Predicting prognosis for adults with depression using individual symptom data: a comparison of modelling approaches.

BACKGROUND: This study aimed to develop, validate and compare the performance of models predicting post-treatment outcomes for depressed adults based on pre-treatment data. METHODS: Individual patient data from all six eligible randomised controlled trials were used to develop (k = 3, n = 1722) and test (k = 3, n = 918) nine models. Predictors included depressive and anxiety symptoms, social support, life events and alcohol use. Weighted sum scores were developed using coefficient weights derived from network centrality statistics (models 1-3) and factor loadings from a confirmatory factor analysis (model 4). Unweighted sum score models were tested using elastic net regularised (ENR) and ordinary least squares (OLS) regression (models 5 and 6). Individual items were then included in ENR and OLS (models 7 and 8). All models were compared to one another and to a null model (mean post-baseline Beck Depression Inventory Second Edition (BDI-II) score in the training data: model 9). Primary outcome: BDI-II scores at 3-4 months. RESULTS: Models 1-7 all outperformed the null model and model 8. Model performance was very similar across models 1-6, meaning that differential weights applied to the baseline sum scores had little impact. CONCLUSIONS: Any of the modelling techniques (models 1-7) could be used to inform prognostic predictions for depressed adults with differences in the proportions of patients reaching remission based on the predicted severity of depressive symptoms post-treatment. However, the majority of variance in prognosis remained unexplained. It may be necessary to include a broader range of biopsychosocial variables to better adjudicate between competing models, and to derive models with greater clinical utility for treatment-seeking adults with depression.

The importance of transdiagnostic symptom level assessment to understanding prognosis for depressed adults: analysis of data from six randomised control trials.

BACKGROUND: Depression is commonly perceived as a single underlying disease with a number of potential treatment options. However, patients with major depression differ dramatically in their symptom presentation and comorbidities, e.g. with anxiety disorders. There are also large variations in treatment outcomes and associations of some anxiety comorbidities with poorer prognoses, but limited understanding as to why, and little information to inform the clinical management of depression. There is a need to improve our understanding of depression, incorporating anxiety comorbidity, and consider the association of a wide range of symptoms with treatment outcomes. METHOD: Individual patient data from six RCTs of depressed patients (total n = 2858) were used to estimate the differential impact symptoms have on outcomes at three post intervention time points using individual items and sum scores. Symptom networks (graphical Gaussian model) were estimated to explore the functional relations among symptoms of depression and anxiety and compare networks for treatment remitters and those with persistent symptoms to identify potential prognostic indicators. RESULTS: Item-level prediction performed similarly to sum scores when predicting outcomes at 3 to 4 months and 6 to 8 months, but outperformed sum scores for 9 to 12 months. Pessimism emerged as the most important predictive symptom (relative to all other symptoms), across these time points. In the network structure at study entry, symptoms clustered into physical symptoms, cognitive symptoms, and anxiety symptoms. Sadness, pessimism, and indecision acted as bridges between communities, with sadness and failure/worthlessness being the most central (i.e. interconnected) symptoms. Connectivity of networks at study entry did not differ for future remitters vs. those with persistent symptoms. CONCLUSION: The relative importance of specific symptoms in association with outcomes and the interactions within the network highlight the value of transdiagnostic assessment and formulation of symptoms to both treatment and prognosis. We discuss the potential for complementary statistical approaches to improve our understanding of psychopathology.

Ileal pouch-anal anastomosis for ulcerative colitis: a Canadian institution's experience.

BACKGROUND: We aimed to summarize the outcomes of ulcerative colitis (UC) patients receiving an ileal pouch-anal anastamosis (IPAA) over an 11-year period at a high-volume Canadian inflammatory bowel disease (IBD) center. METHODS: A retrospective chart review was performed for subjects with UC who underwent IPAA between 2002 and 2013. Patient charts were reviewed for demographic data, clinical characteristics, preoperative medical treatment, and surgical outcomes. Univariate and multivariate logistic regression modeling were used to determine significant factors in postoperative outcomes. RESULTS: Seven hundred fifty-eight were included from the IBD database. The median age at the time of surgery was 37.1 (±12.1). Mean preoperative disease duration was 8.1 years (±8.7). Three hundred sixty-nine patients (48.7 %) had systemic corticosteroids (>15 mg/day) within 30 days prior to surgery. Of these, 286 patients had high dose (>30 mg/day) corticosteroids within 7 days of their first surgery. One hundred nine (14.0 %) IPAA procedures were performed laparoscopically. Pelvic pouches were created in traditional 2 (n = 460) and 3 (n = 285) stages; the remainder (n = 13) was performed in non-traditional staged operations. Early complications, defined as occurring within the same stay in hospital, consisted of pelvic abscess (n = 135, 17.8 %), small bowel obstruction (n = 134, 17.7 %), wound infection (n = 108, 14.3 %), and deep vein thrombosis (n = 33, 4.4 %). The overall pouch leak rate was 92 (12.1 %). There was one death in our study. The median length of stay was 10.3 days (SD6.0). Late complications, defined as occurring after discharge from hospital, consisted of anal stricture (n = 55, 7.3 %), pouch fistula (n = 26, 3.4 %), and functional pouch failure (n = 7, 0.9 %). CONCLUSIONS: IPAA has been found to be a safe and effective method of surgical management of UC patients in a high-volume IBD center.

Pulse oximetry optical sensor using oxygen-bound haemoglobin.

In this paper we report a unique approach to measuring oxygen saturation levels by utilising the wavelength of the haemoglobin instead of the conventional absorption difference. Two experiments are set up to measure the wavelength of the haemoglobin bound to oxygen at different oxygen saturation levels with the help of a spectrometer. We report a unique low cost and robust wavelength monitoring SpO2 sensor that measures the SpO2 by using the colour of the blood and not the absorption difference of oxyhaemoglobin and deoxyhaemoglobin. With use of a spectrometer, we show that the wavelength of the oxygen-bound haemoglobin has a relation to the oxygen saturation level. The proposed device is designed and experimentally implemented with a colour sensor to measure the SpO2 level of the blood.

Peripheral blood-derived, γ9δ2 t cell-enriched cell lines from glioblastoma multiforme patients exert anti-tumoral effects in vitro.

The goal of this work was to assess the potential of T cells expressing Vγ9Vδ2+ T cell receptors (TCR, γ9δ2T cells) present in peripheral blood (PB) m ononuclear cells (MC, PBMC) of glioblastoma multiforme (GBM) patients to act as anti-tumoral agents. We found that γ9δ2T cell levels were decreased in patients' PB relative to a cohort of healthy donors (HD) (respectively 0.52±0.55%, n=16, vs 1.12±0.6%, n=14, p=0.008) but did not significantly correlate with postoperative survival (R=0.6, p=0.063). Importantly, however, the γ9δ2T cells could be expanded in vitro to consist 51±23% of the cultured lymphocytes (98% CD3+). This was achieved after 14 days of culture in medium containing the amino-bisphosphonate (ABP) Zoledronate (Zol) and interleukin (IL)-2, resulting in γ9δ2T cell-enriched lines (gdTCEL) similar to those of HD derived gdTCEL (54±19%). Moreover, gdTCEL from patients and HD mediated cytotoxicity to GBM-derived cell lines (GBMDCL), which was abrogated by immune-magnetic removal of the γ9δ2T cells. Furthermore, low level interferon (IFN) γ secretion was induced by gdTCEL briefly co-cultured with GBMDCL or autologous - tumor-derived cells, which was greatly amplified in the presence of Zol. Importantly, IFNγ secretion was inhibited by mevastatin but enhanced by cross-linking of butyrophilin 3A1 (CD277) on a CD277+ GBMDCL (U251MG) or by pretreatment of GBMDCL with temozolomide (TMZ). Taken together, these data suggest that γ9δ2T cells in PB of GBM patients can give rise to gdTCEL that mediate anti-tumoral activities.

Anal fistula plug: a prospective evaluation of success, continence and quality of life in the treatment of complex fistulae.

AIM: Curing complex anal fistula without compromising continence can be extremely challenging. This study investigated the healing rate, continence and quality of life of patients after treatment of complex anal fistula of cryptoglandular origin with a bioprosthetic plug. METHOD: Consecutive patients were prospectively followed in four referral centres. Following seton conditioning, a bioprosthetic plug was inserted into the fistula and sutured to the anal sphincter. Clinical evaluation was performed at 10 days, 6 weeks and 6 months after surgery, and was completed by telephone interviews. Anal continence and quality of life were evaluated using the Fecal Incontinence Score Index and the Short Form-36 Health Survey, version 2 (SF-36 v2) questionnaire. RESULTS: Forty-six patients presenting with a complex anal fistula and a median of three previous fistula surgeries were included. The 6-month recurrence rate was 30.7% (95% CI: 15.9-42.8%), increasing to 48.0% (95% CI: 30.6-61.1%) after 2 years. Follow up was continued for a median of 68.1 months, and 26 (56.5%) recurrences were identified. Anal continence improved from a median of 19 points to 12 points at 6 months of follow up (P = 0.008). Quality of life markedly improved in all scales. The physical summary score increased from 47.2 to 56.2 (P < 0.001), and the mental summary score increased from 48.5 to 55.3 (P = 0.013). CONCLUSION: The bioprosthetic fistula plug demonstrated a healing rate close to 50% in complex cryptoglandular fistula. Also, it markedly improved anal continence and quality of life. These data support the use of a bioprosthetic plug as first-line therapy for complex fistula instead of more aggressive and potentially debilitating surgical options.

Outcomes following surgery for perforating Crohn's disease.

BACKGROUND: The most common indications for surgery for patients with ileocolic Crohn's disease are fibrostenotic or perforating disease. The objective was to compare surgical outcomes of patients with perforating versus non-perforating disease following ileocolic resection. METHODS: This was a retrospective review of all patients who had their first ileocolic resection between 1990 and 2010, identified from a prospectively maintained inflammatory bowel disease database. Demographic information, preoperative medication, intraoperative findings and postoperative outcome data were collected. Outcomes in patients who had an abscess drained before surgery or were found to have a fistula or abscess at surgery or at pathology were compared with outcomes in all others. RESULTS: A total of 434 patients (56·2 per cent women) were included, 293 with perforating and 141 with non-perforating disease. Median age, tobacco use, and preoperative steroid and biological agent use were similar in the two groups. Forty patients (13·7 per cent) in the perforating group had abscesses drained before surgery and 251 patients had at least one fistula, most commonly to the sigmoid colon. Patients with perforating disease were more likely to require preoperative total parenteral nutrition, need another resection, have an ileostomy and a longer mean postoperative stay, and less likely to undergo a laparoscopic procedure. Patients in this group also developed more postoperative abscesses or leaks (4·8 versus 0 per cent; P = 0·006). The reoperation rate was similar (3·1 versus 0·7 per cent; P = 0·178). CONCLUSION: Patients with penetrating Crohn's disease are more likely to require a more complex procedure, and an ileostomy, and to a have longer postoperative stay.

An ultrasound needle insertion guide in a porcine phantom model.

We compared nerve blockade with and without the Infiniti(TM) needle guide in an ultrasound in-plane porcine simulation. We recruited 30 anaesthetists with varying blockade experience. Using the guide, the needle tip was more visible (for a median (IQR [range]) of 67 (56-100]) % of the time; and invisible for 2 (1-4 [0-19]) s) than when the guide was not used (respectively 23 (13-43 [0-80]) % and 25 (9-52 [1-198]) s; both p < 0.001). The corresponding block times were 8 (6-10 [3-28]) s and 32 (15-67 [5-225]) s, respectively; p < 0.001. The needle guide reduced the block time and the time that the needle was invisible, irrespective of anaesthetist experience.

Genetic variation in the 5q31 cytokine gene cluster confers susceptibility to Crohn disease.

Linkage disequilibrium (LD) mapping provides a powerful method for fine-structure localization of rare disease genes, but has not yet been widely applied to common disease. We sought to design a systematic approach for LD mapping and apply it to the localization of a gene (IBD5) conferring susceptibility to Crohn disease. The key issues are: (i) to detect a significant LD signal (ii) to rigorously bound the critical region and (iii) to identify the causal genetic variant within this region. We previously mapped the IBD5 locus to a large region spanning 18 cM of chromosome 5q31 (P<10(-4)). Using dense genetic maps of microsatellite markers and single-nucleotide polymorphisms (SNPs) across the entire region, we found strong evidence of LD. We bound the region to a common haplotype spanning 250 kb that shows strong association with the disease (P< 2 x 10(-7)) and contains the cytokine gene cluster. This finding provides overwhelming evidence that a specific common haplotype of the cytokine region in 5q31 confers susceptibility to Crohn disease. However, genetic evidence alone is not sufficient to identify the causal mutation within this region, as strong LD across the region results in multiple SNPs having equivalent genetic evidence-each consistent with the expected properties of the IBD5 locus. These results have important implications for Crohn disease in particular and LD mapping in general.

Hereditary colorectal cancer registries in Canada: report from the Colorectal Cancer Association of Canada consensus meeting; Montreal, Quebec; October 28, 2011.

At a consensus meeting held in Montreal, October 28, 2011, a multidisciplinary group of Canadian experts in the fields of genetics, gastroenterology, surgery, oncology, pathology, and health care services participated in presentation and discussion sessions for the purpose of developing consensus statements pertaining to the development and maintenance of hereditary colorectal cancer registries in Canada. Five statements were approved by all participants.

Quality of life and functional outcome for individuals who underwent very early colectomy for familial adenomatous polyposis.

BACKGROUND: The major manifestation of familial adenomatous polyposis is colorectal adenomas, which, if untreated, lead to colorectal cancer. The impact of IPAA on quality of life in adolescents with familial adenomatous polyposis is favorable. There is a group of children who develop polyps at a younger age requiring earlier colectomy. Little is known about this very young subgroup in relation to bowel function or quality of life. OBJECTIVE: The aim of this study was to investigate the outcome in patients with familial adenomatous polyposis who had colectomy at ≤14 years. DESIGN: A cross-sectional quantitative survey was designed to assess outcome. Standardized validated instruments included bowel/psychosocial functioning and quality of life. RESULTS: Among 1337 patients with familial adenomatous polyposis from 409 kindreds, 4% (n = 59) of patients underwent colectomy at ≤14 years of age. Response rate was 84% (n = 32). The mean age at colectomy was 12 years (SD 2), with a current mean age of 24 years (SD 8.5). Fifty-seven percent of patients reported continence. Of the 43% reporting daytime or nighttime incontinence, the majority are <18 years (86%). Younger participants (currently less than 18 years of age) report more restrictions. Mental health is significantly lower among participants with incontinence. They report higher depression and anxiety symptoms, higher levels of intrusion and avoidance, and inferior mental health. The percentage of those worrying about risk of cancer is significantly higher in the younger group (71% vs 24%). Most patients (n = 24, 75%) have had surveillance endoscopy within the past 2 years. LIMITATIONS: This study is limited by study generalizability, selection bias, and small sample size. CONCLUSIONS: Twelve years after colectomy more than half of the patients have favorable bowel function. The rate of incontinence is high, especially among younger patients who have had a shorter time since surgery. Patients with incontinence reported lower psychosocial functioning, are very concerned about their cancer risk, and experience greater distress. This subgroup would benefit from added psychological interventions to enhance coping with familial adenomatous polyposis and surgery.

Long-term outcome of colectomy and ileorectal anastomosis for Crohn's colitis.

BACKGROUND: Ileorectal anastomosis is an important surgical option for patients with Crohn's colitis with relative rectal sparing. OBJECTIVE: This study aimed to audit outcomes of ileorectal anastomosis for Crohn's and factors associated with proctectomy and reoperation. DESIGN: This retrospective study involved a chart review and contacting patients. SETTINGS: Patients with Crohn's colitis who had an ileorectal anastomosis were identified from the Mount Sinai Hospital Inflammatory Bowel Disease Database. PATIENTS: Demographics, operative and perioperative outcomes, and reoperative data were collected. MAIN OUTCOME MEASURES: Five- and 10-year Kaplan-Meier survival estimates and 95% confidence intervals were calculated for survival from proctectomy and Crohn's-related revisional surgery. Cox proportional hazards models were used to model the hazards of proctectomy and Crohn's-related revision on the clinical characteristics of patients. RESULTS: Eighty-one patients had an ileorectal anastomosis for Crohn's disease from 1982 to 2010. The most common indications for surgery were failed medical management (60/81, 74.1%) and a stricture causing obstruction (14/81, 17.3%). Seventy-seven percent (n = 62) had a 1-stage procedure, whereas 23% (n = 19) had a 2-stage procedure (colectomy followed by ileorectal anastomosis). The overall anastomotic leak rate was 7.4% (n = 6). Fifty-six patients had a functioning ileorectal anastomosis at the time of follow-up. At 5 and 10 years, 87% (95% CI: 75.5-93.3) and 72.2% (95% CI: 55.8-83.4) of individuals had a functioning ileorectal anastomosis. Eighteen patients required proctectomy for poor symptom control, whereas 11 patients required a small-bowel resection plus redo-ileorectal anastomosis. The mean time to proctectomy from the original ileorectal anastomosis was 88.3 months (SD = 62.1). Smoking was associated with both proctectomy (HR 3.93 (95% CI: 1.46-10.55)) and reoperative surgery (HR 2.12 (95% CI: 0.96-4.72)). LIMITATIONS: : This study was retrospective. CONCLUSIONS: Ileorectal anastomosis is an appropriate operation for selected patients with Crohn's colitis with sparing of the rectum. However, patients must be counseled that the reoperation rate and/or proctectomy rate is approximately 30%.

Role of age, gender and marital status in prognosis for adults with depression: An individual patient data meta-analysis.

AIMS: To determine whether age, gender and marital status are associated with prognosis for adults with depression who sought treatment in primary care. METHODS: Medline, Embase, PsycINFO and Cochrane Central were searched from inception to 1st December 2020 for randomised controlled trials (RCTs) of adults seeking treatment for depression from their general practitioners, that used the Revised Clinical Interview Schedule so that there was uniformity in the measurement of clinical prognostic factors, and that reported on age, gender and marital status. Individual participant data were gathered from all nine eligible RCTs (N = 4864). Two-stage random-effects meta-analyses were conducted to ascertain the independent association between: (i) age, (ii) gender and (iii) marital status, and depressive symptoms at 3-4, 6-8, and 9-12 months post-baseline and remission at 3-4 months. Risk of bias was evaluated using QUIPS and quality was assessed using GRADE. PROSPERO registration: CRD42019129512. Pre-registered protocol https://osf.io/e5zup/. RESULTS: There was no evidence of an association between age and prognosis before or after adjusting for depressive 'disorder characteristics' that are associated with prognosis (symptom severity, durations of depression and anxiety, comorbid panic disorderand a history of antidepressant treatment). Difference in mean depressive symptom score at 3-4 months post-baseline per-5-year increase in age = 0(95% CI: -0.02 to 0.02). There was no evidence for a difference in prognoses for men and women at 3-4 months or 9-12 months post-baseline, but men had worse prognoses at 6-8 months (percentage difference in depressive symptoms for men compared to women: 15.08% (95% CI: 4.82 to 26.35)). However, this was largely driven by a single study that contributed data at 6-8 months and not the other time points. Further, there was little evidence for an association after adjusting for depressive 'disorder characteristics' and employment status (12.23% (-1.69 to 28.12)). Participants that were either single (percentage difference in depressive symptoms for single participants: 9.25% (95% CI: 2.78 to 16.13) or no longer married (8.02% (95% CI: 1.31 to 15.18)) had worse prognoses than those that were married, even after adjusting for depressive 'disorder characteristics' and all available confounders. CONCLUSION: Clinicians and researchers will continue to routinely record age and gender, but despite their importance for incidence and prevalence of depression, they appear to offer little information regarding prognosis. Patients that are single or no longer married may be expected to have slightly worse prognoses than those that are married. Ensuring this is recorded routinely alongside depressive 'disorder characteristics' in clinic may be important.

Morphological and biochemical features of obesity are associated with mineralization genes' polymorphisms.

BACKGROUND: Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) was recently extensively studied as a candidate gene for obesity phenotypes. As the human homologue of the mouse progressive ankylosis (ANKH) and alkaline phosphatase (ALPL) are known functional partners of ENPP1 in bone mineralization, we hypothesized that these genes may also be jointly involved in determining obesity features. AIM: To examine the effects of the three genes, possible gene-sex and gene-gene interactions on variability of four obesity phenotypes: the body mass index (BMI), the waist-hip ratio (WHR), the epidermal growth factor receptor (EGFR), and leptin. SUBJECTS AND METHODS: In all, 962 healthy individuals from 230 families were genotyped for 45 single nucleotide polymorphisms (SNPs). The association analysis was performed using two family based association tests (family based association test and pedigree disequilibrium test). The combined P-values of the two tests were estimated by Monte-Carlo simulations. Relative magnitude of the genetic and familial effects, gene-sex and gene-gene interactions were assessed using variance component models. RESULTS: Associations were observed between ENPP1 polymorphisms and BMI (P=0.0037) and leptin (P=0.0068). ALPL markers were associated with WHR (P=0.0026) and EGFR (P=0.0001). The ANKH gene was associated with all four studied obesity-related traits (P<0.0184), and its effects were modulated by sex. Gene-gene interactions were not detected. CONCLUSION: The observed pattern of association signals indicates that ANKH may have a generalized effect on adipose tissue physiology, whereas ENPP1 and ALPL affect distinct obesity features. The joint analysis of related genes and integration of the results obtained by different methods used in this research should benefit other studies of similar design.

Linear accelerator stereotactic radiosurgery can modulate the clinical course of Hemangioblastoma: Case series and review of the literature.

Hemangioblastomas (HB) are benign low grade vascular tumors most frequently occurring in the cerebellum, brain stem, and spinal cord. Often associated with Von Hippel Lindau disease (VHL), the lesions are often multifocal requiring complex resection and are difficult to control. Linear Accelerator (LINAC) Stereotactic Radiosurgery (SRS) has been demonstrated to provide additional tumor control. In this case series, we present our multi-center experience utilizing LINAC SRS in fourteen patients with 23 lesions. We observed a tumor control rate of 87% and found interval changes in the peritumoral enhancement to correlate with treatment outcome. In our study, SRS treatment was also well-tolerated in both cystic and noncystic patients with multifocal disease. Disease control was achieved in all but three patients post-resection and no longitudinal radiation-induced secondary malignancy was observed. SRS response correlated highly with lesion size and radiation dose. We conclude that LINAC SRS is safe and effective for patients with HB and should be considered in addition to surgery in asymptomatic, VHL patients, deep seated lesions and isolated lesions.

Germline variants and phenotypic spectrum in a Canadian cohort of individuals with diffuse gastric cancer.

Background: CDH1 pathogenic variants (pvs) cause most cases of inherited diffuse gastric cancer (dgc), but have low detection rates and vary geographically. In the present study, we examined hereditary causes of dgc in patients in Ontario. Methods: CDH1 testing through single-site or multi-gene panels was conducted for patients with dgc meeting the 2015 International Gastric Cancer Linkage Consortium (igclc) criteria, or with isolated dgc at less than 50 years of age, or with a strong family history of cancer identified at the Zane Cohen Centre (zcc). All CDH1-positive patients at zcc, regardless of cancer history, were summarized. Results: In 15 of 85 patients with dgc (17.6%), a pv or likely pv was identified through CDH1 single-site (n = 43) or multi-gene panel (n = 42) testing. The detection rate was 9.4% overall (8 of 85) and 11% using igclc criteria (7 of 65). No CDH1 pvs were identified in patients with isolated dgc at less than 40 years of age, but 1 pv was identified in a patient with isolated dgc at less than 50 years of age. Multi-gene panels identified 9 pvs (21.4%), including CDH1, STK11, ATM, BRCA2, MLH1, and MSH2. Review of 81 CDH1 carriers identified 10% with dgc (median age: 48 years; range: 38-59 years); 41% were unaffected (median age: 53 years; range: 26-89 years). Observed malignancies other than dgc or lobular breast cancer (lbc) included colorectal, gynecologic, kidney or bladder, prostate, testicular, and ductal breast cancers. Lobular-breast cancer was seen only in 3 families. Conclusions: In Ontario, the detection rate of CDH1 pvs in patients with dgc was low: no pvs were identified in patients with isolated dgc at less than 40 years of age, and 1 was identified in a patient with isolated dgc at less than 50 years of age. Isolated lbc with no dgc was observed in CDH1-positive families, as were pathology-confirmed nondgc or non-lbc malignancies, which had not previously been reported. Given a phenotype that overlaps with other hereditary conditions, multi-gene panels are recommended for all patients with dgc at less than 50 years of age and for those meeting igclc criteria.

Mouse major satellite DNA is prone to eccDNA formation via DNA Ligase IV-dependent pathway.

Elevated levels of extrachromosomal circular DNA (eccDNA or spcDNA) are closely associated with genomic instability and aging. Despite extensive studies, the mechanism of its generation in mammalian cells is unknown. We report here that mouse major satellite DNA (MSD) is prone to eccDNA formation and that the resulting molecules are multimeres of the basic repeat. Extrachromosomal circular major satellite (ECMS) DNA constitutes the majority of eccDNA in B16 mouse melanoma cells and is highly abundant in other mouse cells. Production of these molecules is enhanced in proliferating cells, suggesting that processes associated with DNA replication are involved in their appearance. Using siRNA technique we show that DNA Ligase IV is engaged in ECMS synthesis. Based on our findings we propose a novel two-step model for eccDNA formation in mammalian cells.

A survey of Australian and New Zealand anaesthetists' attitudes towards resuscitation orders in the perioperative setting.

Not for resuscitation (NFR) orders are often suspended during anaesthesia, as perioperative care is believed to inherently involve the need for resuscitation including ventilation support. Recent legislative changes in Australia, New Zealand and the UK have enacted the binding nature of advance care directives (ACDs) in healthcare. National guidelines regarding codes of practice and government strategic plans for implementing advance care planning have reinforced the role for advance care planning in modern healthcare. We surveyed a random selection of Australian and New Zealand consultant and trainee anaesthetists to assess their attitudes towards NFR orders and ACDs in the perioperative setting. We received 290 of 790 distributed surveys (37% response rate). The majority (75%) of respondents reported their knowledge as very low, low, or moderate; 37% never or rarely were treating a patient who had an ACD. Over 90% reported that patient's wishes and understanding of ACDs is important and 89% agreed or strongly agreed that advance care planning should be a routine part of hospital admission for high risk patients. Despite this, only 45% of the respondents would always follow an ACD. Although the majority of respondents to this survey support their use in the perioperative setting, clarification of the specific applicability of ACDs to anaesthesia and their binding nature is required.

Serotonin in the regulation of brain microcirculation.

Manipulation of brainstem serotonin (5-HT) raphe neurons induces significant alterations in local cerebral metabolism and perfusion. The vascular consequences of intracerebrally released 5-HT point to a major vasoconstrictor role, resulting in cerebral blood flow (CBF) decreases in several brain regions such as the neocortex. However, vasodilatations, as well as changes in blood-brain barrier (BBB) permeability, which are blocked by 5-HT receptor antagonists also can be observed. A lack of relationship between the changes in flow and metabolism indicates uncoupling between the two variables and is suggestive of a direct neurogenic control by brain intrinsic 5-HT neurons on the microvascular bed. In line with these functional data are the close associations that exist between 5-HT neurons and the microarterioles, capillaries and perivascular astrocytes of various regions but more intimately and/or more frequently so in those where CBF is altered significantly following manipulation of 5-HT neurons. The ability of the microvascular bed to respond directly to intracerebrally released 5-HT is underscored by the expression of distinct 5-HT receptors in the various cellular compartments of the microvascular bed. Thus, it appears that while some 5-HT-mediated microvascular functions involve directly the blood vessel wall, others would be relayed through the perivascular astrocyte. The strategic localization of perivascular astrocytes and the different 5-HT receptors that they harbor strongly emphasize their putative pivotal role in transmitting information between 5-HT neurons and microvessels. It is concluded that the cerebral circulation has full capacity to adequately and locally adapt brain perfusion to changes in central 5-HT neurotransmission either directly or indirectly via the neuronal-astrocytic-vascular tripartite functional unit. Dysfunctions in these neurovascular interactions might result in perfusion deficits and might be involved in specific pathological conditions.

Reevaluation of nitrate and nitrite levels in the human intestine.

Analyses of human fecal and ileostomy samples by a method that is insensitive and free from interferences indicate that nitrate and nitrite levels in the intestine are lower than reported previously. Fecal nitrate and nitrite concentrations ranged from 0 to 14 mumol/kg (0 to 0.9 ppm) and 5 to 19 mumol/kg (0.3 to 0.9 ppm), respectively. Ileostomy samples contained from 0 to 7 mumol/kg (0 to 0.4 ppm) and 0 to 15 mumol/kg (0 to 0.7 ppm) for nitrate and nitrite, respectively. We also showed that, when deliberately added to feces samples, nitrate and nitrite were destroyed during a two-hr incubation period in a reaction that depended on the presence of microorganisms. The results suggest that conditions in the lower gastrointestinal tract favor denitrification, not nitrification as had been proposed previously.