >0.4, >0.8 and >1.5 ml kg(-1). RESULTS: Data from forty parturients were analysed. The areas under the ROC curves ranged from 80% to 86%. The cut-off value for antral area measured in supine position, to detect a volume >0.4 ml kg(-1), was 387 mm(2), with a sensitivity of 87%, a specificity of 70% and a negative predictive value of 85%. A cut-off value of 608 mm(2) predicted a fluid volume >1.5 ml kg(-1), with a specificity of 94%, a sensitivity of 75% and a negative predictive value of 92%. CONCLUSIONS: This study provides cut-off values for GAA that could be used in addition to the qualitative assessment of the antrum to define a full stomach in labouring patients.

Interim estimates of 2013/14 influenza clinical severity and vaccine effectiveness in the prevention of laboratory-confirmed influenza-related hospitalisation, Canada, February 2014.

During the 2013/14 influenza season in Canada, 631 of 654 hospitalisations for laboratory-confirmed influenza enrolled in sentinel hospitals were due to Influenza A. Of the 375 with known subtype, influenza A(H1N1) accounted for 357. Interim unmatched vaccine effectiveness adjusted for age and presence of one or more medical comorbidities was determined by test-negative case-control design to be 58.5% (90% confidence interval (CI): 43.9-69.3%) overall and 57.9% (90% CI: 37.7-71.5) for confirmed influenza A(H1N1).

Modelling the impact of compliance with dietary recommendations on cancer and cardiovascular disease mortality in Canada.

OBJECTIVES: Despite strong evidence indicating that unbalanced diets relate to chronic diseases and mortality, most adults do not comply with dietary recommendations. To help determine which recommendations could yield the most benefits, the number of deaths attributable to cardiovascular diseases and cancer that could be delayed or averted in Canada if adults changed their diet to adhere to recommendations were estimated. STUDY DESIGN: Macrosimulation based on national population-based survey and vital statistics data. METHODS: A macrosimulation model was used to draw age- and sex-specific changes in relative risks based on the results of meta-analyses of relationship between food components and risk of cardiovascular disease and diet-related cancers. Inputs in the model included Canadian recommendations (fruit and vegetable, fibre, salt, and total-, monounsaturated-, polyunsaturated-, saturated-, and trans-fats), average dietary intake (from 35,107 participants with 24-h recall), and mortality from specific causes (from Canadian Vital Statistics). Monte Carlo analyses were used to compute 95% credible intervals (CI). RESULTS: The estimates of this study suggest that 30,540 deaths (95% CI: 24,953, 34,989) per year could be averted or delayed if Canadians adhered to their dietary recommendations. By itself, the recommendation for fruit and vegetable intake could save as many as 72% (55-87%) of these deaths. It is followed by recommendations for fibres (29%, 13-43%) and salt (10%, 9-12%). CONCLUSIONS: A considerable number of lives could be saved if Canadians adhered to the national dietary intake recommendations. Given the scarce resources available to promote guideline adhesion, priority should be given to recommendations for fruit and vegetable intake.

Mechanisms of T cell evasion by Epstein-Barr virus and implications for tumor survival.

Epstein-Barr virus (EBV) is a prevalent oncogenic virus estimated to infect greater than 90% of the world's population. Following initial infection, it establishes latency in host B cells. EBV has developed a multitude of techniques to avoid detection by the host immune system and establish lifelong infection. T cells, as important contributors to cell-mediated immunity, make an attractive target for these immunoevasive strategies. Indeed, EBV has evolved numerous mechanisms to modulate T cell responses. For example, it can augment expression of programmed cell death ligand-1 (PD-L1), which inhibits T cell function, and downregulates the interferon response, which has a strong impact on T cell regulation. It also modulates interleukin secretion and can influence major histocompatibility complex (MHC) expression and presentation. In addition to facilitating persistent EBV infection, these immunoregulatory mechanisms have significant implications for evasion of the immune response by tumor cells. This review dissects the mechanisms through which EBV avoids detection by host T cells and discusses how these mechanisms play into tumor survival. It concludes with an overview of cancer treatments targeting T cells in the setting of EBV-associated malignancy.

The impact of patients as trainers on registered nurses' patient engagement in primary care clinics: a qualitative study.

BACKGROUND: In Canada, primary care is usually the front door to health care for people with health issues. Among these primary care services are primary care clinics (PCC), where the competencies of registered nurses (RNs) are needed. However, nursing practice in PCCs is variable and sometimes suboptimal from one PCC to another. In 2019, the Quebec Ministry of Health and Social Services deployed a practical guide for RNs practicing in PCCs. This guide was intended to support best professional and interprofessional practices and enhance the quality of services offered according to a physical-social vision of care, interprofessional collaboration and partnership with the patient. The Formation de formateurs en première ligne (F2PL) project team developed a train-the-trainer educational intervention to support RNs in assimilating the content of this guide. This educational intervention is uncommon because it includes patients as trainers (PTs). PTs developed and provided andragogic content about patient's experience to enhance patient engagement. OBJECTIVE: To describe the impacts of the educational intervention provided by the PTs in nurses' patient engagement practices in PCCs. METHODS: A descriptive qualitative approach was used to describe in-depth changes in RNs' practices. Individual interviews were conducted with 10 RNs and 3 PTs to explore the changes in RNs' practice and the barriers and facilitators to adopting this new practice. An inductive and deductive thematic analysis was carried out according to a conceptual model of patient engagement (the Montreal Model), and emerging themes were condensed into propositions. To ensure credibility, a peer review was conducted with the F2PL team, which includes a patient co-leader. RESULTS: The educational intervention provided by PTs has impacted RNs' practice in 3 ways: awareness or reminding of general principles, updating commitment to already known principles and enhancing the development of new professional skills. CONCLUSIONS: PTs could effectively support the RNs' motivation to use patient engagement practices in primary care.

Magnetic phase diagram of CuO via high-resolution ultrasonic velocity measurements.

High-resolution ultrasonic velocity measurements have been used to determine the temperature-magnetic-field phase diagram of the monoclinic multiferroic CuO. A new transition at T(N3)=230 K, corresponding to an intermediate state between the antiferromagnetic noncollinear spiral phase observed below T(N2)=229.3 K and the paramagnetic phase, is revealed. Anomalies associated with a first order transition to the commensurate collinear phase are also observed at T(N1)=213 K. For fields with B || b, a spin-flop transition is detected between 11 T-13 T at lower temperatures. Moreover, our analysis using a Landau-type free energy clearly reveals the necessity for an incommensurate collinear phase between the spiral and the paramagnetic phase. This model is also relevant to the phase diagrams of other monoclinic multiferroic systems.

Regulating Brownian fluctuations with tunable microscopic magnetic traps.

A major challenge to achieving positional control of fluid borne submicron sized objects is regulating their Brownian fluctuations. We present a magnetic-field-based trap that regulates the thermal fluctuations of superparamagnetic beads in suspension. Local domain-wall fields originating from patterned magnetic wires, whose strength and profile are tuned by weak external fields, enable the bead trajectories within the trap to be managed and easily varied between strong confinements and delocalized spatial excursions that are described remarkably well by simulations.

Seasonal variations in the levels of PAH-DNA adducts in young adults living in Mexico City.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous components of polluted air. The Mexico City Metropolitan Area (MCMA), one of the most densely populated areas in the world, is 2240 m above sea level. At this altitude, less oxygen is available, making combustion less efficient and therefore producing more PAH pollutants. According to the Automatic Monitoring Network in Mexico City (RAMA, for its Spanish initials; http://www.sma.df.gob.mx/simat2/informaciontecnica/index.php?opcion=5&opciondifusion_bd=90), which performs environmental monitoring, the critical air pollutants in Mexico City are ozone and particulate matter (PM). PM emissions increase during the dry season (winter to spring) and decrease during the rainy season (summer to autumn). The bioactivation of some PAHs produces reactive metabolites that bind to DNA, and the presence of elevated levels of PAH-DNA adducts in tissues such as blood lymphocytes represents an elevated risk for the development of cancer. We have compared the levels of PAH-DNA adducts and the percentage of cells with chromosomal aberrations (CWAs) using a matched set of peripheral blood lymphocytes obtained on two separate occasions from young non-smoking inhabitants of the MCMA (n = 92) during the 2006 dry season and the following rainy season. PAH-DNA adducts were analysed using the r7, t8-dihydroxy-t-9, 10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE)-DNA chemiluminescence immunoassay (CIA). The percentages of CWA were determined in cultured lymphocytes from the same individuals. Both DNA adduct levels and chromosomal aberrations were tested for correlation with lifestyle and the polymorphisms of cytochromes P450 CYP1A1 and CYP1B1 as well as glutathione-S-transferases GSTM1 and GSTT1. The levels of PAH-DNA adducts were significantly higher (P < 0.001) in the dry season (10.66 ± 3.05 per 10(9) nt, n = 92) than during the rainy season (9.50 ± 2.85 per 10(9) nt, n = 92) and correlated with the seasonal levels of particulate matter with a diameter of ≤ 10 µm (PM(10)). The percentage of CWA was not seasonally related; however, significant associations between the number of risk alleles and adduct levels in the dry (R = 0.298, P = 0.048) and in the wet seasons (R = 0.473, P = 0.001) were observed.

Nuclear bud formation: a novel manifestation of Zidovudine genotoxicity.

Normal diploid somatic mammalian cell division generates 2 daughter cells as a result of a strict and well-controlled mitotic process. However, some defects during the progression of that process could generate an unbalanced distribution of chromosomes, aneuploidy and eventually, a malignant phenotype. Previous observations using a transgenic mouse model with diminished DNA repair capacity revealed the presence of nuclear buds (NBs) induced in vitro by the nucleoside analog zidovudine (Retrovir(R), 3'-azido-3'-deoxythymidine, AZT). Here we used bone marrow mesenchymal cells, taken from mice with the Xpa(-/-)Trp53(+/-) genotype, that were cultured and exposed to 0 and 100 muM AZT for 24 hours. Fixed and denatured cells were processed by fluorescence in situ hybridization (FISH) with whole chromosome painting probes used to identify chromosomes in cells growing on glass chamber slides (2 probes/slide). A variety of sizes and shapes of NBs were observed. Some NBs had a large connection with the main nucleus (>(1/4) of the NB diameter), others hada smaller connection (<(1/4) of the NB diameter), some were circular and positioned close to the nucleus, while some resided in the cytoplasm separated from the nucleus or connected by a thin chromatin strand. We had hypothesized that NBs would progress in the process of budding until separation occurred, but this was not proven by time-lapse photography studies performed for 20 hours. From 1,126 cells scored in the unexposed cultures, 10.39 % of cells carried NBs, while from 1,108 cells scored in the AZT-exposed cultures 29.16% of cells carried NBs (p = 0.001). In AZT-exposed cells there were a total of 322 NBs scored; 46.6% or 150 NBs contained positive signals for one or both probes used, while 53% or 172 NBs had no probe signal. In addition, FISH analysis showed no preferential localization of any chromosome within the NBs. Among the NBs that carried no probe signal, the presence of positive signals with inversion of DAPI imaging demonstrated centromeric content. It has been hypothesized that NBs occur as a result of expulsion of amplified DNA from the main nucleus; however, this data demonstrates that NBs may contain any chromosome, suggesting that NBs do not consist of just amplified DNA.

Assessment of SCAR markers to design real-time PCR primers for rhizosphere quantification of Azospirillum brasilense phytostimulatory inoculants of maize.

AIMS: To assess the applicability of sequence characterized amplified region (SCAR) markers obtained from BOX, ERIC and RAPD fragments to design primers for real-time PCR quantification of the phytostimulatory maize inoculants Azospirillum brasilense UAP-154 and CFN-535 in the rhizosphere. METHODS AND RESULTS: Primers were designed based on strain-specific SCAR markers and were screened for successful amplification of target strain and absence of cross-reaction with other Azospirillum strains. The specificity of primers thus selected was verified under real-time PCR conditions using genomic DNA from strain collection and DNA from rhizosphere samples. The detection limit was 60 fg DNA with pure cultures and 4 x 10(3) (for UAP-154) and 4 x 10(4) CFU g(-1) (for CFN-535) in the maize rhizosphere. Inoculant quantification was effective from 10(4) to 10(8) CFU g(-1) soil. CONCLUSION: BOX-based SCAR markers were useful to find primers for strain-specific real-time PCR quantification of each A. brasilense inoculant in the maize rhizosphere. SIGNIFICANCE AND IMPACT OF THE STUDY: Effective root colonization is a prerequisite for successful Azospirillum phytostimulation, but cultivation-independent monitoring methods were lacking. The real-time PCR methods developed here will help understand the effect of environmental conditions on root colonization and phytostimulation by A. brasilense UAP-154 and CFN-535.

[Milnacipran and venlafaxine at flexible doses (up to 200 mg/d) in the outpatient treatment of adults with moderate-to-severe major depressive disorder: a 24-week randomised, double blind exploratory study]. / Milnacipran et venlafaxine à posologie flexible (jusqu'à 200 mg/j) dans le traitement ambulatoire des épisodes dépressifs majeurs modérés à sévères de l'adulte: étude exploratoire de 24 semaines, randomisée en double insu.

INTRODUCTION: Serotonin (HT) and noradrenaline (NA) reuptake inhibitors (SNRIs) are commonly used as first line treatment of major depressive disorders (MDD). As compared to tricyclic antidepressants, they have proved similar efficacy and better tolerability. Milnacipran (MLN) (Ixel) and venlafaxine (VLF) (Effexor) are two SNRIs pharmacologically differing by their NA/HT ratio of potency: 1:1 and 1:30, respectively. OBJECTIVES: To investigate the efficacy and safety/tolerability of MLN and VLF administered at flexible doses (100, 150 or 200 mg/day) for 24 weeks (including 4 weeks of up-titration) in the outpatient treatment of adults with moderate-to-severe MDD. DESIGN: Multicentre, randomised, double blind, 2-parallel-arm, 24-week exploratory trial conducted in France by 50 psychiatrists. DIAGNOSIS AND MAIN INCLUSION CRITERIA: Male or female outpatients, aged 18 to 70, meeting the DSM-IV-TR and related MINI criteria for recurrent, unipolar, moderate-to-severe MDD, with neither psychotic features nor severe suicidal risk. A Montgomery-Asberg depression rating scale (MADRS) score> or =23 was required at inclusion. TREATMENT SCHEDULE: Patients were randomised to receive either MLN or VLF (1:1 ratio) for 24 weeks in double-blind conditions. Regardless of the treatment received, the following dosing schedule was applied: during the initial 4-week up-titration phase, the dosage was progressively increased from 25 mg/day (qd administration) to 150 mg/day (bid administration). At week 4, the dosage was either maintained at 150 mg/day, or adapted to 100 or 200 mg/day, based on the investigator's clinical judgement. At any time during the 20 following treatment weeks, the dose could be lowered for safety concerns until a minimal threshold of 100 mg/day. From Week 24, the dosage was decreased by 50mg/day every five days. After randomisation, eight assessment visits were organised at 2, 4, 6, 8, 12, 18, 24 weeks, and at study end (after the 5-15 days of down-titration and 10 days free of treatment). Efficacy evaluation ratings included the MADRS and global disease severity (CGI-S) total scores. Rates of MADRS response (reduction of initial score> or =50%) and remission (score< or =10) were calculated at Week 8 and Week 24 in the full analysis set as well as in the subgroups of patients with depressive disorder of severe DSM-IV intensity and with a MINI evaluation of suicidal risk (rated as required 'moderate' at the worst). STATISTICAL ANALYSIS: Standard distribution statistics (including mean and standard deviation [S.D.]) of scores and their changes from baseline, were calculated using the observed-case (OC) approach at all assessment times for the MADRS score, and the last-observation-carried-forward (LOCF) at 8 and 24 weeks for both MADRS and CGI-S scores. MADRS response and remission rates at 8 and 24 weeks were calculated using the LOCF approach by normal approximation of the binomial distribution. Bilateral exploratory statistical tests at 5% significance level were performed for results at 8 and 24 weeks of: (i) MADRS score changes from baseline, based on the score progress at each visit (mixed model for repeated measurements [MMRM]), and (ii) global MADRS response and remission rates (Chi(2)). RESULTS AND PATIENTS: A total of 195 patients were randomly assigned MLN (n=97) or VLF (n=98) and 134 (68.7%: 61.9%/MLN and 75.5%/VLF) completed the trial. At the end of the up-titration, patients received 100 mg/day (11.4%/MLN, 10%/VLF), 150 mg/day (30.4%/MLN, 43.8%/VLF), or 200 mg/day (58.2%/MLN, 46.3%/VLF). Totals of 177 patients (90/MLN and 87/VLF) and 181 patients (90/MLN and 91/VLF) were analysed for efficacy and safety, respectively. Treatment groups were similar for baseline characteristics except a higher proportion of MLN patients with a severe depressive episode (63.3% versus 54%). RESULTS AND EFFICACY: MADRS score (mean [S.D.] initial score: 31 [4.5]) progressively decreased all along the treatment course and similarly in both groups (Week 8-OC : -18.8 [7.7]/MLN and -18.6 [7.3]/VLF, p(MMRM)=0.95 ; Week 24-OC : -23.1 [7.8]/MLN and -22.4 [7.3]/VLF, p(MMRM)=0.37 ). At week 8-LOCF, MADRS response rates were similar in both groups (64.4%/MLN, 65.5%/VLF, p(chi2)=0.88) as well as remission rates (42.2%/MLN, 42.5%/VLF p(chi2)=0.97). At week 24 they remained non clinically and statistically different between groups (response rates: 70%/MLN, 77%/VLF, p(chi2)=0.29; remission rates: 52.2%/MLN, 62.1%/VLF, p(chi2)=0.19). In both "severe depressive episode" and "MINI mild or moderate suicidal risk" subgroups (n=104 and 75, respectively), response and remission rates were non clinically different at both time points, however in the "MINI mild-to-moderate suicidal risk" subgroup, MLN tended to be more rapidly active (remission rate at week 8-LOCF: 44.7%/MLN, 35.1%/VLF). The changes in CGI-S were also indicative of a significant improvement of the global illness severity with both treatments. RESULTS AND SAFETY/TOLERABILITY: The tolerability profile of both drugs was in line with their pharmacological activity. About 70% of patients in both groups experienced at least one adverse event (AE). In both groups, the most common AEs were nausea, dizziness, headache and hyperhidrosis, and, in the male patients, genito-urinary problems: orgasmic disorders (VLF only) and dysuria (MLN only). These AEs were mostly responsible for definitive treatment discontinuation for tolerability concerns. None of the 6 serious adverse events (SAEs) on MLN and 4 of the 8 SAEs on VLF were related to the test drug. CONCLUSION: MLN and VLF at flexible doses up to 200 mg/day globally exhibited similar efficacy and tolerability profiles in the long-term treatment of adults with MDD.

Clinical Outcome of Patients with Advanced Biliary Tract Cancer in a Dedicated Phase I Unit.

AIMS: Advanced biliary tract carcinomas (ABC) are malignancies with limited effective therapies for advanced disease. There is little published evidence of outcomes of ABC patients participating in phase I clinical trials. MATERIALS AND METHODS: Patient characteristics, treatment details and outcomes of ABC patients treated at a dedicated phase I unit were captured and analysed from case and trial records. RESULTS: In total, 123 ABC patients were included in the study, of which 48 patients participated in 41 different phase I trials; 75 (61%) did not participate due to rapid disease progression or patient choice. Molecular characterisation of tumours using a targeted panel was conducted in 15 (31%), yielding several potentially actionable mutations, including BRCA, PIK3CA, FGFR, AKT and PTEN loss. Of the 39 evaluable patients there was one exceptional responder. Eighteen (46%) other patients achieved stable disease as their best response, with a clinical benefit rate at 4 months of 10%. Treatment was generally well tolerated with grade 3 or 4 adverse events only observed in eight patients (17 %), of which six were drug related and led to trial discontinuation in one (3%), with no toxicity-related deaths. CONCLUSION: Carefully selected ABC patients have been found to tolerate experimental phase I clinical trials without excess toxicity. The aggressive nature of this disease warrants consideration of early referral to a phase I unit. Future work will require comprehensive molecular profiling in an attempt to understand the biology underlying the exceptional responders and to match patients in real-time to targeted therapies.

Diminished type I collagen synthesis and reduced alpha 1(I) collagen messenger RNA in cultured fibroblasts from patients with dominantly inherited (type I) osteogenesis imperfecta.

Type I osteogenesis imperfecta (OI) is characterized clinically by a moderate fracture frequency with minimal bone deformity and dominant inheritance. Previous studies of the collagenous proteins synthesized by dermal fibroblasts obtained from unrelated patients with this form of OI suggested that the biochemical basis of the disease was reduced production of type I collagen. This study was designed to determine if this biochemical finding segregated with the disease within an individual family. Dermal fibroblast strains were established from three generations of a family having the typical features of type I OI. Analysis of the collagenous proteins made in culture revealed an elevated alpha 1(III) to alpha 1(I) collagen type ratio and an elevated alpha 1(I) to alpha 2(I) collagen chain ratio. The procollagen that accumulated in the medium reflected these ratios to the same degree. Total collagen synthesis was significantly reduced in affected family members. Therefore, the most striking abnormality in affected members was a 50-75% reduction of type I collagen production. Furthermore, the ratio of the alpha 1(I)/alpha 2(I) collagen messenger RNA (mRNA), measured by dot hybridization, was one-half of the value of uninvolved family members and unrelated controls. Since the reduction in the production of type I collagen and the altered alpha 1(I)/alpha 2(I) mRNA ratio clearly segregated with affected individuals within this family, these biochemical measurements may be a useful genetic marker for type I OI.

Quantitation of cis-diamminedichloroplatinum II (cisplatin)-DNA-intrastrand adducts in testicular and ovarian cancer patients receiving cisplatin chemotherapy.

The antitumor activity of cis-diamminedichloroplatinum II (cisplatin) is believed to be related to its covalent interaction with DNA where a major DNA binding product is an intrastrand N7-bidentate adduct on adjacent deoxyguanosines. A novel immunoassay was used to quantitate this adduct in buffy coat DNA from testicular and ovarian cancer patients undergoing cisplatin therapy. 44 out of 120 samples taken from 45 cisplatin patients had detectable cisplatin-DNA adducts. No adducts were detected in 18 samples of DNA taken from normal controls, patients on other chemotherapy, or patients before treatment. The quantity of measurable adducts increased as a function of cumulative dose of cisplatin. This was observed both during repeated daily infusion of the drug and over long-term, repeated 21-28 d cycles of administration. These results suggested that adduct removal is slow even though the tissue has a relatively rapid turnover. Patients receiving cisplatin for the first time on 56-d cycles, and those given high doses of cisplatin as a "salvage" regimen, did not accumulate adducts as rapidly as patients on first time chemotherapy on 21- or 28-d cycles. Disease response data, evaluated for 33 cisplatin-treated patients, showed a positive correlation between the formation of DNA adducts and response to drug therapy. However, more data will be required to confirm this relationship. These data show that specific immunological probes can readily be applied to quantitate DNA adducts in patients undergoing cancer chemotherapy.

Reversible and irreversible unfolding of mitotic newt chromosomes by applied force.

The force-extension behavior of individual mitotic newt chromosomes was studied, using micropipette surgery and manipulation, for elongations up to 80 times native length. After elongations up to five times, chromosomes return to their native length. In this regime chromosomes have linear elasticity, requiring approximately 1 nN of force to be stretched to two times native length. After more than five times stretching, chromosomes are permanently elongated, with force hysteresis during relaxation. If a chromosome is repeatedly stretched to approximately 10 times native length and relaxed, a series of hysteresis loops are obtained that converge to a single reversible elastic response. For further elongations, the linear dependence of force on extension terminates at a force "plateau" of approximately 15-20 nN, near 30 times extension. After >30 times extensions, the elastic moduli of chromosomes can be reduced by more than 20-fold, and they appear as "ghosts": swollen, elongated, and with reduced optical contrast under both phase and differential interference contrast imaging. Antibody labeling indicates that histone proteins are not being lost during even extreme extensions. Results are interpreted in terms of extension and failure of chromatin-tethering elements; the force data allow estimates of the number and size of such connectors in a chromosome.

Membrane mechanics govern spatiotemporal heterogeneity of endocytic clathrin coat dynamics.

Dynamics of endocytic clathrin-coated structures can be remarkably divergent across different cell types, cells within the same culture, or even distinct surfaces of the same cell. The origin of this astounding heterogeneity remains to be elucidated. Here we show that cellular processes associated with changes in effective plasma membrane tension induce significant spatiotemporal alterations in endocytic clathrin coat dynamics. Spatiotemporal heterogeneity of clathrin coat dynamics is also observed during morphological changes taking place within developing multicellular organisms. These findings suggest that tension gradients can lead to patterning and differentiation of tissues through mechanoregulation of clathrin-mediated endocytosis.

Anti-Myeloperoxidase Antibodies Associate with Future Proliferative Lupus Nephritis.

BACKGROUND: The subclinical pathophysiology of proliferative lupus nephritis (PLN) has not been fully elucidated. Myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) is associated with PLN, but prediagnostic levels have not been reported. METHODS: We performed a retrospective case-control Department of Defense Serum Repository (DoDSR) study comparing MPO-ANCA levels in longitudinal prediagnostic serum samples for 23 biopsy confirmed proliferative lupus nephritis (PLN) patients to DoDSR identified age, sex, race, and age of serum matched healthy and SLE without LN disease controls. We also compared the temporal relationship of MPO-ANCA to anti-double stranded DNA antibodies (dsDNAab). RESULTS: A greater proportion of PLN patients had prediagnostic MPO-ANCA levels above ≥3 U/mL and ≥6 U/mL compared to SLE without LN (91% versus 43%, p < 0.001; 57% versus 5%, p < 0.001, resp.). In subgroup analysis, the MPO-ANCA threshold of ≥3 U/mL was significant at <1 year (88% versus 39%, p = 0.007) and 1-4 years (87% versus 38%, p = 0.009) prior to diagnosis. Statistically significant subclinical MPO-ANCA levels (≥3 U/mL) occurred prior to statistically significant dsDNAab ≥ 3 IU/ml (89% versus 11%, p = 0.003). CONCLUSIONS: Subclinical MPO-ANCA levels could distinguish future PLN from SLE without LN. MPO-ANCA manifests prior to clinical disease and subclinical dsDNAab to suggest that it may contribute directly to PLN pathogenicity.

Enhanced malignant conversion of benign mouse skin tumors by cisplatin.

The chemotherapeutic agent cisplatin, reported to be a complete carcinogen in rodents and a tumor initiator for mouse skin, was tested for activity to enhance the conversion of carcinogen-induced skin papillomas to carcinomas. Initiation of mouse skin by 7,12-dimethylbenz[a]anthracene followed by 12 weeks of promotion by 12-O-tetradecanoylphorbol-13-acetate produced seven to eight papillomas/mouse. Ten weekly injections of 100 micrograms of cisplatin into these papilloma-bearing mice induced a 2.3-fold enhancement of conversion relative to the spontaneous rate of 1.9%. Even a single exposure to cisplatin in tumor-bearing mice increased the carcinoma incidence to the same extent as 10 exposures to urethane, an agent previously shown to enhance malignant conversion. At the dose tested, cisplatin was inactive as a complete carcinogen or a tumor promoter. Cisplatin-DNA adducts, measured in samples from skin, liver, and kidneys, were persistent for at least 4 weeks after the last exposure to cisplatin. Thus cisplatin is a relatively potent inducer of the putative genotoxic changes required for conversion of skin tumors from a benign to a malignant phenotype. The activity of cisplatin in the initiation and malignant conversion stages in this animal model for carcinogenesis suggests that patients given cisplatin-based chemotherapy are at increased risk for the development of treatment-induced second cancers.