Mid-term clinical and sonographic outcomes of minimally invasive acromioclavicular joint reconstruction: mini-open versus arthroscopically assisted

INTRODUCTION

The current literature describes various operative stabilization strategies which achieve good clinical outcomes after acute acromioclavicular joint (ACJ) dislocation. The aim of this study was to compare the mid-term clinical and sonographic treatment outcomes after minimally invasive mini-open and arthroscopic reconstruction.

MATERIALS AND METHODS

We conducted a retrospective two-center study of patients with acute ACJ dislocation. Surgical treatment was performed using either a mini-open approach (MIOP) or an arthroscopic technique (AR). The primary outcome parameters of this study were the sonographically measured acromioclavicular (ACD) and coracoclavicular distances (CCD). Secondary outcome parameters included the Constant-Murley score (CS), range of motion (ROM), postoperative pain scale (VAS), return to daily routine, return to sports, complications, as well as operative revisions.

RESULTS

After a mean follow-up of 29 months, 30 patients were included in this study with an average age of 41.3 ± 14.8 years (MIOP) and 41.2 ± 15.4 years (AR). The sonographic ACD (MIOP 9.11 mm vs. AR 8.93 mm, p = 0.41) and CCD (MIOP 25.08 mm vs. AR 24.36 mm, p = 0.29) distances showed no statistically significant differences. Furthermore, there was no statistically significant difference when compared to the contralateral side (p = 0.42). With both techniques, patients achieved excellent clinical outcome parameters without statistically significant differences in CS (MIOP 95 vs. AR 97, p = 0.11) and VAS (MIOP 1.76 vs. AR 1.14, p = 0.18). The return to daily activity and return to sport rates did not differ. There were neither complications nor revisions in both groups.

CONCLUSION

Both minimally invasive techniques for acute ACJ stabilization achieved excellent clinical and sonographic outcomes without one technique being statistically superior to the other.

Zeolite-loaded alginate-chitosan hydrogel beads as a topical hemostat

Hemorrhage is the leading cause of preventable death after a traumatic injury, and the largest contributor to loss of productive years of life. Hemostatic agents accelerate hemostasis and help control hemorrhage by concentrating coagulation factors, acting as procoagulants and/or interacting with erythrocytes and platelets. Hydrogel composites offer a platform for targeting both mechanical and biological hemostatic mechanisms. The goal of this work was to develop hydrogel particles composed of chitosan, alginate, and zeolite, and to assess their potential to promote blood coagulation via multiple mechanisms: erythrocyte adhesion, factor concentration, and the ability to serve as a mechanical barrier to blood loss. Several particle compositions were synthesized and characterized. Hydrogel bead composition was optimized to achieve the highest swelling capacity, greatest erythrocyte adhesion, and minimal in vitro cytotoxicity. These results suggest a polymer hydrogel-aluminosilicate composite material may serve as a platform for an effective hemostatic agent that incorporates multiple mechanisms of action. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1662-1671, 2018.

Controlling the Growth of Staphylococcus epidermidis by Layer-By-Layer Encapsulation

Commensal skin bacteria such as Staphylococcus epidermidis are currently being considered as possible components in skin-care and skin-health products. However, considering the potentially adverse effects of commensal skin bacteria if left free to proliferate, it is crucial to develop methodologies that are capable of maintaining bacteria viability while controlling their proliferation. Here, we encapsulate S. epidermidis in shells of increasing thickness using layer-by-layer assembly, with either a pair of synthetic polyelectrolytes or a pair of oppositely charged polysaccharides. We study the viability of the cells and their delay of growth depending on the composition of the shell, its thickness, the charge of the last deposited layer, and the degree of aggregation of the bacteria which is varied using different coating procedures-among which is a new scalable process that easily leads to large amounts of nonaggregated bacteria. We demonstrate that the growth of bacteria is not controlled by the mechanical properties of the shell but by the bacteriostatic effect of the polyelectrolyte complex, which depends on the shell thickness and charge of its outmost layer, and involves the diffusion of unpaired amine sites through the shell. The lag times of growth are sufficient to prevent proliferation for daily topical applications.

6-Phosphofructo-2-kinase/fructose-2,6-biphosphatase 4 is essential for p53-null cancer cells

The bifunctional enzyme 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase-4 (PFKFB4) controls metabolic flux through allosteric regulation of glycolysis. Here we show that p53 regulates the expression of PFKFB4 and that p53-deficient cancer cells are highly dependent on the function of this enzyme. We found that p53 downregulates PFKFB4 expression by binding to its promoter and mediating transcriptional repression via histone deacetylases. Depletion of PFKFB4 from p53-deficient cancer cells increased levels of the allosteric regulator fructose-2,6-bisphosphate, leading to increased glycolytic activity but decreased routing of metabolites through the oxidative arm of the pentose-phosphate pathway. PFKFB4 was also required to support the synthesis and regeneration of nicotinamide adenine dinucleotide phosphate (NADPH) in p53-deficient cancer cells. Moreover, depletion of PFKFB4-attenuated cellular biosynthetic activity and resulted in the accumulation of reactive oxygen species and cell death in the absence of p53. Finally, silencing of PFKFB4-induced apoptosis in p53-deficient cancer cells in vivo and interfered with tumour growth. These results demonstrate that PFKFB4 is essential to support anabolic metabolism in p53-deficient cancer cells and suggest that inhibition of PFKFB4 could be an effective strategy for cancer treatment.

[Safety of sedation during gastroscopy and colonoscopy in low-risk patients - results of a retrospective subgroup analysis of a registry study including over 170 000 endoscopies]

INTRODUCTION

Administering sedation is an established standard in gastrointestinal endoscopy, particularly in situations in which sedation is used to make the examination more comfortable for the patient (e. g., during preventive check-up examinations). It is important to have precise information about the risk of sedation-associated complications.

AIMS AND METHODS

The aim of this study was to record the incidence and type of sedation-associated complications in a low-risk group of patients (ASA 1 or 2) undergoing elective diagnostic esophagogastroduodenoscopy or colonoscopy. Risk factors for the development of a sedation complication were also to be identified. Using a prospective multicenter study design, sedation-associated complications were documented in the ProSed2 study using an electronic endoscopy documentation system.

RESULTS

Thirty-nine research centers took part in the study from December 2011 to June 2014. A total of 368 206 endoscopies were recorded. 177 944 of the procedures met the defined criteria for subgroup analysis (endoscopy with sedation, patient in ASA class 1 or 2, esophagogastroduodenoscopy or colonoscopy, no emergency endoscopies, no therapeutic procedures). The patients received propofol alone in 64.4 % of the sedations, or a combination of propofol and midazolam in 22.4 %. Sedation was administered by the endoscopist or endoscopy assistant in 56.5 % of cases, or by a third person in 43.5 % (anesthesist < 0.1 %, intensive-care specialist 5.7 %, nurse-administered propofol sedation 37.8 %). A total of 332 minor complications were documented (0.2 %). No major complications or deaths occurred. The following risk factors were identified for the development of sedation-associated complications: Patients in ASA class 2 and sedation with midazolam in combination with an opiate.

CONCLUSIONS

These findings on sedation-associated complications show that severe complications and deaths do not occur, and that minor complications occur very rarely. Sedation can therefore be regarded as extremely safe in this group of patients. Even though this analysis did not include therapeutic colonoscopies (e. g. polypectomy), these data should lower the threshold for patients undergoing preventive check-up examinations and it should therefore be offered as a standard.

[Detection of early neoplasia in Barrett's oesophagus: focus attention on index endoscopy in short-segment-Barrett's oesophagus with random biopsies]

BACKGROUND

Detecting early neoplasias in Barrett's oesophagus (BE) is challenging. Recent publications have been focusing on improving the detection of such lesions during Barrett's surveillance. However in a recently published Danish register study calculating the risk for cancer-development in BE two-thirds of the diagnosed tumors were identified during the first examination or in the first year. This means that index endoscopy might be more effective than surveillance in detecting early neoplasia in BE. 

METHODS

In the period from January 2010 to April 2011, all patients who consecutively presented with a diagnosis of early neoplastic changes in BE were recorded prospectively.

ANALYSIS

The analysis included data for 121 patients. In patients with short-segment BE (SSBE), neoplasia was only diagnosed in 6 % of cases in the surveillance examination, compared with 44 % of cases in long-segment BE (LSBE). The neoplastic lesion was identified visually in 43 patients (36 %) during the external EGD. Type II tumours were detected in 40 % (39/98) and were correctly assessed as neoplastic in 25 % of cases (24/98).

CONCLUSIONS

1. in patients with SSBE almost all early tumours are diagnosed by index endoscopy and not by Barrett's surveillance; 2. around 40 % of all early neoplasias are endoscopically invisible and are only diagnosed using four-quadrant biopsies; 3. the macroscopic tumour type has a substantial influence on the detection rate for neoplasia. If efforts to increase the detection rate for early neoplasia in BE are focused solely on the Barrett's surveillance method, then only a minority of patients - 20 % in the present group - will benefit from the measure. German clinical trials register, DRKS00 004 168.

Endoscopic management for patients with serrated polyposis syndrome is feasible and effective: a prospective observational study at a tertiary centre

BACKGROUND AND STUDY AIMS

Serrated polyposis syndrome is a rare condition in which multiple serrated lesions develop all over the colon, which is thought to be associated with an increased risk for the development of cancer. The aim of this study was to investigate the feasibility of endoscopic treatment and standardised surveillance in patients with this increasingly recognised syndrome.

METHODS

From September 2010 to November 2013, consecutive patients were included in a prospective study. All patients underwent chromoendoscopy at first presentation and during surveillance. Follow-up examinations were carried out at 3 month intervals until complete clearance was achieved. Afterwards, patients entered a standardised surveillance protocol with a chromoendoscopic colonoscopy annually.

RESULTS

Altogether 100 colonoscopies were carried out in 28 patients, with endoscopic resection of 436 lesions. Total clearance was accomplished in 27 patients (96.0 %) after 2.5 colonoscopies (range 1 - 8). Histology revealed 359 hyperplastic polyps (82.3 %), 37 sessile serrated adenomas (8.5 %), 36 low-grade adenomas (8.3 %), and one patient with advanced colorectal cancer. Twelve patients (42.8 %) had serrated polyps > 10 mm in size. During the surveillance period, 86 additional lesions were detected and resected. The mean follow-up period was 21.5 months (range 2 - 39 months). No interval carcinoma was detected during the surveillance.

CONCLUSIONS

The present study indicates that endoscopic management in patients who meet the diagnostic criteria for serrated polyposis syndrome is feasible and safe. In particular, the incidence of colorectal cancer in this cohort was lower in comparison with previous studies.

ATM signalling and cancer

ATM, the protein kinase mutated in the rare human disease ataxia telangiectasia (A-T), has been the focus of intense scrutiny over the past two decades. Initially this was because of the unusual radiosensitive phenotype of cells from A-T patients, and latterly because investigating ATM signalling has yielded valuable insights into the DNA damage response, redox signalling and cancer. With the recent explosion in genomic data, ATM alterations have been revealed both in the germline as a predisposing factor for cancer and as somatic changes in tumours themselves. Here we review these findings, as well as advances in the understanding of ATM signalling mechanisms in cancer and ATM inhibition as a strategy for cancer treatment.

[Challenges and limits for endoscopic resection of oesophageal and oesophagogastric cancer]

There is good evidence for the safety and efficacy of endoscopic treatment for early neoplasia in Barrett's oesophagus and in oesophageal squamous epithelium within defined margins, and this form of therapy is therefore the treatment of choice. With a low morbidity rate, it offers patients a good quality of life with preservation of the organ. The mortality risk is minimal. The decisive element for success is early diagnosis. Oesophageal resection and radiotherapy/chemotherapy are nowadays reserve procedures in the treatment of early oesophageal carcinoma and should only be used in patients in whom the tumour shows defined histological risk factors or endoscopic therapy has failed. Discussion is currently taking place on whether the criteria used to indicate endoscopic therapy for early Barrett's adenocarcinoma can be expanded to include lesions with superficial submucosal infiltration and no additional histological risk factors.

Limits on spin-dependent WIMP-nucleon cross sections from 225 live days of XENON100 data

We present new experimental constraints on the elastic, spin-dependent WIMP-nucleon cross section using recent data from the XENON100 experiment, operated in the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 224.6 live days×34 kg of exposure acquired during 2011 and 2012 revealed no excess signal due to axial-vector WIMP interactions with 129Xe and 131Xe nuclei. This leads to the most stringent upper limits on WIMP-neutron cross sections for WIMP masses above 6 GeV/c², with a minimum cross section of 3.5×10(-40) cm² at a WIMP mass of 45 GeV/c², at 90% confidence level.

[How safe is sedation in gastrointestinal endoscopy? A multicentre analysis of 388,404 endoscopies and analysis of data from prospective registries of complications managed by members of the Working Group of Leading Hospital Gastroenterologists (ALGK)]

BACKGROUND

Gastrointestinal endoscopies are increasingly being carried out with sedation. All of the drugs used for sedation are associated with a certain risk of complications. Data currently available on sedation-associated morbidity and mortality rates are limited and in most cases have substantial methodological limitations. The aim of this study was to record severe sedation-associated complications in a large number of gastrointestinal endoscopies.

METHODS

Data on severe sedation-associated complications were collected on a multicentre basis from prospectively recorded registries of complications in the participating hospitals (median documentation period 27 months, range 9 - 129 months).

RESULTS

Data for 388,404 endoscopies from 15 departments were included in the study. Severe sedation-associated complications occurred in 57 patients (0.01 %). Forty-one percent of the complications and 50 % of all complications with a fatal outcome (10/20 patients) occurred during emergency endoscopies. In addition, it was found that 95 % of the complications and 100 % of all fatal complications affected patients in ASA class ≥ 3.

CONCLUSIONS

Including nearly 400,000 endoscopies, this study represents the largest prospective, multicenter record of the complications of sedation worldwide. The analysis shows that sedation is carried out safely in gastrointestinal endoscopy. The morbidity and mortality rates are much lower than previously reported in the literature in similar groups of patients. Risk factors for the occurrence of serious complications include emergency examinations and patients in ASA class ≥ 3.

[Esophageal precancerous lesions: early diagnosis, treatment, and preservation of quality of life]

Modern high-resolution video endoscopes allow detailed examination of the esophageal mucosa and diagnosis of early neoplastic changes in the gastrointestinal tract. Whereas Barrett's esophagus is a precancerous condition that can develop into adenocarcinoma, there is no defined precancerous lesion for squamous cell carcinoma. Various diseases are associated with the development of esophageal squamous cell carcinoma. Chromoendoscopy has become an established method in the diagnostic work-up for better visualization of early neoplasia. If Barrett's esophagus is present, acetic acid spraying or virtual chromoendoscopy can be used to accentuate the display of superficial gyriform structures in the mucosa. The gold standard for detecting squamous cell carcinoma is still the use of Lugol solution. When early neoplasia is suspected, diagnostic endoscopic resection should be performed. This allows precise histological assessment of the tumor. Early diagnosis of neoplastic changes in the esophagus provides patients not only with the option of curative therapy but also with a good quality of life through preservation of the esophagus.

Are intracranial pressure wave amplitudes measurable through lumbar puncture?

OBJECTIVE

The aim of this study was to investigate whether pulsations measured in the brain correspond to those measured in lumbar space, and subsequently whether lumbar punctures could replace invasive recordings.

METHODS

In ten patients with normal pressure hydrocephalus, simultaneous recordings of the intracranial pressure (ICP; intraparenchymal) and lumbar pressure (LP; cerebrospinal fluid pressure) were performed. During registration, pressure was altered between resting pressure and 45 mmHg using an infusion test. Data were analyzed regarding pulsations (i.e., amplitudes). Also, the pressure sensors were compared in a bench test.

RESULTS

The correlation between intracranial and lumbar amplitudes was 0.98. At resting pressure, and moderately elevated ICP, intracranial pulse amplitudes exceeded that of lumbar space with about 0.9 mmHg. At the highest ICP, the difference changed to -0.2 mmHg. The bench test showed that the agreement of sensor readings was good at resting pressure, but reduced at higher amplitudes.

CONCLUSIONS

Compared to intracranial registrations, amplitudes measured through lumbar puncture were slightly attenuated. The bench test showed that differences were not attributable to dissimilarities of the sensor systems. A lumbar pressure amplitude measurement is an alternative to ICP recording, but the thresholds for what should be interpreted as elevated amplitudes need to be adjusted.

Dark matter results from 225 live days of XENON100 data

We report on a search for particle dark matter with the XENON100 experiment, operated at the Laboratori Nazionali del Gran Sasso for 13 months during 2011 and 2012. XENON100 features an ultralow electromagnetic background of (5.3 ± 0.6) × 10(-3) events/(keV(ee) × kg × day) in the energy region of interest. A blind analysis of 224.6 live days × 34 kg exposure has yielded no evidence for dark matter interactions. The two candidate events observed in the predefined nuclear recoil energy range of 6.6-30.5 keV(nr) are consistent with the background expectation of (1.0 ± 0.2) events. A profile likelihood analysis using a 6.6-43.3 keV(nr) energy range sets the most stringent limit on the spin-independent elastic weakly interacting massive particle-nucleon scattering cross section for weakly interacting massive particle masses above 8 GeV/c(2), with a minimum of 2 × 10(-45) cm(2) at 55 GeV/c(2) and 90% confidence level.

[A rare cause of recurrent small bowel intussusception. Case report and review of the literature]

Small bowel intussusception is a rare cause of abdominal pain in adult patients. Due to varying symptoms and different underlying causes its diagnosis and treatment is challenging for physicians. This case report describes recurrent intussusception in an adult female patient and celiac disease could only be diagnosed as the cause of these symptoms after surgery. In addition a review of the literature regarding adult intussusception is presented.

Dark matter results from 100 live days of XENON100 data

We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a two-phase time-projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows the selection of only the innermost 48 kg as the ultralow background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in the signal region with an expected background of (1.8 ± 0.6) events. This leads to the most stringent limit on dark matter interactions today, excluding spin-independent elastic weakly interacting massive particle (WIMP) nucleon scattering cross sections above 7.0 × 10(-45) cm(2) for a WIMP mass of 50 GeV/c(2) at 90% confidence level.

First dark matter results from the XENON100 experiment

The XENON100 experiment, in operation at the Laboratori Nazionali del Gran Sasso in Italy, is designed to search for dark matter weakly interacting massive particles (WIMPs) scattering off 62 kg of liquid xenon in an ultralow background dual-phase time projection chamber. In this Letter, we present first dark matter results from the analysis of 11.17 live days of nonblind data, acquired in October and November 2009. In the selected fiducial target of 40 kg, and within the predefined signal region, we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross sections above 3.4 × 10⁻⁴⁴  cm² for 55  GeV/c² WIMPs at 90% confidence level. Below 20  GeV/c², this result constrains the interpretation of the CoGeNT and DAMA signals as being due to spin-independent, elastic, light mass WIMP interactions.

Spatially uniform calibration of a liquid xenon detector at low energies using (83m)Kr

A difficult task with many particle detectors focusing on interactions below approximately 100 keV is to perform a calibration in the appropriate energy range that adequately probes all regions of the detector. Because detector response can vary greatly in various locations within the device, a spatially uniform calibration is important. We present a new method for calibration of liquid xenon (LXe) detectors, using the short-lived (83m)Kr. This source has transitions at 9.4 and 32.1 keV, and as a noble gas like Xe, it disperses uniformly in all regions of the detector. Even for low source activities, the existence of the two transitions provides a method of identifying the decays that is free of background. We find that at decreasing energies, the LXe light yield increases, while the amount of electric field quenching is diminished. Additionally, we show that if any long-lived radioactive backgrounds are introduced by this method, they will present less than 67x10(-6) events kg(-1) day(-1) keV(-1) in the next generation of LXe dark matter direct detection searches.

Computer-aided classification of colorectal polyps based on vascular patterns: a pilot study

BACKGROUND AND STUDY AIMS

Recent studies have shown that narrow-band imaging (NBI) is a powerful diagnostic tool for differentiating between neoplastic and nonneoplastic colorectal polyps. The aim of the present study was to develop and evaluate a computer-based method for automated classification of colorectal polyps on the basis of vascularization features.

PATIENTS AND METHODS

In a prospective pilot study with 128 patients who were undergoing zoom NBI colonoscopy, 209 detected polyps were visualized and subsequently removed for histological analysis. The proposed computer-based method consists of image preprocessing, vessel segmentation, feature extraction, and classification. The results of the automated classification were compared to those of human observers blinded to the histological gold standard.

RESULTS

Consensus decision between the human observers resulted in a sensitivity of 93.8 % and a specificity of 85.7 %. A "safe" decision, i. e., classifying polyps as neoplastic in cases when there was interobserver discrepancy, yielded a sensitivity of 96.9 % and a specificity of 71.4 %. The overall correct classification rates were 91.9 % for the consensus decision and 90.9 % for the safe decision. With ideal settings the computer-based approach achieved a sensitivity of approximately 90 % and a specificity of approximately 70 %, while the overall correct classification rate was 85.3 %. The computer-based classification showed a specificity of 61.2 % when a sensitivity of 93.8 % was selected, and a 53.1 % specificity with a sensitivity of 96.9 %.

CONCLUSIONS

Automated classification of colonic polyps on the basis of NBI vascularization features is feasible, but classification by observers is still superior. Further research is needed to clarify whether the performance of the automated classification system can be improved.

Long-term results and risk factor analysis for recurrence after curative endoscopic therapy in 349 patients with high-grade intraepithelial neoplasia and mucosal adenocarcinoma in Barrett's oesophagus

OBJECTIVE

Endoscopic therapy is increasingly being used in the treatment of high-grade intraepithelial neoplasia (HGIN) and mucosal adenocarcinoma (BC) in patients with Barrett's oesophagus. This report provides 5 year follow-up data from a large prospective study investigating the efficacy and safety of endoscopic treatment in these patients and analysing risk factors for recurrence.

DESIGN

Prospective case series.

SETTING

Academic tertiary care centre.

PATIENTS

Between October 1996 and September 2002, 61 patients with HGIN and 288 with BC were included (173 with short-segment and 176 with long-segment Barrett's oesophagus) from a total of 486 patients presenting with Barrett's neoplasia. Patients with submucosal or more advanced cancer were excluded.

INTERVENTIONS

Endoscopic therapy.

MAIN OUTCOME MEASURES

Rate of complete remission and recurrence rate, tumour-associated death.

RESULTS

Endoscopic resection was performed in 279 patients, photodynamic therapy in 55, and both procedures in 13; two patients received argon plasma coagulation. The mean follow-up period was 63.6 (SD 23.1) months. Complete response (CR) was achieved in 337 patients (96.6%); surgery was necessary in 13 (3.7%) after endoscopic therapy failed. Metachronous lesions developed during the follow-up in 74 patients (21.5%); 56 died of concomitant disease, but none died of BC. The calculated 5 year survival rate was 84%. The risk factors most frequently associated with recurrence were piecemeal resection, long-segment Barrett's oesophagus, no ablative therapy of Barrett's oesophagus after CR, time until CR achieved >10 months and multifocal neoplasia.

CONCLUSIONS

This study showed that endoscopic therapy was highly effective and safe, with an excellent long-term survival rate. The risk factors identified may help stratify patients who are at risk for recurrence and those requiring more intensified follow-up.

Tissue-specific induction of EROD activity and CYP1A protein in Sparus aurata exposed to B(a)P and TCDD

The purpose of this study was to compare xenobiotic CYP1A induction in liver, gills, and excretory kidney of gilthead seabream, Sparus aurata. Fishes were exposed via water for 20 days to different concentrations of benzo(a)pyrene (B(a)P) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). CYP1A was measured at the enzyme activity level as 7-ethoxyresorufin-O-deethylase (EROD) activity, and at the protein level by means of ELISA. The liver displayed the highest absolute levels of EROD activity, both under non-exposed and exposed conditions. Organ- or inducer-related differences in the time course of CYP1A induction were moderate; however, the magnitude of the induction response varied between the organs and between B(a)P and TCDD. In the case of TCDD, liver, and kidney yielded a comparable induction response, whereas in the case of B(a)P, the kidney showed a substantially higher maximum induction factor than the liver. In the gills, the two xenobiotics resulted in similar maximum induction factors. In B(a)P-exposed seabream, EROD activities and CYP1A protein levels showed a good correlation in all three organs, whereas with TCDD as inducer the correlation was poor, what was mainly due to a decrease of EROD activities at the higher concentrations of TCDD, while CYP1A protein levels showed no concomitant decline. Overall, the study revealed both similarities and differences in the time-, concentration-, and inducer-dependent CYP1A responses of the three target organs, liver, kidney, and gills. Although, the findings of this study principally confirm the notion of the liver as the major metabolic organ in fish, they also provide evidence for substantial metabolic potential in gills and particularly in the kidney.

Prospective evaluation of the macroscopic types and location of early Barrett's neoplasia in 380 lesions

BACKGROUND AND STUDY AIMS

The macroscopic appearance of early gastric cancers, classified according to the Japanese criteria, has been shown to be an important prognostic factor for local endoscopic therapy. No prospective data about the distribution of macroscopic types and their location in early Barrett's neoplasia are available, however. The present study was conducted to evaluate the clinical applicability of this macroscopic classification and to analyze the relative proportions of the different gross types in early Barrett's neoplasms and the correlation between the macroscopic classification and the stage or grade of differentiation.

PATIENTS AND METHODS

A total of 344 patients with 380 Barrett's neoplastic lesions who were referred between October 1996 and September 2005 for endoscopic therapy of early Barrett's high-grade intraepithelial neoplasia and carcinoma were prospectively included in the study. Routine endoscopy prior to endoscopic resection in our center included assessment of the macroscopic type (according to the Japanese classification) and documentation of the radial location of the neoplastic lesions. Images were recorded which were later assessed by six independent reviewers; intra- and interobserver agreement for the assessment of the macroscopic type were calculated using kappa statistics.

RESULTS

The distribution of the lesions by gross type was as follows: type I, n = 49 (13 %); type IIa, n = 139 (37 %); type IIb, n = 106 (28 %); type IIc, n = 17 (4 %); type IIa + c, n = 62 (16 %); type III, n = 7 (2 %). Type IIb lesions seem to be the most favorable type with regard to differentiation and T category ( P < 0.05). The mean kappa value for the interobserver agreement was 0.86 and the mean kappa value for the intraobserver agreement was 0.89. Most lesions were found at the 12 o'clock and 3 o'clock positions.

CONCLUSIONS

Assessment of the macroscopic type may provide important information about the possibility of endoscopic treatment. The harder-to-detect flat lesions are by far the most frequent macroscopic type of neoplastic lesion in Barrett's esophagus.

Biomarker Evidence for a Major Preservation Pathway of Sedimentary Organic Carbon

Hydrogenation processes leading from biomolecules to fossil biomarkers in anoxic sediments are crucial for the preservation of organic matter. However, these processes are still poorly understood. The present identification of several reduced carotenoids in recent sediments attests that these processes operate at the earliest stages of diagenesis without structural or stereochemical specificity, implying a nonbiological reduction pathway. Sulfur species (e.g., H2S) are the hydrogen donors involved in such reduction, as demonstrated with laboratory experiments. These reactions allow the preservation of abundant organic carbon in the rock record.

A new donor cornea harvesting technique for posterior lamellar keratoplasty

AIMS

To describe a technique for posterior lamellar keratoplasty donor preparation.

METHODS

In an experimental study eight human donor research corneas were mounted onto an artificial anterior chamber and deep stromal pockets dissected. Four corneas were mounted in the standard endothelial side down orientation and dissected using standard instruments (group 1). Another four corneas were mounted endothelial side up and dissected using a flat spatula (group 2). Trephined lamellar graft thickness was assessed by ultrasound pachymetry. The grafts were also analysed using vital staining of the endothelium and standard histological preparation.

RESULTS

Achieved posterior graft thickness was 118 (SD 32) microm (group 1) and 92 (23) microm (group 2) (p=0.324). Percentage of devitalised endothelial cells was 0.86% (1.48%) (group 1) and 3.9% (2.9%) (group 2) (p=0.185). The dissections using both harvesting techniques remained in plane and were smooth.

CONCLUSIONS

A blunt spatula and endothelium side up orientation on an artificial anterior chamber can be used to create posterior lamellar dissections without compromising endothelial cell number or planarity when compared to standard endothelium side down harvest.

Curative treatment for high-grade intraepithelial neoplasia in Barrett's esophagus

BACKGROUND AND STUDY AIMS

The incidence of premalignant and malignant lesions in specialized intestinal metaplasia of the esophagus has increased dramatically in the industrialized world in recent years. This report evaluates the efficacy and safety of local endoscopic therapy for high-grade intraepithelial neoplasia (HGIN) in Barrett's esophagus.

PATIENTS AND METHODS

Over a 5-year period between October 1996 and September 2001, a total of 379 patients were referred with a suspicion of early Barrett's cancer. In a prospective study, 44 patients with HGIN in Barrett's esophagus were selected for local endoscopic treatment. Endoscopic resection was carried out in 14 patients in whom the HGIN was re-detectable, and 27 patients in whom the HGIN was not re-detectable underwent photodynamic therapy (PDT). Endoscopic resection and PDT were combined in three patients.

RESULTS

Complete remission was achieved in 43 of the 44 patients (97.7 %). No major complications occurred. A mean of 1 session was needed to achieve complete local remission. During a mean follow-up period of 36 months (range 7 - 61 months), recurrent or metachronous lesions were observed in six patients (17.1 %), all of whom received a second successful endoscopic treatment.

CONCLUSIONS

Endoscopic therapy is a safe alternative treatment regimen for HGIN in Barrett's esophagus, providing a middle way between the widely promulgated options of a "watch-and-wait" policy and radical esophagectomy.

Prion proteins and infertility: insight from mouse models

A wealth of evidence points to an abnormal form of the prion protein called PrP(Sc) as the transmissible agent responsible for prion diseases. However, the physiological function of its normal conformer, the cellular prion protein (PrP(C)), is still unknown. Recently, a homologue of PrP(C) was discovered and denoted Doppel (Dpl). In contrast to PrP, mice deficient for Dpl suffer from an important pathological phenotype: male sterility. This phenotype shifts the attention from the brain, where most of the investigations on Dpl have been performed, to testis, raising hope to resolve the long lasting search of PrP(C) function.

Expression, cellular distribution and induction of cytochrome p4501A (CYP1A) in gilthead seabream, Sparus aurata, brain

The presence and induction of cytochrome p4501A (CYP1A) in the brain of a teleost fish, the seabream, Sparus aurata, was studied. Cerebral CYP1A expression of control fish or fish exposed to various concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was assessed at the enzyme activity level-measured as 7-ethoxyresorufin-O-deethylase; at the protein level-measured by means of Western blot and ELISA; and at the mRNA level-estimated by means of RT-PCR. Cellular localization of CYP1A in the brain tissue was studied using immunohistochemistry. In non-exposed control fish, expression of CYP1A could be demonstrated only in the olfactory bulbs. After TCDD exposure, the olfactory bulbs still showed the highest expression levels of CYP1A, however, other brain regions were now CYP1A-positive as well. Immunohistochemical examination of brain tissue sections from control fish demonstrated CYP1A immunoreactive fibers in the ventral telencephalon, in the glomerular layer of the olfactory bulbs, and in the endothelia of the cerebral vascular system. The same structures reacted positive in TCDD-exposed fish, but cell bodies and fibers from additional brain areas including telencephalon, diencephalon, mesencephalon and cerebellum showed CYP1A immunostaining. In the pituitary of TCDD-treated fish, putative GTH cells were positive for CYP1A, whereas in control fish no staining of the adenohypophysis was observed. The present findings provide evidence for basal expression of CYP1A in the telencephalon of Sparus aurata, and for the presence of inducible CYP1A in all other major brain regions, including the pituitary.

Thiofunctional vanadium complexes

The neutral tetradentate ligand 1,6-bis(2'-pyridyl)-2,5-dithiahexane (N(2)S(2)), containing two thioether functions, reacts with [VX(2)L(4)] (X = Br, L(4) = 2 tmeda (tmeda = Me(2)NCH(2)CH(2)NMe(2)); X = I, L = tetrahydrofuran (THF)) and [VX(3)(THF)(3)] (X = Br, I) to form the complexes [VX(2)(N(2)S(2))] (1) and [VX(2)(N(2)S(2))]X (2), respectively. [V(2)(mu-Cl)(3)(THF)(6)]I and N(2)S(2) yield the V(IV) complex [VOCl(N(2)S(2)]I (3). The pentadentate, dianionic ligand 2,6-bis(2'-mercaptophenylthio)dimethylpyridine, NS(2)S'(2)(2-), which contains two thioether (S) and two thiophenolate (S') functions, reacts with [VBr(3)(THF)(3)] to afford [VBr(NS(2)S'(2))] (4). The complex [VO(Cl)S'NS'] (5; H(2)S'NS' is the Schiff base formed between o-mercaptoaniline and o-mercaptobenzaldehyde) is obtained by redox interaction between [VCl(3)(THF)(3)] and 2,2'-dithiodibenzaldehyde in the presence of o-mercaptoaniline. The crystal and molecular structures have been obtained for 3. THF, 4. THF, and 5. n-C(5)H(12). The relevance of these compounds and their formation for the interaction between vanadium and thiofunctional biomolecules is addressed.

Simple organ cornea culture model for re-epithelialization after in vitro excimer laser ablation

BACKGROUND AND OBJECTIVE

Most of the in vitro work to characterize the effects of clinical laser surgery on corneal tissues has concentrated on the effects on stromal keratocytes and endothelium with little attention being paid to corneal epithelium. Our purpose is to describe the epithelial healing rates observed in freshly cultured rabbit corneas treated with phototherapeutic keratectomy (PTK).

STUDY DESIGN/MATERIALS AND METHODS

Corneas were placed in a simple organ culture system, with media change every 2 days. A clinical excimer laser was used to perform a 6 mm diameter, 100 microm depth transepithelial PTK on 24 cultured rabbit corneas, 1 day after culture initiation. For each post-treatment day, one experimental and one control cornea were removed from culture and stained with fluorescein, photographed, and fixed for histology. Epithelial defect area was measured with digital imaging software and analyzed statistically to assess the re-epithelialization rate.

RESULTS

Control corneas, maintained in culture for 1-4 days, had no epithelial defects. Those corneas treated with PTK exhibited an immediate epithelial defect that slowly healed over 3 days. This was confirmed on histopathological analysis. A significant linear trend in re-epithelialization across the time points studied was found (F = 80.48, P = 0.0029). The slope of the linear regression model showed an estimate rate of re-epithelialization of -6.70 over the 3 days.

CONCLUSION

We have described the development of a simple, whole organ, rabbit cornea culture model for re-epithelialization after PTK. Our rates of epithelial healing resemble those found in the literature in live rabbit models. Therefore, this model may possibly be used to monitor epithelial wound healing in different corneal diseases or injuries.

Re-epithelialization in cornea organ culture after chemical burns and excimer laser treatment

OBJECTIVE

To describe the epithelial healing rates observed in freshly cultured rabbit corneas chemically burned with high-concentration hydrochloric acid (HCl) and sodium hydroxide (NaOH) and subsequently treated with phototherapeutic keratectomy (PTK).

METHODS

We obtained 126 fresh corneoscleral rims from cadaveric New Zealand white rabbits. Each cornea was exposed to 4-mm cellulose sponges soaked in a solution of topical 0.9% isotonic sodium chloride solution, 2M HCl, or 0.5M NaOH. A transepithelial PTK (6-mm zone; 100-microm ablation depth) was then performed using the excimer laser (150-mJ/cm(2) energy pulse; 20 nanosecond duration; and 10-Hz frequency). Corneas were placed in tissue culture, and 1 cornea from each group was taken out of culture each day after treatment. Re-epithelialization was monitored by means of fluorescein staining, slitlamp photography, and histopathological analysis.

RESULTS

Corneas treated with HCl and NaOH exhibited immediate epithelial defects that slowly healed over time. In PTK-treated corneas, the re-epithelialization rate was accelerated compared with that of controls (P =.003 for the HCl group, and P<.001 for the NaOH group). The new epithelial layers were smoother in PTK-treated corneas, as confirmed by results of histopathological analysis.

CONCLUSION

Corneal damage caused by HCl and NaOH may be modulated in vitro by PTK in this rabbit model.

CLINICAL RELEVANCE

After corneal chemical damage, 193-nm excimer laser PTK accelerates epithelial wound healing.

Precision and accuracy of an artificial anterior chamber system in obtaining corneal lenticules for lamellar keratoplasty

PURPOSE

To determine the precision and accuracy of an artificial anterior chamber and a manual microkeratome in obtaining corneal lenticules for lamellar keratoplasty.

SETTING

Department of Ophthalmology, Cornea, External Diseases and Refractive Surgery Service, University of California Irvine, Irvine, California, USA.

METHODS

A lamellar keratectomy was performed in 47 human corneoscleral rims. Three lenticule thicknesses (180, 300, and 360 microm heads) and 3 diameters (7.0, 8.0, and 9.0 mm) were attempted. Diameters and thicknesses were measured by planimetry and pachymetry, respectively.

RESULTS

Peripheral lenticule thickness was more likely to be within +/-50 microm of the intended depth in thinner cuts (180 microm, 9/15 corneas, 60%; 300 microm, 6/16 corneas, 40%; 360 microm, 3/12 corneas, 33.3%) (P = .045). Eighty percent (32/40 corneas) were within +/-0.5 mm of the expected diameter. Accuracy was best in the 8.0 mm group, with 47.1% (8/17 corneas) within +/-0.2 mm of the expected diameter. A thickness/diameter correlation was not observed (r(s) < or = 0.28).

CONCLUSIONS

The precision and accuracy of this system varied according to the attempted thickness and diameter.

AP-1 mediated retinal photoreceptor apoptosis is independent of N-terminal phosphorylation of c-Jun

Apoptosis is essential for retinal development but it is also a major mode of cell loss in many human retinal dystrophies. High levels of visible light induce retinal apoptosis in mice and rats. This process is dependent on the induction of the transcription factor AP-1, a dimeric complex composed of c-Fos and c-Jun/JunD phosphoproteins. While c-Fos is essential, JunD is dispensable for light-induced photoreceptor apoptosis. Here we show that N-terminal phosphorylation of c-Jun, the other main partner of c-Fos in induced AP-1 complexes is not required for programmed cell death during retinal development in vivo and is also dispensable for photoreceptor apoptosis induced by the exogenous stimuli "excessive light" and N-nitroso-N-methylurea (MNU). Mice expressing a mutant c-Jun protein (JunAA) that cannot be phosphorylated at its N-terminus are apoptosis competent and their retina is not distinguishable from wild-type mice. Accordingly, Jun kinase, responsible for phosphorylation of wild-type c-Jun protein is at best only marginally induced by the apoptotic stimuli "light" and MNU. Complex composition of light-induced AP-1 complexes is similar in wild-type and JunAA mice. This shows that the mutant c-Jun protein can be part of the DNA binding complex AP-1 and demonstrates that induction of the DNA binding activity of AP-1 after light insult does not depend on N-terminal phosphorylation of c-Jun. Our results suggest that transactivation of target genes by phosphorylated c-jun/AP-1 is not required for MNU- or light-induced apoptosis of photoreceptor cells.