Sensitivity of temperature-based time since death estimation on measurement location.

Rectal temperature measurement (RTM) from crime scenes is an important parameter for temperature-based time of death estimation (TDE). Various influential variables exist in TDE methods like the uncertainty in thermal and environmental parameters. Although RTM depends in particular on the location of measurement position, this relationship has never been investigated separately. The presented study fills this gap using Finite Element (FE) simulations of body cooling. A manually meshed coarse human FE model and an FE geometry model developed from the CT scan of a male corpse are used for TDE sensitivity analysis. The coarse model is considered with and without a support structure of moist soil. As there is no clear definition of ideal rectal temperature measurement location for TDE, possible variations in RTM location (RTML) are considered based on anatomy and forensic practice. The maximum variation of TDE caused by RTML changes is investigated via FE simulation. Moreover, the influence of ambient temperature, of FE model change and of the models positioning on a wet soil underground are also discussed. As a general outcome, we notice that maximum TDE deviations of up to ca. 2-3 h due to RTML deviations have to be expected. The direction of maximum influence of RTML change on TDE generally was on the line caudal to cranial.

Changes in the multidisciplinary management of rectal cancer from 2009 to 2015 and associated improvements in short-term outcomes.

AIM: Significant recent changes in management of locally advanced rectal cancer (LARC) include preoperative staging, use of extended neoadjuvant therapies and minimally invasive surgery (MIS). This study was aimed at characterizing these changes and associated short-term outcomes. METHOD: We retrospectively analysed treatment and outcome data from patients with T3/4 or N+ LARC ≤ 15 cm from the anal verge who were evaluated at a comprehensive cancer centre in 2009-2015. RESULTS: In total, 798 patients were identified and grouped into five cohorts based on treatment year: 2009-2010, 2011, 2012, 2013 and 2014-2015. Temporal changes included increased reliance on MRI staging, from 57% in 2009-2010 to 98% in 2014-2015 (P < 0.001); increased use of total neoadjuvant therapy, from 17% to 76% (P < 0.001); and increased use of MIS, from 33% to 70% (P < 0.001). Concurrently, median hospital stay decreased (from 7 to 5 days; P < 0.001), as did the rates of Grade III-V complications (from 13% to 7%; P < 0.05), surgical site infections (from 24% to 8%; P < 0.001), anastomotic leak (from 11% to 3%; P < 0.05) and positive circumferential resection margin (from 9% to 4%; P < 0.05). TNM downstaging increased from 62% to 74% (P = 0.002). CONCLUSION: Shifts toward MRI-based staging, total neoadjuvant therapy and MIS occurred between 2009 and 2015. Over the same period, treatment responses improved, and lengths of stay and the incidence of complications decreased.

Adipose tissue grafting for management of persistent anastomotic leak after low anterior resection.

BACKGROUND: An anastomotic leak is the most dreaded complication after low anterior resection. Adipose tissue grafting may induce healing in a persistent anastomotic defect. The aim of the present study was to report retrospectively reviewed outcomes for a series of patients who were managed with heterotopic grafted adipose tissue to facilitate anastomotic healing. METHODS: Patients with anastomotic leakage after low anterior resection sequentially treated with grafting of adipose tissue were included in the study. All patients had pelvic radiation during treatment and had a diverting ileostomy in situ. The cohort had a persistent defect despite being treated with available modalities such as suture repair, fibrin glue, Endo-Sponge and surgical debridement. The outcomes were reviewed and reported. RESULTS: There were 11 patients (8 males and 3 females) with a median age of 54 years (range 33-72 years). Five patients experienced complete healing of the anastomotic defect with successful reversal of the diverting ileostomy. The anastomotic defect of one other patient in the series appeared to have healed and hence his diverting ileostomy was reversed. However, he presented with a recurrent leak, which ultimately necessitated an abdominoperineal resection. Another patient had a persistent defect after an attempt at adipose tissue grafting and opted to proceed with a takedown of the anastomosis. In the remaining four patients, the outcome after adipose tissue grafting remains unknown, as two patients succumbed to metastatic disease, one was lost to follow-up and the remaining patient developed a recurrence which required pelvic exenteration. Procedural associated morbidity occurred in one patient who developed fat embolism, which was treated expectantly. CONCLUSIONS: Adipose tissue grafting is safe and feasible, though its effectiveness remains uncertain. It may be useful selectively in the management of persistent anastomotic leak after radiation and low anterior resection.

Effectiveness of a multidisciplinary patient care bundle for reducing surgical-site infections.

BACKGROUND: Surgical-site infection (SSI) is associated with significant healthcare costs. To reduce the high rate of SSI among patients undergoing colorectal surgery at a cancer centre, a comprehensive care bundle was implemented and its efficacy tested. METHODS: A pragmatic study involving three phases (baseline, implementation and sustainability) was conducted on patients treated consecutively between 2013 and 2016. The intervention included 13 components related to: bowel preparation; oral and intravenous antibiotic selection and administration; skin preparation, disinfection and hygiene; maintenance of normothermia during surgery; and use of clean instruments for closure. SSI risk was evaluated by means of a preoperative calculator, and effectiveness was assessed using interrupted time-series regression. RESULTS: In a population with a mean BMI of 30 kg/m2 , diabetes mellitus in 17·5 per cent, and smoking history in 49·3 per cent, SSI rates declined from 11·0 to 4·1 per cent following implementation of the intervention bundle (P = 0·001). The greatest reductions in SSI rates occurred in patients at intermediate or high risk of SSI: from 10·3 to 4·7 per cent (P = 0·006) and from 19 to 2 per cent (P < 0·001) respectively. Wound care modifications were very different in the implementation phase (43·2 versus 24·9 per cent baseline), including use of an overlying surface vacuum dressing (17·2 from 1·4 per cent baseline) or leaving wounds partially open (13·2 from 6·7 per cent baseline). As a result, the biggest difference was in wound-related rather than organ-space SSI. The median length of hospital stay decreased from 7 (i.q.r. 5-10) to 6 (5-9) days (P = 0·002). The greatest reduction in hospital stay was seen in patients at high risk of SSI: from 8 to 6 days (P < 0·001). SSI rates remained low (4·5 per cent) in the sustainability phase. CONCLUSION: Meaningful reductions in SSI can be achieved by implementing a multidisciplinary care bundle at a hospital-wide level.

Suicide risk assessment among psychiatric inpatients: a systematic review and meta-analysis of high-risk categories.

BACKGROUND: The clinical care of psychiatric patients is often guided by perceptions of suicide risk. The aim of this study was to examine the methods and results of studies reporting high-risk models for inpatient suicide. METHODS: We conducted a registered meta-analysis according to PRISMA guidelines. We searched for relevant peer-reviewed cohort and controlled studies indexed in Medline, EMBASE and PsychINFO. RESULTS: The pooled odds ratio (OR) among 18 studies reporting high-risk models for inpatient suicide was 7.1 [95% confidence interval (CI) 4.2-12.2]. Between-study heterogeneity in ORs was very high (range 0-94.8, first quartile 3.4, median 8.8, third quartile 26.1, prediction interval 0.80-63.1, I2 = 88.1%). The meta-analytically derived sensitivity was 53.1% (95% CI 38.2-67.5%, I2 = 95.9%) and specificity was 84.2% (95% CI 71.6-91.9%, I2 = 99.9%) with an associated meta-analytic area under the curve of 0.83. The positive predictive value of risk categorization among six cohort studies was 0.43% (95% CI 0.014-1.3%, I2 = 95.9%). A history of suicidal behavior and depressive symptoms or affective disorder was included in the majority of high-risk models. CONCLUSIONS: Despite the strength of the pooled association between high-risk categorization and suicide, the very high degree of observed heterogeneity indicates uncertainty about our ability to meaningfully distinguish inpatients according to suicide risk. The limited sensitivity and low positive predictive value of risk categorization suggest that suicide risk models are not a suitable basis for clinical decisions in inpatient settings.

Religiosity as a protective factor against suicidal behaviour.

OBJECTIVE: Data suggest that adherence to religious beliefs is associated with lower rates of suicide. A number of mediating factors have been hypothesized to explain this association, including enhanced social support, less substance abuse, and lower rates of psychopathology. METHOD: We utilized data from a two-phase population-based, epidemiological study of mental disorders among young Jewish Israel born in a 10-year birth-cohort conducted in the 1980s. This study included data on religiosity and suicidal behaviour. Twenty-five years thereafter, mortality data were obtained from a national vital statistics registry. RESULTS: Rates of suicidal ideation were similar among secular, partially observant, and religious subjects (9.4%, 6.7%, and 6.2%, respectively; adjusted OR for linear trend: 0.80, 95% CI: 0.58-1.09). Rates of suicide attempts were significantly lower among religious subjects (2.4%, 2.5%, and 0.4% for secular, partially observant, and religious, respectively; adjusted OR for linear trend: 0.62, 95% CI: 0.43-0.88). Of the 4914 subjects, eight died by suicide: Seven of them were secular and one was partially observant (χ(2) = 2.52, P = 0.09). There were no differences in social functioning or rates of psychopathology among the study groups. CONCLUSION: Religiosity has a protective effect against suicide attempts, which is independent of social functioning, psychopathology, and substance use.

A Diet and Fitness Program Similarly Affects Weight Reduction in Schizophrenia Patients Treated with Typical or Atypical Medications.

INTRODUCTION: Schizophrenia patients, receiving new generation antipsychotics, many times suffer from obesity sometimes leading to metabolic syndrome. Diet and fitness programs which reduce weight should be combined in the treatment plan of these patients. This study evaluated patients' adherence and the effect of a diet and fitness program in schizophrenia patients treated with typical vs. atypical antipsychotics. METHODS: 106 stabilized schizophrenia patients participated in a 9-months diet and fitness program, receiving their own menu and a personal workout plan. RESULTS: 60 patients (57%), 27.8±4.8y age, participated in the program for at least one month, i. e., adherent participants, with 4.0±2 months participation average. Months of participation were correlated with weight loss (r=-0.417; p=0.002). Throughout the study patients lost 3.34±1.2 kg in average: 85.95±14.66 at baseline and 82.61±13.78 at the end of program (t=4.969; p<0.001). No association was found between specific types or dose of medication and weight loss (F=0.437, p=0.85). DISCUSSION: Patients with schizophrenia are capable of adhering to a diet and fitness program and successfully lose weight, regardless to taking typical or atypical medications.

Schizophrenia and violent crime: a population-based study.

BACKGROUND: Previous studies have found that patients with schizophrenia are more likely to be violent than the general population. The aim of this study was to investigate the association between schizophrenia and violent crime in the Israeli population. METHOD: Using the Israeli Psychiatric Hospitalization Case Registry we identified 3187 patients with a discharge diagnosis of schizophrenia. For each proband we identified parents and siblings, and gender- and age-matched controls for patients, parents and siblings. Information on violent crimes was obtained from police records. RESULTS: Patients with schizophrenia were at increased risk for violent crimes compared with controls [odds ratio (OR) 4.3, 95% confidence interval (CI) 3.8-4.9], especially women (OR 9.9, 95% CI 6.2-15.7). Risk for violent crimes was higher among patients with co-morbid substance misuse than in patients without such co-morbidity (OR 5.1, 95% CI 4.2-6.3). CONCLUSIONS: The results of this study suggest that increased risk of violence is part of the clinical picture of schizophrenia and needs to be recognized as a legitimate, essential, aspect of clinical management.

Prognostic aspects of DCE-MRI in recurrent rectal cancer.

OBJECTIVE: To explore whether pre-reoperative dynamic contrast-enhanced (DCE)-MRI findings correlate with clinical outcome in patients who undergo surgical treatment for recurrent rectal carcinoma. METHODS: A retrospective study of DCE-MRI in patients with recurrent rectal cancer was performed after obtaining an IRB waiver. We queried our PACS from 1998 to 2012 for examinations performed for recurrent disease. Two radiologists in consensus outlined tumour regions of interest on perfusion images. We explored the correlation between K(trans), Kep, Ve, AUC90 and AUC180 with time to re-recurrence of tumour, overall survival and resection margin status. Univariate Cox PH models were used for survival, while univariate logistic regression was used for margin status. RESULTS: Among 58 patients with pre-treatment DCE-MRI who underwent resection, 36 went directly to surgery and 18 had positive margins. K(trans) (0.55, P = 0.012) and Kep (0.93, P = 0.04) were inversely correlated with positive margins. No significant correlations were noted between K(trans), Kep, Ve, AUC90 and AUC180 and overall survival or time to re-recurrence of tumour. CONCLUSION: K(trans) and Kep were significantly associated with clear resection margins; however overall survival and time to re-recurrence were not predicted. Such information might be helpful for treatment individualisation and deserves further investigation.

Progressive plasticity during colorectal cancer metastasis.

Metastasis is the principal cause of cancer death, yet we lack an understanding of metastatic cell states, their relationship to primary tumor states, and the mechanisms by which they transition. In a cohort of biospecimen trios from same-patient normal colon, primary and metastatic colorectal cancer, we show that while primary tumors largely adopt LGR5 + intestinal stem-like states, metastases display progressive plasticity. Loss of intestinal cell states is accompanied by reprogramming into a highly conserved fetal progenitor state, followed by non-canonical differentiation into divergent squamous and neuroendocrine-like states, which is exacerbated by chemotherapy and associated with poor patient survival. Using matched patient-derived organoids, we demonstrate that metastatic cancer cells exhibit greater cell-autonomous multilineage differentiation potential in response to microenvironment cues than their intestinal lineage-restricted primary tumor counterparts. We identify PROX1 as a stabilizer of intestinal lineage in the fetal progenitor state, whose downregulation licenses non-canonical reprogramming.

Multivisceral resections for rectal cancer.

BACKGROUND: En bloc resection of adjacent pelvic organ(s) may be needed to achieve clear surgical margins in rectal cancer surgery. An institutional experience is reported with perioperative morbidity and oncological outcomes. METHODS: Patients were identified retrospectively from a prospectively collected institutional database (1992-2010). Outcomes, and clinical and pathological factors were determined from medical records. Estimated overall survival, overall recurrence and local recurrence were compared using the log rank method and Cox regression analysis. RESULTS: Among 1831 patients with rectal cancer, 124 (6·8 per cent) underwent en bloc resection of part or all of an adjacent organ (vagina/uterus/ovary 90, prostate/seminal vesicle 23, bladder/ureter 15, small bowel/appendix 7). Five-year overall survival and local recurrence rates were 53·3 and 18·8 per cent respectively. There was one postoperative death, from multiple organ failure in a patient with liver cirrhosis. Fifty-two patients underwent sphincter-preserving surgery and three (6 per cent) developed an anastomotic leak. On univariable analysis, the only factor associated with local recurrence was completeness of resection (local recurrence rate 15 per cent versus 69 per cent for R0 versus R1 resection; P < 0·001). On multivariable analysis, factors associated with overall survival were sphincter-preserving surgery, absence of metastatic disease and R0 resection. CONCLUSION: Multiple organ resection for locally advanced primary rectal cancer had good oncological outcomes when clear resection margins were achieved.

Do subthreshold psychotic experiences predict clinical outcomes in unselected non-help-seeking population-based samples? A systematic review and meta-analysis, enriched with new results.

BACKGROUND: The base rate of transition from subthreshold psychotic experiences (the exposure) to clinical psychotic disorder (the outcome) in unselected, representative and non-help-seeking population-based samples is unknown. METHOD: A systematic review and meta-analysis was conducted of representative, longitudinal population-based cohorts with baseline assessment of subthreshold psychotic experiences and follow-up assessment of psychotic and non-psychotic clinical outcomes. RESULTS: Six cohorts were identified with a 3-24-year follow-up of baseline subthreshold self-reported psychotic experiences. The yearly risk of conversion to a clinical psychotic outcome in exposed individuals (0.56%) was 3.5 times higher than for individuals without psychotic experiences (0.16%) and there was meta-analytic evidence of dose-response with severity/persistence of psychotic experiences. Individual studies also suggest a role for motivational impairment and social dysfunction. The evidence for conversion to non-psychotic outcome was weaker, although findings were similar in direction. CONCLUSIONS: Subthreshold self-reported psychotic experiences in epidemiological non-help-seeking samples index psychometric risk for psychotic disorder, with strong modifier effects of severity/persistence. These data can serve as the population reference for selected and variable samples of help-seeking individuals at ultra-high risk, for whom much higher transition rates have been indicated.

Dynamic contrast enhanced-MRI for the detection of pathological complete response to neoadjuvant chemotherapy for locally advanced rectal cancer.

OBJECTIVE: To determine the ability of dynamic contrast enhanced (DCE-MRI) to predict pathological complete response (pCR) after preoperative chemotherapy for rectal cancer. METHODS: In a prospective clinical trial, 23/34 enrolled patients underwent pre- and post-treatment DCE-MRI performed at 1.5T. Gadolinium 0.1 mmol/kg was injected at a rate of 2 mL/s. Using a two-compartmental model of vascular space and extravascular extracellular space, K(trans), k(ep), v(e), AUC90, and AUC180 were calculated. Surgical specimens were the gold standard. Baseline, post-treatment and changes in these quantities were compared with clinico-pathological outcomes. For quantitative variable comparison, Spearman's Rank correlation was used. For categorical variable comparison, the Kruskal-Wallis test was used. P ≤ 0.05 was considered significant. RESULTS: Percentage of histological tumour response ranged from 10 to 100%. Six patients showed pCR. Post chemotherapy K(trans) (mean 0.5 min(-1) vs. 0.2 min(-1), P = 0.04) differed significantly between non-pCR and pCR outcomes, respectively and also correlated with percent tumour response and pathological size. Post-treatment residual abnormal soft tissue noted in some cases of pCR prevented an MR impression of complete response based on morphology alone. CONCLUSION: After neoadjuvant chemotherapy in rectal cancer, MR perfusional characteristics have been identified that can aid in the distinction between incomplete response and pCR. KEY POINTS: Dynamic contrast enhanced (DCE) MRI provides perfusion characteristics of tumours. These objective quantitative measures may be more helpful than subjective imaging alone Some parameters differed markedly between completely responding and incompletely responding rectal cancers. Thus DCE-MRI can potentially offer treatment-altering imaging biomarkers.

Effects of country of origin and wave of immigration on prevalence of schizophrenia among first and second-generation immigrants: A 30-year retrospective study.

OBJECTIVES: To compare the rates of schizophrenia among 1st and 2nd generation immigrants from two distinct backgrounds and across sequential periods of immigration. METHODS: A 30-years retrospective cohort study (187,184 individuals) of 1st and 2nd generation East-African immigrants (EAIs) and former Soviet-Union immigrants (FSUIs) who migrated to Israel between 1980 and 2012. EAIs were further divided according to waves of immigration. Period prevalence was calculated between the years 2002-2012. Multivariate logistic regression models were used to examine the association between immigration-related factors and prevalence of schizophrenia (Native-Born Israelis serving as reference group). RESULTS: The prevalence of schizophrenia in 1st generation EAIs and FSUIs was 1.8% and 1.2%, respectively, compared to 1.0% among NBIs (p<0.001). The prevalence of schizophrenia among 2nd generation EAIs and FSUIs was 1.3% and 0.8%, respectively, compared to 0.6% among NBIs (p<0.001). Adjusted odds ratios for developing schizophrenia compared to NBIs were 1.6 (95%CI:1.4-1.8) and 2.1 (95%CI:1.6-2.7), among 1st and 2nd generation EAIs and 1.1 (95%CI:0.9-1.2) and 1.3 (95%CI:1.0-1.8) among 1st and 2nd generation FSUIs respectively. Among EAIs, we observed the highest rate of schizophrenia in the pioneer wave of immigrants with gradual decline across subsequent waves: 2.4%, 1.9% and 1.0% for the 1st, 2nd and 3rd waves of immigration, respectively (p<0.001). CONCLUSIONS: The increased risk for developing schizophrenia among 2nd generation immigrants and among pioneer groups of immigrants emphasizes the importance of persistent investment in acculturation. Further studies elucidating the impact of country of origin and ethnic density on the risk for developing schizophrenia are warranted.

Asymmetry in thermal tolerance trade-offs between the B and Q sibling species of Bemisia tabaci (Hemiptera: Aleyrodidae).

We investigated life history trade-offs related to thermal tolerance in two sibling species, commonly referred to as the B and Q biotypes, of Bemisia tabaci. We focused on basal resistance to short unpredicted heat stress, which reflects the organism investment, during both optimal and stressful conditions, in insuring its survival. At 27 °C, the relative reproductive performance of B was seven-fold higher than Q. After short stress of 42 °C, these differences increased to 23-fold. A turnover took place after short stress of 43 and 45 °C, in which Q adults performed better. As the expression of the analysed Hsp70 and other stress-related genes was found to be higher in the Q species, our data likely reflects two different strategies for optimal performance. B lowers soma protection for achieving maximum reproduction ('direct inhibitory' trade-off model), whereas Q invests significant resources in being always 'ready' for a challenge.

Reperfusion injury of ischemic skeletal muscle is mediated by natural antibody and complement.

Reperfusion of ischemic tissue induces an acute inflammatory response that can result in necrosis and irreversible cell injury to both local vascular endothelium and parenchyma. To examine the pathogenesis of ischemia/reperfusion injury, we have used mice deficient in complement components C3, C4, or serum immunoglobulin in a hindlimb model of ischemia. We found that mice homozygous deficient in C3 or C4 were equally protected against reperfusion injury based on a significant reduction in leakage of radiolabeled albumin out of the vasculature. This demonstrates that classical pathway complement is an important factor in the initiation of inflammation following reperfusion. Furthermore, mice deficient in serum immunoglobulin were equally protected and this protection could be reversed by reconstitution with serum from normal mice. Thus, this report describes a novel mechanism for reperfusion injury that involves antibody deposition and activation of complement leading to inflammation permeability.

Meeting the 12 lymph node (LN) benchmark in colon cancer.

BACKGROUND: Examining >or=12 LN in colon cancer has been suggested as a quality metric. The purpose of this study was to determine whether the 12 LN benchmark is achieved at NCCN centers compared to a US population-based sample. METHODS: Patients with stage I-III disease resected at NCCN centers were identified from a prospective database (n = 718) and were compared to 12,845 stage I-III patients diagnosed in a SEER region. Age, gender, location, stage, number of positive nodes were compared for NCCN and SEER data in regards to number of nodes evaluated. Multivariate logistic regression models were developed to identify factors associated with evaluating 12 LNs. RESULTS: 92% of NCCN and 58% of SEER patients had >or=12 LN evaluated. For patients treated at NCCN centers, factors associated with not meeting the 12 LN target were left-sided tumors, stage I disease and BMI >30. CONCLUSIONS: >or=12 LN are almost always evaluated in NCCN patients. In contrast, this target is achieved in 58% of SEER patients. With longer follow-up of the NCCN cohort we will be able to link this quality metric to patterns of recurrence and survival and thereby better understand whether increasing the number of nodes evaluated is a priority for cancer control.

Risk-reducing surgery in FAP: role for surgeons beyond the incision.

BACKGROUND: Although primary therapy in familial adenomatous polyposis (FAP) is surgical, little is known about patients' surgical decision-making experience. The objective was to explore the decision-making process surrounding risk-reducing surgery in FAP using qualitative methodology. METHODS: In-depth, semi-structured interviews with 14 FAP patients and 11 healthcare providers with experience caring for FAP patients were conducted. Using grounded theory, line-by-line content analysis identified categories from which themes describing patients' experiences emerged; analysis continued until data saturation. RESULTS: Median age at surgery was 23 (7-37) years; at interview 41 (19-74) years. Two patients underwent surgery secondary to cancer, the remainder for risk-reduction. Content experts included colorectal surgeons (3), geneticists (2), gastroenterologists (3), nurses (3).Three themes emerged: Information: Family was the primary information source, and patients' level of information varied. The importance of up-front information was emphasized. Influences on decision-making: Influential factors included family experiences, youth, emotional state, support, and decision-making role. Although patients often sought opinions, most (12/14) wanted an active/shared role in decision-making. Life after surgery: Patients described surgery as the "easy part," emphasizing the need for long-term relationships with care providers. CONCLUSIONS: Decisions surrounding risk-reducing surgery in FAP are unique. A decision support tool may facilitate decision-making, better preparing patients for life after surgery.

Optimal surgical treatment of locally advanced low rectal cancer.

Colorectal adenocarcinoma is the second leading cause of cancer deaths in Western countries. Rectal cancer comprises approximately 25% of the malignancies arising in the large bowel. However, the past two decades have seen many major advances in the diagnosis and treatment of this disease. While surgery is still the cornerstone of curative therapy, a multidisciplinary approach including neoadjuvant chemoradiotherapy has resulted in significantly improved outcomes. Information concerning the T, N, M stage and the exact location of tumor in relation to the anal verge are of crucial importance when planning a curative rectal cancer resection. Preoperative staging, utilizing a combination of diagnostic modalities, must be undertaken to determine whether or not neoadjuvant therapy is indicated. In radical resection of locally advanced low rectal cancer, several unique surgical management issues should be considered: 1) total mesorectal excision (TME); 2) longitudinal and circumferential resection margins; 3) autonomic nerve preservation (ANP); 4) sphincter preservation versus abdominoperineal resection (APR); 5) restoration of bowel continuity; and 6) laparoscopic versus open resection. The surgeon must first strive to achieve an oncologic cure, but whenever possible this should be undertaken with the goal of maintaining the patient's quality of life. The purpose of this review is to outline the critical surgical issues involved in management of locally advanced low rectal cancer.

Orchid seed sensitivity to nitrate reflects habitat preferences and soil nitrate content.

Orchids are distributed around the world, however, the factors shaping their specific distribution and habitat preferences are largely unknown. Moreover, many orchids are at risk of becoming threatened as landscapes change, sometimes declining without apparent reason. One important factor affecting plant distribution is nutrient levels in the environment. Nitrates can inhibit not only orchid growth and persistence, but also seed germination. We used in vitro axenic cultures to exactly determine the germination sensitivity of seven orchid species to nitrates and correlated this with soil properties of the natural sites and with the species' habitat preferences. We found high variation in response to nitrate between species. Orchids from oligotrophic habitats were highly sensitive, while orchids from more eutrophic habitats were almost insensitive. Sensitivity to nitrate was also associated with soil parameters that indicated a higher nitrification rate. Our results indicate that nitrate can affect orchid distribution via direct inhibition of seed germination. Nitrate levels in soils are increasing rapidly due to intensification of agricultural processes and concurrent soil pollution, and we propose this increase could cause a decline in some orchid species.