Adoption of Optimal Small (6-9 mm) Colorectal Polyp Resection Technique Over Time

BACKGROUND

Cold snare polypectomy (CSP) is the preferred resection technique for small (6-9 mm) polyps due to lower rate of incomplete resection compared to cold forceps polypectomy (CFP) and improved safety profile over hot snare polypectomy (HSP).

AIMS

To describe resection techniques for small (6-9 mm) polyps and determine factors associated with sub-optimal technique.

METHODS

This was retrospective cohort study of colonoscopies performed by gastroenterological and surgical endoscopists from 2012 to 2019 where at least one 6-9 mm polyp was removed. Patient, provider, and procedure characteristics were collected. Univariate and multivariate regression analyses were performed to determine factors associated with sub-optimal technique.

RESULTS

In total, 773 colonoscopies where 1,360 6-9 mm polyps removed by 21 endoscopists were included. CSP was used for 1,122 (82.5%), CFP for 61 (4.5%), and HSP for 177 (13.0%). Surgeon specialty was associated with CFP use (aOR 7.81; 95% CI 3.02-20.16). Polyp location in left colon (aOR 1.65; 95% CI 1.17-2.33) and pedunculated morphology (aOR 12.76; 95% CI 7.24-22.50) were associated with HSP. There was a significant increase in overall CSP use from 30.4% in 2012 to 96.8% in 2019.

CONCLUSIONS

82.5% of all 6-9 mm polyps removed from 2012 to 2019 were removed using a cold snare with significant increase in CSP from 2012 to 2019. Differences in how optimal technique was adopted over time based on specialty highlight the need for standardized practice guidelines and quality monitoring.

Laparoscopic colectomy in obese patients: a comparison of laparoscopic and hand-assisted laparoscopic techniques

BACKGROUND

Recent American College of Surgeons National Surgical Quality Improvement Project (ACS-NSQIP)-based evidence indicates that laparoscopic (LAP) colectomy results in improved outcomes compared to hand-assisted laparoscopic (HAL) colectomy in the general population. Previous comparative studies demonstrated that the HAL technique offers distinct advantages for obese patients. The aim of this study was to perform comparative analyses of HAL and LAP colectomy and low anterior resection (LAR) in obese patients.

METHODS

The ACS-NSQIP public use file and targeted colectomy dataset, 2012-2014, were utilized for patients undergoing colectomy and LAR. Only obese patients (BMI > 30) and laparoscopic or hand-assisted operations were included. Patient, operation, and outcome variables were compared in two separate cohorts: colectomy and LAR. Bivariate analysis compared the approaches, followed by multivariable regression.

RESULTS

Of 9610 obese patients included, HAL and LAP colectomy were performed in 3126 and 3793 patients and LAR in 1431 and 1260 patients, respectively. In comparison to LAP colectomy, HAL colectomy patients had increased comorbidities including class 2 and 3 obesity. HAL colectomy was associated with higher overall morbidity (20 vs. 16%, p < 0.001), infectious complications (10.2 vs. 7.7%, p < 0.001), anastomotic leaks (3.0 vs. 2.2%, p = 0.03), and ileus (11 vs. 8%, p < 0.001). Multivariate analysis indicated that overall morbidity (OR 1.27, 95% CI 1.11-1.44), infectious complications (OR 1.35, 95% CI 1.14-1.59), and ileus (OR 1.33, 95% CI 1.12-1.57) were each increased in the HAL colectomy cohort but not different for HAL and LAP LAR.

CONCLUSIONS

In comparison to LAP colectomy, the HAL technique is used more often in obese patients with an increased operative risk profile. While inherent bias and unmeasured variables limit the analysis, the available data indicate that the HAL technique is associated with increased perioperative morbidity. Alternatively, HAL and LAP LAR are performed in obese patients with a similar risk profile and result in similar postoperative outcomes.

Management of Rectal Polyps

Colorectal cancer is one of the most common causes of cancer and cancer morbidity in the United States. In comparison to colon polyps, rectal polyps pose a unique challenge. Advances in endoscopic techniques have allowed for more thorough rectal adenoma detection and removal; however, there remains a concern over piecemeal resection and negative resection margins. Advances in transanal excision techniques, such as transanal endoscopic microsurgery, have been proposed for the removal of benign polyps as well as some early stage rectal cancers, with emphasis on proper patient selection. This review will discuss the current endoscopic and surgical considerations of both benign and malignant rectal polyps.

Dynamic sound scattering: Field fluctuation spectroscopy with singly scattered ultrasound in the near and far fields

Dynamic sound scattering (DSS) is a powerful acoustic technique for investigating the motion of particles or other inclusions inside an evolving medium. In DSS, this dynamic information is obtained by measuring the field autocorrelation function of the temporal fluctuations of singly scattered acoustic waves. The technique was initially introduced 15 years ago, but its technical aspects were not adequately discussed then. This paper addresses the need for a more complete account of the method by describing in detail two different implementations of this sound scattering technique, one of which is specifically adapted to a common experimental situation in ultrasonics. The technique is illustrated by the application of DSS to measure the mean square velocity fluctuations of particles in fluidized suspensions, as well as the dynamic velocity correlation length. By explaining the experimental and analytical methods involved in realizing the DSS technique in practice, the use of DSS will be facilitated for future studies of particulate suspension dynamics and particle properties over a wide range of particle sizes and concentrations, from millimeters down to nanometers, where the use of optical techniques is often limited by the opacity of the medium.

Fibrous ingluvial foreign bodies in 33 cockatiels (Nymphicus hollandicus)

The presentation, treatment and outcomes of 33 ingluvial fibrous foreign bodies in cockatiels (Nymphicus hollandicus) are described. Vomiting, lethargy and weight loss were the most common presenting signs. Diagnosis was made on palpation of a mass in the crop (ingluvies). Both surgical and non-surgical treatment regimens were evaluated. The overall mortality rate was 33%, suggesting fibrous materials are not safe for cockatiels to groom or ingest and should not be offered as cage accessories.

Herpesvirus in a captive Australian Krefft's river turtle (Emydura macquarii krefftii)

CASE REPORT

A mature, captive Krefft's river turtle (Emydura macquarii krefftii) was presented with severe proliferative and ulcerative lesions of the skin and shell. The areas were biopsied and histopathological examination demonstrated orthokeratotic hyperkeratosis with keratinocytes containing eosinophilic intranuclear inclusions. Molecular diagnostics confirmed the presence of a herpesvirus in the affected tissues.

CONCLUSION

This is the first recorded case of herpesvirus infection in an Australian freshwater turtle species.

Plasma cell densities and glomerular filtration rates predict renal allograft outcomes following acute rejection

The contribution of T cells and graft-reactive antibodies to acute allograft rejection is widely accepted, but the role of graft-infiltrating B and plasma cells is controversial. We examined 56 consecutive human renal transplant biopsies classified by Banff schema into T-cell-mediated (N = 21), antibody-mediated (N = 18), and mixed (N = 17) acute rejection, using standard immunohistochemistry for CD3, CD20, CD138, and CD45. In a predominantly African-American population (75%), neither Banff classification nor C4d deposition predicted the return to dialysis. Immunohistochemical analysis revealed CD3(+) T cells as the dominant cell type, followed by CD20(+) B cells and CD138(+) plasma cells in all acute rejection types. Using univariate Cox Proportional Hazard analysis, plasma cell density significantly predicted graft failure while B-cell density trended toward significance. Surprisingly T-cell density did not predict graft failure. The estimated glomerular filtration rate (eGFR) at diagnosis of acute rejection also predicted graft failure, while baseline eGFR ≥6 months prior to biopsy did not. Using multivariate analysis, a model including eGFR at biopsy and plasma cell density was most predictive of graft loss. These observations suggest that plasma cells may be a critical mediator and/or an independently sensitive marker of steroid-resistant acute rejection.

Outcomes of critically ill patients with cirrhosis admitted to intensive care: an important perspective from the non-transplant setting

BACKGROUND

Hospital admissions for cirrhosis have been increasing in the United Kingdom, leading to increased pressure on intensive care (ICU) services. Outcome data for patients admitted to ICU are currently limited to transplant centre reports, with mortality rates exceeding 70%. These tertiary reports could fuel a negative bias when patients with cirrhosis are reviewed for ICU admission in secondary care.

AIMS

To determine whether disease severity and mortality rates in non-transplant general ICU are less severe than those reported by tertiary datasets.

METHODS

A prospective dual-centre non-transplant ICU study. Admissions were screened for cirrhosis and physiological and biochemical data were collected. Disease-specific and critical illness scoring systems were evaluated.

RESULTS

Cirrhosis was present in 137/4198 (3.3%) of ICU admissions. ICU and hospital mortality were 38% and 47%, respectively; median age 50 [43-59] years, 68% men, 72% alcoholic cirrhosis, median Child Pugh Score (CPS) 10 [8-11], Model for End-Stage Liver Disease (MELD) 18 [12-24], Acute Physiology and Chronic Health Evaluation II score (APACHE II) 16 [13-22].

CONCLUSIONS

Mortality rates and disease staging were notably lower than in the published literature, suggesting that patients have a more favourable outlook than previously considered. Transplant centre data should therefore be interpreted with caution when evaluating the merits of intensive care admission for patients in general secondary care ICUs.

The increasing hospital disease burden of haemochromatosis in England

BACKGROUND

Hereditary haemochromatosis is a preventable cause of liver disease with an increasing disease burden.

AIMS

To investigate time trends for hospital admission ascribed to haemochromatosis in England during the period from 1989/1990 to 2002/2003 and mortality from 1979 to 2005.

METHODS

Hospital admission data, relating to both in-patients and day-cases, were obtained from the Hospital Episodes Statistics service. Mortality rates for England and Wales were provided by the Office for National Statistics.

RESULTS

Haemochromatosis is an uncommon cause for hospital admission. Age-standardized in-patient admission rates increased over the study period by 269% in men and by 290% in women: (from 0.64 to 2.36 and from 0.21 to 0.81 per year per 100 000). The increase in age-standardized day-case admission rates was even higher (men: from 2.78 to 34.9 per year per 100 000, 1155%; women: from 0.58 to 11.67 per year per 100 000, 1924%). Haemochromatosis was recorded as an uncommon cause of death.

CONCLUSIONS

Hospital in-patient and day case admissions for haemochromatosis increased markedly over the study period while mortality remained low. Both admission rates and mortality were higher in men than in women. The increase in admission rate may reflect improved recognition and diagnosis of iron overload disorders following identification of the HFE gene.

Mesoscopic phase statistics of diffuse ultrasound in dynamic matter

Temporal fluctuations in the phase of waves transmitted through a dynamic, strongly scattering, mesoscopic sample are investigated using ultrasonic waves, and compared with theoretical predictions based on circular Gaussian statistics. The fundamental role of phase in diffusing acoustic wave spectroscopy is revealed, and phase statistics are also shown to provide a sensitive and accurate way to probe scatterer motions at both short and long time scales.

Ultrafast noncollinear optical parametric chirped pulse amplification in KTiOAsO4

Amplification of femtosecond pulses at 1.56 microm based on noncollinear parametric chirped pulse amplification in a potassium titanyl arsenate (KTA) crystal with pumping at 1.05 microm is reported. The 100 fs pulses of an erbium fiber laser are parametrically amplified while synchronously pumped by an amplified mode-locked Nd:YLF laser. This amplifier has a saturated gain of 65 dB with 30% conversion efficiency and has produced 160 fs pulses with peak powers of up to 0.75 GW. The system produced 380 mW before compression and can be readily scaled to the multiwatt range with bandwidths to support sub-100 fs pulses.

Anharmonic couplings underlying the ultrafast vibrational dynamics of hydrogen bonds in liquids

The multilevel structure and vibrational couplings of O-H stretching transitions in intermolecular hydrogen bonds of acetic acid dimers are determined by femtosecond two-dimensional photon-echo spectroscopy in the infrared. Combining experiment and theoretical calculations, we separate Fermi resonances with combination tones of fingerprint modes from anharmonic couplings to underdamped low-frequency modes of the dimer. A multilevel density matrix approach based on density functional theory calculations reproduces the experimental results and reveals coupling strengths of both mechanisms on the order of 40-150 cm(-1).

Ultrafast memory loss and energy redistribution in the hydrogen bond network of liquid H2O

Many of the unusual properties of liquid water are attributed to its unique structure, comprised of a random and fluctuating three-dimensional network of hydrogen bonds that link the highly polar water molecules. One of the most direct probes of the dynamics of this network is the infrared spectrum of the OH stretching vibration, which reflects the distribution of hydrogen-bonded structures and the intermolecular forces controlling the structural dynamics of the liquid. Indeed, water dynamics has been studied in detail, most recently using multi-dimensional nonlinear infrared spectroscopy for acquiring structural and dynamical information on femtosecond timescales. But owing to technical difficulties, only OH stretching vibrations in D2O or OD vibrations in H2O could be monitored. Here we show that using a specially designed, ultrathin sample cell allows us to observe OH stretching vibrations in H2O. Under these fully resonant conditions, we observe hydrogen bond network dynamics more than one order of magnitude faster than seen in earlier studies that include an extremely fast sweep in the OH frequencies on a 50-fs timescale and an equally fast disappearance of the initial inhomogeneous distribution of sites. Our results highlight the efficiency of energy redistribution within the hydrogen-bonded network, and that liquid water essentially loses the memory of persistent correlations in its structure within 50 fs.

Focusing of sound in a 3D phononic crystal

We present a combined experimental and theoretical study of phonon focusing phenomena in a pass band above the complete band gap in a 3D phononic crystal. Wave propagation was found to depend dramatically on both frequency and incident direction. This propagation anisotropy leads to very large negative refraction, which can be used to focus a diverging ultrasonic beam into a narrow focal spot with a large focal depth. The experimental field patterns are well explained using a Fourier imaging technique, based on the 3D equifrequency surfaces calculated from multiple scattering theory.

Observation of the cascaded atomic-to-global length scales driving protein motion

Model studies of the ligand photodissociation process of carboxymyoglobin have been conducted by using amplified few-cycle laser pulses short enough in duration (<10 fs) to capture the phase of the induced nuclear motions. The reaction-driven modes are observed directly in real time and depict the pathway by which energy liberated in the localized reaction site is efficiently channeled to functionally relevant mesoscale motions of the protein.

Diffusing acoustic wave spectroscopy

We have developed a technique in ultrasonic correlation spectroscopy called diffusing acoustic wave spectroscopy (DAWS). In this technique, the motion of the scatterers (e.g., particles or inclusions) is determined from the temporal fluctuations of multiply scattered sound. In DAWS, the propagation of multiply scattered sound is described using the diffusion approximation, which allows the autocorrelation function of the temporal field fluctuations to be related to the dynamics of the multiply scattering medium. The expressions relating the temporal field autocorrelation function to the motion of the scatterers are derived, focusing on the types of correlated motions that are most likely to be encountered in acoustic measurements. The power of this technique is illustrated with ultrasonic data on fluidized suspensions of particles, where DAWS provides a sensitive measure of the local relative velocity and strain rate of the suspended particles over a wide range of time and length scales. In addition, when combined with the measurements of the rms velocity of the particles using dynamic sound scattering, we show that DAWS can be used to determine the spatial extent of the correlations in the particle velocities, thus indirectly measuring the particle velocity correlation function. Potential applications of diffusing acoustic wave spectroscopy are quite far reaching, ranging from the ultrasonic nondestructive evaluation of the dynamics of inhomogeneous materials to geophysical studies of mesoscopic phenomena in seismology.

CD5-mediated inhibition of TCR signaling during intrathymic selection and development does not require the CD5 extracellular domain

CD5 functions as a negative regulator of TCR signaling during intrathymic T cell development, but it is not known if this negative regulatory function requires CD5 engagement of an extracellular ligand. The present study has specifically examined the role of the CD5 extracellular domain in T cell development by introducing into CD5-/- mice a chimeric CD5 molecule in which the extracellular domain of CD5 is replaced with the extracellular domain of human IL-2R p55 (Tac) for which no ligand exists in the mouse. We now report that CD5 mediated down-regulation of TCR signaling during thymocyte development does not require the CD5 extracellular domain and, consequently, does not involve CD5 binding of an extracellular ligand in the thymus.

Ultrasound tunneling through 3D phononic crystals

We report the study of ultrasound tunneling in 3D phononic crystals, consisting of fcc arrays of close-packed tungsten carbide beads in water. The transmission coefficient, phase velocity, and group velocity were measured along the [111] direction, allowing us to systematically investigate the tunneling of ultrasound at frequencies in the lowest band gap. Our experimental data are interpreted using multiple scattering theory, which provides a good explanation of our results. The effect of absorption and the difference between the tunneling of classical waves and quantum waves are discussed.

Velocity fluctuations in fluidized suspensions probed by ultrasonic correlation spectroscopy

Velocity fluctuations in a fluidized suspension of particles are investigated using two new ultrasonic correlation spectroscopies: diffusing acoustic wave spectroscopy and dynamic sound scattering. These techniques probe both the local strain rate and rms velocity of the particles, providing important information about the spatial extent of velocity correlations. Our results demonstrate the power of these techniques to probe particle dynamics of fluidized suspensions, and suggest that the velocity correlations are essentially independent of Reynolds numbers for Re(p)<1.

Crisis intervention following disasters: are we doing enough? (A second look)

During mass casualty events the consequences of psychological trauma are an important cause of morbidity among survivors and rescue personnel. Data available from military and civilian disasters over the past 70 years has shown a fairly predictable ratio of acute and severe emotional trauma associated with mass casualty events. Long-term morbidity from psychological trauma can rival or exceed that of the physical injuries of survivors. Psychological intervention reduces this morbidity, and early psychological intervention is more effective before adverse psychological symptoms have fully developed. However, the widely accepted value of early psychological intervention is not universal, with controversy over the degree of emotional trauma expected after a large-scale catastrophic mass casualty event, as well as the number of victims and the effectiveness of immediate psychological intervention. Some research even suggests that there is only a minor risk of acute emotional trauma among survivors of a major disaster. The United States faces the possibility of mass casualties from national disasters--particularly earthquakes--and conventional warfare. It has been predicted that 100,000 major injuries requiring hospitalization and 20,000 deaths would result from the maximum plausible natural disaster incident in the United States. Pentagon planners expect thousands of servicemen to be evacuated to the United States for hospitalization on a daily basis during an overseas conventional war. With these estimates of potential casualties, it is imperative that this controversy be resolved as quickly as possible. The National Disaster Medical System recently established plans to provide immediate treatment for psychological trauma to disaster survivors and rescue personnel.(ABSTRACT TRUNCATED AT 250 WORDS)

Mental health issues related to the development of a national disaster response system

With the creation of the National Disaster Medical System (NDMS), the federal government has moved to develop a national medical plan for responding to major mass casualty situations resulting from either a civilian disaster which overwhelms state and local resources or an overseas conventional conflict. To date, the mental health aspects of this plan have received little attention. This article discusses the rationale for adding a comprehensive mental health component to NDMS within the context of the complementary needs of disaster survivors and rescuers.

Developing a regional and national burn disaster response

The supplement on burns by the National Disaster Medical System (NDMS) requires an evaluation of burn centers' and burn hospitals' capabilities for treating seriously burned victims. The American Burn Association (ABA) and its members, as experts in burn care, should take the lead in working with local, state, and federal disaster planners. Proposals based on standards adopted by the ABA support classification of facilities (levels I, II, III), identify minimum and maximum bed availability, require minimum training for personnel (e.g., ABLS), and encourage enrollment of all burn centers and burn hospitals as contract hospitals in the National Disaster Medical System. Periodically, the ABA should verify that the burn care facilities identified in the disaster plan meet its standards. Once the burn disaster system is developed, drills should be held locally on a regular basis and nationally on an annual basis.

Exercise-induced changes in populations of peripheral blood mononuclear cells

The effects of maximal treadmill exercise on changes in the expression and distribution of peripheral blood B-lymphocytes, T-lymphocytes, and natural killer cells (NK) were examined in 20 healthy men with a mean age of 32.0 +/- 1.3 yr. The percentage and absolute number of peripheral blood mononuclear cells that reacted with specific monoclonal antibodies which bind to B-cells (anti-Leu-12 and anti-human-immunoglobulin D-delta chain-specific), T-cells (OKT3), and NK cells (anti-Leu-11 and anti-Leu-7) were enumerated by a fluorescence-activated cell sorter in samples obtained before (Pre), immediately after (Post), and 1 h after a bout of exercise to exhaustion. In contrast to earlier studies, the results of this study indicate that maximal exertion effects a decrease in the percentage, but no change in the absolute number of peripheral blood B-cells (Pre: 0.21 +/- 0.01; Post: 0.31 +/- 0.02 cells x 10(-6).ml-1). In addition, a small, transient increase in the number of peripheral blood cells reacting with surface markers associated with T-lymphocytes (Pre: 1.15 +/- 0.09; Post: 2.05 +/- 0.19 cells x 10(-6).ml-1) and a striking, transient increase in lymphocytes having NK phenotype activity (Pre: 0.34 +/- 0.03; Post: 1.51 +/- 0.19 cells x 10(-6).ml-1) were noted. All of the pre-exercise values were re-established 1 h after exercise. Whether the mobilization of cells with surface markers associated with NK activity in response to maximal exertion serves any physiologic function during periods of physical stress remains to be determined.

Medical simulation for disaster casualty management training

A required, role-intensive leadership simulation in emergency and disaster medicine management for fourth-year medical students is described, and the value of an extended role-playing experience discussed. The week-long (120 hours) simulation exercise is designed to provide an opportunity for Federal medical students to experience a realistic combat or disaster environment similar to environments in which they may be required to operate medical support systems. Students function in a variety of roles and have the opportunity to place into practice all emergency medical knowledge and skills acquired throughout medical school. As a prerequisite to the exercise, students successfully complete a 3-week didactic course in Operational and Emergency Medicine which includes Advanced Cardiac Life Support (ACLS) and Advanced Trauma Life Support (ATLS) Provider Courses. By means of disaster simulation they refine medical skills, leadership style, substantially improve clinical judgment, and deal with the complexities of problems associated with their future roles as medical officers.

New concepts in triage

The triage process is a valid concept in the initial approach to multiple casualties. Triage tags are, in theory, a reasonable adjunct to the process, but have proved to be a failure in practice. Based on the historical perspective and on the authors' experience with approximately 180 mass casualty drills and incidents, it is recommended that the "daily routine doctrine" be applied and that conventional, color-coded triage tags be replaced by a process of "geographical triage." A valid model for disaster planning is needed, and organizers must conduct drills that are based on the actual threat to the community in order to determine the most efficacious way to manage medical response.

A personal medical emergency kit

The professional and promotional literature is replete with advertisements for emergency kits. For many years, we have pursued the question from the perspective of immediate accessibility. This paper presents four case reports relating the authors' experience with such a small, personal emergency kit.

Effects of some steroids in oral contraceptives on the cleavage of rabbit eggs in vitro

The effects of the oestrogens and progestins in some common oral contraceptives on the cleavage of fertilized rabbit ova were studied in vitro. Three concentrations (5, 10 and 25 μg./ml.) of each of four progestins (norethynodrel, norethindrone, norethindrone acetate and 17α-hydroxy-6α-methylprogesterone acetate) and of two oestrogens (mestranol and ethinyloestradiol) were tested. All but norethindrone and norethynodrel had some effects on the cleavage of ova. Three effects were seen: complete inhibition of cleavage, slowing or retardation of cleavage, and fragmentation (division of the egg into numerous spherical or ovular bodies).

Differences between conditions in vivo and in vitro and the mechanism of these actions of the steroids are discussed.