Cosmic Ray Background Removal With Deep Neural Networks in SBND

In liquid argon time projection chambers exposed to neutrino beams and running on or near surface levels, cosmic muons, and other cosmic particles are incident on the detectors while a single neutrino-induced event is being recorded. In practice, this means that data from surface liquid argon time projection chambers will be dominated by cosmic particles, both as a source of event triggers and as the majority of the particle count in true neutrino-triggered events. In this work, we demonstrate a novel application of deep learning techniques to remove these background particles by applying deep learning on full detector images from the SBND detector, the near detector in the Fermilab Short-Baseline Neutrino Program. We use this technique to identify, on a pixel-by-pixel level, whether recorded activity originated from cosmic particles or neutrino interactions.

Do we need cardiopulmonary exercise to determine the optimal time for intervention in valvular heart disease?

Introduction

Cardiopulmonary exercise testing (CPET) is underused in many clinical conditions other than HF. In valvular heart disease (VHD), CEPT can aid in choosing the right timing for surgery. The goals of this study were to compare the assessment of functional capacity (FC) by CEPT and NYHA scale, and to analyze the relationship between ventilatory efficiency (VE) parameters and time to surgery.

Methods

197 CPET were performed in 163 patients with moderate or severe VHD (51% female). Real METS (RM) were calculated as indexed peak VO2/3.5 (1 MET = 3.5 ml O2/kg/min) and compared to estimated METS (EM) derived by the exercise duration. An agreement analysis between RM, EM and NYHA was performed. The association among VE/VCO2 slope, pet CO2 at anaerobic threshold (AT), OUES and time to surgical indication was also studied using Cox logistic regression analysis.

Results

See Table. The RM and EM were 4,7±1,7and 6,2±2,9, respectively (p<0.01), and the correlation was low (ICC=0,7, p<0.001). The agreement between NYHA class and % of peak predicted V02 was very low (kappa index = 0.1, p<0.001). VE parameters were predictive of an earlier surgical indication: petCO2 AT (p=0.02), VE/VCO2 slope (p=0.069), OUES (p=0.014).

Conclusions

In asymptomatic VHD patients, the surgical indication should not rely solely in their FC assessed by either NYHA scale or EM derived by duration of exercise. In our series, these parameters clearly overestimated the FC of the population. Also, the ventilatory inefficiency may be a surrogate marker of advanced disease and lead to a closer surveillance for an earlier intervention.

Real and estimated METS by type of VHD

Funding Acknowledgement

Type of funding source: None

A real world analysis of recurrence risk factors for early colorectal cancer T1 treated with standard endoscopic resection

BACKGROUND AND STUDY AIM

Currently, endoscopic resection of early colorectal cancer defined as carcinoma with limited invasion of the mucosa (Tis) and submucosa (T1) is possible. However, lymph node spreading increases to 16.2% of cases when tumor invades the submucosa. We analyzed the previously identified factors for lymph node dissemination and recurrence, in our population.

PATIENTS AND METHODS

We analyzed retrospectively all patients with T1 tumors, treated at our center with endoscopic resection and some with additional surgery between January 2006 and January 2018. Statistical analysis was performed using IBM SPSS Statistics 25.0.

RESULTS

One hundred fifty-nine patients were treated with endoscopic resection, 56.6% with additional surgery. The mean age was 68.74 years and 69. 9% were male. All patients who underwent additional surgery presented negative margins and 8.8% presented positive lymph nodes. In a mean follow-up of 23.36 months, 13 patients had relapsed. The risk of relapse did not differ between patients treated with additional surgery from those who only underwent endoscopic resection (p = 0.506). On the other hand, lymph node dissemination (p = 0.007) and a positive endoscopic margin (p = 0.01) were independent risk factors for relapse. There was a positive association between lymph node dissemination and lymphatic (p = 0.07), vascular (p = 0.007), and perineural (p = 0.001) invasion and also with degree of histological differentiation (p = 0.001).

CONCLUSION

In our study, lymphatic, vascular, and perineural invasion and also the degree of histological differentiation were associated with lymph node dissemination. However, the only independent risk factors for long-term recurrence were a positive margin and lymph node dissemination.

P4344An example that big data analysis is ready for the prime time

Introduction

Data about the epidemiology of valvular heart disease (VHD) is scarce. The increasing aging of the population may cause an augmented prevalence of VHD, with a great number of comorbidities that conveys a higher surgical risk. The aim of this study was to describe the prevalence of VHD in the patients attended at our institution from 2007 until 2017 and to describe the main characteristics of this population.

Methods

We used a new tool based on EHRead Technology to extract clinical relevant information from Electronic Health Records, designed for descriptive and predictive big data analysis. All medical reports generated at the outpatient clinic, ER or hospitalization ward were examined. Patients with a diagnosis of moderate or severe VHD were selected. The prevalence of VHD was also estimated in 2 quintiles, from 2008 until Feb 2013 and from March 2013 until Dec 2017.

Results

The total prevalence of VHD in our population was 1.04% (n=3431). Mitral regurgitation was the most frequent valvular lesion (0.4%, n=1318), followed by aortic stenosis (0.3%, n=967) and aortic regurgitation (0.28%, n=938). There was a clear female predominance (63%), and the median age was 76.4. In the 1st quintile the prevalence of VHD was 0.25%, and increased to 0.79% in the 2nd. This trend was consistent in all type of valvular lesions. The prevalence of comorbidities was higher than in other epidemiological studies (Table).

Prevalence of comorbidities Severe MR Severe AS Severe AR Euro Heart Valve Survey Hypertension 54,5% 69,1% 47,9% 49% Dyslipidemia 32,2% 40,6% 27,4% 35% Diabetes Mellitus 28,0% 31,5% 16,4% 15% Smoking (current) 5,6% 5,4% 13,7% 39% Coronary heart disease 12,0% 17,0% 12,3% 13% Stroke 7,0% 8,9% 5,5% 7% Chronic kidney disease 18,9% 16,9% 20,5% 15% Chronic obstructive pulmonary disease 11,2% 9,9% 11,0% 15% MR: Mitral regurgitation, AS: aortic stenosis, AR: aortic regurgitation, MS: mitral stenosis.

Sex Distribution

Conclusions

The older age and greater number of comorbidities seen in our series over the past ten years, compared to the Euroheart Valve Survey reinforce the idea that the percutaneous valvular therapies should play a major role in the treatment of patients with VHD. Although, the prevalence of VHD may be underestimated in our population, due to the methodology, it reflects an ever-growing pathology in an older and sicker population.

Werner's Syndrome: Understanding the Phenotype of Premature Aging-First Case Described in Colombia

Werner's syndrome (WS) is an autosomal recessive genetic disease, which is mainly characterized by scleroderma-like skin changes, juvenile cataracts, short stature, and signs of premature aging. We report a case of a 48-year-old male patient, who presents with cardinal signs of WS including high-pitched voice, sclerotic skin lesions mainly on feet, premature greying of scalp hair, bilateral cataracts, and "bird-like" facial appearance. In addition, the patient presents other clinical characteristics observed in patients with WS such as short stature, type 2 diabetes mellitus, hypogonadism, parental consanguinity, and a history of a sibling with similar clinical characteristics. WRN gene sequencing identified the homozygous pathogenic variant NM_00553.4: c.2581C>T (NP_000544.2: pGln861Ter). This is the first case of WS reported in the Colombian population. We report this case to avoid misdiagnosis of this infrequent condition and allow timely identification of potential complications associated with premature aging, especially malignancies, cardiovascular and metabolic diseases.

CCR-CARESS score for predicting operative mortality in patients with colorectal cancer

BACKGROUND

The aim of this study was to assess factors associated with outcomes after surgery for colorectal cancer and to design and internally validate a simple score for predicting perioperative mortality.

METHODS

Patients undergoing surgery for primary invasive colorectal cancer in 22 centres in Spain between June 2010 and December 2012 were included. Clinical variables up to 30 days were collected prospectively. Multiple logistic regression techniques were applied and a risk score was developed. The Hosmer-Lemeshow test was applied and the area under the receiver operating characteristic (ROC) curve (AUC, with 95 per cent c.i.) was estimated.

RESULTS

A total of 2749 patients with a median age of 68·5 (range 24-97) years were included; the male : female ratio was approximately 2 : 1. Stage III tumours were diagnosed in 32·6 per cent and stage IV in 9·5 per cent. Open surgery was used in 39·3 per cent, and 3·6 per cent of interventions were urgent. Complications were most commonly infectious or surgical, and 25·5 per cent of patients had a transfusion during the hospital stay. The 30-day postoperative mortality rate was 1·9 (95 per cent c.i. 1·4 to 2·4) per cent. Predictive factors independently associated with mortality were: age 80 years or above (odds ratio (OR) 2·76), chronic obstructive pulmonary disease (COPD) (OR 3·62) and palliative surgery (OR 10·46). According to the categorical risk score, a patient aged 80 years or more, with COPD, and who underwent palliative surgery would have a 23·5 per cent risk of death within 30 days of the intervention.

CONCLUSION

Elderly patients with co-morbidity and palliative intention of surgery have an unacceptably high risk of death.

Non-inferiority multicenter prospective randomized controlled study of rectal cancer T2-T3s (superficial) N0, M0 undergoing neoadjuvant treatment and local excision (TEM) vs total mesorectal excision (TME)

PURPOSE

The standard treatment of rectal adenocarcinoma is total mesorectal excision (TME), in many cases requires a temporary or permanent stoma. TME is associated with high morbidity and genitourinary alterations. Transanal endoscopic microsurgery (TEM) allows access to tumors up to 20 cm from the anal verge, achieves minimal postoperative morbidity and mortality rates, and does not require an ostomy. The treatment of T2, N0, and M0 cancers remains controversial. Preoperative chemoradiotherapy (CRT) in association with TEM reduces local recurrence and increases survival. The TAU-TEM study aims to demonstrate the non-inferiority of the oncological outcomes and the improvement in morbidity and quality of life achieved with TEM compared with TME.

METHODS

Prospective, multicenter, randomized controlled non-inferiority trial includes patients with rectal adenocarcinoma less than 10 cm from the anal verge and up to 4 cm in size, staged as T2 or T3-superficial N0-M0. Patients will be randomized to two areas: CRT plus TEM or radical surgery (TME). Postoperative morbidity and mortality will be recorded and patients will complete the quality of life questionnaires before the start of treatment, after CRT in the CRT/TEM arm, and 6 months after surgery in both arms. The estimated sample size for the study is 173 patients. Patients will attend follow-up controls for local and systemic relapse.

CONCLUSIONS

This study aims to demonstrate the preservation of the rectum after preoperative CRT and TEM in rectal cancer stages T2-3s, N0, M0 and to determine the ability of this strategy to avoid the need for radical surgery (TME).

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01308190. Número de registro del Comité de Etica e Investigación Clínica (CEIC) del Hospital universitario Parc Taulí: TAU-TEM-2009-01.

[Rituximab: its efficacy, effectiveness and safety in the treatment of multiple sclerosis]

INTRODUCTION

There is increasing evidence that B cells and humoral immunity play key roles in the pathogenesis of multiple sclerosis (MS). Ocrelizumab, an anti-CD20 monoclonal antibody, has been shown to be effective in controlling the disease and has recently been aproved by the Food and Drug Administration for the treatment of primary progressive and relapsing MS. While awaiting its marketing authorization, the use of rituximab, with a similar mechanism of action, has expanded widely in the area of demyelinating diseases.

AIM

To address the main aspects of efficacy, effectiveness and safety of rituximab in the treatment of MS.

DEVELOPMENT

PubMed review of placebo-controlled clinical trials, prospective open label studies, retrospective observational studies, and case series using rituximab in adult MS affected populations were performed. Its impact on the clinical and radiological control of the disease was evaluated, as well as any relevant safety issues.

CONCLUSIONS

In all of the studies reviewed, rituximab demonstrated a consistent benefit in controlling inflammatory activity, both clinically, reducing the incidence of relapses, and radiologically, avoiding the appearance of new and/or active lesions. On the contrary, with regards to the progression of disability, its effect is more controversial. Safety profile appears acceptable. Rituximab seems to be an effective and safe drug in the treatment of MS.

Predictive factors for early- and late-onset surgical site infections in patients undergoing elective colorectal surgery. A multicentre, prospective, cohort study

BACKGROUND

Surgical site infections (SSIs) are the leading cause of healthcare-associated infections in acute care hospitals in Europe. However, the risk factors for the development of early-onset (EO) and late-onset (LO) SSI have not been elucidated.

AIM

This study investigated the predictive factors for EO-SSI and LO-SSI in a large cohort of patients undergoing colorectal surgery.

METHODS

We prospectively followed-up adult patients undergoing elective colorectal surgery in 10 hospitals (2011-2014). Patients were divided into three groups: EO-SSI, LO-SSI, or no infection (no-SSI). The cut-off defining EO-SSI and LO-SSI was seven days (median time to SSI development). Different predictive factors for EO-SSI and LO-SSI were analysed, comparing each group with the no-SSI patients.

FINDINGS

Of 3701 patients, 320 (8.6%) and 349 (9.4%) developed EO-SSI and LO-SSI, respectively. The rest had no-SSI. Patients with EO-SSI were mostly males, had colon surgery and developed organ-space SSI whereas LO-SSI patients frequently received chemotherapy or radiotherapy and had incisional SSI. Male sex (odds ratio (OR): 1.92; P < 0.001), American Society of Anesthesiologists' physical status >2 (OR: 1.51; P = 0.01), administration of mechanical bowel preparation (OR: 0.7; P = 0.03) and stoma creation (OR: 1.95; P < 0.001) predicted EO-SSI whereas rectal surgery (OR: 1.43; P = 0.03), prolonged surgery (OR: 1.4; P = 0.03) and previous chemotherapy (OR: 1.8; P = 0.03) predicted LO-SSI.

CONCLUSION

We found distinctive predictive factors for the development of SSI before and after seven days following elective colorectal surgery. These factors could help establish specific preventive measures in each group.

Dynamic contact angle cycling homogenizes heterogeneous surfaces

In order to reduce restenosis, the necessity to develop the appropriate coating material of metallic stent is a challenge for biomedicine and scientific research over the past decade. Therefore, biodegradable copolymers of poly((R,S)-3,3 dimethylmalic acid) (PDMMLA) were prepared in order to develop a new coating exhibiting different custom groups in its side chain and being able to carry a drug. This material will be in direct contact with cells and blood. It consists of carboxylic acid and hexylic groups used for hydrophilic and hydrophobic character, respectively. The study of this material wettability and dynamic surface properties is of importance due to the influence of the chemistry and the potential motility of these chemical groups on cell adhesion and polymer kinetic hydrolysis. Cassie theory was used for the theoretical correction of contact angles of these chemical heterogeneous surfaces coatings. Dynamic Surface Analysis was used as practical homogenizer of chemical heterogeneous surfaces by cycling during many cycles in water. In this work, we confirmed that, unlike receding contact angle, advancing contact angle is influenced by the difference of only 10% of acidic groups (%A) in side-chain of polymers. It linearly decreases with increasing acidity percentage. Hysteresis (H) is also a sensitive parameter which is discussed in this paper. Finally, we conclude that cycling provides real information, thus avoiding theoretical Cassie correction. H(10)is the most sensible parameter to %A.

Optimizing preoperative haemoglobin in major orthopaedic surgery using intravenous iron with or without erythropoietin. An epidemiologic study

AIM

To evaluate the effectiveness of intravenous iron treatment, with or without associated erythropoietin (rHuEPO), measured as haemoglobin (Hb) increase. The relationships between the Hb increase and parameters used to evaluate anaemia were analysed.

MATERIAL AND METHOD

Retrospective observational study carried out in two third-level hospitals between January 2005 and December 2009. The study included patients with iron deficiency anaemia scheduled for elective orthopaedic surgery and treated with intravenous iron sucrose alone or associated with rHuEPO. Treatment efficacy was analysed based on the Hb increase from baseline to just before surgery.

RESULTS

A total of 412 patients who received a median of 800mg of iron sucrose were included; 125 of them (30.4%) additionally received 2.4 vials of rHuEPO. The Hb increase was 0.8 (1.1) g/dL in patients treated with intravenous iron and 1.5 (1.3) g/dL in those additionally given rHuEPO(P<.01). The percentage of hypochromic red blood cells (r=0.52) and soluble transferrin receptor (r=0.59) value were significantly correlated to the Hb increase in patients receiving iron.

CONCLUSIONS

In patients with iron deficiency anaemia, the effectiveness of iron sucrose treatment to optimize Hb before surgery was moderate; adjuvant administration of erythropoietin improved the results. Determination of functional iron status parameters may improve the treatment effectiveness.

Prospective, controlled, randomized study of intraoperative colonic lavage versus stent placement in obstructive left-sided colonic cancer

BACKGROUND

The main aim of this study was to compare short-term results and long-term outcomes of patients who underwent intraoperative colonic lavage (IOCL) with primary anastomosis with those who had stent placement prior to scheduled surgery for obstructive left-sided colonic cancer (OLCC).

METHODS

We conducted a prospective, controlled, randomized study of patients diagnosed with OLCC. Patients were divided into two groups: stent and deferred surgery (group 1) and emergency IOCL (group 2). Demographic variables, risk prediction models, postoperative morbidity and mortality, staging, complications due to stent placement, surgical time, clinical follow-up, health costs, and follow-up of survival were recorded.

RESULTS

Twenty-eight patients (15 group 1 and 13 group 1) were enrolled. The study was suspended upon detecting excess morbidity in group 2. The two groups were homogeneous in clinical and demographic terms. Overall morbidity in group 1 was 2/15 (13.3%) compared with 7/13 (53.8%) in group 2 (p = 0.042). None of the 15 patients in group 1 presented anastomotic dehiscence compared with 4/13 (30.7%) in group 2 (p = 0.035). Surgical site infection was detected in 2 (13.3%) patients in group 1 and in 6 (46.1%) in group 2 (p = 0.096). Postoperative stay was 8 days (IQR 3, group 1) and 10 days (IQR 10, group 2) (p = 0.05). The mean follow-up period was 37.6 months (SD = 16.08) with no differences in survival between the groups.

CONCLUSION

In our setting, the use of a stent and scheduled surgery is safer than IOCL and is associated with lower morbidity, shorter hospital stay, and equally good long-term survival.

[Thromboprophylaxis in multiple trauma and head injury patients]

Venous thromboembolic disease (VTD) is a frequent condition with serious clinical consequences and elevated mortality related to underdiagnosis or undertreatment, especially in patients with multiple trauma. The incidence of VTD in these patients ranges from 5% to 58% and thromboprophylaxis is considered essential for proper management. Traditionally, pelvic and lower extremity fractures, head injury, and prolonged immobilization have been cited as risk factors for VTD; however, how these factors combine with others to predict high risk is still unclear. The best way to approach VTD prophylaxis in multiple trauma patients is currently unclear. Both mechanical and pharmacologic means are available. The main clinical practice guidelines recommend thromboprophylaxis with low-molecular weight heparin, which can be started 48 hours after trauma, unless patients are still bleeding, in which case mechanical compression is recommended in spite of the limited effectiveness of that measure. Compression is maintained until the risk of hemorrhage has diminished. There is insufficient evidence to support routine use of ultrasound imaging or venography. In patients with head injury who are at risk for intracranial bleeding, the use of low-molecular weight heparin should be delayed until risk disappears but mechanical prophylaxis (compression) can be considered according to clinical status.

Protein kinase C phosphorylates the cAMP response element binding protein in the hypothalamic paraventricular nucleus during morphine withdrawal

BACKGROUND AND PURPOSE

Exposure to drugs of abuse or stress results in adaptation in the brain involving changes in gene expression and transcription factors. Morphine withdrawal modulates gene expression through various second-messenger signal transduction systems. Here, we investigated changes in activation of the transcription factor, cAMP-response element binding protein (CREB), in the hypothalamic paraventricular nucleus (PVN) and the kinases that may mediate the morphine withdrawal-triggered activation of CREB and the response of the hypothalamic-pituitary-adrenocortical (HPA) axis after naloxone-induced morphine withdrawal.

EXPERIMENTAL APPROACH

The effects of morphine dependence and withdrawal, phosphorylated CREB (pCREB), corticotrophin-releasing factor (CRF) expression in the PVN and HPA axis activity were measured using immunoblotting, immunohistochemistry and radioimmunoassay in controls and in morphine-dependent rats, withdrawn with naloxone and pretreated with vehicle, calphostin C, chelerythrine (inhibitors of protein kinase C (PKC) or SL-327 [inhibitor of extracellular signal regulated kinase (ERK) kinase]. In addition, changes in PKCα and PKCγ immunoreactivity were measured after 60 min of withdrawal.

KEY RESULTS

In morphine-withdrawn rats, pCREB immunoreactivity was increased within CRF immunoreactive neurons in the PVN and plasma corticosterone levels were raised. SL-327, at doses that reduced the augmented pERK levels in the PVN, did not attenuate the rise in pCREB immunoreactivity or plasma corticosterone secretion. In contrast, PKC inhibition reduced the withdrawal-triggered rise in pCREB, pERK1/2 and corticosterone secretion.

CONCLUSIONS AND IMPLICATIONS

PKC mediated, in part, both CREB activation and the HPA response to morphine withdrawal. The ERK kinase/ERK pathway might not be necessary for either activation of CREB or HPA axis hyperactivity.

Electrochemical impedance spectroscopy as a highly sensitive tool for a dynamic interaction study between heparin and antithrombin: a novel antithrombin sensor

Specific recognition between two biological partners is widely exploited in biosensors nowadays. To explore this avenue, a novel biosensor for antithrombin (AT) detection was constructed. Heparin was used as the affinity ligand. A well-known acrylic monomer (butyl methacrylate) was polymerized and grafted onto the heparin polysaccharide by the use of ceric ammonium nitrate as a redox initiator in aqueous nitric acid medium. Polymers were deposited as a thin layer onto surface of stainless steel electrode (SS316L). The obtained polymers were studied by Fourier transform infrared spectroscopy (FTIR) and analyzed by differential scanning calorimetry (DSC). Moreover, the films were characterized by electrochemical impedance spectroscopy (EIS), contact-angle measurements and AFM. EIS was used to study the biosensor affinity to AT and the relationship between functionalization growth of modified electrode and the response of the sensor. The proposed approach appears to be simple, sensitive and correlated with methods that analyse the detection of antithrombin.

Enhanced tyrosine hydroxylase phosphorylation in the nucleus accumbens and nucleus tractus solitarius-A2 cell group after morphine-conditioned place preference

Although dopamine (DA) has been extensively implicated in the morphine-induced conditioned place preference (CPP; a measure of reward), noradrenaline (NA) and other systems may play a larger role than previously suspected. The mesolimbic DA system, comprised of projections from the ventral tegmental area (VTA) to the nucleus accumbens (NAc), receives noradrenergic innervations from the nucleus tractus solitaries (NTS)-A2 cell group and is modulated by NA. The purpose of the present study was to evaluate the turnover of DA and NA in the NAc and the site-specific phosphorylation of TH in the NAc, VTA, and NTS on the CPP mice conditioned by morphine. A dose-effect curve for morphine-induced CPP (0.5-8 mg/kg, s.c.) was obtained using 6-day conditioning sessions followed by a CPP test. TH phosphorylation was determined by quantitative blot immunolabeling and immunohistochemistry using phosphorylation state-specific antibodies; NA and DA turnover was evaluated by high-performance liquid chromatography. Morphine-induced CPP phosphorylates TH at serine (Ser)40 but not Ser31 in NAc, which is associated with an enhanced of DA and NA turnover. We also found that morphine-induced CPP increased levels of TH phosphorylated at Ser31 and Ser40 in the NTS. The present study demonstrates that morphine-induced CPP might stimulate TH activity and accelerate DA and NA turnover in the NAc via a mechanism involving phosphorylation of TH.

Colorectal stenting as an effective therapy for preoperative and palliative treatment of large bowel obstruction: 9 years' experience

BACKGROUND

Since their introduction, selfextending metal stents (SEMS) have established themselves as an option in the treatment of obstructive colorectal cancer. Thanks to stenting, patients traditionally treated with emergency surgery can now be converted to scheduled surgery with mechanical preparation of the colon and primary anastomosis. Stenting represents a valid one-step surgical alternative for intestinal obstruction of the colon.

METHODS

We performed a prospective study of 95 patients (mean age, 68 years; range 48-94) with large bowel obstruction due to colorectal cancer treated with SEMS placed under fluoroscopic guidance, some as a bridge to surgery (group A) and others with palliative intent (group B). Computed tomography was performed for diagnostic purposes and to study the extent of disease.

RESULTS

Treatment was palliative in 28 cases (group B) and as a bridge to surgery in 67 (group A). The latter group underwent mechanical preparation of the colon and elective surgery. No patients died as a result of the procedure. In 90 cases (95%), treatment was effective and the obstruction resolved. Complications were 4 cases of perforation, 1 of tenesmus, 4 obstructions and 4 migrations. In 7 cases, a second stent was inserted to allow subsequent scheduled surgery.

CONCLUSIONS

Self-extending stents resolve colorectal cancer obstruction and allow optimal patient staging and scheduled surgical treatment. Stenting is also a useful option in advanced or irresectable tumors, avoiding the need for surgery and offering good palliation.

Evolutionary conserved chromosomal segments in the human karyotype are bounded by unstable chromosome bands

In this paper an ancestral karyotype for primates, defining for the first time the ancestral chromosome morphology and the banding patterns, is proposed, and the ancestral syntenic chromosomal segments are identified in the human karyotype. The chromosomal bands that are boundaries of ancestral segments are identified. We have analyzed from data published in the literature 35 different primate species from 19 genera, using the order Scandentia, as well as other published mammalian species as out-groups, and propose an ancestral chromosome number of 2n = 54 for primates, which includes the following chromosomal forms: 1(a+c(1)), 1(b+c(2)), 2a, 2b, 3/21, 4, 5, 6, 7a, 7b, 8, 9, 10a, 10b, 11, 12a/22a, 12b/22b, 13, 14/15, 16a, 16b, 17, 18, 19a, 19b, 20 and X and Y. From this analysis, we have been able to point out the human chromosome bands more "prone" to breakage during the evolutionary pathways and/or pathology processes. We have observed that 89.09% of the human chromosome bands, which are boundaries for ancestral chromosome segments, contain common fragile sites and/or intrachromosomal telomeric-like sequences. A more in depth analysis of twelve different human chromosomes has allowed us to determine that 62.16% of the chromosomal bands implicated in inversions and 100% involved in fusions/fissions correspond to fragile sites, intrachromosomal telomeric-like sequences and/or bands significantly affected by X irradiation. In addition, 73% of the bands affected in pathological processes are co-localized in bands where fragile sites, intrachromosomal telomeric-like sequences, bands significantly affected by X irradiation and/or evolutionary chromosomal bands have been described. Our data also support the hypothesis that chromosomal breakages detected in pathological processes are not randomly distributed along the chromosomes, but rather concentrate in those important evolutionary chromosome bands which correspond to fragile sites and/or intrachromosomal telomeric-like sequences.

Comparing zonal and CFD model predictions of isothermal indoor airflows to experimental data

It is inappropriate to use the assumption of instantaneously well-mixed zones to model airflows and pollutant transport in large indoor spaces. We investigate two approaches for describing the details of airflows in large indoor spaces, for accuracy and suitability for integration with multi-zone infiltration models. One approach, called the zonal method, was developed over the last 15 years to provide an improvement over the well-mixed assumption. The second approach is the use of a computational fluid dynamics simulation using a coarse grid model of the large indoor space. We compare velocity predictions from different formulations of zonal methods and coarse-grid k-epsilon computational fluid dynamics (CFD) models, to measurements, in a 2D mechanically ventilated isothermal room. Our results suggest that, when airflow details are required, coarse-grid CFD is a better-suited method to predict airflows in large indoor spaces coupled with complex multi-zone buildings, than are the zonal methods. Based on the comparison of pressure predictions from different models, we offer guidance regarding the coupling of a model of detailed airflow in large spaces to algebraic multi-zone infiltration models.

Randomized clinical study of Gastrografin administration in patients with adhesive small bowel obstruction

BACKGROUND

Oral Gastrografin has been used to differentiate partial from complete small bowel obstruction (SBO). It may have a therapeutic effect and predict the need for early surgery in adhesive SBO. The aim of this study was to determine whether contrast examination in the management of SBO allows an early oral intake and reduces hospital stay.

METHODS

Eighty-three patients admitted between February 2000 and November 2001 with 90 episodes of symptoms and signs suggestive of postoperative adhesive SBO were randomized into two groups, a control group and Gastrografin group. Patients in the control group were treated conservatively. If symptoms of strangulation developed or the obstruction did not resolve spontaneously after 4-5 days, a laparotomy was performed. Patients in the Gastrografin group received 100 ml Gastrografin. Those in whom the contrast medium reached the colon in 24 h were considered to have partial SBO, and were fed orally. If Gastrografin failed to reach the colon and the patient did not improve in the following 24 h a laparotomy was performed.

RESULTS

Conservative treatment was successful in 77 episodes (85.6 per cent) and 13 (14.4 per cent) required operation. Among patients treated conservatively, hospital stay was shorter in the Gastrografin group (P < 0.001). All patients in whom contrast medium reached the colon tolerated an early oral diet. Gastrografin did not reduce the need for operation (P = 1.000). No patient died in either group.

CONCLUSION

Oral Gastrografin helps in the management of patients with adhesive SBO and allows a shorter hospital stay.

Arthroscopic retrieval of an unusual foreign body of the knee

We report an unusual use of the arthroscope in the case of a man who accidentally shot himself through his left thigh, the bullet ending up in the ipsilateral knee joint. After radiographic diagnosis, the bullet was successfully removed through a standard arthroscopic procedure. The patient had a quick and complete recovery. Review of the literature and the 4 steps of successful management of gunshot wounds are included.

Granulocyte colony-stimulating factor induces neutrophils to secrete macrophage colony-stimulating factor

In this work we provide evidence showing that granulocytes produce macrophage colony-stimulating factor (M-CSF) from the band cell stage and secrete this factor when induced to differentiate into polymorphonuclear cells by recombinant human granulocyte colony-stimulating factor (rhG-CSF). Using an enriched population of myeloid band cells from murine bone marrow, we identified the presence of M-CSF with a chromophore-labelled monoclonal anti-M-CSF antibody. Using ELISA we detected the secretion of M-CSF in the supernatants of cultures of enriched band cells when induced with rhG-CSF to differentiate into mature neutrophils. We also found that M-CSF is the only factor responsible for the colony forming activity in the supernatants and lysates of band cells treated with rhG-CSF.

Cleavage of colicin D is necessary for cell killing and requires the inner membrane peptidase LepB

Colicin D is known to kill target cells by cleaving tRNA(Arg). A colicin D-resistant mutant was selected that was altered in the inner membrane leader peptidase, LepB. The substituted residue (Asn274Lys) is located close to the catalytic site. The mutation abolishes colicin D cleavage but not the processing of exported proteins. LepB is required for colicin D cleavage, releasing a small C-terminal fragment that retains full tRNase activity. The immunity protein was found to prevent colicin D processing and furthermore masks tRNase activity, thus protecting colicin D against LepB-mediated cleavage during export. Catalytic colicins share a consensus sequence at their putative processing site. Mutations affecting normal processing of colicin D abolish cytotoxicity without affecting the in vitro tRNase activity.

A post-translational modification in the GGQ motif of RF2 from Escherichia coli stimulates termination of translation

A post-translational modification affecting the translation termination rate was identified in the universally conserved GGQ sequence of release factor 2 (RF2) from Escherichia coli, which is thought to mimic the CCA end of the tRNA molecule. It was shown by mass spectrometry and Edman degradation that glutamine in position 252 is N:(5)-methylated. Overexpression of RF2 yields protein lacking the methylation. RF2 from E.coli K12 is unique in having Thr246 near the GGQ motif, where all other sequenced bacterial class 1 RFs have alanine or serine. Sequencing the prfB gene from E.coli B and MRE600 strains showed that residue 246 is coded as alanine, in contrast to K12 RF2. Thr246 decreases RF2-dependent termination efficiency compared with Ala246, especially for short peptidyl-tRNAs. Methylation of Gln252 increases the termination efficiency of RF2, irrespective of the identity of the amino acid in position 246. We propose that the previously observed lethal effect of overproducing E.coli K12 RF2 arises through accumulating the defects due to lack of Gln252 methylation and Thr246 in place of alanine.

Diagnosis and management of diffuse leiomyomatosis of the oesophagus

Diffuse leiomyomatosis of the oesophagus is a rare entity among oesophageal diseases. Histopathologically it is characterized by diffuse hypertrophy of the muscular layer extending to the whole oesophagus predominantly in the lower third, where it can result in tumour formation. Leiomyomatosis can involve the upper part of the stomach and is frequently associated with genital or tracheobronchial (bronchitracheal) muscular localizations. Also, it can be associated with Alport's syndrome in familial cases. For diagnosis, barium swallow, computerized tomography (CT) scan and, in recent years, endoscopic ultrasonography are used. Oesophageal resection is the only suitable treatment in symptomatic cases. We report three observations during 1979-95.

Thinner abuse alters optokinetic nystagmus parameters

BACKGROUND

Deliberate self-inhalation of solvents such as thinner is a recognized problem in underdeveloped countries, with chronic abuse resulting in neurological impairment. In this article, we use electronystagmography (ENG) to study optokinetic nystagmus abnormalities (OKN) that may be induced by thinner consumption.

METHODS

Twenty-five patients exposed to thinner for 5-20 years, in an irregular fashion of consumption, were recruited from a toxicologic center. Twenty-five control subjects were invited to participate as volunteers matched by age (+/-2 years) and gender. At the time of evaluation, all had abstained from intoxicants for at least 4 weeks. ENG recordings were performed by clinicians masked to the patient's group. Clockwise and counterclockwise stimulation were performed at 20 and 40 degrees /sec.

RESULTS

None of the patients showed spontaneous nystagmus during the test period. Differences between thinner abusers and controls on clockwise and counterclockwise OKN on number of beats of nystagmus elicited on the 40 degrees /sec velocity were identified. The thinner abusers group showed a lesser number of nystagmus (p level was 0.02 and 0.005, respectively).

CONCLUSIONS

The present results confirm the sensibility of OKN as an early marker of solvent abuse. These results were obtained in middle-term chronic exposure to solvent mixtures and are in favor of both cortical and brainstem dysfunction.

Disseminated histoplasmosis in infants

BACKGROUND

Disseminated histoplasmosis usually occurs in immunocompromised patients who reside in Histoplasma capsulatum-endemic regions. It has also been described in immunocompetent infants after exposure to a large inoculum of the pathogen resulting in case fatality rates of 40 to 50%.

METHODS

From 1983 through 1996 all infants with documented disseminated histoplasmosis were treated with amphotericin B followed by daily ketoconazole for 3 months. Immunologic workups were performed at the time of diagnosis and at 4 to 6 weeks of therapy. Surviving patients were followed for at least 1 year. Time to resolution of signs and symptoms was recorded, as were complications.

RESULTS

We managed 40 patients with disseminated histoplasmosis. The age in months at diagnosis was 15.3+/-10.2 (mean +/- SD), and 24 were male. All patients were from endemic regions and they presented with fever, spleen and/or liver enlargement and hematologic abnormalities. Diagnosis was made by histology and culture of bone marrow, spleen, lymph node, bronchoalveolar or liver samples. Twenty patients presented with T cell deficiency that resolved at 4 to 6 weeks of therapy in all of the retested patients, and 10 of 12 tested patients had hyperglobulinemia that resolved. Thirty-five (88%) patients were cured by treatment; 4 died and 1 relapsed.

CONCLUSIONS

Disseminated histoplasmosis should be considered in infants from endemic areas who present with fever, hepatosplenomegaly and hematologic abnormalities. These patients develop transient hyperglobulinemia and T cell deficiency that resolve with treatment. Treatment with amphotericin B followed by an oral azole for 3 months is effective in most patients.

Expression of insulin-like growth factor-1 receptor in human colorectal cancer

The activation of the insulinlike growth factor 1/IGF-1 receptor system (IGF1/IGF1-R) has recently emerged as critical event in transformation and tumorigenicity of several murine and human tumors. Expression of IGF1 and of IGF1-R has been demonstrated in normal and neoplastic intestinal cell lines of rats and humans. However, the modulation of IGF1-R expression during the progression from normal colonic mucosa to adenoma, to carcinoma, and to metastasis, has not been evaluated. In this retrospective study, we investigated the expression of IGF1-R in 12 colonic adenomas (AD), 36 primary colorectal adenocarcinomas (CA), and in 27 corresponding metastases (MT). Normal colonic mucosa (N) was adjacent to the CA in 34 cases. Formalin-fixed, paraffin-embedded tissues of each case were immunostained using the avidin-biotin-peroxidase method. We used an anti-IGF1-R rabbit polyclonal antibody (Santa Cruz Biotechnology, CA; dilution 1:100). Positive staining was quantitated by CAS-200. Moderate to strong cytoplasmic immunostaining was observed in 34 of 36 CA (96%), and in 25 of 27 MT (93%). In all of the positive MTs, the intensity of the staining was always strong. In 10 of 12 ADs (83%), only a faint cytoplasmic stain was identified. Normal mucosa when present was negative. Strong IGF1-R positivity correlated with higher grade and higher-stage tumors (P < .01). These data suggest a role of IGF1-R expression during the progression of colorectal adenoma to carcinoma. An increased number of IGF1-R receptors may favor the metastasis of colorectal cancer.

Visceral leishmaniasis in Costa Rica: first case report

We describe a 15-month-old eutrophic immunocompetent male who presented with fever, hepatosplenomegaly, pancytopenia, and hypergammaglobulinemia. Leishmania amastigotes were identified in spleen and bone marrow specimens. In addition, tissue culture, animal inoculation, and isoenzyme analysis identified the parasite as Leishmania donovani infantum or Leishmania donovani chagasi. The infant was successfully treated with an antimonial drug. These findings represent the first case of visceral leishmaniasis reported in Costa Rica.

Significance of Fas and retinoblastoma protein expression during the progression of Barrett's metaplasia to adenocarcinoma

BACKGROUND

Barrett's esophagus (BE) is a premalignant lesion characterized by replacement of normal squamous epithelium with columnar epithelium. This lesion can progress to dysplasia and adenocarcinoma. Recently, the Fas receptor and retinoblastoma (Rb) protein have been described as important mediators of apoptosis and tumor suppression, respectively. This study was undertaken to examine their expression during the progression of metaplasia to adenocarcinoma in BE.

METHODS

In a review of 56 adenocarcinomas arising in BE, the specimen blocks were examined using the immunohistochemical avidin-biotin-peroxidase complex technique. For each specimen, areas of normal epithelium were compared with areas of metaplasia, dysplasia, or carcinoma (when present). Monoclonal mouse anti-human antibodies were used to identify Rb protein (Rb-Ab5, 1/50 dilution; Oncogene Science) and the 40-50-kDa cell membrane Fas protein (APO-1/Fas, 1/5 dilution; DAKO Corp.).

RESULTS

Loss of Rb staining was observed as the metaplasia progressed to dysplasia and carcinoma, indicating accumulation of unstainable aberrant protein. Conversely, Fas protein staining was undetectable or weak in normal or metaplastic epithelium, increasing in the areas of high-grade dysplasia and carcinoma. These differences were statistically significant (P < .001).

CONCLUSIONS

The accumulation of abnormal Rb protein during the progression of Barrett's metaplasia to carcinoma leads to unsuppressed tumor growth. Fas overexpression may represent a cellular attempt to balance the uncontrolled tumor proliferation by promoting apoptosis.

Cyclin D1 expression as a prognostic parameter in papillary carcinoma of the thyroid

Papillary carcinoma of the thyroid is the most common thyroid cancer. At the time of clinical presentation, most papillary carcinomas are still confined to the thyroid gland, and appropriate surgical treatment achieves a 95% 5-year survival rate. Certain carcinomas, however, behave in a much more aggressive fashion. Because specific therapies do not exist, for those tumors that have escaped local control, patients with disseminated disease have little or no chance of permanent cure or long-term survival. Cyclin D1, a protein that plays a critical role in the control of the cell cycle, has been shown to be overexpressed in a variety of human neoplasias and may serve as a prognostic parameter of disease progression. To explore the role played by cyclin D1 in the pathogenesis of thyroid papillary carcinoma, we have quantitated, by computerized image analysis, the immunohistochemical expression of cyclin D1 in formalin-fixed, paraffin-embedded tissue from 35 conventional papillary carcinomas of the thyroid and correlated the results with established clinicopathologic parameters and available survival data.

Ribosome release factor RF4 and termination factor RF3 are involved in dissociation of peptidyl-tRNA from the ribosome

Peptidyl-tRNA dissociation from ribosomes is an energetically costly but apparently inevitable process that accompanies normal protein synthesis. The drop-off products of these events are hydrolysed by peptidyl-tRNA hydrolase. Mutant selections have been made to identify genes involved in the drop-off of peptidyl-tRNA, using a thermosensitive peptidyl-tRNA hydrolase mutant in Escherichia coli. Transposon insertions upstream of the frr gene, which encodes RF4 (ribosome release or recycling factor), restored growth to this mutant. The insertions impaired expression of the frr gene. Mutations inactivating prfC, encoding RF3 (release factor 3), displayed a similar phenotype. Conversely, production of RF4 from a plasmid increased the thermosensitivity of the peptidyl-tRNA hydrolase mutant. In vitro measurements of peptidyl-tRNA release from ribosomes paused at stop signals or sense codons confirmed that RF3 and RF4 were able to stimulate peptidyl-tRNA release from ribosomes, and showed that this action of RF4 required the presence of translocation factor EF2, known to be needed for the function of RF4 in ribosome recycling. When present together, the three factors were able to stimulate release up to 12-fold. It is suggested that RF4 may displace peptidyl-tRNA from the ribosome in a manner related to its proposed function in removing deacylated tRNA during ribosome recycling.