A Photograph-Based Visualization and Prediction Framework for Radiation-Induced Dermatitis

PURPOSE/OBJECTIVE(S)

This study aimed to suggest a photograph-based prediction system for acute radiation-induced dermatitis (RID), which can be applied to notify patients about the risk of the development of skin discomfort during radiotherapy.

MATERIALS/METHODS

The proposed system compared the spatial dose distribution with the RID region using the following methods. Skin photographs of patients were taken using an RGB-depth camera to acquire the shape information of RID. The skin surface data measured from the camera was registered with the shape of the external body contour using an iterative closest point algorithm. Spatial dose distribution of skin was extracted from the external body contour to a depth of 2 mm and projected onto the plane of the skin photograph using a transformation matrix for skin depth data. To compare the spatial distribution of skin dose with the shape of RID, the region of RID in patients' skin was delineated on photographs into three toxicity symptoms referring to the CTCAE criteria grade 1 (skin redness), grade 2 (dry desquamation), and grade 3 (moist desquamation). The degree of overlap between the shape of each RID and skin dose distribution was evaluated using the dice similarity coefficient (DSC). Threshold doses for predicting RID occurrence were estimated by skin isodose lines with the highest DSC. The developed system was validated using data from 19 patients who received volumetric modulated arc therapy for head-neck cancer at a single institution.

RESULTS

Threshold doses for RID grades 1, 2, and 3 were estimated using 18, 18, and 2 individual RID labels delineated on skin photographs, respectively. Isodose lines with the highest DSC for RID grades 1, 2, and 3 were calculated as 26.0 Gy, 36.5 Gy, and 54.0 Gy, respectively. A strong overlap (average DSC > 0.6) was observed between isodose skin lines and the shape of RID labels in all RID grades.

CONCLUSION

Assessing the spatial information of skin dose can be helpful in predicting acute RID. The region of RID shows a strong similarity with the skin dose distribution in head-neck patients. Visualization of skin dose on the patient photograph is potent to patient education for preparing the cosmetic discomfort during radiotherapy, which may lead to the improvement of the patient satisfaction in treatment.

P2877The incidence, predictors, and long-term outcomes of new-onset ventricular tachycardia after cardiac surgery

Background

Incidence and outcomes of new-onset ventricular tachycardia (VT) after cardiac surgery are not fully evaluated.

Purpose

We retrospectively analyzed the occurrence of new-onset VTs after cardiac surgery, and their implications on short and long-term mortality.

Methods

Data of 11,004 adult patients who underwent cardiac surgery at our center from 2006 to 2016 were analyzed. VT was diagnosed when 3 or more consecutive wide QRS complexes (>100 bpm) were documented on ECG. The major study outcomes were in-hospital and 5-years overall mortality rates.

Results

During index hospitalization for cardiac surgery, clinical VTs were documented in 184 patients (1.7%), which included 74 sustained VTs (SusVT, ≥30 seconds) and 110 non-sustained VTs (NSVT). Those patients with SusVT and NSVT showed higher in-hospital mortality compared to those without VTs (31.1% vs. 24.5% vs. 2.0% for SusVT, NSVT, and no VT, respectively, P<0.001). During follow-up after discharge from index hospitalization, patients with SusVT showed higher 5-years mortality than those without VTs, while patients with NSVT did not showed significant differences (22.0% vs. 11.7% vs. 9.2%, P<0.001). In the subgroup of patients with sustained VT who were discharged from index hospitalization (n=51), those with recurrent VTs (>24 hours apart from initial episode) were at higher 5-years mortality rate compared to those without (40.7% vs. 15.8%, P=0.018).

Conclusion

Patients with SusVT and NSVT were at higher risk of in-hospital mortality, and patients with SusVT were associated with higher risk of long-term mortality. The mortality risk was even higher in those with recurrent episodes of VTs.

Acknowledgement/Funding

None

P1012Radiofrequency catheter ablation of accessory pathways at the site of prior valve surgery

Background

Radiofrequency catheter ablation (RFCA) for accessory pathways (APs) at the site of prior valve surgery remains challenging. We aimed to clarify the factors associated with successful RFCA for such APs.

Methods

Upon reviewing a RFCA registry and previous case reports, we included nine patients who underwent RFCA of APs at the site of prior valve surgery (total-VS group; age, 34.0 [24.5–45.0] years; men, 4/9) and 196 patients who underwent RFCA of APs with no history of valve surgery (no-VS group; age, 40.5 [23.0–54.0] years; men, 114/196). Electrophysiological features, procedural details, and outcomes were examined.

Results

AP exhibited decremental conduction in four of nine patients in the total-VS group. The number of RFCA attempts was significantly higher in the total-VS group than in the no-VS group (10.0 [4.5–14.5] vs 2.0 [1.0–3.0]; p<0.001). In four patients who underwent mitral valve surgery, successful RFCA was achieved using the transaortic approach, coronary sinus approach, or bipolar ablation. In three patients who underwent tricuspid valve surgery, successful RFCA was achieved using the above-prosthetics or trans-prosthetics approach. In two patients, RFCA failed. The trans-prosthetics approach and bipolar ablation technique were effective. The transaortic and coronary sinus approaches were occasionally effective. The transseptal approach was ineffective. Based on the success rate and accessibility, we suggest a stepwise approach to RFCA of APs at the site of prior mitral or tricuspid valve surgery (Figure).

Stepwise approach to AP at valve surgery

Conclusions

Successful RFCA of APs at the site of prior valve surgery can be achieved by detailed mapping of the areas both above and below the prosthetic valve, as well as by ensuring effective radiofrequency energy delivery using various catheter approaches and RFCA techniques.

P3452Differential implication of gender on future thromboembolic risk in patients with and without atrial fibrillation

Background

Gender difference in stroke risk by the presence of atrial fibrillation was not well evaluated.

Purpose

We hypothesized that the gender showed different impacts on future thromboembolic risk in patients with and without atrial fibrillation.

Methods

The study population comprised of 26,226 patients (mean 56.3 years old, 52.6% male) with (n=3147, 12.0%) or without (n=23079, 88.0%) atrial fibrillation who underwent cardiac evaluations consisted of electrocardiography, echocardiography, and holter monitoring in our center. The main study outcomes were thromboembolic events defined as composite of ischemic stroke and systemic embolism.

Results

During mean follow-up period of 2.8 years, thromboembolic event occurred in 610 patients (2.3%). In the overall population, the 3-year rate of thromboembolic event of female patients was lower than males (2.2% vs. 2.8%, P=0.011). However, when the population was divided according to the presence of AF, females showed higher rate of thromboembolic events in those with AF (6.7% vs 3.1%, P<0.001), whereas lower rate in those without AF (1.7% vs. 2.7%, P<0.001, P for interaction between gender and AF <0.001). After multivariable adjustment, female gender was at higher risk of future thromboembolic events in those with AF (HR 1.61, 95% CI 1.13–2.29, P<0.001), whereas at lower risk in those without AF (HR 0.75, 95% CI 0.62–0.91, P=0.003). The interaction between gender and AF was significant in those who had one or more components of CHA2DS2-VASc score other than gender (CHA2DS2-VA score ≥1, P for interaction = 0.001), but not in those without (P for interaction = 0.196)

Conclusion

Female gender demonstrated differential thromboembolic risk according to the presence of AF.

Acknowledgement/Funding

None

Morphometric Analysis of Platelets in Bernard-Soulier Syndrome: Size and Configuration in Patients and Carriers

Quantitative ultrastructural morphometric analysis has been carried out on thin sections of platelets from two Bernard-Soulier sisters and their parents. Measurements were made for the major and minor axes, axial ratios, cross-sectional circumference and cross-sectional area. Platelets were collected either into CPD anticoagulant or directly into glutaraldehyde. The results confirm that Bemard-Soulier platelets are significantly larger than normals (p <0.05) in all the parameters mentioned and indicate (I) that the morphology of platelets from Bernard-Soulier patients is affected by the presence of anticoagulant, and (II) a more spherocytic configuration is characteristic of Bemard-Soulier disease both in patients and carriers.

Observation of Reverse Saturable Absorption of an X-ray Laser

A nonlinear absorber in which the excited state absorption is larger than the ground state can undergo a process called reverse saturable absorption. It is a well-known phenomenon in laser physics in the optical regime, but is more difficult to generate in the x-ray regime, where fast nonradiative core electron transitions typically dominate the population kinetics during light matter interactions. Here, we report the first observation of decreasing x-ray transmission in a solid target pumped by intense x-ray free electron laser pulses. The measurement has been made below the K-absorption edge of aluminum, and the x-ray intensity ranges are 10^{16} -10^{17}  W/cm^{2}. It has been confirmed by collisional radiative population kinetic calculations, underscoring the fast spectral modulation of the x-ray pulses and charge states relevant to the absorption and transmission of x-ray photons. The processes shown through detailed simulations are consistent with reverse saturable absorption, which would be the first observation of this phenomena in the x-ray regime. These light matter interactions provide a unique opportunity to investigate optical transport properties in the extreme state of matters, as well as affording the potential to regulate ultrafast x-ray free-electron laser pulses.

Vaginal Brenner tumor with literature review: does this tumour originate from Walthard nests?

Vaginal Brenner tumor is extremely rare. Only five cases have been reported in the English literature to date. Here we report a vaginal Brenner tumor in a 76-year old postmenopausal woman, who presented with a 2.5cm-sized sessile vaginal polyp. Microscopically, it showed characteristic features of Brenner tumor consisting of three components; transitional islands, glands, and dense fibrous stroma. The epithelial tumor cells were positive for GATA-3, p63 and ER, but negative for PAX8. The origin of Brenner tumors in the vagina is unclear, but previous reports suggested of Müllerian origin. However, our case revealed that vaginal Walthard nests could be possible precursor lesions based on their immunohistochemical staining results.

Safe anastomosis in laparoscopic and robotic low anterior resection for rectal cancer: a narrative review and outcomes study from an expert tertiary center

Anastomotic leak and stricture formation are recognised complications of colorectal anastomoses. Surgical technique has been implicated in its aetiology. The use of innovative anastomotic techniques and technical standardisation may facilitate risk modification. Early detection of complications using novel diagnostic tests can lead to reduction in delay of diagnosis as long as a standard system is used. We review our practice for creation a safe anastomosis for minimal invasive rectal cancer resection. Several technical points discussed and evaluated based on the evidence. We propose several recommendations aiming to standardize the technique and to minimize anastomotic complications.

Disability following combat-sustained nerve injury of the upper limb

Injuries to the limb are the most frequent cause of permanent disability following combat wounds. We reviewed the medical records of 450 soldiers to determine the type of upper limb nerve injuries sustained, the rate of remaining motor and sensory deficits at final follow-up, and the type of Army disability ratings granted. Of 189 soldiers with an injury of the upper limb, 70 had nerve-related trauma. There were 62 men and eight women with a mean age of 25 years (18 to 49). Disabilities due to nerve injuries were associated with loss of function, neuropathic pain or both. The mean nerve-related disability was 26% (0% to 70%), accounting for over one-half of this cohort’s cumulative disability. Patients injured in an explosion had higher disability ratings than those injured by gunshot. The ulnar nerve was most commonly injured, but most disability was associated with radial nerve trauma. In terms of the final outcome, at military discharge 59 subjects (84%) experienced persistent weakness, 48 (69%) had a persistent sensory deficit and 17 (24%) experienced chronic pain from scar-related or neuropathic pain. Nerve injury was the cause of frequent and substantial disability in our cohort of wounded soldiers.

Cite this article: Bone Joint J 2014;96-B:254–8.

An oriP expression vector containing the HIV-1 Tat/TAR transactivation axis produces high levels of protein expression in mammalian cells

A mammalian gene expression vector based on cytomegalovirus (CMV)enhancer/promoter (CMVe/p) for the regulation of gene expression was further optimized by adding oriP elements derived from Epstein-Barr virus (EBV) and the Tat/TAR transactivation axisfrom human immunodeficiency virus type 1 (HIV-1). Using the Tat/TAR-oriP expression vector, a transient transfection system was optimized for an extended culture period to produce large amounts of secreted IL-2SA (an IL-2 mutein) in HKB11 cells. We observed a 4-fold increase in IL-2SA expression in cells transfected with vectors containing the HIV-1 transactivation axis (Tat/TAR) or oriP elements alone when compared to cells transfected with the control vector having a CMVe/p. Cells transfected with expression vectors equipped with both oriP and Tat/TAR showed an 18-fold increase in IL-2SA expression. This transient transfection system maintained high secretion of IL-2SA for a period of 10-day with no appreciable loss in expression. We demonstrate that during this 10-day culture period, it was possible to produce 1-100 mg of proteins using 500 mug of plasmid DNA.

A low sintering temperature and electrical performance of nanoparticle copper ink for use in ink-jet printing

Copper nanoparticles were successfully synthesized from copper chloride with various capping agents. The formation of copper nanoparticles was controlled by varying the species and concentration of the capping agents. The Cu nanoparticles were easily re-dispersed into n-tetradecane, and Cu films were prepared by solution deposition. The thin Cu films form a highly conducting film at low temperature via sintering due to the high surface area to volume ratio. The films were thermally treated at a range of temperatures and then their morphology and resistivity were analyzed. When the Cu films were sintered at 200 degrees C, their electrical resistivity was about 40 microomega. cm.

Optimization of mechanical performance of oxidative nano-particle electrode nitrile butadiene rubber conducting polymer actuator

Present work delivers a systematical evaluation of actuation efficiency of a nano-particle electrode conducting polymer actuator fabricated based on Nitrile Butadiene Rubber (NBR). Attempts are made for maximizing mechanical functionality of the nano-particle electrode conducting polymer actuator that can be driven in the air. As the conducting polymer polypyrrole of the actuator is to be fabricated through a chemical oxidation polymerization process that may impose certain limitations on both electrical and mechanical functionality of the actuator, a coordinated study for optimization process of the actuator is necessary for maximizing its performance. In this article actuation behaviors of the nano-particle electrode polypyrrole conducting polymer is studied and an optimization process for the mechanical performance maximization is performed.

Carpal tunnel volume changes of the wrist under distraction

This study attempts to determine changes in carpal canal volume with distraction across the wrist. Uniform longitudinal distraction was maintained with two external fixators on the radial and ulnar aspects of the forearm axis of five cadaver specimens. After CT scanning, volume determinations were made at 5 mm increments beginning at the lunocapitate joint to a point 1.5 cm distal to the middle finger carpometacarpal joint. There was a statistically significant decrease of the mean total carpal canal volume from 0 to 4.54 kg of distraction, with no statistically significant decrease from 0 to 2.27 kg or 2.27 to 4.54 kg. The largest decrease occurred at 15 and 20 mm distal to the proximal edge of the transverse carpal ligament corresponding to the level of the hamate hook. Reduction in mean carpal canal volume was 10.2% and 7.5% at these distances, respectively, from 0 to 4.54 kg of distraction. Progressive distraction across the wrist causes a decrease in total carpal canal volume.

Establishment of a human somatic hybrid cell line for recombinant protein production

Cell fusion techniques were used to derive mammalian host cell lines suitable for large-scale production of therapeutic proteins. Although the 293S cell line, of human embryonic kidney origin, is an excellent host cell for mammalian gene expression, these cells have a tendency to form large and tight aggregates in suspension cultures and bioreactors. To solve the problem of aggregation, 293S cells were fused to a human suspension cell line, 2B8 (a Burkitt's lymphoma derivative), using polyethylene glycol (PEG). The PEG-treated 293S and 2B8 cells were selected in a medium supplemented with hypoxanthine-aminopterin-thymidine and G418 (1 mg/ml) to eliminate nonfused cells. These hybrid clones, designated as HKB (hybrid of kidney and B cells), are negative for endogenous immunoglobulin expression. Most clones are readily adaptable to serum-free suspension culture under shaking conditions without forming large and tight aggregates. One clone, HKB11, was shown to support high-level expression of cytokines [interleukin (IL)-2 and IL-4], ICAM-1 and rFVIII in a side-by-side comparison with 293 and Chinese hamster ovary cells. The above-described characteristics of HKB cells indicate that HKB11 is a favorable cell host for the production of human therapeutic proteins.

Effects of Puerariae Flos and Puerariae Radix extracts on antioxidant enzymes in ethanol-treated rats

This study was performed to investigate the effect of Puerariae Flos (PF) and Puerariae Radix (PR) water extracts on the activities and mRNA expression of three hepatic antioxidant enzymes in ethanol-treated rats. Male Sprague-Dawley rats were divided into four groups, a control, ethanol-treated, ethanol plus PF-treated, and ethanol plus PR-treated group with seven rats per group. Ethanol (25 % v/v, 5 g/kg body weight) was orally administered once a day for 5 weeks. The PF and PR water extracts were supplemented in a diet based on 1.2 g of raw PF or PR/kg body weight/day. Ethanol administration without the PF or PR supplement significantly lowered the activities of hepatic Cu/Zn SOD and catalase (CAT), whereas it increased the hepatic GSH-Px activity. However, the PF and PR supplementation resulted in a significant increase in the Cu/Zn SOD and/or CAT activities and a significant decrease in the GSH-Px activity in the ethanol-treated rats. The mRNA levels of these antioxidant enzymes in the ethanol-treated rats were normalized to the control level by the PF or PR supplement. The hepatic glutathione content, which was significantly lower in the ethanol-treated group than in the control group, was also normalized to the control level by supplementing with either PF or PR. The PF or PR supplement resulted in lowering the hepatic malondialdehyde to the control level in the ethanol-treated rats.

Endoscopic factors predisposing to rebleeding following endoscopic hemostasis in bleeding peptic ulcers

BACKGROUND AND STUDY AIMS

Various clinical and endoscopic factors have been proposed and used as predictors of endoscopic treatment failure in bleeding peptic ulcers. Recently, several endoscopic factors have been considered to be more significant than various clinical factors, except for shock. Detailed knowledge of which endoscopic factors can be classified as predictors of rebleeding following endoscopic hemostasis is needed. This study describes newly defined endoscopic variables and evaluates their usefulness as predictors of endoscopic treatment failure.

PATIENTS AND METHODS

Between January 1996 and April 1999, diagnostic and therapeutic endoscopies were carried out in 143 patients with active bleeding peptic ulcers. Nine clinical and eight endoscopic variables were studied. Endoscopic factors were classified by three types of stigmata bleeding, 14 locations, two ulcer sizes, three ulcer bases, three visible vessel colors, two ulcer depths, two margin shapes, and three endoscopic treatment methods (injection, hemoclipping, and combination).

RESULTS

36 patients experienced rebleeding (25.2 %), 11 patients needed operations (7.7 %) and five deaths occurred (3.5 %). In univariate analysis, rebleeding was significantly related to: i) presence of spurting activity (odds ratio [OR] = 4.91, P = 0.006), ii) ulcer size larger than 2 cm (OR = 2.78, P = 0.017); and iii) location in stomach (OR = 2.81, P = 0.026). Clinical variables including age, shock, and initial hemoglobin levels were not significantly related to rebleeding. In multiple logistic regression using selected significant variables, presence of spurting activity remained a significant independent predictor of rebleeding (adjusted OR = 6.48, P = 0.003).

CONCLUSION

Our data support the hypothesis that endoscopic factors are more important than clinical ones when predicting rebleeding of peptic ulcers. Based on statistical analysis of risk factors, the ulcers most likely to rebleed after endoscopic therapy are those which are located in the stomach, are greater than 2 cm in diameter and exhibit oozing or spurting of blood.

Molecular cloning and characterization of a gene encoding a 13.1 kDa antigenic protein of Naegleria fowleri

An antigen-related gene was cloned from a cDNA expression library of Naegleria fowleri by immunoscreening with sera obtained from mice that were either immunized with an amoebic lysate or infected with trophozoites. The coding nucleotide sequence of the cloned gene consisted of 357 bases that were translated into 119 amino acids. This gene was designated as nfa1. The predicted amino acid sequence of Nfa1 protein has two potential glycosylation and three potential phosphorylation sites, and its predicted secondary structure consists of four helices and three corners. The deduced amino acid sequence of Nfa1 protein shares 43% identity with the myohemerythrin (myoHr) protein from a marine annelid, Nereis diversicolor, including 100% identity in conserved regions and iron-binding residues. A phylogenetic tree constructed from amino acid sequences placed the N. fowleri Nfa1 protein outside of a cluster of myoHr proteins from eight invertebrates. A purified recombinant protein that migrated as a 13.1 kDa species in SDS-PAGE was produced. This recombinant protein exhibited a strong immunoreactivity with infected, immune, and anti-Nfal sera. In addition, an anti-Nfa1 serum reacted with an amoeba lysate in immunoblotting analysis. The present nfal gene encoding the myoHr-like protein is the first myoHr gene cloned from protozoa, and the Nfal antigen may be useful in diagnostic studies

Expression of CD40 and apoptosis related molecules in autoimmune thyroid diseases

Apoptosis is responsible for the loss of thyrocytes in autoimmune thyroiditis. Recent investigations into the pathogenesis of apoptosis have revealed that the important roles of suicide molecules expression on both thyrocytes and cytotoxic T-lymphocytes. To study the mechanism of thyrocyte loss in various forms of thyroiditis, we evaluated in situ expression patterns of CD40, Fas, and Fas-L on thyrocytes and infiltrating inflammatory cells by immunohistochemical staining of thyroid samples obtained from 49 patients (Graves' disease, n=10: Hashimoto's thyroiditis, n=14; nonspecific lymphocytic thyroiditis, n=11; subacute granulomatous thyroiditis, n=11; normal, n=3). The role of cytotoxic T-lymphocytes was also evaluated by analyzing the expression of granzyme B along with their phenotypic characteristics. CD40 was not expressed on thyrocytes of normal controls while they showed a diffuse expression of Fas and a scattered focal expression of Fas-L. The plump thyrocytes proximal to the inflammatory infiltrates showed more intense expressions of these three molecules in various forms of thyroiditis and a close correlation was found between CD40 and Fas-L expression on thyrocytes. Unlike Fas, which was expressed on infiltrating lymphocytes in all groups, Fas-L was not expressed on infiltrating lymphocytes, except those in subacute granulomatous thyroiditis. Granzyme B expressing activated cytotoxic T-lymphocytes occupied a negligible proportion of CD8+ T-lymphocytes in various forms of thyroiditis, and no difference was found in terms of their proportions according to the type of thyroiditis. These results show the acquisition of CD40, Fas and Fas-L molecules on thyrocytes proximal to inflammatory cell aggregates and the negligible expression of granzyme B and Fas-L on the infiltrating lymphocytes, and suggest that Fas and Fas-L mediated apoptosis of thyrocytes (fratricide) may be more important than T cell-mediated cytotoxicity in various forms of thyroiditis.

Cytopathic changes in rat microglial cells induced by pathogenic Acanthamoeba culbertsoni: morphology and cytokine release

To determine whether pathogenic Acanthamoeba culbertsoni trophozoites and lysate can induce cytopathic changes in primary-culture microglial cells, morphological changes were observed by transmission electron microscopy (TEM). In addition, the secretion of two kinds of cytokines, tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta), from microglial cells was observed. Trophozoites of pathogenic A. culbertsoni made contact with microglial cells and produced digipodia. TEM revealed that microglial cells cocultured with amoebic trophozoites underwent a necrotic process, accompanied by lysis of the cell membrane. TEM of microglial cells cocultured with amoebic lysate showed that the membranes of the small cytoplasmic vacuoles as well as the cell membrane were lysed. The amounts of TNF-alpha secreted from microglial cells cocultured with A. culbertsoni trophozoites or lysate increased at 6 h of incubation. The amounts of IL-1beta secreted from microglial cells cocultured with A. culbertsoni trophozoites at 6 h of incubation was similar to those secreted from the control group, but the amounts decreased during cultivation with A. culbertsoni lysate. These results suggest that pathogenic A. culbertsoni induces the cytopathic effects in primary-culture rat microglial cells, with the effects characterized by necrosis of microglial cells and changes in levels of secretion of TNF-alpha and IL-1beta from microglial cells.

Inhibition of breast cancer growth in vivo by antiangiogenesis gene therapy with adenovirus-mediated antisense-VEGF

Increased expression of VEGF in several types of tumours has been shown to correlate with poor prognosis. We used a replication-deficient adenoviral vector containing antisense VEGF cDNA (Ad5CMV-alphaVEGF) to down-regulate VEGF expression and increase the efficiency of delivery of the antisense sequence in the human breast cancer cell line MDA231-MB. Transfection of these cells with Ad5CMV-alphaVEGF in vitro reduced secreted levels of VEGF protein without affecting cell growth. Moreover, injection of the Ad5CMV-alphaVEGF vector into intramammary xenografts of these cells established in nude mice inhibited tumour growth and reduced the amount of VEGF protein and the density of microvessels in those tumours relative to tumours treated with the control vector Ad5(dl312). Our results showed that antisense VEGF(165)cDNA was efficiently delivered in vivo via an adenoviral vector and that this treatment significantly inhibited the growth of established experimental breast tumours. The Ad5CMV-alphaVEGF vector may be useful in targeting the tumour vasculature in the treatment of breast cancer.

ctr1, a gene involved in a signal transduction pathway of the gliding motility in the cyanobacterium Synechocystis sp. PCC 6803

We generated random Tn5 mutations in Synechocystis sp. PCC 6803 in search for genes involved in the signal transduction cascade for the cyanobacterial gliding motility. One of the non-gliding Tn5 mutants, S1-105, had an insertional inactivation in the slr1044 gene encoding a putative methyl-accepting chemotaxis protein. Interposon mutation on the slr1044 (named ctr1) in the bacterium also eliminated gliding motility. In the interposon mutant, the expression of pilA1 was 5-fold decreased compared with that of wild-type and thick pili, that are believed to be the motor for gliding, could not be observed by an electron microscope. Therefore, we suggest that the Ctr1 protein functions as a transducer that regulates the expression of pilA1, and thus is required for the biogenesis of thick pili.

Bleeding Dieulafoy's lesions and the choice of endoscopic method: comparing the hemostatic efficacy of mechanical and injection methods

BACKGROUND

Dieulafoy's lesion has unique endoscopic and histopathologic characteristics. This is a clinical trial of endoscopic therapy in 24 patients with Dieulafoy's lesions.

METHODS

Patients were divided into 2 groups according to initial endoscopic treatment method. Data were analyzed with respect to clinical and endoscopic characteristics as well as outcomes. The 24 patients were evenly divided into mechanical (9 hemoclipping, 3 band ligation) and injection groups (12).

RESULTS

The average number of therapeutic endoscopic sessions needed to achieve permanent hemostasis for the mechanical and injection groups were 1.17 and 1.67, respectively. Initial hemostasis was achieved in 91.7% of patients undergoing mechanical therapy and 75% of those undergoing injection therapy, with none in the former group needing subsequent surgery in comparison to 17% of the latter group. The rate of recurrent bleeding in the mechanical therapy group was significantly lower in comparison to the injection therapy group (8.3% versus 33.3%, p < 0. 05).

CONCLUSIONS

Higher efficacy in terms of initial hemostasis and less recurrent bleeding was achieved by mechanical hemostatic therapy with hemoclip and band ligation compared with injection therapy. Endoscopic mechanical therapy is recommended as effective for bleeding Dieulafoy's lesions.

A rat model for radiation-induced proctitis

Radiation proctitis is a frequent acute complication encountered with pelvic irradiation. This study was aimed at establishing the optimal radiation dose for radiation-induced proctitis in rats. Female Wistar rats were used. The rectal specimens were examined morphologically at 5th and 10th day following 10-30 Gy irradiation in single fraction. With increasing dose, mucosal damage became worse, and there was a prominent reaction after > or =15 Gy. We selected 17.5 Gy as an optimal dose for radiation proctitis and examined specimens at day 1-14 and at week 4, 6, 8, and 12 after 17.5 Gy. The rectal mucosa revealed characteristic histological changes with time. An edema in lamina propria started as early as 1-2 days after irradiation and progressed into acute inflammation. On day 7 and 8, regeneration was observed with or without ulcer. Four weeks later, all regeneration processes have been completed with end result of either fibrosis or normal appearing mucosa. This study showed that the radiation injury of the rectum in rat develops in dose-dependent manner as it has reported in previous studies and suggested that 17.5 Gy in single fraction is the optimum dose to evaluate the protective effect of various medications for radiation proctitis in face of the clinical situation.

Multiple local contact sites are induced by GPI-linked influenza hemagglutinin during hemifusion and flickering pore formation

Membrane fusion intermediates induced by the glycosylphosphatidylinositol-linked ectodomain of influenza hemagglutinin (GPI-HA) were investigated by rapid freeze, freeze-substitution, thin section electron microscopy, and with simultaneous recordings of whole-cell admittance and fluorescence. Upon triggering, the previously separated membranes developed numerous hourglass shaped points of membrane contact (approximately 10-130 nm waist) when viewed by electron microscopy. Stereo pairs showed close membrane contact at peaks of complementary protrusions, arising from each membrane. With HA, there were fewer contacts, but wide fusion pores. Physiological measurements showed fast lipid dye mixing between cells after acidification, and either fusion pore formation or the lack thereof (true hemifusion). For the earliest pores, a similar conductance distribution and frequency of flickering pores were detected for both HA and GPI-HA. For GPI-HA, lipid mixing was detected prior to, during, or after pore opening, whereas for HA, lipid mixing is seen only after pore opening. Our findings are consistent with a pathway wherein conformational changes in the ectodomain of HA pull membranes towards each other to form a contact site, then hemifusion and pore formation initiate in a small percentage of these contact sites. Finally, the transmembrane domain of HA is needed to complete membrane fusion for macromolecular content mixing.

In vitro cytotoxicity of Acanthamoeba spp. isolated from contact lens containers in Korea by crystal violet staining and LDH release assay

In order to observe the cytotoxicity of Acanthamoeba spp., which were isolated from contact lens containers as ethiological agents for the probable amoebic keratitis in Korea, the crystal violet staining method and LDH release assay were carried out. In the crystal violet staining method, among eight contact lens container isolates, isolate 3 (Acanthamoeba KA/LS5) showed 83.6% and 81.8% of cytotoxicity, and isolate 7 (Acanthamoeba KA/LS37) showed 28.2% and 25.1% of cytotoxicity, in 1 mg/ml and 0.5 mg/ml lysate treatments, respectively. Acanthamoeba culbertsoni and A. healyi showed 84.0% and 82.8% of cytotoxicity. Similar results were observed in A. castellanii and A. hatchetti which showed 83.6% and 75.5% of cytotoxicity. Acanthamoeba royreba and A. polyphaga showed 9.0% and 1.7% of cytotoxicity. In the LDH release assay, isolate 3 (20.4%) showed higher cytotoxicity than other isolates in 1 mg/ml lysate treatment. The results provide that at least isolate 3 has the cytotoxic effect against CHO cells and seems to be the pathogenic strain.

Apoptosis of primary-culture rat microglial cells induced by pathogenic Acanthamoeba spp

To determine whether trophozoites and lysates of pathogenic Acanthamoeba spp. induce apoptosis in primary-culture microglial cells, transmission electron microscopic (TEM) examinations, assessment of DNA fragmentation by agarose gel electrophoresis, and the TdT-mediated dUTP nick-end labeling assay were performed. When a trophozoite of pathogenic Acanthamoeba culbertsoni came in contact with a microglial cell, the digipodium was observed by TEM. Nuclear chromatin condensation was observed in 10% of microglial cells, while it was not revealed when they were cocultured with weakly pathogenic Acanthamoeba royreba trophozoites. DNA fragmentation in microglial cells cocultured with the A. culbertsoni lysate was detected by electrophoresis, showing DNA ladder formation, whereas it was hardly observed in microglial cells cocultured with A. royreba. DNA fragmentation of microglial cells was also confirmed by flow cytometry analysis. The fluorescence of TdT-stained apoptotic bodies became intensely visible with microglial cells cocultured with the A. culbertsoni lysate. In contrast, with microglial cells cocultured with the A. royreba lysate, only a background level of fluorescence of TdT-stained apoptotic bodies was detected. These results suggest that some rat microglial cells cocultured with pathogenic A. culbertsoni undergo cytopathic changes which show the characteristics of the apoptotic process, such as nuclear condensation and DNA fragmentation.

A stage-specific preparation to study the Ca(2+)-triggered fusion steps of exocytosis: rationale and perspectives

Despite groundbreaking work to identify numerous proteins and to focus attention on molecular interactions, the mechanism of calcium-triggered membrane fusion remains unresolved. A major difficulty in such research has been the many overlapping and interacting membrane trafficking steps in the secretory pathway, including those of membrane retrieval. Identifying the specific role(s) of a given protein, beyond its general involvement in exocytosis, has therefore proven problematic. Furthermore, the power of time-resolved optical and electrophysiological assays can be best applied to testing the function of known proteins rather than to the identification of unknown, critical membrane components. The identification of essential membrane constituents requires combined biochemical (molecular) and functional (physiological) analyses. A fully functional, stage-specific physiological membrane preparation would be one direct approach to dissecting the calcium-triggered fusion steps of regulated exocytosis. Herein we review our use of specific minimal membrane preparations consisting of fully primed and docked secretory vesicles, or the isolated vesicles themselves, and characterize the late events of exocytosis, with an aim towards identification of essential molecular components. We have established a functional definition of the fusion complex and its activation by calcium, based on our kinetic analyses. Together with a variety of biochemical and alternate functional assays, we have tested whether the SNARE core complex that is present in our vesicle membranes satisfies the criteria of the functionally defined fusion complex. Rather than a direct fusogenic role, the SNARE complex may promote the calcium sensitivity of fusion, possibly by defining or delimiting a localized, focal membrane fusion site that ensures rapid and efficient exocytosis in vivo.

Isoenzyme patterns and phylogenetic relationships in Acanthamoeba spp. isolated from contact lens containers in Korea

In order to refer to the basic information regarding the identification of isolates obtained from a contact lens container in Korea, the isoelectric focusing gel electrophoresis was employed to compare the isoenzyme band patterns among Acanthamoeba spp. including eight isolates and the simple pairwise dissimilarity analysis was carried out. For an alkaline phosphate development, isolate 7 and Acanthamoeba polyphaga showed homologous band patterns, and isolates 1, 2, and 3 showed the same patterns. For lactate dehydrogenase, similar patterns were observed in isolates 2 and 3. Isolates 3 and 5 showed homologous band patterns for malate dehydrogenase and glucose phosphate isomerase. For hexokinase, isolates 4, 7, and A, hatchetti showed the same band patterns. In others, a considerable number of interstrain polymorphisms was observed in nine isoenzyme band patterns. In Acanthamoeba group II, genetic distances among isolates 1, 2, 3, 4, and 5 ranged from 0.104 to 0.200. In comparison to A. castellanii, A. hatchetti, and A. polyphaga, genetic distances of isolates 7 and 8 were 0.254 and 0.219, respectively. In Acanthamoeba group III, including A. culbertsoni, A. healyi, and A. royreba, isolate 6 had genetic distances which ranged from 0.314 to 0.336. Finally, when comparing to the six reference Acanthamoeba, it was possible to classify isolates 1, 2, 3, 4, and 5, as genetically close-related species and as independent species group. Furthermore, isolates 6, 7 and 8 were identified as independent species as well.

Allelic frequencies of six (CA)n microsatellite markers of the dystrophin gene in the Korean population

Using the polymerase chain reaction, we examined the allele frequencies and heterozygosities of six (CA)n markers of the dystrophin gene in Koreans. Allele frequencies of these markers were different from those reported for Caucasians. The heterozygosity values for these markers range from 29 to 86%. With the exception of the STR50 marker, these values were lower than those of Caucasians. However, all markers except for the 3'CA marker showed PIC values over 0.5, suggesting a high degree of polymorphism. Therefore, this study will be useful in linkage analysis for Duchenne and Becker muscular dystrophy families in the Korean population.

Dihydropyrimidine dehydrogenase activity in a Korean population

Dihydropyrimidine dehydrogenase (DPD) is the major metabolic enzyme in the catabolism of 5-fluorouracil, and the activity in normal tissues shows a wide variation among individuals. Recent studies demonstrate the relevance of DPD in the pharmacokinetics, toxicity, and antitumor efficacy of 5-fluorouracil. We investigated the DPD activity in peripheral blood mononuclear cell form 114 healthy subjects in Korea. The DPD activities in healthy volunteers were shown to follow a unimodal distribution. The mean of the activity was 0.28 +/- 0.16 nmol/min/mg protein. A wide (13-fold) intersubject variability was observed (range, 0.06-0.80 nmol/min/mg protein), and, on average, DPD activity in women (0.26 +/- 0.14) was 13% lower than in men (0.30 +/- 0.16). These findings indicate that the activity of DPD in this study was higher than in reports of research with French and white American populations.

An analysis of the role of the target membrane on the Gp64-induced fusion pore

Influenza hemagglutinin (HA) and GP64 of the baculovirus Autographa californica multicapsid nuclear polyhedrosis virus induce strikingly different initial fusion pores when mediating fusion between host cells that express these fusion proteins and target cells (Plonsky and Zimmerberg, 1996; Spruce et al., 1989, 1991; Zimmerberg et al., 1994). However, in these experiments, variations in host and target membranes confounded the analysis of the role that major components of the fusion reaction play in determining initial pore characteristics. To determine the contribution of the target cell plasma membrane to the fusion pore phenotype, we studied GP64-induced fusion of stably transfected cells (Sf9(Op1D)) to either red blood cells (RBCs) or Sf9 cells. Initial fusion pores in Sf9(Op1D)/RBC and Sf9(Op1D)/Sf9 cell pairs exhibited the same conductance, and pore flickering was not observed in either combination of cells. This indicates that the target cell determines neither the size nor the reversibility of the initial pore. However, the target cell does influence the kinetics of pore formation. The waiting time between triggering and pore appearance was shorter for Sf9(Op1D)/RBC fusion than for Sf9(Op1D)/Sf9 pairs. No correlation between pore waiting time and conductance was found. This argues against a molecular model that assumes aggregation of the pore wall from a nonfixed number of components as the rate-limiting step in GP64 fusion pore formation.

Submaximal responses in calcium-triggered exocytosis are explained by differences in the calcium sensitivity of individual secretory vesicles

A graded response to calcium is the defining feature of calcium-regulated exocytosis. That is, there exist calcium concentrations that elicit submaximal exocytotic responses in which only a fraction of the available population of secretory vesicles fuse. The role of calcium-dependent inactivation in defining the calcium sensitivity of sea urchin egg secretory vesicle exocytosis in vitro was examined. The cessation of fusion in the continued presence of calcium was not due to calcium-dependent inactivation. Rather, the calcium sensitivity of individual vesicles within a population of exocytotic vesicles is heterogeneous. Any specific calcium concentration above threshold triggered subpopulations of vesicles to fuse and the size of the subpopulations was dependent upon the magnitude of the calcium stimulus. The existence of multiple, stable subpopulations of vesicles is consistent with a fusion process that requires the action of an even greater number of calcium ions than the numbers suggested by models based on the assumption of a homogeneous vesicle population.

The calcium sensitivity of individual secretory vesicles is invariant with the rate of calcium delivery

Differences in the calcium sensitivity of individual secretory vesicles can explain a defining feature of calcium-regulated exocytosis, a graded response to calcium. The role of the time dependence of calcium delivery in defining the observed differences in the calcium sensitivity of sea urchin egg secretory vesicles in vitro was examined. The calcium sensitivity of individual secretory vesicles (i.e., the distribution of calcium thresholds) is invariant over a range of calcium delivery rates from faster than micromolar per millisecond to slower than micromolar per second. Any specific calcium concentration above threshold triggers subpopulations of vesicles to fuse, and the size of these subpopulations is independent of the time course required to reach that calcium concentration. All evidence supports the hypothesis that the magnitude of the free calcium is the single controlling variable that determines the fraction of vesicles that fuse, and that this fraction is established before the application of calcium. Submaximal responses to calcium cannot be attributed to alterations in the calcium sensitivity of individual secretory vesicles arising from the temporal properties of the calcium delivery. Models that attempt to explain the cessation of fusion using changes in the distribution of calcium thresholds arising from the rate of calcium delivery and/or adaptation are not applicable to this system, and thus cannot be general.

Epstein-Barr virus and gastrointestinal lymphomas in Korea

To analyze the association of Epstein-Barr virus (EBV) with gastrointestinal non-Hodgkin's lymphomas arising in immunocompetent patients, 56 consecutive cases of gastrointestinal lymphomas (B-cell: 52-cases, T-cell: 3 cases, T/NK-cell: 1 case) occurring in the stomach (33 cases), intestine (22 cases) and esophagus (1 case) were investigated for the presence of EBV using polymerase chain reaction analysis as a screening method followed by EBER-1 RNA and DNA in situ hybridization (ISH) and immunohistochemistry for the expression of latent membrane protein 1 (LMP-1). Forty-seven cases demonstrated extractable DNA and EBV DNA was detected only in 4 cases. Among the, RNA (EBER-1) and DNA ISH analysis confirmed the presence of the EBV genome in tumor cells in 3 cases (T/NK-cell lymphoma of ileum, gastric high-grade B-cell lymphoma of mucosa-associated lymphoid tissue, gastric diffuse large B-cell lymphoma). Only the T/NK cell lymphoma showed diffuse positivity of tumor cells while 2 gastric B-cell lymphomas demonstrated a scattered positive reaction and no cases expressed LMP-1. Nine cases without extractable DNA by the PCR method showed no nuclear signal by EBER-1 ISH. These findings suggest that most sporadic primary gastrointestinal lymphomas in Korea are not associated with EBV.

Reconstitution of calcium-triggered membrane fusion using "reserve" granules

Calcium-gated secretion of proteins involves the transfer of "reserve" granules, exocytotic vesicles that are cytoplasmic and, hence, plasma membrane-naive, from the cell interior to the surface membrane where they dock prior to fusion. Docking and subsequent priming steps are thought to require cytoplasmic factors. These steps are believed to induce fusion competence. We have tested this hypothesis by isolating reserve granules from sea urchin eggs and determining under which conditions these granules will fuse. We find that isolated reserve granules, lacking soluble cofactors, support calcium-dependent membrane fusion in vitro. Preincubation with adenosine 5'-3-O-(thio)triphosphate and guanosine 5'-3-O-(thio)triphosphate did not prevent fusion. Thus, isolated reserve granules have all the necessary components required for calcium-gated fusion prior to docking.

Granzyme B immunoreactivity in T/natural killer cell lymphomas

Granzyme B is one of the serine proteases expressed in natural killer (NK) cells and activated cytotoxic T-lymphocytes. To evaluate the usefulness of granzyme B immunoreactivity in the diagnosis of T/NK-cell lymphoma, we studied 69 cases of lymphomas occurring in the upper aerodigestive tract by paraffin-section immunohistochemistry using a commercially available monoclonal antibody to granzyme B (GrB-7). All 19 cases of T/NK-cell lymphomas defined by the expression of CD56 (NHK-1) and one or both T-cell markers (polyclonal CD3 and CD45RO) expressed granular cytoplasmic granzyme B immunoreactivity. Two out of 9 cases of T-cell lymphomas showing no CD56 expression demonstrated strong granzyme B immunoreactivity. No tumor cells among 39 cases of B-cell diffuse large cell lymphomas and 2 cases of null cell diffuse large cell lymphomas were immunoreactive for granzyme B, however a few scattered granzyme B-positive reactive small lymphoid cells were consistently observed. Based on its sensitivity in this study as well as its reactivity in routinely processed tissue sections, even without heat-induced epitope retrieval technique, monoclonal antibody to granzyme B (GrB-7) can be applied as a useful marker in the diagnosis of T/NK-cell lymphomas in conjunction with CD56.