Does dissemination of guidelines alone increase the use of palliative single-fraction radiotherapy? Initial report of a longitudinal change management campaign at a provincial cancer program

Background

Despite level 1 evidence demonstrating the equivalence of single-fraction radiotherapy (sfrt) and multiple-fraction radiotherapy (mfrt) for the palliation of painful bone metastases, sfrt remains underused. In 2015, to encourage the sustainable use of palliative radiation oncology resources, CancerCare Manitoba disseminated, to each radiation oncologist in Manitoba, guidelines from Choosing Wisely Canada (cwc) that recommend sfrt. We assessed whether dissemination of the guidelines influenced sfrt use in Manitoba in 2016, and we identified factors associated with mfrt.

Methods

All patients treated with palliative radiotherapy for bone metastasis in Manitoba from 1 January 2016 to 31 December 2016 were identified from the provincial radiotherapy database. Patient, treatment, and disease characteristics were extracted from the electronic medical record and tabulated by fractionation schedule. Univariable and multivariable logistic regression analyses were performed to identify risk factors associated with mfrt.

Results

In 2016, 807 patients (mean age: 70 years; range: 35-96 years) received palliative radiotherapy for bone metastasis, with 69% of the patients having uncomplicated bone metastasis. The most common primary malignancies were prostate (27.1%), lung (20.6%), and breast cancer (15.9%). In 62% of cases, mfrt was used-a proportion that was unchanged from 2015. On multivariable analysis, a gastrointestinal [odds ratio (or): 5.3] or lung primary (or: 3.3), complicated bone metastasis (or: 4.3), and treatment at a subsidiary site (or: 4.4) increased the odds of mfrt use.

Conclusions

Dissemination of cwc recommendations alone did not increase sfrt use by radiation oncologists in 2016. A more comprehensive knowledge translation effort is therefore warranted and is now underway to encourage increased uptake of sfrt in Manitoba.

Effect of Scapular Stabilization Exercise during Standing on Upper Limb Function and Gait Ability of Stroke Patients

Background

The purpose of this study was to determine the effect of scapular stabilization exercise during standing on a paretic side on upper limb function and gait ability of stroke patients.

Methods

This study was a hospital-based, randomized controlled trial with a blinded assessor. A total of 17 patients with hemiplegic diagnosis after stroke were divided into two groups (9 patients in a study group and 8 patients in a control group). The study group received physical therapy and scapular stabilization exercise on a paretic side. Participants were subjected to initial evaluation before the treatment. Subjects were subsequently re-evaluated 4 and 8 weeks later to compare the changes. Measurements of hand function and gait ability were performed.

Results

Based on multivariate analysis of variance for repeated-measures, there was a significant time effect for Timed Up and Go test (TUG) (F = 13.816, P = 0.000), Functional Gait Assessment (FGA) (F = 18.613, P = 0.000), and manual function test (MFT) (F = 16.777, P = 0.000). The group × time interaction effect was also significant for FGA (F = 4.966, P = 0.024) and MFT (F = 6.946, P = 0.003), but not for TUG test (F = 3.343, P = 0.069).

Conclusion

Results of the present study indicated that scapular stabilization exercise during standing on a paretic side for 8 weeks had an effect on hand function and gait ability of hemiplegic patients after stroke. Further studies are needed to find the most proper exercise for stroke patients who have gait disability and upper limb dysfunction.

A Small GTPase RHO2 Plays an Important Role in Pre-infection Development in the Rice Blast Pathogen Magnaporthe oryzae

The rice blast pathogen Magnaporthe oryzae is a global threat to rice production. Here we characterized RHO2 gene (MGG_02457) that belongs to the Rho GTPase family, using a deletion mutant. This mutant ΔMorho2 exhibited no defects in conidiation and germination but developed only 6% of appressoria in response to a hydrophobic surface when compared to the wild-type progenitor. This result indicates that MoRHO2 plays a role in appressorium development. Furthermore, exogenous cAMP treatment on the mutant led to appressoria that exhibited abnormal morphology on both hydrophobic and hydrophilic surfaces. These outcomes suggested the involvement of MoRHO2 in cAMP-mediated appressorium development. ΔMorho2 mutation also delayed the development of appressorium-like structures (ALS) at hyphal tips on hydrophobic surface, which were also abnormally shaped. These results suggested that MoRHO2 is involved in morphological development of appressoria and ALS from conidia and hyphae, respectively. As expected, ΔMorho2 mutant was defective in plant penetration, but was still able to cause lesions, albeit at a reduced rate on wounded plants. These results implied that MoRHO2 plays a role in M. oryzae virulence as well.

Effectiveness of Different Classes of Fungicides on Botrytis cinerea Causing Gray Mold on Fruit and Vegetables

Botrytis cinerea is a necrotrophic pathogen causing a major problem in the export and post-harvest of strawberries. Inappropriate use of fungicides leads to resistance among fungal pathogens. Therefore, it is necessary to evaluate the sensitivity of B. cinerea to various classes of fungicide and to determine the effectiveness of different concentrations of commonly used fungicides. We thus evaluated the effectiveness of six classes of fungicide in inhibiting the growth and development of this pathogen, namely, fludioxonil, iprodione, pyrimethanil, tebuconazole, fenpyrazamine, and boscalid. Fludioxonil was the most effective (EC50 < 0.1 μg/ml), and pyrimethanil was the least effective (EC50 = 50 μg/ml), at inhibiting the mycelial growth of B. cinerea. Fenpyrazamine and pyrimethanil showed relatively low effectiveness in inhibiting the germination and conidial production of B. cinerea. Our results are useful for the management of B. cinerea and as a basis for monitoring the sensitivity of B. cinerea strains to fungicides.

MicroRNA expression profiling of sputum for the detection of early and locally advanced non-small-cell lung cancer: a prospective case-control study

BACKGROUND

Non-small-cell lung cancer (nsclc) is associated with very poor overall survival because 70% of patients present with locally advanced or metastatic disease at the time of diagnosis. Micrornas (mirnas) are a class of short, noncoding rna molecules whose presence in samples of biologic fluids such as sputum has demonstrated promise as a potential means of detecting nsclc. We investigated the stage-specific nsclc detection potential of an efficient panel of 3 mirnas (mir-21, mir-210, mir-372) using a single sputum sample.

METHODS

A single spontaneously expectorated sputum sample was prospectively collected from 21 early nsclc (≤stage ii) patients, 22 advanced nsclc (≥stage iii) patients, and 10 control subjects. Mirna expression profiles were determined by quantitative real-time polymerase chain reaction and were analyzed by unsupervised hierarchical cluster analysis.

RESULTS

Mean tumour size (±95% confidence interval) in the early and advanced nsclc patients was 3.3 cm ± 0.9 cm and 4.8 cm ± 0.7 cm respectively. Adenocarcinoma constituted 61.9% of the early and 45.5% of the advanced nsclc cases respectively. In comparing the early nsclc group with the control group, the mirna panel yielded a diagnostic sensitivity of 67% and a specificity of 90.0%. For the advanced nsclc group, the mirna panel detected nsclc with a sensitivity and specificity of 64% and 100% respectively.

CONCLUSIONS

A sputum mir-21, mir-210, and mir-372 expression profile might provide a sensitive and highly specific means for detecting nsclc. Sputum mirna analysis demonstrates promise as a potential complementary screening tool.

Effects of water temperature on mortality in Megalocytivirus-infected rock bream Oplegnathus fasciatus (Temminck et Schlegel) and development of protective immunity

Rock bream iridovirus (RBIV) causes huge losses, especially in rock bream Oplegnathus fasciatus. Rock bream injected with RBIV and held at 29, 26, 23 or 20 °C had 100% mortality. Conversely, all infected fish held at 17 °C survived even after the temperature was progressively increased to 26 °C at 100 dpi. Rock bream exposed to virus and held for 2, 4 and 7 days at 23/26 °C before the temperature was reduced to 17 °C had mortality rates of 26.6/73.2%, 66.6/100% and 93.4/100%, respectively, through 100 dpi. When surviving fish had the water temperature increased from 17 to 26 °C at 100 dpi, they did not exhibit signs of disease and had low virus copy numbers (below 10(3)). To investigate the development of a protective immune, rock bream were infected with RBIV and held at 23 °C before shifting the water temperature to 17 °C at 4 dpi. All injected fish survived until 120 dpi. While 100% of the previously unexposed fish died, 80.2% of the previously infected fish survived. When the survivors were rechallenged again at 160 dpi, no further mortality occurred. The high survival rate of fish following rechallenge with RBIV indicates that protective immunity was established in the surviving rock bream.

The influence of geometrical characteristics on the photocatalytic activity of TiO2 nanotube arrays for degradation of refractory organic pollutants in wastewater

The effects of geometrical characteristics such as surface area (SA) and porosity of TiO2 nanotube arrays (TNAs) on its photocatalytic activity were investigated by applying variable voltages and reaction times for the anodization of Ti substrates. While larger SA of nanotubes was observed under higher applied potential, the porosity of TNAs decreased by increasing anodizing voltage. Under applied potential of 80 V, the SA of TNAs increased from 0.164 to 0.471 m2/g as anodization time increased from 1 to 5 hours, respectively. However, no significant effect on the porosity of TNAs was observed. On the other hand, both SA and porosity of TNAs, synthesized at 60 V, increased by augmenting the anodization time from 1 to 3 hours. But further increasing of anodization time to 5 hours resulted in a decreased SA of TNAs with no effect on their porosity. Accordingly, the TNAs with SA of 0.368 m2/g and porosity of 47% showed the highest photocatalytic activity for degradation of 4-chlorobenzoic acid (4CBA). Finally, the degradation of refractory model compounds such as carbamazepine and bisphenol-A was tested and more than 50% of both compounds could be degraded under UV-A irradiation (λmax=365 nm).

Environmental implications and applications of carbon nanomaterials in water treatment

Carbon nanomaterials have been proposed as a basis for developing new technologies for photocatalytic oxidation and disinfection, improved membrane processes, adsorbents, and biofilm-resistant surfaces. This study details recent progress towards the development of these proposed applications. We explored the use of carbon nanomaterials such as fullerene C60, single-wall carbon nanotubes (SWCNTs), and multi-wall carbon nanotubes (MWCNTs) for a range of new technologies including, degradation of a probe organic compound by in situ generation of reactive oxygen species (ROS), new strategies for microbial disinfection, and the inhibition of biofilm development on membrane surfaces. The results show that the degradation of 2-chlorophenol by ROS produced microbial inactivation, and the mobility of the nanoparticle aggregates of the carbon nanomaterials all increased as suspensions were fractionated to enrich with smaller aggregates with sonication followed by successive membrane filtration.

Criteria for decision making after endoscopic resection of well-differentiated rectal carcinoids with regard to potential lymphatic spread

BACKGROUND AND STUDY AIM

Rectal carcinoids are low-grade malignancies that are usually treated by endoscopic resection. However, on pathologic examination, resection margins that are positive for carcinoid cells are frequently found. Patient outcomes were reviewed after endoscopic resection of rectal carcinoids and the clinical significance of possible residual disease, as defined by pathologic and endoscopic examination, was evaluated.

PATIENTS AND METHODS

The medical records and endoscopic findings of 347 patients presenting with rectal carcinoids to 14 university hospitals in Korea between January 1999 and June 2007 were retrospectively analyzed.

RESULTS

A total of 304 patients were treated with endoscopic resection, and 43 patents were treated with surgery. In the endoscopic resection group, the complete resection rate was 88.2% based on endoscopic appearance (CR-E) and 60.2% based on pathologic evaluation (CR-P). The agreement between CR-E and CR-P was low (κ=0.192). No residual tumors were found in 77 of 85 patients (90.6%) who were CR-E but not CR-P and who had endoscopic biopsy taken at 24-month follow-up. The receiver-operating characteristic curve identified an optimal cut-off value of 10.5 mm, at which the sensitivity and the specificity for metastasis were 100% and 89%, respectively. The risk factors for metastasis by multivariate analysis were tumor size, increased mitotic rate, and lymphovascular invasion.

CONCLUSIONS

Endoscopic resection is a safe and effective modality for treating well-differentiated rectal carcinoids smaller than 10 mm in diameter. Discrepancies were observed between CR-E and CR-P. The risk factors for metastasis were tumor size, increased mitotic rate, and lymphovascular invasion.

Borderline mucinous tumor arising in a paratubal cyst: a case report

BACKGROUND

Paratubal borderline tumors (PBTs) are found incidentally at frozen section or permanant pathology, and are extremely rare. We describe the first case of a paratubal borderline mucinous tumor (PBMT).

CASE REPORT

A 20-year-old woman was referred with a complex right adnexal mass on pelvic sonogram. She underwent laparoscopic paratubal cyst enucleation. We used an endobag for cyst extraction. Cyst rupture or tearing of the endobag in the laparoscopic field was absent. Frozen section analysis was reported as a borderline mucinous tumor of low malignant potential. Currently, she has had no evidence of disease recurrence after a laparoscopic fertility-sparing staging procedure.

CONCLUSION

A proper preoperative differential diagnosis of an adnexal mass is difficult. Thus, laparoscopy is needed in large or symptomatic cysts. Although growth, torsion and malignancy are rare in paratubal cysts, the possibility of tumor seeding should be excluded with use of an endobag.

A case of primary ovarian adenomyoma mimicking ovarian malignancy

Adenomyoma is a benign tumor composed of smooth muscle and benign endometrium. These tumors typically originate within the uterus. An extrauterine adenomyoma is an extremely rare entity. After an extensive literature search, only four cases of primary ovarian adenomyoma appear to have thus far been reported. Here, we report a case of ovarian adenomyoma in a 39-year-old woman mimicking malignant neoplasma of the ovary, along with a brief literature review.

Ancient schwannoma of the thigh mimicking a malignant tumour: a report of two cases, with emphasis on MRI findings

Ancient schwannomas are rare, encapsulated tumours of long duration and are benign in nature. The tumour is solitary and may grow to a large size before detection of notable degenerative changes. The term "ancient schwannoma" is used to describe a tumour that has undergone such changes, typified by relative loss of Antoni type A tissue, perivascular hyalinisation, calcification, cystic necrosis, haemorrhage and the presence of degenerative nuclei that may be misinterpreted as sarcomatous pleomorphism. We report two cases of ancient schwannoma in the thigh mimicking malignancies. Identifying the fibrous capsule of the mass and a split fat sign using MRI is important for differentiating ancient schwannoma from other malignant tumours.

A case of small cell lung cancer treated with chemoradiotherapy followed by photodynamic therapy

Here, we present the case of a 51-year-old man with limited-stage small cell lung cancer (LS-SCLC) who received concurrent chemoradiotherapy and photodynamic therapy (PDT). The patient was diagnosed as having LS-SCLC with an endobronchial mass in the left main bronchus. Following concurrent chemoradiotherapy, a mass remaining in the left lingular division was treated with PDT. Clinical and histological data indicate that the patient has remained in complete response for 2 years without further treatment. This patient represents a rare case of complete response in LS-SCLC treated with PDT.

Effect of drug-eluting metal stents in benign esophageal stricture: an in vivo animal study

BACKGROUND AND STUDY AIMS

The aim of this study in canines was to investigate the effectiveness and safety of self-expandable metal stents, which were coated with paclitaxel to minimize the tissue response.

MATERIALS AND METHODS

14 dogs (5-10 kg) were randomly allocated to two groups. Drug-eluting stents (DES, n = 7) or nondrug-eluting stents (non-DES, n = 7) were endoscopically inserted and fixed in the esophagus of healthy dogs. Every 2 weeks, for a maximum period of 8 weeks, an endoscopic examination was performed to evaluate the status of stent insertion, the grade of tissue hyperplasia, and mucosal change at both ends of the stent.

RESULTS

One case of stent migration was observed after 4 weeks in the non-DES group. In this group, tissue reaction and hyperplasia remained for more than 4 weeks after stent insertion. By contrast, an endoscopic examination of the surrounding esophageal mucosa in the DES group showed very little tissue reaction, and the stent was easily separated from the esophageal tissue.

CONCLUSION

Although further studies are required to confirm our results, we suggest that these newly designed DES may provide an alternative tool to manage refractory benign esophageal stricture.

Endoscopic evaluation of significant gastrointestinal lesions in patients with iron deficiency with and without anaemia: a Korean Association for the Study of Intestinal Disease study

BACKGROUND

Although endoscopy is recommended for patients with iron deficiency anaemia, there is, currently, no consensus on the role of endoscopy for iron-deficient patients without anaemia. The goal of this study was to determine the prevalence of serious gastrointestinal (GI) lesions, identified by endoscopy in patients with iron deficiency and anaemia compared with patients with iron deficiency without anaemia.

METHODS

One thousand five hundred and eighteen patients with a ferritin value of <or=50 ng/mL and a total iron-binding capacity >or=300 mg/dL were retrospectively investigated using oesophagogastroduodenoscopy and colonoscopy between January 2005 and September 2006. The lesions identified were classified as clinically important according to standard predetermined criteria.

RESULTS

Among the 1518 cases, 749 patients had anaemia and 769 had normal haemoglobin levels. Clinically important lesions were identified in 24.6% of the patients with anaemia and in 22.8% of the patients without anaemia (P > 0.05). The frequency of lower GI tract lesions (13.6 vs 11.4%, P > 0.05) and upper GI tract lesions (11.9 vs 12.5%, P > 0.05) was similar in the comparisons between the two groups. However, the frequency of malignant GI lesions was higher in the patients with anaemia (5.1 vs 0.7%, P < 0.01). In addition, the patients without anaemia were significantly more likely to have early-stage neoplasia (adenoma, early gastric cancer and Dukes' A and B colon cancer) than were the patients with anaemia (98.4 vs 52.5%, P < 0.01).

CONCLUSION

The results of this study suggest that patients with iron deficiency should undergo endoscopic evaluation of the GI tract, irrespective of whether they have anaemia. The endoscopic evaluation of the GI tract in patients with iron deficiency without anaemia could provide an opportunity for the detection of early-stage neoplasia at a curable stage.

Primary colon lymphoma in Korea: a KASID (Korean Association for the Study of Intestinal Diseases) Study

Although almost all primary colorectal lymphomas are of B-cell lineage in Western countries, primary colorectal T-cell lymphomas are not uncommon in the East. The aim of this study was to review the clinical characteristics and treatment outcomes of primary colorectal lymphomas, with special emphasis on the differences between T-cell and B-cell lymphomas. Ninety-five cases of primary colorectal lymphomas that satisfied Dawson's criteria were identified from the clinical databases of 13 university hospitals in Korea. The mean age at the time of presentation was 51.1 years and the male:female ratio was 64:31. The clinical information, including endoscopic and histological characteristics, was retrospectively analyzed. Of the primary colorectal lymphomas, 78 cases (82.1%) were of B-lineage and 17 cases (17.9%) were of T-cell lineage. Patients with T-cell lymphomas presented at a younger age than patients with B-cell lymphomas (42.8 vs 52.9 years, respectively; P = 0.016). The most common presenting symptom was abdominal pain (87.1%) for B-cell lymphomas, whereas hematochezia or night fever was more common for T-cell lymphomas (52.9% and 35.3%, respectively). The most common endoscopic type was fungating mass (54.0%) for B-cell lymphomas and ulcerative/ulcero-infiltrative lesions (80.0%) for T-cell lymphomas. Intussusception was more common in B-cell lymphomas than in T-cell lymphomas (30.8% vs 5.9%, respectively; P = 0.035), but perforation was more common in T-cell lymphomas than in B-cell lymphomas (23.5% vs 3.8%, respectively; P = 0.005). The prognosis was significantly worse for T-cell lymphomas than for B-cell lymphomas (P = 0.002). Primary colorectal T-cell lymphomas are characterized by multifocal ulcerative lesions in relatively young patients, a high rate of hematochezia, fever, or perforation, and a poor prognosis even for cases of localized disease.

Management of malignant stricture of the esophagogastric junction with a newly designed self-expanding metal stent with an antireflux mechanism

BACKGROUND AND STUDY AIMS

When stents are placed across the esophagogastric junction for palliative treatment of malignant strictures, they may lead to esophagogastric reflux. The aim of this study was to compare the effectiveness of a newly designed antireflux stent with that of a standard open stent and a currently available antireflux stent (Dostent) in preventing gastroesophageal reflux symptoms in patients with inoperable cancer at the esophagogastric junction.

PATIENTS AND METHODS

Thirty-six consecutive patients with cancer at the esophagogastric junction were randomly assigned to undergo placement of a newly designed antireflux stent (n = 12), a Dostent (n = 12), or a standard open stent (n = 12). Technical and clinical success, dysphagia score, reflux symptoms, complications and ambulatory 24-h esophageal pH monitoring were assessed.

RESULTS

The technical success rates were 100 %. After 1 week, dysphagia had improved in all patient groups ( P < 0.05), but the degree of improvement did not differ between the three groups. The DeMeester score was significantly lower in the group with the newly designed antireflux stent than in the other groups. The fraction of the total recording time during which esophageal pH was below 4 was 3.14 +/- 5.78 % using the newly designed antireflux stent, in comparison with 29.25 +/- 15.41 % in the Dostent group and 15.01 +/- 11.72 % in the standard open stent group ( P < 0.001). Fewer reflux episodes occurred with the newly designed antireflux stent than with the Dostent or standard open stent. There were no complications with any of the three stents.

CONCLUSIONS

The newly designed antireflux stent is effective in relieving dysphagia caused by malignant cancer at the esophagogastric junction. The newly designed antireflux stent is significantly more effective in preventing gastroesophageal reflux than currently available antireflux stents.

Management of malignant strictures of the cervical esophagus with a newly-designed self-expanding metal stent

Recently, the use of self-expanding metal stents has become a well-established method of palliative treatment for stenotic malignant diseases in the middle and distal esophagus. However, published results on the use of self-expanding metal stents in cervical esophageal cancer are somewhat limited by a paucity of clinical details and experience. A new self-expanding esophageal metal stent with a short upper flange 0.7 cm in length was studied prospectively in order to assess its efficacy for palliative treatment. This report presents experience in three patients in whom this new stent was used in the treatment of cervical esophageal cancers. Stent placement was successful in all three patients, with no serious complications such as esophageal perforation, hemorrhage, or foreign-body sensation. All of the patients experienced rapid improvement in dysphagia and clinical symptoms. The newly designed self-expanding stent can be of value in the treatment of stenotic cervical esophageal cancer.

Simultaneous removal of organic and strong nitrogen from sewage in a pilot-scale BNR process supplemented with food waste

As the sewerage system is incomplete, sewage in Korea lacks easily biodegradable organics for nutrient removal. In this country, about 11,400 tons of food waste of high organic materials is produced daily. Therefore, the potential of food waste as an external carbon source was examined in a pilot-scale BNR (biological nutrient removal) process for a half year. It was found that as the supply of the external carbon increased, the average removal efficiencies of T-N (total nitrogen) and T-P (total phosphorus) increased from 53% and 55% to 97% and 93%, respectively. VFAs (volatile fatty acids) concentration of the external carbon source strongly affected denitrification efficiency and EBPR (enhanced biological phosphorus removal) activity. Biological phosphorus removal was increased to 93% when T-N removal efficiency increased from 78% to 97%. In this study, several kinds of PHAs (poly-hydroxyalkanoates) in cells were observed. The observed PHAs was composed of 37% 3HB (poly-3-hydroxybutyrate), 47% 3HV (poly-3-hydroxyvalerate), 9% 3HH (poly-3-hydroxyhexanoate), 5% 3HO (poly-3-hydroxyoctanoate), and 2% 3HD (poly-3-hydroxydecanoate).

Performance evaluation of leachate treatment system using innovative sulfur circulation method

A pilot-scale experimental study was carried out to evaluate the performance of an innovative method for early stabilization of landfill. This method employs sequential processes of: leachate collection; nitrification through aeration; sulfate addition in effluent tank; and leachate injection back to the landfill. This study focused on: 1) decomposition of recalcitrant organic matters, 2) the characteristics of denitrification, 3) sulfide oxidation for sulfate recovery, and 4) nitrification by aerating discharged leachate. It was found that, when sulfate (SO4(2-)) added leachate was introduced inside the landfill, sulfate-reducing bacteria decomposed recalcitrant organic matters like lignocellulose by using SO4(2-) as an electron acceptor and simultaneously sulfur-oxidizing bacteria denitrified the leachate using sulfides (H2S, HS-, S2-) as electron donors. These two types of bacteria existed not competitively but symbiotically on substrate utilization. Sulfate-reducing bacteria produced S2- while sulfur-oxidizing bacteria oxidized S2- to SO4(2-). During aeration, the concentration of NO3(-)-N increased from near zero up to 925 mg l(-1). Eventual denitrification efficiency in the simulated waste landfill was observed to be approximately 92.3%. Also, S2- present in the discharged leachate was converted to SO4(2-) again in the aeration process. Sulfate needed in this process could be recirculated. Therefore, the amount of sulfate required in the operation of this method could be maintained marginal after the initial addition of sulfate in the effluent tank. Decomposition of recalcitrant organic matters and denitrification hastened the stabilization of landfill. The results of this study indicated that this innovative method was effective and economic.

Biodegradation of gaseous benzene with microbial consortium in a biofilter

The objective of this study was to investigate the biodegradation of gaseous benzene in a biofilter inoculated with benzene-oxidizing microorganisms. The biofilter performance was monitored in terms of benzene removal efficiency and carbon dioxide production. The biofilter was capable of achieving as much as 96% benzene removal efficiency at a residence time of 2 min and an inlet concentration of 220 ppm. During operation with an inlet benzene of 220 ppm, the maximum elimination capacity of the biofilter was 483 g of C6H6 m(-3) day(-1). Under the same conditions, carbon dioxide with a concentration of up to 726 ppm was produced. It was found that carbon dioxide wasproduced at a rate of 608 mg day(-1), which corresponded to a volume of 0.35 l day(-1). Observable features of the microorganisms, meaning microbial activity occurrence in the biofilter, were investigated with the microscopy analysis.

Two cases of large solitary fibrous tumors of the pleura associated with fasting hypoglycemia

We describe two cases of elderly women who presented hypoglycemic episodes with suppressed levels of insulin and insulin-like growth factor I. They were found to have huge malignant solitary fibrous tumor of the pleura. The tumors had rich vascularization on enhanced CT scans and showed characteristic low signal intensity on T2-weighted MR images. This paraneoplastic hypoglycemia is caused by an incompletely processed precursor of insulin-like growth factor II secreted from the tumor. Hypoglycemia and insulin suppression were resolved after removal of the tumors.

Application of membrane-coupled anaerobic volatile fatty acids fermentor for dissolved organics recovery from coagulated raw sludge

To investigate the treatment performance of membrane-coupled anaerobic volatile fatty acids fermentor system, the effects of operational parameters for volatile fatty acids production were evaluated through experiments and a mathematical model. The volatile fatty acids recovery ratio was largely affected by the change of hydraulic retention time, reaching its maximum value at 12 hrs. Over the range of hydraulic retention time 8 to 96 hrs, the volatile fatty acids recovery ratio decreased with the increase of hydraulic retention time above 12 hrs, while the ratio of mineralization and gasification increased. Hydraulic retention time and membrane filtration ratio should be maintained less than 1 day and above 0.9, respectively, to attain over 40% of organic materials recovery ratio at 10 days of solids retention time. When the hydrolysis rate constant was 0.01 hr-1, the organic loading rate should be maintained at above 1.0 (kgC/m3/day) to attain over 45% of volatile fatty acids recovery ratio. Based on experimental and simulated results, membrane-coupled anaerobic volatile fatty acids fermentor system was thought to be effective for dissolved organics recovery from coagulated sewage sludge.

A Monte Carlo study of radiation transport through multileaf collimators

Due to the significant increase in the number of monitor units used to deliver a dynamic IMRT treatment, the total MLC leakage (transmission plus scatter) can exceed 10% of the maximum in-field dose. To avoid dosimetric errors, this leakage must be accurately accounted for in the dose calculation and conversion of optimized intensity patterns to MLC trajectories used for treatment delivery. In this study, we characterized the leaf end transmission and leakage radiation for Varian 80- and 120-leaf MLCs using Monte Carlo simulations. The complex geometry of the MLC, including the rounded leaf end, leaf edges (tongue-and-groove and offset notch), mounting slots, and holes was modeled using MCNP4b. Studies were undertaken to determine the leakage as a function of field size, components of the leakage, electron contamination, beam hardening and leaf tip effects. The leakage radiation with the MLC configured to fully block the field was determined. Dose for 6 and 18 MV beams was calculated at 5 cm depth in a water phantom located at 95 cm SSD, and normalized to the dose for an open field. Dose components were scored separately for radiation transmitted through and scattered from the MLC. For the 80-leaf MLC at 6 MV, the average leakage dose is 1.6%, 1.7%, 1.8%, and 1.9% for 5 x 5, 10 x 10, 15 x 15, and 20 x 20cm2 fields, respectively. For the 120-leaf MLC at 6 MV, the average leakage dose is 1.6%, 1.6%, 1.7%, and 1.9% for the same field sizes. Measured leakage values for the 120-leaf MLC agreed with calculated values to within 0.1% of the open field dose. The increased leakage with field size is attributed to MLC scattered radiation. The fractional electron contamination for a blocked MLC field is greater than that for an open field. The MLC attenuation significantly affects the photon spectrum, resulting in an increase in percent depth dose at 6 MV, however, little effect is observed at 18 MV. Both phantom scatter and the finite source size contribute to the leaf tip profile observed in phantom. The results of this paper can be applied to fluence-to-trajectory and trajectory-to-fluence calculations for IMRT.

Fixation of a modified covered esophageal stent: its clinical usefulness for preventing stent migration

BACKGROUND AND STUDY AIMS

Membrane-covered self-expandable metal stents are effective in preventing tumor ingrowth and stent obstruction in patients with inoperable esophageal cancer, but migration of stents continues to be a major problem. We therefore constructed a modified covered self-expandable esophageal metal stent capable of being fixed using a silk thread. The stent was studied prospectively to define its palliative characteristics and whether it is effective in preventing migration.

PATIENTS AND METHODS

Modified covered self-expandable metal stents were placed in 17 patients with malignant gastric cardiac cancer involving the esophagogastric junction, 41 patients with esophageal cancer, and three patients with tracheoesophageal fistulas. Clinical and radiographic follow-up examinations were carried out at regular intervals.

RESULTS

Placement of the stent was successful in all patients, with good symptomatic relief and no serious stent-related complications such as esophageal perforation or hemorrhage. Acute stent placement problems, such as incomplete expansion or acute angulation of the stent, were noted in four patients. However, during a mean follow-up period of 7.5 months (range 1 to 17 months), there was no stent migration.

CONCLUSIONS

Modified covered self-expandable esophageal metal stents of this type would be very effective in preventing stent migration, especially in patients with malignant gastric cardiac cancer extending to the lower esophagus, those with short-segment esophageal cancer, and those with tracheoesophageal fistulas.

The role of percutaneous transhepatic papillary balloon dilation in percutaneous choledochoscopic lithotomy

BACKGROUND

When choledochoscopic lithotomy with basket and electrohydraulic lithotripsy is used to remove intrahepatic duct stones, fragments or small stones usually remain in the bile duct that are too small to be captured with a basket.

METHODS

An attempt was made to remove stone fragments in 16 patients with intrahepatic duct stones by antegrade balloon dilation of the sphincter of Oddi with a conventional balloon catheter. After balloon dilation, remnant stones and sludge were pushed through the papilla with the choledochoscope.

RESULTS

Bile duct stones were completely removed in 12 of 16 patients (75%); stones were removed in 1 session. There was no clinical evidence of procedure-related pancreatitis or fatal complications.

CONCLUSIONS

Percutaneous transhepatic papillary balloon dilation of the sphincter of Oddi and clearance of remnant bile duct stones and stone fragments with the tip of choledochoscope is simple and effective in patients undergoing percutaneous transhepatic choledochoscopic lithotomy.

Arthroscopic anterior cruciate ligament reconstruction with quadriceps tendon composite autograft

At present, no single graft option clearly outperforms another. Autografts (patellar tendon, hamstring) and allografts (Achilles tendon, patellar tendon) are the grafts most often used. However, each grafts has advantages and disadvantages. Quadriceps tendon graft for anterior cruciate ligament reconstruction is not new, but an alternative composite graft is introduced here that consists of quadriceps tendon-patellar bone and bone obtained from a coring reamer used to create the tibial tunnel. This composite graft retains reduced morbidity while allowing the secure bone-to-bone fixation associated with bone-patellar tendon-bone graft.

Monte Carlo dose calculations for dynamic IMRT treatments

Dose calculations for intensity modulated radiation therapy (IMRT) face new challenges due to the complex leaf geometry and time dependent nature of the delivery. A fast method of particle transport through a dynamic multileaf collimator (MLC) geometry that accounts for photon attenuation and first-scattered Compton photon production has been incorporated into an existing Monte Carlo code used for patient dose calculations. Dosimetric agreement between calculation and measurement for two photon energies and MLC types is within experimental error for the sliding window tests. For a patient IMRT field, the Monte Carlo calculations are closer to measured dose than similar superposition or pencil beam calculations.

Pyogenic spondylitis in an S1-S2 immobile segment

STUDY DESIGN

A case of pyogenic spondylitis in S1-S2 is presented.

OBJECTIVE

To describe the diagnosis and management of this rare spondylitis.

SUMMARY OF BACKGROUND DATA

The segment including the first and second sacral vertebrae is not mobile. Therefore, discitis of S1-S2 and adjacent spondylitis is very rare. To the authors' knowledge, this is the first reported case of infectious spondylitis in an immobile segment: S1-S2.

METHODS

In addition to radiography and bone scintigraphy, magnetic resonance imaging was used to confirm the diagnosis. Changes consistent with infectious spondylitis were shown, including an epidural abscess.

RESULTS

The patient was treated with laparoscopic drainage and biopsy. Staphylococcus aureus was cultured, and adequate antibiotics were administered. Repeat magnetic resonance imaging at approximately 4 months demonstrated normal signal intensity and disappearance of the abscess.

CONCLUSION

Findings from this study show that pyogenic spondylitis can occur in immobile S1-S2.

Prediction of a membrane-coupled anaerobic VFA fermenter efficiency using an empirical model

An empirical model based on some statistical analysis for predicting produced volatile fatty acids (VFA) concentration was developed to establish reliable design conditions of a membrane-coupled anaerobic VFA fermenter (MCAVF) and assess its performance with influent organics concentration (Ci), membrane filtration ratio (phi) and hydraulic loading rate (HLR). The empirical model followed the same trend as the experimental data, which showed the effectiveness of the model. The relationship involving these three independent variables explained more than 90% of the variation in the dependent variable. A model explains that the produced VFA concentration is more sensitive to changes in influent organics concentration (Ci) and membrane filtration ratio (phi) than hydraulic loading rate (HLR). This empirical model can predict the optimum values of operation parameters on many scenarios. Due to its simplicity, the empirical model can be used to design and operate a membrane-coupled anaerobic VFAs fermenter.

Effective combination of microfiltration and intermittent ozonation for high permeation flux and VFAs recovery from coagulated raw sludge

This research was conducted to investigate the effect of intermittent ozonation on permeation flux recovery and production for soluble organic materials in a membrane-coupled anaerobic VFAs fermenter (MCAVF) system. Flux recovery ratio exceeded 80% with 22.2 gO3 l-1 of ozone injection and then showed nearly 95% with 43 gO3 l-1 in batch experiment. Under the same ozone concentration, extending contact time was more effective than increasing bubbling dose rate for flux recovery. In continuous-flow operation, the value of average permeation flux was 0.69 m3 m-2 d-1 during without ozonation period, while average permeation flux for 70 days with intermittent ozone bubbling was 1.17 m3 m-2 d-1 that corresponds to 1.7 times that with no ozonation period. Moreover, in spite of intermittent ozone bubbling for 70 days, significant inhibition was not observed for volatile fatty acids (VFAs) producing bacteria and VFAs production. It was found that the average value of [permeates total organic carbon (TOC) concentration: Influent TOC concentration] with ozonation period was about 1.5 times higher than that of no ozonation period. Consequently, it is believed that a membrane-coupled anaerobic VFAs fermenter (MCAVF) process combined with intermittent ozonation is suitable to overcome the flux decline of membrane and simultaneously is useful to the recovery of soluble organic materials from coagulated raw sludge.

Effect of hydraulic loading rate on acidogenesis in a membrane-coupled anaerobic VFAs fermenter

A membrane-coupled anaerobic VFAs fermenter (MCAVF) was operated with five different hydraulic loading rates (3, 2, 1, 0.5 and 0.25 day-1) to evaluate its influence on acid phase VFAs production from coagulated raw sludge. Results show that C2 to C5 volatile fatty acids were formed as predominant compounds. At constant solids retention time (SRT) of 10 days, VFAs production ratio moderately increased over the range of hydraulic loading rate (HLR) of 3 day-1 to 2 day-1, but significantly decreased at other HLR conditions. First order hydrolysis rate constant decreased with a decrease in HLR. The relatively high degradation percentages of carbohydrate and protein were observed, ranging from 25 to 47%, 27 to 47%, respectively. However, lipid and fiber component were degraded at much lower ratio than the previous other two organic materials. On the other hand, despite some variation in the minor acids in five HLR cases, VFAs speciation appeared to be independent of HLR. The results obtained emphasize that; at least in the range investigated, the optimal HLR for VFAs production and recovery from coagulated raw sludge is in the range of 2 day-1 and 1 day-1.

Cloning and characterization of thermostable endoglucanase (Cel8Y) from the hyperthermophilic Aquifex aeolicus VF5

Aquifex aeolicus is the hyperthermophilic bacterium known, with growth-temperature maxima near 95 degrees C. The cel8Y gene, encoding a thermostable endoglucanase (Cel8Y) from Aquifex aeolicus VF5, was cloned into a vector for expression and expressed in Escherichia coli XL1-Blue. A clone of 1.7 kb fragment containing endoglucanase activity, designated pKYCY100, was sequenced and found to contain an ORF of 978 bp encoding a protein of 325 amino acid residues, with a calculated molecular mass of 38,831 Da. This endoglucanase was designated cel8Y gene. The endoglucanase has an 18-amino-acid signal peptide but not cellulose-binding domain. The endoglucanase of A. aeolicus VF5 had significant amino acid sequence similarities with endoglucanases from glycosyl hydrolase family 8. The predicted amino acid sequence of the Cel8Y protein was similar to that of CMCase of Cellulomonas uda, BcsC of Escherichia coli, CelY of Erwinia chrysanthemi, and CMCase of Acetobacter xylinum. The molecular mass of Cel8Y was calculated to be 36,750 Da, which is consistent with the value obtained from result of CMC-SDS-PAGE of the purified enzyme. Cel8Y was thermostable, exhibiting maximal activity at 80 degrees C and pH optima of 7.0 and with half-lives of 2 h at 100 degrees C, 4 h at 90 degrees C.

A mechanistic study of the antibacterial effect of silver ions on Escherichia coli and Staphylococcus aureus

To investigate the mechanism of inhibition of silver ions on microorganisms, two strains of bacteria, namely Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), were treated with AgNO(3) and studied using combined electron microscopy and X-ray microanalysis. Similar morphological changes occurred in both E. coli and S. aureus cells after Ag(+) treatment. The cytoplasm membrane detached from the cell wall. A remarkable electron-light region appeared in the center of the cells, which contained condensed deoxyribonucleic acid (DNA) molecules. There are many small electron-dense granules either surrounding the cell wall or depositing inside the cells. The existence of elements of silver and sulfur in the electron-dense granules and cytoplasm detected by X-ray microanalysis suggested the antibacterial mechanism of silver: DNA lost its replication ability and the protein became inactivated after Ag(+) treatment. The slighter morphological changes of S. aureus compared with E. coli recommended a defense system of S. aureus against the inhibitory effects of Ag(+) ions.

A humanized anti--4-1BB monoclonal antibody suppresses antigen-induced humoral immune response in nonhuman primates

The interaction of 4-1BB and its ligand plays an important role in the regulation of T-cell-mediated immune responses. In this study, the authors examined the effect of a humanized anti--4-1BB monoclonal antibody (H4B4) on ovalbumin-induced immune responses in baboons. Previously, a mouse monoclonal antibody, 4B4 against the human 4-1BB molecule, was generated and characterized. Based on this antibody, a humanized version of 4B4 monoclonal antibody was constructed and the resultant antibody, H4B4, showed full recovery of the binding activity of the original antibody 4B4: a 1.5-fold increase in affinity for 4-1BB. In addition, H4B4 mediated antibody-dependent cellular cytotoxicity of activated human peripheral blood T cells and CEM cells in a dose-dependent manner. Weekly administration of H4B4 at doses of 1 or 4 mg/kg could suppress immunoglobulin G production against ovalbumin. This was not a result of the overall immune suppression, because the numbers of B and T cells and the total immunoglobulin G production were not altered during treatment with H4B4. These findings suggest that treatment with H4B4 may be a valid therapeutic approach to control unwanted immune responses in persons with autoimmune diseases.

A method for determining multileaf collimator transmission and scatter for dynamic intensity modulated radiotherapy

The main purpose of this work is to demonstrate a practical means of determining the leaf transmission and scatter characteristics of a multileaf collimator (MLC) pertinent to the commissioning of dynamic intensity modulated radiotherapy, especially for the sweeping window technique. The data are necessary for the conversion of intensity distributions produced by intensity-modulated radiotherapy optimization systems into trajectories of MLC leaves for dynamic delivery. Measurements are described for two, tungsten alloy MLCs: a Mark II 80-leaf MLC on a Varian 2100C accelerator and a Millenium 120-leaf MLC on a Varian 2100EX accelerator. MLC leakage was measured by film for a series of field sizes. Measured MLC leakage was 1.68% for a 10 x 10 cm2 field for both 6 and 18 MV for the 80-leaf MLC. For the 6 MV field, the 1.68% leakage consisted of 1.48% direct transmission and 0.20% leaf scatter. Direct transmission through the 80-leaf MLC, including the rounded leaf tip, was calculated analytically taking into account the detailed leaf geometry and a Monte Carlo-generated energy spectrum of the accelerator. The integrated fluence under the leaf tip was equivalent to an inward shift of 0.06 cm of a hypothetical leaf with a flat, focused tip. Monte Carlo calculations of the dose to phantom beyond a closed 80-leaf MLC showed excellent agreement with the analytic results. The transmission depends on the density of the MLC alloy, which may differ among individual MLCs. Thus, it is important to measure the transmission of any particular MLC. Calculated doses for a series of uniform fields produced by dynamic sweeping windows of various widths agree with measurements within 2%.

Improvement of oxidative stability of conjugated linoleic acid (CLA) by microencapsulation in cyclodextrins

Oxidative stability of conjugated linoleic acid (CLA) encapsulated in alpha-, beta-, and gamma-cyclodextrins (designated CLA/CDs microencapsules) was studied by measuring the headspace-oxygen depletion in airtight serum bottles and by measuring the peroxide values (POV). The rate of oxygen depletion was reduced from 41.0 (control) to 21.5, 2.1, 1.2, and 1.1 micromol/L.h(-)(1) by CLA/alpha-CD microencapsules at 1:1, 1:2, 1:4, and 1:6 mole ratios, respectively, indicating that CLA oxidation was completely protected by a 1:4 mole ratio of CLA/alpha-CD. Such a protective effect by CLA/beta-CD or CLA/gamma-CD microencapsules was achieved at a 1:6 mole ratio, but the effect by CLA/beta-CD was slightly greater than that by CLA/gamma-CD. The protective effect of alpha-, beta-, and gamma-CDs for CLA oxidation was confirmed by their POV-reducing abilities in CLA/CDs. These results suggest that alpha-CD was the most effective for the protection of CLA oxidation by microencapsulation, followed by beta-CD and gamma-CD.

IL-6 in CSF during ventriculitis in preterm infants with posthemorrhagic hydrocephalus

Treatment of infants with posthemorrhagic hydrocephalus by diversion of CSF is frequently complicated by bacterial ventriculitis. We report the CSF values before and during bacterial ventriculitis of four very low birth weight infants with progressive posthemorrhagic ventricular dilatation. Extremely high CSF IL-6 concentrations of between 8,000 and 61,000 pg/ml were observed and compared with values reported in the literature. IL-6 seems to be a useful marker for bacterial ventriculitis in preterm infants. The role of IL-6 monitoring in the CSF of preterm infants with posthemorrhagic hydrocephalus for early diagnosis of bacterial ventriculitis prior to clinical manifestation should be clarified by further studies.

Cloning and sequencing of cel5Z gene from Erwinia chrysanthemi PY35

The phytopathogenic bacterium Erwinia chrysanthemi (Ech) secretes multiple isozymes of plant cell wall disrupting enzymes such as pectate lyase and endoglucanases. We cloned genomic DNA from Ech PY35 digested with Sau3AI and ligated into pBluescript II SK+. One of the E. coli XL1-blue clones had the ability to hydrolyze carboxymethyl cellulose and polygalacturonic acid. By subsequent subcloning from this 2.9 kb fragment, we obtained a 2.0 kb (pPY401), designated cel5Z, which had the activity of hydrolyzation of carboxymethyl cellulose. The cel5Z gene had an open reading frame (ORF) of 1,281 bp starting with an ATG start codon and followed by a TAA stop codon, encoding 426 amino acids with a signal peptide of 41 amino acids. Since the deduced amino acid sequence of this protein was very similar to that of CelE of Pseudomonas fluorescens, and had the conserved region, VIYEIYNEPL, it belonged to the glycoside hydrolase family 5 of EC 3.2.1.4. The molecular mass of Cel5Z protein from E. coli XL1-blue, as analyzed by CMC-SDS-PAGE, appeared to be 42 kDa. The optimum pH was 6, and the optimum temperature was about 40 degrees C for its enzymatic activity.

Fetal heart rate observations in the brain-damaged infant

The objective of this study was to describe the fetal heart rate patterns and underlying pathophysiologic changes in the brain-damaged fetus. Fetuses with brain damage from hypoxic ischemic encephalopathy do not manifest uniform fetal heart rate patterns. However, these fetuses do show distinct fetal heart rate patterns that permit categorization based on their admission heart rate, subsequent changes in their baseline rate; and neonatal findings. Based on the observations of infants brain damaged in utero because of hypoxic ischemic encephalopathy, the intrapartum fetal management will depend on the admission fetal heart rate pattern, and the subsequent changes in the baseline rate.

Characterization of Erwinia chrysanthemi PY35 cel and pel gene existing in tandem and rapid identification of their gene products

Genomic DNA of the phytopathogenic Erwinia chrysanthemi PY35 was partially digested with Sau3AI, ligated into the BamHI site of pBluescript II SK+, and introduced into E. coli. One clone that was able to hydrolyse carboxymethylcellulose and polygalacturonic acid was selected. A 2.9 kb fragment containing the pelL1 gene (pPY300) and cel5Z gene (pPY401) in tandem was subcloned and sequenced. The pelL1 and cel5Z genes had open reading frames of 1,278 bp and 1,281 bp encoding 425 and 426 amino acid residues with calculated molecular weights of 45,649 Da and 46,473 Da, respectively. pelL1 and cel5Z carried a typical prokaryotic signal peptide of 24 and 41 amino acid residues, respectively. The apparent molecular masses of the proteins when expressed in E. coli cells were approximately 43 kDa (PelL1) and 42 kDa (Cel5Z) as assessed by PGA-SDS-PAGE and CMC-SDS-PAGE.

Mini-detachable snare ligation for the treatment of esophageal varices

BACKGROUND

We manufactured and studied the usefulness of a newly designed mini-detachable snare in the treatment of esophageal varices. The use of a multiple rubber band ligator, although generally effective and well tolerated, has certain limitations, including high cost, reduced visual field, and inadvertent band release.

METHODS

We performed a prospective randomized controlled trial of the use of mini-detachable snare ligation vs. multiple band ligation in patients with recent or active esophageal variceal bleeding. The outcomes assessed were immediate hemostasis and rates of recurrent bleeding, eradication, and recurrence.

RESULTS

From March 1997 to October 1998, 103 patients were entered into this trial; 46 underwent mini-detachable snare ligations and 57 multiple band ligations. Among patients with active bleeding, hemostasis was achieved in 6 of 7 (86%) in the mini-detachable snare ligation group and 11 of 13 (85%) in multiple band ligation group. Recurrent bleeding after initial treatment occurred in 2 of 46 (5.5%) in the mini-detachable snare ligation group and 3 of 57 (5.3%) in the multiple band ligation group. Esophageal varices were eradicated or reduced to grade I in 4.8 +/- 2.1 and 4.5 +/- 1.9 sessions in the mini-detachable snare ligation group and multiple band ligation group, respectively. The recurrence rate was 5 of 46 (11%) and 6 of 57 (11%) in the mini-detachable snare ligation group and multiple band ligation group during a follow-up period of 6 and 16 months, respectively. No serious complication occurred in either group.

CONCLUSION

The mini-detachable snare is a new device that provides safe and effective treatment for esophageal varices that is comparable to multiple band ligation.

Left ventricular muscle mass regression after aortic valve replacement

Implanting a valve that will reduce left ventricular mass is critical in aortic stenosis. Regression of left ventricular hypertrophy in 46 aortic valve replacement (AVR) patients receiving a St. Jude Medical (SJM) valve was assessed by serial electrocardiographic and echocardiographic studies during the preoperative, immediate, and late postoperative periods. The patients were divided into three groups according to valve size; 19 mm group (n=9), 21 mm group (n=20), and 23+mm group (n=17). There was no surgical mortality. The NYHA functional class improved from an average of 2.2+/-0.8 preoperatively to 1.3+/-0.5 post-operatively. Left ventricular muscle mass index (LVMI) regression failed to reach statistical significance in the 19 mm group, whereas in the other two groups a steady decrease in the LVMI occurred with follow up. ECG findings were less remarkable showing insignificant differences in voltage among the three groups (p=0.000). In conclusion, the current data suggest that the 19 mm SJM valve may not result in satisfactory left ventricular muscle mass regression despite adequate function, even in small patients. Therefore, additional procedures to accommodate a larger valve may be warranted in the aortic annulus smaller than 21 mm.

Activation of phonological codes during eye fixations in reading

Two experiments addressed the issue of whether phonological codes are activated early in a fixation during reading using the fast-priming technique (S. C. Sereno & K. Rayner, 1992). Participants read sentences and, at the beginning of the initial fixation in a target location, a priming letter string was displayed, followed by the target word. Phonological priming was assessed by the difference in the gaze duration on the target word between when the prime was a homophone and when it was a control word equated with the homophone on orthographic similarity to the target. Both experiments demonstrated homophonic priming with prime durations of about 35 ms, but only for high-frequency word primes, indicating that lexicality was guiding the speed of the extraction of phonological codes early in a fixation. Evidence was also obtained for orthographic priming, and the data suggest that orthographic and phonological priming effects interact in a mutually facilitating manner.

Activation of phonological codes during eye fixations in reading

Two experiments addressed the issue of whether phonological codes are activated early in a fixation during reading using the fast-priming technique (S. C. Sereno & K. Rayner, 1992). Participants read sentences and, at the beginning of the initial fixation in a target location, a priming letter string was displayed, followed by the target word. Phonological priming was assessed by the difference in the gaze duration on the target word between when the prime was a homophone and when it was a control word equated with the homophone on orthographic similarity to the target. Both experiments demonstrated homophonic priming with prime durations of about 35 ms, but only for high-frequency word primes, indicating that lexicality was guiding the speed of the extraction of phonological codes early in a fixation. Evidence was also obtained for orthographic priming, and the data suggest that orthographic and phonological priming effects interact in a mutually facilitating manner.