Assessing the importance of nitric acid and ammonia for particle growth in the polluted boundary layer

Aerosols formed and grown by gas-to-particle processes are a major contributor to smog and haze in megacities, despite the competition between growth and loss rates. Rapid growth rates from ammonium nitrate formation have the potential to sustain particle number in typical urban polluted conditions. This process requires supersaturation of gas-phase ammonia and nitric acid with respect to ammonium nitrate saturation ratios. Urban environments are inhomogeneous. In the troposphere, vertical mixing is fast, and aerosols may experience rapidly changing temperatures. In areas close to sources of pollution, gas-phase concentrations can also be highly variable. In this work we present results from nucleation experiments at -10 °C and 5 °C in the CLOUD chamber at CERN. We verify, using a kinetic model, how long supersaturation is likely to be sustained under urban conditions with temperature and concentration inhomogeneities, and the impact it may have on the particle size distribution. We show that rapid and strong temperature changes of 1 °C min-1 are needed to cause rapid growth of nanoparticles through ammonium nitrate formation. Furthermore, inhomogeneous emissions of ammonia in cities may also cause rapid growth of particles.

Nitrate Radicals Suppress Biogenic New Particle Formation from Monoterpene Oxidation

Highly oxygenated organic molecules (HOMs) are a major source of new particles that affect the Earth's climate. HOM production from the oxidation of volatile organic compounds (VOCs) occurs during both the day and night and can lead to new particle formation (NPF). However, NPF involving organic vapors has been reported much more often during the daytime than during nighttime. Here, we show that the nitrate radicals (NO3), which arise predominantly at night, inhibit NPF during the oxidation of monoterpenes based on three lines of observational evidence: NPF experiments in the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber at CERN (European Organization for Nuclear Research), radical chemistry experiments using an oxidation flow reactor, and field observations in a wetland that occasionally exhibits nocturnal NPF. Nitrooxy-peroxy radicals formed from NO3 chemistry suppress the production of ultralow-volatility organic compounds (ULVOCs) responsible for biogenic NPF, which are covalently bound peroxy radical (RO2) dimer association products. The ULVOC yield of α-pinene in the presence of NO3 is one-fifth of that resulting from ozone chemistry alone. Even trace amounts of NO3 radicals, at sub-parts per trillion level, suppress the NPF rate by a factor of 4. Ambient observations further confirm that when NO3 chemistry is involved, monoterpene NPF is completely turned off. Our results explain the frequent absence of nocturnal biogenic NPF in monoterpene (α-pinene)-rich environments.

Molecular Understanding of the Enhancement in Organic Aerosol Mass at High Relative Humidity

The mechanistic pathway by which high relative humidity (RH) affects gas-particle partitioning remains poorly understood, although many studies report increased secondary organic aerosol (SOA) yields at high RH. Here, we use real-time, molecular measurements of both the gas and particle phase to provide a mechanistic understanding of the effect of RH on the partitioning of biogenic oxidized organic molecules (from α-pinene and isoprene) at low temperatures (243 and 263 K) at the CLOUD chamber at CERN. We observe increases in SOA mass of 45 and 85% with increasing RH from 10-20 to 60-80% at 243 and 263 K, respectively, and attribute it to the increased partitioning of semi-volatile compounds. At 263 K, we measure an increase of a factor 2-4 in the concentration of C10H16O2-3, while the particle-phase concentrations of low-volatility species, such as C10H16O6-8, remain almost constant. This results in a substantial shift in the chemical composition and volatility distribution toward less oxygenated and more volatile species at higher RH (e.g., at 263 K, O/C ratio = 0.55 and 0.40, at RH = 10 and 80%, respectively). By modeling particle growth using an aerosol growth model, which accounts for kinetic limitations, we can explain the enhancement in the semi-volatile fraction through the complementary effect of decreased compound activity and increased bulk-phase diffusivity. Our results highlight the importance of particle water content as a diluting agent and a plasticizer for organic aerosol growth.

High Gas-Phase Methanesulfonic Acid Production in the OH-Initiated Oxidation of Dimethyl Sulfide at Low Temperatures

Dimethyl sulfide (DMS) influences climate via cloud condensation nuclei (CCN) formation resulting from its oxidation products (mainly methanesulfonic acid, MSA, and sulfuric acid, H₂SO₄). Despite their importance, accurate prediction of MSA and H₂SO₄ from DMS oxidation remains challenging. With comprehensive experiments carried out in the Cosmics Leaving Outdoor Droplets (CLOUD) chamber at CERN, we show that decreasing the temperature from +25 to -10 °C enhances the gas-phase MSA production by an order of magnitude from OH-initiated DMS oxidation, while H₂SO₄ production is modestly affected. This leads to a gas-phase H₂SO₄-to-MSA ratio (H₂SO₄/MSA) smaller than one at low temperatures, consistent with field observations in polar regions. With an updated DMS oxidation mechanism, we find that methanesulfinic acid, CH₃S(O)OH, MSIA, forms large amounts of MSA. Overall, our results reveal that MSA yields are a factor of 2-10 higher than those predicted by the widely used Master Chemical Mechanism (MCMv3.3.1), and the NO_x effect is less significant than that of temperature. Our updated mechanism explains the high MSA production rates observed in field observations, especially at low temperatures, thus, substantiating the greater importance of MSA in the natural sulfur cycle and natural CCN formation. Our mechanism will improve the interpretation of present-day and historical gas-phase H₂SO₄/MSA measurements.

Survival of newly formed particles in haze conditions

Intense new particle formation events are regularly observed under highly polluted conditions, despite the high loss rates of nucleated clusters. Higher than expected cluster survival probability implies either ineffective scavenging by pre-existing particles or missing growth mechanisms. Here we present experiments performed in the CLOUD chamber at CERN showing particle formation from a mixture of anthropogenic vapours, under condensation sinks typical of haze conditions, up to 0.1 s⁻¹. We find that new particle formation rates substantially decrease at higher concentrations of pre-existing particles, demonstrating experimentally for the first time that molecular clusters are efficiently scavenged by larger sized particles. Additionally, we demonstrate that in the presence of supersaturated gas-phase nitric acid (HNO₃) and ammonia (NH₃), freshly nucleated particles can grow extremely rapidly, maintaining a high particle number concentration, even in the presence of a high condensation sink. Such high growth rates may explain the high survival probability of freshly formed particles under haze conditions. We identify under what typical urban conditions HNO₃ and NH₃ can be expected to contribute to particle survival during haze.

Illustration of how ammonium nitrate formation can cause rapid growth of nucleating particles, increasing survival of particles in polluted conditions.

[An unusually painful leg ulcer in an 81-year-old patient: an interdisciplinary challenge]

An 81-year-old male patient with a history of peripheral arterial disease (PAD) was admitted to the authors' outpatient clinic with a painful lower leg ulcer. As the degree of PAD did not correspond to the clinical findings, multiple biopsies were taken from the base and edge of the ulcer. This resulted in the histopathological and clinical diagnosis of pyoderma gangrenosum (PG). Since PG is often associated with numerous underlying diseases, further thorough examinations were performed. A mass in the gastric antrum suspicious for malignancy was histopathologically identified as gastric cancer (signet ring cell carcinoma). The PG was successfully treated with cortisone p.o. and tacrolimus ointment. Since the cancer was locally limited, the patient underwent surgery involving gastric resection with D2 lymphadenectomy and gastrojejunostomy (Roux-en‑Y anastomosis).

Role of iodine oxoacids in atmospheric aerosol nucleation

Iodic acid (HIO3) is known to form aerosol particles in coastal marine regions, but predicted nucleation and growth rates are lacking. Using the CERN CLOUD (Cosmics Leaving Outdoor Droplets) chamber, we find that the nucleation rates of HIO3 particles are rapid, even exceeding sulfuric acid-ammonia rates under similar conditions. We also find that ion-induced nucleation involves IO3 - and the sequential addition of HIO3 and that it proceeds at the kinetic limit below +10°C. In contrast, neutral nucleation involves the repeated sequential addition of iodous acid (HIO2) followed by HIO3, showing that HIO2 plays a key stabilizing role. Freshly formed particles are composed almost entirely of HIO3, which drives rapid particle growth at the kinetic limit. Our measurements indicate that iodine oxoacid particle formation can compete with sulfuric acid in pristine regions of the atmosphere.

Rapid growth of new atmospheric particles by nitric acid and ammonia condensation

A list of authors and their affiliations appears at the end of the paper New-particle formation is a major contributor to urban smog1,2, but how it occurs in cities is often puzzling3. If the growth rates of urban particles are similar to those found in cleaner environments (1-10 nanometres per hour), then existing understanding suggests that new urban particles should be rapidly scavenged by the high concentration of pre-existing particles. Here we show, through experiments performed under atmospheric conditions in the CLOUD chamber at CERN, that below about +5 degrees Celsius, nitric acid and ammonia vapours can condense onto freshly nucleated particles as small as a few nanometres in diameter. Moreover, when it is cold enough (below -15 degrees Celsius), nitric acid and ammonia can nucleate directly through an acid-base stabilization mechanism to form ammonium nitrate particles. Given that these vapours are often one thousand times more abundant than sulfuric acid, the resulting particle growth rates can be extremely high, reaching well above 100 nanometres per hour. However, these high growth rates require the gas-particle ammonium nitrate system to be out of equilibrium in order to sustain gas-phase supersaturations. In view of the strong temperature dependence that we measure for the gas-phase supersaturations, we expect such transient conditions to occur in inhomogeneous urban settings, especially in wintertime, driven by vertical mixing and by strong local sources such as traffic. Even though rapid growth from nitric acid and ammonia condensation may last for only a few minutes, it is nonetheless fast enough to shepherd freshly nucleated particles through the smallest size range where they are most vulnerable to scavenging loss, thus greatly increasing their survival probability. We also expect nitric acid and ammonia nucleation and rapid growth to be important in the relatively clean and cold upper free troposphere, where ammonia can be convected from the continental boundary layer and nitric acid is abundant from electrical storms4,5.

Presentation of a Sedation Standard Using the Example of Transesophageal Echocardiographies (TEE) in Pediatric Outpatients

Introduction Most pediatric patients require deep sedation for a TEE examination. We analyzed the data of our sedation protocols relating to all outpatient TEEs in patients under 18 years of age for the year 2011. On the basis of the data records of a total of 40 patients, we will describe our standard and compare it with the findings of the international literature. Material and Methods In a retrospective analysis, we inspected our sedation protocols in terms of patient-related data, vital parameters, drug applications, occurring complications and necessary interventions as well as nausea and vomiting during the post-sedative monitoring phase. Results In line with our standard, we applied atropine, midazolam, S-ketamine and propofol; complications occurred in 5 patients. They could be handled using simple measures. With regard to the vital parameters, no severe complications occurred. Dizziness was observed in 4 patients during the recovery phase; one patient complained about nausea and vomiting during the first fluid intake. All patients could be discharged 4 h after the termination of sedation. Conclusion Our standard is a practicable and safe procedure for preforming TEE examinations in pediatric outpatients.

Autologous skeletal-muscle-derived cell injection for anal incontinence due to obstetric trauma: a 5-year follow-up of an initial study of 10 patients

AIM

Our aim was to determine whether the benefits of autologous skeletal-muscle-derived cell injection to treat obstetric anal incontinence are sustained at 5 years.

METHOD

An observational study was performed of 10 women suffering from obstetric anal incontinence refractory to non-surgical therapy. Autologous skeletal-muscle-derived cells were injected into the external sphincter defect under ultrasound guidance. Incontinence diaries and quality of life questionnaires were obtained pre-implantation and annually after implantation for 5 years. Anal physiology testing was performed before implantation and at 1, 2 and 5 years after implantation. The end-points included were adverse events, Wexner incontinence scores, incontinence episodes, anal squeeze pressures and quality of life over 5 years. An independent statistician used multilevel linear regression to analyse changes in repeated measures over time. Any skewed distributions were log transformed prior to analysis.

RESULTS

No procedure-related adverse events occurred and haematological and biochemical parameters were normal during the 5-year period. There were sustained significant improvements in the Wexner incontinence score and reduced frequency of defaecation and number of incontinence episodes (all comparisons P < 0.001). Anal resting and squeeze pressures showed sustained improvement (all P < 0.001) and quality of life improved overall (P < 0.001), including all submeasures studied (P < 0.001).

CONCLUSION

Autologous skeletal-muscle-derived cells to treat obstetric anal incontinence resulted in sustained improvement in incontinence episodes, physiological measurements of anal function and quality of life at 5 years.

Surgical options to treat constipation: A brief overview

Patients with intractable chronic constipation should be evaluated with physiological tests after structural disorders and extracolonic causes have been excluded. Conservative treatment options should be tried unstintingly. It should be pointed out that especially new drugs such as prucalopride and linaclotide seem to be a big step forward in treating patients with chronic constipation. If surgery is indicated, for many years subtotal colectomy with IRA was the treatment of choice, although segmental resections were also a good option for isolated megasigmoid, sigmoidocele or recurrent sigmoid volvulus. Nowadays, less invasive procedures like sacral nerve modulation (SNM) should be tried first. If unsuccessful, colectomy can still be considered. In general, patients with a gastrointestinal dysmotility syndrome (GID) should not be offered any surgical options because of their anticipated poor results. Moreover, patients with psychiatric disorders should be actively discouraged from resection, as they tend to have a poorer prognosis. Patients must be counseled that pain and/or bloating will likely persist even if surgery normalizes bowel frequency. Patients with associated problems may be better served by having a stoma without resection as both a therapeutic maneuver and a diagnostic trial. Colectomy is not an option for the treatment of pain and/or abdominal bloating. In most cases outlet obstruction can be treated successfully with a conservative approach. However, nowadays there are also a variety of surgical options on the market. Each technique has its special place in the armamentarium of a colorectal surgeon but its exact role is not defined yet.The aim of this article is to give a brief overview, how to diagnose and treat chronic constipation from the standpoint of a colorectal surgeon.Surgical treatment of chronic constipation is not routine and is performed only in exceptional cases. But one thing first: a "too long gut" (dolichocolon) per se is never an indication for surgery. The aim of this manuscript is to give a brief overview about possible mechanisms of constipation, diagnostic methods and tools and the various conservative and operative treatment options. Moreover, please always keep in mind that constipation may not only be a symptom, but even a distinct disease!

Binding characteristics of [3H]-JSM10292: a new cell membrane-permeant non-peptide bradykinin B2 receptor antagonist

BACKGROUND AND PURPOSE

A (3) H-labelled derivative of the novel small-molecule bradykinin (BK) B(2) receptor antagonist JSM10292 was used to directly study its binding properties to human and animal B(2) receptors in intact cells and to closely define its binding site.

EXPERIMENTAL APPROACH

Equilibrium binding, dissociation and competition studies with various B(2) receptor ligands and [(3) H]-JSM10292 were performed at 4°C and 37°C. The experiments were carried out using HEK293 cells stably (over)expressing wild-type and mutant B(2) receptors of human and animal origin.

KEY RESULTS

[(3) H]-JSM10292 bound to B(2) receptors at 4°C and at 37°C with the same high affinity. Its dissociation strongly depended on the temperature and increased when unlabelled B(2) receptor agonists or antagonists were added. [(3) H]-JSM10292 is cell membrane-permeant and thus also bound to intracellular, active B(2) receptors, as indicated by the different 'nonspecific' binding in the presence of unlabelled JSM10292 or of membrane-impermeant BK. Equilibrium binding curves with [(3) H]-JSM10292 and competition experiments with unlabelled JSM10292 and [(3) H]-BK showed a different affinity profile for the wild-type B(2) receptor in different species (man, cynomolgus, rabbit, mouse, rat, dog, pig, guinea pig). Characterization of B(2) receptor mutants and species orthologues combined with homology modelling, using the CXCR4 as template, suggests that the binding site of JSM10292 is different from that of BK but overlaps with that of MEN16132, another small non-peptide B(2) receptor ligand.

CONCLUSIONS AND IMPLICATIONS

[(3) H]-JSM10292 is a novel, cell membrane-permeant, high-affinity B(2) receptor antagonist that allows direct in detail studies of active, surface and intracellularly located wild-type and mutant B(2) receptors.

Guidelines for the management of third and fourth degree perineal tears after vaginal birth from the Austrian Urogynecology Working Group

The purpose of this guideline is to provide a decision aid for diagnosis, treatment, and follow-up of patients with major perineal tears and thus minimize the risk of persistent symptoms. In 2007, the "Guideline for the management of third and fourth degree perineal tears after vaginal birth" was established by members of the Austrian Urogynecologic Working Group (AUB). The guideline was updated in 2011, including literature published up to 30 November 2011. The DELPHI method was used to reach consensus. Evidence-based and consensus-based statements were defined for epidemiology, risk factors, classification, diagnosis, surgery, and follow-up of major perineal lacerations at vaginal birth.

Surgical management of lower gastrointestinal bleeding

PURPOSE

Lower gastrointestinal bleeding (LGIB) is any form of bleeding distal to the Ligament of Treitz. In most cases, acute LGIB is self-limited and resolves spontaneously with conservative management.

METHODS

Only a minority of approximately 10% is admitted to hospital with signs of massive bleeding and shock requiring resuscitation, urgent evaluation and treatment.

RESULTS

Over the past decade, there has been a progressive decrease in upper GI events and a significant increase in lower GI events. Overall, mortality has also decreased, but in-hospital fatality due to upper or lower GI complications have remained constant. The problem is that LGIB can arise from a number of sources and may be a significant cause of hospitalisation and mortality in elderly patients.

CONCLUSIONS

After initial resuscitation, the diagnosis and treatment of LGIB remains a challenge for acute care surgeons, whereby the identification of the source of bleeding is of utmost importance.

The surgical anatomy and etiology of gastrointestinal fistulas

BACKGROUND

Fistulas are abnormal communications between two epithelial surfaces, either between two portions of the intestine, between the intestine and some other hollow viscus, or between the intestine and the skin of the abdominal wall. The etiology of intestinal fistulas is in most cases a result of multiple contributing factors. Despite significant advances in their management over the past decades, intestinal fistulas remain a major clinical problem, with a high overall mortality rate of up to 30% due to the high rate of complications. This paper aims to describe classification systems based on the anatomy, physiology and etiology that may be helpful in the clinical management of intestinal fistulas.

METHODS

On the basis of anatomical differences, fistulas can be classified based by the site of origin, by site of their openings, or as simple or complex. Physiologic classification as low, moderate or high output fistulas is most useful for the non-surgical approach. Concerning the etiology, we classified the possible causes as (postoperative) trauma, inflammation, infection, malignancy, radiation injury or congenital.

CONCLUSION

Fistula formation can cause a number of serious or debilitating complications ranging from disturbance of fluid and electrolyte balance to sepsis and even death. They still remain an important complication following gastrointestinal surgery.

Muscle-derived cell injection to treat anal incontinence due to obstetric trauma: pilot study with 1 year follow-up

OBJECTIVE

To treat anal incontinence due to obstetric external anal sphincter disruption via injection of autologous myoblast cells.

DESIGN

Observational pilot study.

SETTING

University hospital and district hospital

PATIENTS

10 women suffering from anal incontinence due to obstetric anal sphincter injury, refractory to conventional non-surgical therapy.

INTERVENTIONS

Autologous myoblasts were cultured from a pectoralis muscle biopsy, harvested, and injected into the external anal sphincter defect using direct ultrasound guidance.

MAIN OUTCOME MEASURES

Wexner incontinence score, anal squeeze pressures, and quality of life 12 months after injection. Safety and technical feasibility.

RESULTS

The procedure was well tolerated and no adverse events were observed. At 12 months the Wexner incontince score had decreased by a mean of 13.7 units (95% CI, -16.3 to -11.2), anal squeeze pressures were unchanged, and overall quality of life scores improved by a median of 30 points (95% CI, 25 to 42). Anal squeeze pressures did rise significantly at 1 month and 6 months post-injection (p = 0.03).

CONCLUSIONS

Injection of autologous myoblasts is safe, well tolerated, and significantly improves symptoms of anal incontinence due to obstetric anal sphincter trauma.

Management of complications in surgery of the colon

BACKGROUND

General surgeons are frequently confronted with colorectal diseases in their daily practice, whereby colorectal cancer is the second most common malignant tumour, with almost 5000 new cases every year in Austria. The incidence of benign colon disorders requiring surgery (e.g. colon polyps, sigmoid diverticulitis) is also increasing. The first aim in colon surgery should be to avoid complications and if they occur to treat them properly.

METHODS

We basically distinguish between general and special complications. As general complications, prevention of malnutrition and support of the immune system should receive special attention. As the number of elderly patients increases, so does the risk not only of thrombembolic complications but also of critical cardiocirculatory situations, and renal and hepatic failure. Special complications depend either on the type of surgery (laparoscopic assisted, conventional open surgery) or the techniques employed (stapled, hand sutured). Handling of the tissue also plays a major role (e.g. dry versus wet pads).

RESULTS

Shortening of the postoperative stay decreases both hospital costs and the incidence of infections, meaning that minimally invasive surgery and postoperative "fast track nutrition" should be promoted. Emergency operations should be avoided (e.g. bridging through colonic stents), as morbidity and mortality are clearly increased in comparison to (semi-) elective operations. During the operation itself, new equipment and techniques (such as Ultracision®, Ligasure®) as well as a well coordinated team help to reduce complications and duration of surgery.

CONCLUSIONS

To avoid is better than to repair. If complications do occur, appropriate surgical and intensive - care measures should be taken immediately.

Anorectal manometry: are fatigue rate and fatigue rate index of any clinical importance?

BACKGROUND

Loss of voluntary contraction of the external anal sphincter is thought to be a factor in fecal incontinence. During anal manometry, computerized systems produce several parameters including fatigue rate (FR), which is the basis for calculating the fatigue rate index (FRI). Our aim was to evaluate FR and FRI and their clinical importance in patients suffering from fecal incontinence or severe constipation.

MATERIALS AND METHODS

All patients scheduled for an anal physiology work-up were included in the study. FR was determined by a computer program and FRI was calculated manually with the following equation: FRI (minutes) = [squeeze pressure (mm Hg) - resting pressure (mmHg)] / - FR (mmHg/min). FR and FRI were compared in patients suffering from fecal incontinence (group I) and severe constipation (group II). Furthermore, subgroups (<50 and > or = 50 years of age) were compared. Lastly, a possible relation between length of the high-pressure zone (HPZ) and FR and FRI was assessed.

RESULTS

Between January 2000 and December 2004, 131 patients (96 with fecal incontinence, 35 with constipation) were studied. Both FR and FRI were similar between groups I and II; no significant differences were found when younger and older patients were compared within the same group. We also did not find any relation between HPZ length and either FR or FRI.

CONCLUSIONS

FR and FRI do not seem to be helpful in routine colorectal practice for evaluating the strength of the external anal sphincter.

Quality of life after sphincteroplasty

The operative technique of sphincteroplasty is only for isolated disruption of the sphincter muscle. Patients best suited for surgical corrections are those in whom incontinence is secondary to an anterior (obstetrical) sphincter defect. Due to the disappointing long-term results, the operation may be postponed if appropriate. At present, firstline treatment often is a biofeedback training program. It is well known that a persistent defect after repair is associated with an immediate poor outcome From 1995 - 2003 we have performed 40 sphincteroplasty on 38 patients with a mean age of 34 (range 19 - 71) years. The long-term results the of sphincteroplasty are not so promising. 3 techniques are available for measuring quality of life: Descriptive measures. Severity measures, Impact measures Sphincteroplasty, despite poor long-term results, is the best surgical treatment option for isolated, preferably anterior sphincter defects.

Should we treat hemorrhoids according to the stage

Hemorrhoidal disease is a very common and widespread disease, and it is estimated that about one subject out of three may suffer from this pathology. Hemorrhoids generally cause symptoms when enlarged, inflamed, thrombosed, or prolapsed. Internal hemorrhoids arise above the dentate line (in comparison to external hemorrhoids perianal phlebothrombosis) and are covered by transitional or columnar epithelium. Scleotherapy is one of the oldest therapy forms mainly for bleeding hemorrhoids. The so called Barron ligature is an office procedure in which a small rubber band is placed at the base of the internal hemorrhoid with a special applicator.

Acute pseudo-obstruction of the small intestine following high-dose chemotherapy and stem cell support

BACKGROUND

Acute intestinal pseudo-obstruction is a potentially life-threatening disease which is characterized by massive dilation of the colon or small intestine without mechanical obstruction and may develop after surgery or severe illness.

PATIENTS AND METHODS

We report 2 cases in which acute small intestinal pseudo-obstruction occurred after high-dose chemotherapy and autologous stem cell support. In 1 patient explorative abdominal laparoscopy was performed to rule out mechanical ileus. However, after having initiated treatment with acetylcholinesterase inhibitors a prompt small intestinal decompression was observed in both patients.

CONCLUSIONS

Acetylcholinesterase inhibitors should be considered as an early conservative intervention in the treatment of acute intestinal pseudo-obstruction to avoid surgery of patients undergoing high-dose chemotherapy with autologous stem cell support.

Partial splenectomy in cystic fibrosis patients with hypersplenism

We report three cystic fibrosis (CF) patients with hypersplenism who underwent partial splenectomy. The postoperative course was uneventful in two patients; one patient developed a complication necessitating resection of the rest of the spleen. Haematological parameters improved and oesophageal varices regressed in all patients. On follow up, one patient showed a normal spleen, the other a normally functioning accessory spleen; the third patient again developed splenomegaly with hypersplenism. Partial splenectomy is a promising therapeutic option for CF patients with hypersplenism.

Nonoperative treatment of blunt splenic injury

A spleen-preserving program was implemented at the author's institution during the mid-1980s using a five-part injury-grading scale that is similar and comparable to the AAST classification. Since that time, all patients with splenic injuries admitted to the Department of Surgery at the Karl-Franzens University Hospital in Graz, a level I trauma center, have been prospectively evaluated with respect to splenic preservation. Analysis of the relation of the severity of organ injury to the use of nonoperative management showed that degree I or II injuries were treated nonoperatively, whereas degree III and IV injuries were usually treated with adhesives, partial resection, or mesh splenorrhaphy; only degree V injuries almost always required splenectomy. With increasing experience in nonoperative management of splenic injuries the initial criteria have become less rigid, and there is now a tendency to attempt it in patients who formerly would have undergone surgery.

A polymorphism in the endothelin-A receptor gene predicts survival in patients with idiopathic dilated cardiomyopathy

AIMS

The endothelin system plays a role in the complex pathophysiology of idiopathic dilated cardiomyopathy. We investigated whether genetic polymorphisms of the endothelin system might be associated with dilated cardiomyopathy-related cardiac phenotypes and differences in disease outcome.

METHODS

One hundred and twenty-five unrelated dilated cardiomyopathy patients of a well characterized dilated cardiomyopathy cohort were genotyped for six common polymorphisms of the endothelin-1, endothelin-A (ETA) and endothelin-B (ETB) receptor genes using hybridization with allele-specific oligonucleotides.

RESULTS

The H323H (C/T) polymorphism in exon 6 of the ETA receptor gene was significantly associated with a shorter survival time after diagnosis. The odds ratio for carriers of the less frequent ET(A)T allele to die within 2 years after diagnosis was 5.5 (95% confidence interval, 1.4 to 21.0, P=0.013) compared to non-carriers. Kaplan-Meier analysis revealed a significantly different survival time for T allele carriers as compared to non-carriers as tested by logrank (P=0.0196), Breslow (P=0.0195), and Tarone tests (P=0.020). The influence of the ETA H323H polymorphism on survival remained significant when known predictors of prognosis such as left ventricular ejection fraction, left ventricular end-diastolic diameter, age and NYHA functional classification were entered in a Cox proportional hazards analysis. In this model, end-diastolic diameter showed a trend to influence survival (P=0.07) but only the ETA H323H polymorphism (P=0.0029) was a significant independent predictor of survival.

CONCLUSIONS

Our results suggest that genetic variation in the ETA receptor predicts survival in dilated cardiomyopathy patients, which might have important consequences for the identification of high-risk individuals.

Chromosome 22q dosage in composite extrarenal rhabdoid tumors: clonal evolution or a phenotypic mimic?

Composite extrarenal rhabdoid tumors (CERTs) represent a diverse group of neoplasms with rhabdoid shape in combination with one of several distinctive tumor types. Like the classic renal and extrarenal malignant rhabdoid tumor (MRT), as well as the atypical teratoid/rhabdoid tumor (AT/RT) of the central nervous system, CERTs typically show aggressive clinical behavior. Deletions and mutations of the INII gene on 22q11.2 have been identified in most classic MRTs and AT/RTs; however, it is not known whether the rhabdoid components in CERTs have similar genetic abnormalities. Using fluorescence in situ hybridization (FISH) on archival, paraffin-embedded tissue with a commercially available probe in close proximity to the INII locus (bcr), as well as other chromosome 22 probes, we studied 4 cases of MRT, 13 of AT/RT, and 16 of CERT (3 melanoma, 4 meningioma, 7 carcinoma, 1 rhabdomyosarcoma, and 1 neuroblastoma). Deletion of the 22q11.2 locus was demonstrated in 10 (77%) of 13 AT/RTs and 3 (75%) of 4 MRT, including 1 congenital MRT. Of the 16 CERTs, only 2 (a rhabdoid meningioma and a carcinoma with rhabdoid features; 13%) harbored a deletion at this locus. This difference was statistically significant (P <.001). We conclude that deletion of 22q11.2, typical of most classic MRTs and AT/RTs, is infrequently seen in CERTs. This suggests that the rhabdoid component of CERTs does not evolve by way of the genetic alteration characteristic of MRTs or AT/RTs, but represents instead a distinct phenotype shared by a number of tumors as they undergo anaplastic progression.

New approaches to molecular profiling of tissue samples

Figures on http://www.esacp.org/acp/2000/20-1/best.htm.

Laparoscopic cholecystectomy using 2-mm instruments

Today, laparoscopic cholecystectomy is the method of choice for treatment of symptomatic gallbladder disorders. It minimizes effects of the operation that are independent of the gallbladder, such as trauma to the abdominal wall and other soft tissue. The surgical wounds were even smaller when 2-mm trocars were used. Laparoscopic cholecystectomy using 2-mm instruments was performed in a consecutive series of 14 patients with symptomatic gallstones. The procedure was completed in 12 cases, with conversion to open surgery in two cases. Intraoperative cholangiography was always performed. The postoperative course was always uneventful. The cosmetic effect was highly satisfactory. The procedure using 2-mm instruments could be indicated in selected patients with uncomplicated gallstone disease.

Comparative study between intra-anal sponge and needle electrode for electromyographic evaluation of constipated patients

PURPOSE

The aim of this study was to compare the intra-anal sponge electrode with the conventional needle electrode for electromyography of the pelvic floor in constipated patients.

MATERIALS AND METHODS

Forty consecutive patients (27 females) with a mean age of 64.3 (range, 15-87) years who had chronic constipation were prospectively evaluated for electromyographic evidence of nonrelaxation or paradoxical contraction of the puborectalis and external anal sphincter during simulated defecation. The soft intra-anal sponge electrode and then the concentric needle electrode were used in each patient as an internal control. Furthermore, in all patients, cinedefecography was used as an independent standard to confirm the diagnosis. Agreement was calculated using the kappa statistic.

RESULTS

Confirmation of needle electromyography was noted in 19 of 20 patients (95 percent) who had sponge electromyographic evidence of paradoxical activity. Similarly, concurrence was noted in 19 of 20 patients (95 percent) with normal relaxation of the puborectalis observed with the sponge electrode. Agreement between needle and sponge electromyography was very good (kappa = 0.9), between needle electromyography and cinedefecography was fair (kappa = 0.4), and between sponge electromyography and cinedefecography was moderate (kappa = 0.5). Furthermore, needle electromyography was more painful in all patients compared with sponge electromyography.

CONCLUSION

The soft sponge surface intra-anal electrode is an excellent alternative to the needle electrode for assessment of puborectalis activity in constipated patients. Sponge electromyography has the advantage of being as accurate as, but less painful than, needle electromyography.

Laceration of a benign adrenal adenoma mimicking a splenic rupture

Lacerations of adrenal tumors are very rare events and have been described for myelolipoma, pheochromocytoma, and cortisol-producing adenoma. We report on a patient who was admitted with suspected splenic rupture. Computed tomography showed a mass 14 cm in diameter adjacent to the spleen, but selective angiography revealed blood supply by the left suprarenal artery. A ruptured adrenal tumor was therefore diagnosed and resected. No hormone production was detected. Histologically a benign adrenal adenoma was found. Frequency, diagnosis and therapy of adrenal masses are discussed.