[A comparative study on the depth of cure, hardness and microleakage applied to primary teeth of different types of bulk-fill resins]

Objective: To compare the depth of cure, surface hardness and microleakage applied to primary teeth of three types of bulk-fill resins, so as to provide reference for clinical application. Methods: Composite resin FiltekTM Z350 XT (group A) and giomer Beautifil Ⅱ (group B) were used as controls, high-viscosity bulk-fill resin FiltekTM Bulk Fill (group C), sonic-activated bulk-fill resin SonicFill 2 (group D) and flowable bulk-fill resin SDR® flow+(group E) were studied. The microstructure of each group was observed by scanning electron microscope (SEM). Specimens of each group were prepared (6 pieces per group), and the Vickers microhardness of the surface layer and different depths of each group were measured, and then the depths of cure were calculated. Twenty-five primary molars dentin were filled by resins of each group (5 teeth per group), sliced, then aged, slices of each group were developed by silver ion staining. SEM was used to observed the distribution of silver ions. Microleakage of each group were analyzed by Jonckheere-Terpstra rank sum test. Results: SEM showed that the filler particles in groups A and C were spherical and evenly distributed. The shape of the fillers in groups B, D and E were polygonal and unevenly distributed. The surface hardness of groups A, B, C, D and E were (84.97±6.30), (65.04±5.95), (57.80±1.18), (60.77±2.34), (33.32±1.83) MPa respectively. Group A had the highest hardness, while group E was the lowest, and the differences between the two groups and other groups was statistically significant (P<0.05). There were no statistically significant differences among groups B, C, and D (P>0.05). The curing depths of groups A, B, C, D and E were 2.6, 3.4, 5.8, 3.8 and 7.8 mm respectively. The largest microleakage was found in group E [2% (1/50) for grade 0, 22% (11/50) for grade 1, 30% (15/50) for grade 2, 24% (12/50) for grade 3, and 22% (11/50)for grade 4], which was statistically different from other groups (P<0.05). No statistically significant differences were found among other 3 groups (P>0.05). Conclusions: Both high-viscosity and sonic-activated bulk-fill resins have the greater depth of cure, the same hardness and microleakage as giomer, which might be an option for restoration in primary teeth.

Tumor Regression with 5-Aminolevulinic Acid (5-ALA)-Mediated Radiodynamic Therapy (RDT) Using Different Megavoltage Energies

PURPOSE/OBJECTIVE(S)

5-aminolevulinic acid (5-ALA) accumulates in target tumor cells, where it is metabolized to a photosensitizer - protoporphyrin IX (PpIX). Cherenkov light induced by high-energy photon beams effectively activates the PpIX due to the Soret band. The activated photosensitizers lead to cellular toxicities to kill malignant tumor cells by converting surrounding tissue oxygens into singlet oxygens. Radiodynamic therapy (RDT) utilizes cellular damage caused by both radiation dose and activated photosensitizer. The emission of Cherenkov light was observed higher with higher energy irradiation in phantom and ex-vivo tissues. Therefore, using an in-vivo mouse model, this study aimed to investigate the efficacy and energy dependency of RDT combined with 5-ALA and different ranges of megavoltage photon irradiation.

MATERIALS/METHODS

In order to investigate individual and synergistic effects of 5-ALA administration and radiation treatment, the tumors (n = 344) were randomized into eight groups: control (untreated), 5-ALA only, 6-, 15-, and 45-MV conventional radiation treatment (RT) only, 6-, 15-, and 45-MV RDT. 4 Gy in a single fraction was delivered to the tumors using three different energy photons for RT only and RDT groups. 5-ALA was systemically injected into 5-ALA only and RDT groups at 100 mg/kg by tail-vein 4 hours before irradiation for endogenous PpIX accumulation in the tumor. Tumor growth was measured using a 1.5 T MR scanner on the day of treatment (prior to the treatment), 3, 7, and 14 days post-treatment. Two-way repeated ANOVA with Bonferroni correction was used to compare each treatment group to determine the statistically significant difference in tumor growth.

RESULTS

A total of 45 MV RDT resulted in the most significant decrease in tumor growth by 58.8 ± 3.4 %, 58.0 ± 3.0 %, and 55.0 ± 3.0 % compared to 5-ALA, 45 MV RT, and control group on 7 days post-treatment (P<0.001), respectively. Moreover, a synergistic effect of 45 MV RDT causes a 47.1-54.1 % additional decrease in tumor growth toward the effective treatment outcome. Compared to the different energies, 45 MV RDT resulted in a 52.2 ± 3.1 % and 19.7 ± 7.2 % decrease in tumor growth compared to 6 MV RDT and 15 MV RDT on 7 days post-treatment, respectively (P<0.001), whereas the conventional RT was not.

CONCLUSION

Radiodynamic therapy using 5-ALA administration and 45MV photon beam irradiation resulted in the most significant tumor growth control. A photon energy dependency was observed in radiodynamic therapy. 45MV photon beams showed greater in activating PpIX, improving the synergistic effects of radiation dose and activated photosensitizer than the other energies. The preliminary results provide a foundation for new innovative treatment strategies that have the potential to improve cancer treatment.

Investigation of Hydrogen Peroxide for 45MV 5-Aminolevulinic Acid-Mediated Radiodynamic Therapy

PURPOSE/OBJECTIVE(S)

Cytotoxicity caused by the reactive oxygen species (ROS), such as singlet oxygen species (1O2), superoxide radical (O2-), and hydroxyl radical (HO), is a mechanism for treating cancer cells in radiation therapy. 5-aminolevulinic acid (5-ALA)-mediated radiodynamic therapy (RDT) is more effective in killing tumor cells than conventional radiation therapy. ROS is produced not only by ionizing radiation but also by Cherenkov light-activated protoporphyrin IX (PpIX), which is metabolized endogenously from 5-ALA. Moreover, PpIX also catalyzes hydrogen peroxide to generate 1O2, and an enhanced catalytic yield of 1O2 was observed in X-ray irradiation in vitro. Therefore, using an in-vivo mouse model, this study aimed to investigate the effect of hydrogen peroxide as a coenzyme catalyst on a novel 45MV 5-ALA-mediated RDT.

MATERIALS/METHODS

A subcutaneous C57BL/6 mouse model of KP1 cell line was used. The tumors (n = 240) were randomized into six groups, consisting of untreated, conventional radiation treatment (RT), and RDT with or without hydrogen peroxide: 1. control (untreated), 2. hydrogen peroxide, 3. 45MV RT, 4. 45MV RT + hydrogen peroxide, 5. 45MV RDT, 6. 45MV RDT + hydrogen peroxide. For 45MV photon irradiation, a single fraction of 4 Gy was delivered to the tumors. 5-ALA was systemically injected at 100 mg/kg by tail-vein 4 hours before the treatment for endogenous PpIX accumulation in the tumor. Carbamide peroxide was used to deliver hydrogen peroxide to tissue and was administered at 60 mg/kg intratumorally into tumors ∼3-5 min before the treatment. The treatment effect of a single fraction of treatment was measured by calculating tumor growth, measured using a 1.5 T MR scanner on the day of treatment (prior to the treatment), 3 and 7 days post-treatment. Two-way repeated ANOVA with Bonferroni correction was used to compare each treatment group to determine the statistically significant difference in tumor growth.

RESULTS

A total of 45MV RDT with hydrogen peroxide was shown to significantly delay the tumor growth for the mouse model and cell line investigated in this work. 45MV RDT with hydrogen peroxide group resulted in a decrease in tumor growth by 51.3 ± 4.1 % and 56.1 ± 5.1 % compared to the control group on 3 and 7 days post-treatment, respectively (P<0.001), and 43.4 ± 0.8 % and 50.9 ± 0.8 % compared to 45MV RT alone on 3 and 7 days post-treatment, respectively. Moreover, the enhancement effect of hydrogen peroxide on 45MV RDT was 2.2-4.7 times greater on 45MV RT alone (P<0.05). Hydrogen peroxide did not contribute to tumor growth when administered alone.

CONCLUSION

A total of 45MV 5-ALA-mediated RDT with hydrogen peroxide resulted in the most significant tumor growth delay compared to the other groups. The catalytic effect of PpIX and hydrogen peroxide was observed in-vivo. These preliminary results demonstrate an effective cancer treatment modality.

[A comparative study on early childhood caries detection by using international caries detection and assessment system-Ⅱ and WHO criteria]

Objective: To investigate and compare the sensitivities of early childhood caries detection by using international caries detection and assessment system (ICDAS)-Ⅱ and WHO criteria. Methods: A total of 449 3-year-old children from four day care kindergartens in Beijing were enrolled in this study. Both ICDAS-Ⅱ and WHO criteria were used to assess the prevalence of caries in the given subjects. The decayed, missing, and filled teeth (dmft) index scores were calculated. In ICDAS-Ⅱ system, four cut-off points (D1, D2, D3 and D4) were employed to differentiate sound and decayed teeth: D1 (score 0 as sound, scores 1-6 as caries); D2 (0-1 sound, 2-6 caries); D3 (0-2 sound, 3-6 caries) and D4 (0-3 sound, 4-6 caries). SPSS software was used to analyze the data to decide the significance of differences. Results: The caries prevalence using ICDAS-Ⅱ were 76.6% (344/449), 71.3% (320/449), 52.8% (237/449) and 46.1% (207/449) for D1 to D4, respectively; the corresponding mean dmft scores were 4.95±4.85, 4.41±4.77, 2.54±3.69 and 1.97±3.10. The sites with highest caries prevalence were occlusal surface of mandibular molars in groups of D1 and D2 and proximal surface of maxillary anterior teeth in groups D3 and D4. In contrast, the caries prevalence was 48.8% (219/449) and the mean dmft was 2.27±3.54 when using WHO criteria, significantly lower than the detection rates by using ICDAS-Ⅱ (D1-D2) (P=0.00). This suggested that ICDAS-Ⅱ system was a more sensitive method in detecting early childhood caries. Conclusions: ICDAS-Ⅱ system might be superior in detection of incipient caries and be of specific value in prevention of early childhood caries.

[Impact on the incidence of postoperative ventricular arrhythmias after cardiac resynchronization therapy defibrillator with quadripolar lead]

Objective: To evaluate incidence of postoperative ventricular arrhythmias in patients who received cardiac resynchronization therapy defibrillator (CRT-D ) with left ventricular quadripolar lead. Methods: The patients received CRT-D who had complete follow-up data in Anhui Provincial Hospital from June 2013 to June 2016 were included and divided into quadripolar lead group and bipolar lead group according to the type of left ventricular lead. And ventricular arrhythmia (VA), implantable cardioverter-defibrillator (ICD) shocks treatment, antitachycardia pacing therapy (ATP), and other indicators of the two groups were compared. Prognosis of the two groups was assessed by re-hospitalization for heart failure and cardiac death. Results: Of the 220 patients enrolled in the study, 58 patients were in quadripolar lead group and 162 in bipolar lead group, and there were no significant differences in baseline characteristics between the two groups. The VA episode per patient was not significantly different between the two groups [(0.60±2.38) VA per person vs (0.93±2.24) VA per person, P=0.055]; the quadripolar lead group had significantly lower burden of VA compared with bipolar lead group [(0.22±0.91) per person-year vs (0.46±1.13) per person-year, P=0.044]. Compared with bipolar lead group, there were significant reduction in both the ICD shocks per patient and the burden of ICD shocks in quadripolar lead group: [(0.12±0.36) shocks per person vs (0.23±0.52) shocks per person, P=0.034] and [(0.04±0.17) per person-year vs (0.12±0.46) per person-year, P=0.029], respectively. There were no significant differences between the two groups in both the ATP per patient and the burden of ATP: [(1.07±3.77) ATP per person vs (1.26±3.01) ATP per person, P=0.073] and [(0.38±1.39) per person-year vs (0.63±1.48) per person-year, P=0.058], respectively. And there were no significant differences between the two groups for the survival (P=0.496). Conclusion: Compared with bipolar lead group, the burden of VA could be significantly reduced after CRT-D in the quadripolar lead group.

[Morphology character and reduction methods of sagittally unstable intertrochanteric fractures]

OBJECTIVE

To investigate the morphology character of sagittally unstable intertrochanteric fractures and reduction methods.

METHODS

A retrospective study was used to analyze the clinical data of sagittally unstable intertrochanteric fractures cases, which were treated with proximal femoral nail anti-rotation (PFNA) fixation from March 2009 to June 2016. In the study, 36 cases were followed up completely, in which 17 cases accepted open reduction, and the other 19 cases accepted minimally invasive reduction. The operation time, amount of bleeding, the fluoroscopy times, postoperative radiographic measurements, such as tip-apex distance (TAD) and sliding distance of the spiral screw, and hip Harris scores were analyzed. The morphology character of the fractures was documented and investigated.

RESULTS

The average follow-up time was 15 months. The amount of bleeding of the open reduction group was (170.5±19.7) mL, and the amount of bleeding of the minimally invasive group was (54.7±12.5) mL. The amount of bleeding of the minimally invasive group was significantly less than that of the open reduction group (P<0.001). Between the two groups, there were no significant differences in other evaluation parameter, including operation time (P=0.054), the fluoroscopy times (P=0.053), fracture healing time (P=0.305), postoperative radiographic measurements, such as TAD (P=0.317) and sliding distance of the spiral screw (P=0.206), and hip Harris scores (P=0.459). In regard to morphology character of the fractures, the proximal anterior unstable fractures with separation displacement were more common than the proximal posterior unstable fractures with impaction. The characteristic feature of the proximal anterior unstable fractures was the proximal anterior and medial long oblique fracture, and a V shape cortical defect in the distal fracture fragment on the externally rotation X-ray.

CONCLUSION

Sagittally unstable intertrochanteric fractures can be divided into the proximal anterior unstable fractures with separation displacement, and the proximal posterior unstable fractures with impaction. The two types have their own morphology character individually. The reduction should be performed by minimally invasive techniques.

Comparison of Characteristics and Outcomes of Heart Failure Patients With Preserved Versus Reduced Ejection Fraction in a Multiethnic Southeast Asian Cohort

There are few data comparing the patient characteristics and outcomes of heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced EF (HFrEF) in Asian cohorts. We aimed to evaluate the prevalence, clinical characteristics, and 1-year outcomes of a well-defined Southeast Asian HFpEF cohort in comparison to an HFrEF cohort. We conducted a retrospective observational study of 1,978 patients discharged from Changi General Hospital, Singapore with a primary diagnosis of HF from 2009 to 2013. About 29% of discharges had HFpEF. Patients with HFpEF were more likely to be women, older age, and have a higher prevalence of hypertension. There were no significant differences in the absolute rates of 30-day outcomes between the 2 groups. The absolute rate of death at 1 year was similar in HFrEF and HFpEF at 17% and 15%, respectively (p = 0.3). After multivariate adjustment, there was no difference in the outcomes of the 2 groups. Atrial fibrillation at baseline was a predictor of death or HF hospitalization in HFpEF but not HFrEF (interaction p = 0.003). In conclusion, in this study of a Southeast Asian population with well-defined HF, we found that the clinical profile of patients with HF was similar to that in the West and 30-day and 1-year mortality and morbidity were not significantly different between cohorts.

Molecular analysis of MLH1 variants in Chinese sporadic colorectal cancer patients

Single nucleotide polymorphisms (SNPs) in mismatch repair genes, especially in the MLH1 gene, are closely associated with susceptibility to hereditary nonpolyposis colorectal cancer. However, few relevant findings are available regarding the association between sporadic colorectal cancer (SCRC) and SNPs of MLH1 in Chinese patients. Therefore, the present study aimed to describe the pathogenic association between three important MLH1 polymorphisms and SCRC in the Chinese population. Peripheral blood samples from 156 SCRC patients and 311 healthy controls were collected. DNA was purified from peripheral blood, and the V384D, R217C, and I219V polymorphisms were evaluated using high-resolution melting analysis and direct sequencing. The association between the three important MLH1 polymorphisms and clinical pathological features of the SCRC patients was analyzed. In addition, PMS2-MLH1 protein interactions were determined by co-immunoprecipitation (Co-IP) to determine the protein functional alteration induced by these SNPs. Among the three polymorphisms, V384D was significantly associated with the risk of SCRC (OR = 31.36, P < 0.0001). The allele frequencies were 4.81 and 0.16% in the SCRC group. No association was found between SCRC and R217C, or between SCRC and I219V. Moreover, the allele frequency of R217C was significantly higher in the SCRC patients younger than 60 years than in those older than 60 years. Co-IP showed that the MLH1 R217C, V384D, and I219V variants had relative binding abilities with PMS2 of 0.59, 0.70, and 0.80, respectively, compared with the wild-type. These findings suggest that MLH1 V384D could be a promising genetic marker for susceptibility to SCRC.

Gastrointestinal stromal tumours (GISTs) with a thousand faces: atypical manifestations and causes of misdiagnosis on imaging

Gastrointestinal stromal tumours (GISTs) can lead to emergency situations, such as gastrointestinal bleeding, intestinal obstruction, and tumoural rupture with haemoperitoneum or peritonitis. In addition, if a GIST grows exophytically to a large size, it is often misdiagnosed as a tumour arising from adjacent organs. Sometimes, the atypical appearance of GISTs on imaging causes diagnostic confusion. In this article, we illustrate a variety of GISTs with atypical presentations and also discuss the important diagnostic clues for differentiating GISTs from other lesions.

Gallbladder carcinoma: causes of misdiagnosis at CT

Gallbladder carcinomas can present with varied imaging features on computed tomography. The three major imaging features include (1) focal or diffuse wall thickening with or without irregularity of the gallbladder; (2) polypoidal intraluminal mass; and (3) large mass obscuring and replacing the gallbladder, often extending to the liver. Patterns of wall thickening or polypoid growth are often confused with various benign gallbladder diseases due to overlap of imaging findings. Moreover, gallbladder carcinomas that coexist with benign gallbladder diseases make accurate preoperative diagnosis more difficult. Recently, high-resolution ultrasound (HRUS) has been regarded as a problem-solving tool for gallbladder diseases. In this article, we will illustrate various imaging presentations of gallbladder cancer, along with imaging pitfalls and recently updated HRUS findings.

Comparison of the clinical characteristics and imaging findings of acute cholangitis with and without biliary dilatation

OBJECTIVE

To evaluate the causes of acute cholangitis without biliary dilatation and to compare the clinical characteristics and the imaging findings between patients with acute cholangitis with and without biliary dilatation.

METHODS

93 patients diagnosed with acute cholangitis underwent contrast-enhanced CT. Among them, 17 patients were classified as not having biliary dilatation (Group 1) and 76 patients were classified as having biliary dilatation (Group 2). The causes of acute cholangitis were evaluated in both groups. Clinical characteristics and imaging findings were compared between the two groups.

RESULTS

The causes of acute cholangitis without biliary dilatation included common bile duct (CBD) stones (n=11), CBD sludge (n=3), a passed stone (n=1) and unknown causes (n=2). The total bilirubin levels of Group 1 were significantly lower than those of Group 2 (p=0.001). By contrast, Group 1 had higher median alanine aminotransferase (ALT) levels than Group 2 (p=0.04). The length of hospital stay was significantly longer in Group 2 than in Group 1 patients (p<0.001). In the imaging findings, the extent of transient hepatic attenuation differences (THADs) (p=0.003) were significantly smaller in Group 1 than in Group 2.

CONCLUSION

CBD stones and sludge were the most common causes of acute cholangitis in patients without biliary dilatation. These patients showed lower levels of bilirubin and higher levels of ALT than those with acute cholangitis with biliary dilatation, and had a shorter duration of hospital stay. The extent of THADs was the only discriminative CT finding between the two groups.

ADVANCES IN KNOWLEDGE

Acute cholangitis can present without biliary dilatation on imaging, and the most common causes are CBD stones and sludge. The patients with acute cholangitis without biliary dilatation have different clinical characteristics and imaging findings compared with those with acute cholangitis presenting with biliary dilatation.

Perforated tumours in the gastrointestinal tract: CT findings and clinical implications

Perforation usually requires emergency surgery and may affect the prognosis of patients with gastrointestinal tumours. Accurate pre-operative diagnosis of these conditions is important because proper management such as curative surgical treatment may be needed. The aims of this article are to illustrate CT appearances of perforated tumours of the gastrointestinal tract and to discuss their impact on clinical management.

Time-resolved MR angiography for detecting and grading ovarian venous reflux: comparison with conventional venography

OBJECTIVE

The purpose of this study was to compare the diagnostic accuracy of time-resolved MR angiography (TR-MRA) with that of conventional venography for the detection and grading of ovarian venous reflux, which aid in the diagnosis of pelvic venous congestion.

METHODS

We performed a retrospective analysis of 19 consecutive patients who underwent TR-MRA and conventional venography. The images were analysed by two radiologists in a randomised "blinded" manner. With the use of conventional venography as a gold standard, the images were reviewed to determine if differences in the detection and grading of ovarian venous reflux were seen between TR-MRA and conventional venography; the sensitivity, specificity and accuracy of TR-MRA compared with that of conventional venography were evaluated. The McNemar test was performed to determine the significance of any differences. Interobserver agreement was analysed using generalised κ statistics.

RESULTS

There was no significant difference between TR-MRA and conventional venography for grading ovarian venous reflux (p>0.05). The sensitivity, specificity and diagnostic accuracy of TR-MRA were found to be 66.7%, 100% and 78.9%, and 75%, 100% and 84.2%, respectively, for the two observers. The weighted κ-values indicated excellent agreement between the two observers for grading ovarian venous reflux on TR-MRA (κ = 0.894).

CONCLUSION

TR-MRA is an accurate method for accessing pelvic venous congestion.

Acute appendicitis: relationships between CT-determined severities and serum white blood cell counts and C-reactive protein levels

OBJECTIVES

The aim of this study was to evaluate the relationships between the severity of appendicitis as depicted on CT and blood inflammatory markers of serum white blood cell (WBC) count and C-reactive protein (CRP).

METHODS

CT images in 128 patients (109 surgically proven and 19 with clinically excluded appendicitis) were retrospectively reviewed. Two radiologists by consensus evaluated and scored (using a 0, 1 or 2 point scale) severities based on CT-determined appendiceal diameters, appendiceal wall changes, caecal changes, periappendiceal inflammatory stranding and phlegmon or abscess formation. We investigated whether CT findings were significantly related to elevated WBC counts or CRP levels and performed the correlations of WBC counts and CRP levels with CT severity scores. Patients were also subjectively classified using four grades from normal (Grade I) to perforated appendicitis (Grade IV) on the basis of CT findings to evaluate differences in WBC counts and CRP levels between grades.

RESULTS

Only appendiceal wall changes and the phlegmon or abscess formation were related to elevated WBC counts and CRP levels, respectively (p<0.05). CT severity scores were found to be more strongly correlated with CRP levels (r = 0.669) than with WBC counts (r = 0.222). On the basis of CT grades, the WBC counts in Grade I were significantly lower than in other grades (p<0.001), whereas CRP levels in Grade IV were significantly higher than in other grades (p<0.001).

CONCLUSION

CRP levels were found to correlate with CT-determined acute appendicitis severity and could be a useful predictor for perforated appendicitis, whereas WBC counts might be useful to detect early acute appendicitis.

The detection and discrimination of malignant and benign focal hepatic lesions: T2 weighted vs diffusion-weighted MRI

OBJECTIVE

The purpose of this study was to evaluate the use of diffusion-weighted imaging (DWI) for the detection and characterisation of focal hepatic lesions compared with the use of T(2) weighted imaging.

METHOD

45 patients with 97 hepatic lesions (51 malignant lesions and 46 benign lesions) were included in this retrospective study. Malignant hepatic lesions included 12 hepatocellular carcinomas, 26 metastases and 13 intrahepatic cholangiocarcinomas. Benign hepatic lesions included 19 haemangiomas and 27 cysts. The MRI protocol for the upper abdomen included T(2) weighted images, in- and opposed-phase T(1) weighted images and dynamic T(1) weighted images. Breath-hold fat-suppressed single-shot echo planar DWI was performed with the following parameters: 1338/66; b factors, 0, 50 and 800 s mm(-2). Two independent observers reviewed the T(2) weighted images and the DWI to detect and to characterise the hepatic lesions.

RESULTS

For detection of malignant hepatic lesions, the use of DWI showed a significantly higher detection rate than the use of T(2) weighted images (p<0.05). However, there was no significant difference between the use of DWI and T(2) weighted images for benign hepatic lesions. For the differentiation between malignant and benign hepatic lesions, there was no significant difference in sensitivity, specificity and accuracy between the use of T(2) weighted images and the use of DWI.

CONCLUSION

The use of DWI was better for the detection of malignant hepatic lesions than the use of T(2) weighted images. However, for detection of benign hepatic lesions and characterisation of hepatic lesions, the use of DWI was equivalent to the use of T(2) weighted images.

Identification of the normal appendix in healthy adults by 64-slice MDCT: the value of adding coronal reformation images

The aim of this study was to assess retrospectively the value of adding coronal reformation images to the identification of the normal appendix using 64-slice multidetector CT (MDCT). 200 consecutive healthy adults with no history of abdominal surgery underwent abdominal CT using 64-slice MDCT without oral contrast administration and were enrolled in the study. Two gastrointestinal radiologists first interpreted the axial images only; after a 2-week interval, they then interpreted both the axial and the coronal images while blinded to the first interpretation. The identification of the normal appendix was interpreted using a four-point scale: 1, not identified; 2, identified with low confidence; 3, probably identified; 4, definitely identified. Agreement between the readers was determined with the use of weighted kappa statistics. Differences in confidence ratings for identification of the appendix were determined with the Wilcoxon signed rank test. The agreement between the readers was higher when both axial and coronal images were reviewed (kappa = 0.85) than when only the axial scans images were reviewed (kappa = 0.43). The mean confidence scores for the identification of the normal appendix by the two readers were significantly higher when both the axial and coronal images were reviewed (mean, 3.81+/-0.498 and 3.83+/-0.485 for the two readers, respectively) than when only the axial images were reviewed (mean, 3.27+/-0.819 and 3.47+/-0.856, respectively) (all p<0.01). Therefore, adding coronal reformation images to 64-slice MDCT significantly improves inter-reader agreement and confidence in the identification of the normal appendix.

Arsenite-induced cytotoxicity in dorsal root ganglion explants

Peripheral neuropathy is common in people chronically overexposed to arsenic. We studied sodium arsenite (arsenite)-induced cytotoxicity in dorsal root ganglion (DRG) explants. Incubation with arsenite concentration- and time-dependently increased the expression of stress proteins, heat shock protein 70, and heme oxygenase-1 in DRG explants. Furthermore, apoptosis was involved in the arsenite-induced cytotoxicity in the treated DRG. Elevation in cytosolic cytochrome c levels and reduction in procaspase 3 levels suggested an involvement of the mitochondrial pathway in arsenite-induced apoptosis in this preparation. At the same time, increases in the activating transcription factor-4 and C/EBP homologous protein and reduction in procaspase 12 levels indicated activation of the endoplasmic reticulum (ER) pathway in the arsenite-induced cytotoxicity in DRG explants. Salubrinal (30 microM), an ER inhibitor, was found to attenuate arsenite-induced DNA fragmentation and reduction in procaspase 12 in DRG explants. Cytotoxic effects by arsenite, sodium arsenate (arsenate), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) were compared, and the potency was as follows: arsenite >>> arsenate>MMA and DMA. Recombinant adenovirus vectors encoding glial-cell-derived neurotrophic factor (AdGDNF) genes allowed a stable delivery of GDNF genes to the infected cells in DRG explants. Applied in this manner, AdGDNF was found to inhibit arsenite-induced DNA fragmentation in DRG explants. Moreover, AdGDNF attenuated the arsenite-induced reduction in procaspases 3 and 12 levels. Taken together, our study demonstrates that arsenite is capable of inducing cytotoxicity in DRG explants. Both ER and mitochondria pathways are involved in the arsenite-induced apoptosis in DRG explants. Glial-cell-derived neurotrophic factor appears to be protective against arsenite-induced peripheral neuropathy.

Iron-generated hydroxyl radicals kill retinal cells in vivo: effect of ferulic acid

Siderosis bulbi is vision threatening. An investigation into its mechanisms and management is crucial. Experimental siderosis was established by intravitreous administration of an iron particle (chronic) or FeSO4 (acute). After siderosis, there was a significant dose-responsive reduction in eletroretinogram (a/b-wave) amplitude, and an increase in •OH level, greater when caused by 24 mM FeSO4 than that by 8 mM FeSO4. Furthermore, the FeSO4-induced oxidative stress was significantly blunted by 100 μM ferulic acid (FA). Siderosis also resulted in an excessive glutamate release, increased [Ca++]i, and enhanced superoxide dismutase immunoreactivity. The latter finding was consistent with the Western blot result. Obvious disorganization including loss of photoreceptor outer segments and cholinergic amacrines together with a wide-spreading ferric distribution across the retina was present, which were related to the eletro-retinographic and pathologic dysfunctions. Furthermore, b-wave reduction and amacrine damage were respectively, significantly, dose-dependently, and clearly ameliorated by FA. Thus, siderosis stimulates oxidative stress, and possibly, subsequent excitotoxicity, and calcium influx, which explains why the retina is impaired electro-physiologically and pathologically. Importantly, FA protects iron toxicity perhaps by acting as a free radical scavenger. This provides an approach to the study and treatment of the iron-related disorders such as retained intraocular iron and Alzheimer disease.

Imaging findings of idiopathic localized dilatation of the ileum

We report imaging findings in a case of idiopathic localized dilatation of the ileum (ILDI). CT revealed a large cystic mass containing air in the pelvic cavity. Sonography showed a cystic lesion with internal echo in the pelvic cavity. In addition, slow peristaltic movement was seen in the lesion. Small bowel series showed a bilobular dilatation of the ileum with two narrow transitions connecting the proximal and distal bowel loops.

Zinc-induced apoptosis in substantia nigra of rat brain: neuroprotection by vitamin D3

Accumulation of transition metals has been suggested to be responsible for the deteriorated nigrostriatal dopaminergic system in Parkinson's patients. In the present study, the mechanism underlying the zinc-induced neurotoxicity was investigated in the nigrostriatal dopaminergic system in vivo. Our 6-methoxy-8-paratoluene sulfonamide quinoline fluorescence study showed zinc translocation in the infused nigral cells after intranigral infusion of zinc. Furthermore, lipid peroxidation in the zinc-infused substantia nigra was consistently elevated 4 h to 7 d after the infusion. At the same time, an abrupt increase in cytosolic cytochrome c content in the infused substantia nigra was observed 4 h after zinc infusion and gradually decreased to basal levels 7 d after infusion. Both TUNEL-positive neurons and DNA fragmentation, indicatives of apoptosis, were detected in the zinc-infused substantia nigra. Furthermore, striatal dopamine content was reduced 7 d after the infusion. In attempt to prevent zinc-induced neurotoxicity, vitamin D3 was systemically administered. Zinc-induced increases in lipid peroxidation and cytosolic cytochrome c in the infused substantia nigra were prevented by this treatment. Moreover, zinc-induced reduction in striatal dopamine content was attenuated after vitamin D3 treatment. Our in vivo data suggest that zinc-induced oxidative stress may result in apoptosis followed by reduced dopaminergic function in the nigrostriatal dopaminergic system. Furthermore, vitamin D3 prevented zinc-induced oxidative injuries in the rat brain.

Portal vein aneurysm of the umbilical portion: imaging features and the relationship with portal vein anomalies

BACKGROUND

We evaluated the imaging features of portal vein aneurysm occurring at the umbilical portion and the relation between portal vein aneurysm of the umbilical portion and portal vein anomaly.

METHODS

Retrograde analysis was performed in 18 patients with portal vein aneurysm of the umbilical portion of the portal vein. We analyzed the size, shape, and imaging findings of portal vein aneurysm. In addition, we evaluated associated portal vein anomalies, specifically, the branching pattern of the intrahepatic portal vein and the position of the umbilical portion of the left portal vein.

RESULTS

The diameter of the portal vein aneurysm ranged from 1.5 to 2.2 cm and the shape of the portal vein aneurysm was saccular (n = 14) or fusiform (n = 4). Imaging findings of the portal vein aneurysm of the umbilical portion were typical for its vascular nature. Portal vein anomalies were seen in eight of 18 patients (44%): the right anterior segmental portal vein (n = 7) or the right anterior and posterior segmental portal veins (n = 1) originating from the umbilical portion of the left portal vein and a rightward deviation of the umbilical portion of the left portal vein (n = 4).

CONCLUSION

Due to its vascular nature, noninvasive diagnostic modalities can enable the detection of portal vein aneurysm of the umbilical portion, and there is a close relation between portal vein aneurysm of the umbilical portion and portal vein anomaly.

Pictorial review: various causes of hepatic capsular retraction: CT and MR findings

Hepatic capsular retraction adjacent to hepatic tumour is rare, although this finding has been described in a variety of malignant tumours and haemangioma. The authors have seen various causes of hepatic capsular retraction associated with hepatic tumours, including a variety of malignant tumours, haemangioma and post-treatment of malignant tumours, as well as cases not associated with a hepatic tumour, including confluent hepatic fibrosis, oriental cholangiohepatitis and bile duct necrosis. Furthermore, causes of pseudoretraction of the hepatic capsule, including accessory fissure and normal liver parenchyma between the protruded masses, are described.

Brenner tumor of the ovary with extensive stromal luteinization presenting in pregnancy: report of a case and review of the literature

Brenner tumor in pregnancy is rare, with only two reported cases in association with intrauterine pregnancy. A 30-year-old woman, G1P0, was found to have an adnexal mass at 15 weeks of gestation. The mass was resected at Cesarean section and found to be a Brenner tumor with areas of stromal luteinization. Brenner tumor should be considered in the differential diagnosis of adnexal masses presenting during pregnancy. The stromal luteinization was probably related to the hormonal environment of the pregnancy.

Comparison of tuberculous and pyogenic epididymal abscesses: clinical, gray-scale sonographic, and color Doppler sonographic features

OBJECTIVE

The purpose of this study was to evaluate the capability of clinical, gray-scale sonographic, and color Doppler sonographic features for differentiating tuberculous and pyogenic epididymal abscesses.

MATERIALS AND METHODS

Retrospective analysis was performed in 10 cases of tuberculous epididymal abscess and in 13 cases of pyogenic epididymal abscess. The following clinical, gray-scale sonographic, and color Doppler sonographic features were analyzed: patient's age; duration of symptoms; scrotal tenderness; presence of sinus tract; concurrent tuberculosis in other organs; location, size, and echogenicity of the abscess; hyperechoic rim; testicular involvement; hydrocele; and blood flow in the epididymal lesion.

RESULTS

Tuberculous epididymal abscess had a longer duration of symptoms (p = 0.0001) and a lower frequency of scrotal tenderness (p = 0.0048) than pyogenic epididymal abscess. The size of the abscess was larger in tuberculous epididymal abscess than in pyogenic epididymal abscess (p = 0.0002). The degree of blood flow in the peripheral portion of the abscess was lower in tuberculous epididymal abscess (p = 0.001). The patient's age, location and echogeninicity of the abscess, presence of sinus tract, hyperechoic rim, testicular involvement, and hydrocele did not differ between the tuberculous and pyogenic epididymal abscesses.

CONCLUSION

Some clinical findings, gray-scale sonography, and color Doppler sonography were useful in differentiating tuberculous epididymal abscess from pyogenic epididymal abscess. The presence of long-term scrotal swelling without tenderness and a lower degree of blood flow in the peripheral portion of a large abscess are suggestive of tuberculous epididymal abscess.

CT findings of portal vein aneurysm caused by gastric adenocarcinoma invading the portal vein

The known causes of acquired origin portal vein aneurysm are portal hypertension, pancreatitis and trauma. We describe the CT findings of an additional cause of acquired origin portal vein aneurysm, namely gastric adenocarcinoma invading the portal venous system.

Relative contribution of the Na(+)/Ca(2+) exchanger, mitochondria and endoplasmic reticulum in the regulation of cytosolic Ca(2+) and catecholamine secretion of bovine adrenal chromaffin cells

The relative importance of mitochondria, the Na(+)/Ca(2+) exchanger (NCX) and the endoplasmic reticulum (ER) in the regulation of the cytosolic Ca(2+) concentration ([Ca(2+)](i)) were examined in bovine chromaffin cells using fura-2 for average [Ca(2+)](i) and amperometry for secretory activity, which reflects the local Ca(2+) concentration near the exocytotic sites. Chromaffin cells were stimulated by a high concentration of K(+) when the three Ca(2+) removal mechanisms were individually or simultaneously inhibited. When the mitochondrial Ca(2+) uptake was inhibited, the [Ca(2+)](i) decayed at a significantly slower rate and the secretory activity was higher than the control cells. The NCX appears to function only in the initial phase of [Ca(2+)](i) decay and when the ER Ca(2+) pump is blocked. Similarly, the ER had a significant effect on the [Ca(2+)](i) decay and on the secretion only when the NCX was blocked. Inhibition of all three mechanisms leads to a substantial delay in [Ca(2+)](i) recovery and an increase in the secretion. The results suggest that the three mechanisms work together in the regulation of the Ca(2+) near the Ca(2+) channels and exocytotic sites and therefore modulate the secretory activity. When Ca(2+) diffuses away from the exocytotic sites, the mitochondrial Ca(2+) uptake becomes the dominant mechanism.

Presacral epidermoid cyst: imaging findings with histopathologic correlation

BACKGROUND

The aim of this study was to determine the imaging characteristics of presacral epidermoid cysts and correlate the imaging findings with the histopathologic findings.

METHODS

We retrospectively reviewed sonographic, computed tomographic, and magnetic resonance examinations in four consecutive patients with a pathologically proven presacral epidermoid cyst. Imaging findings of the presacral epidermoid cyst were correlated with the histopathologic findings.

RESULTS

In all four patients, sonography showed a presacral mass with a heterogeneous low echogenicity, and computed tomography showed a discrete well-defined hypodense presacral mass with a thin wall. In the three patients who underwent magnetic resonance imaging, the mass showed a heterogeneous low signal intensity on the T1-weighted image and a high signal intensity with multiple small foci of low signal intensity in the nondependent portion of the mass on the T2-weighted image. These imaging findings correlated well with the pathologic results. Aggregates of keratinous material contributed to these imaging findings.

CONCLUSION

In the diagnosis of the presacral epidermoid cyst, sonographic and magnetic resonance imaging findings may be helpful.

Capsular retraction in hepatic giant hemangioma: CT and MR features

We report two cases of hepatic giant hemangiomas with capsular retraction of the liver adjacent to the tumor on computed tomography and magnetic resonance images. Our cases show that the retraction of the liver capsule adjacent to the tumor is not a finding specific to malignant hepatic tumors but can also be observed in benign hepatic tumors.

Neural electrophysiological effect of crude venom of conus textile from the south China Sea

In the present study, we characterized effects of the crude venom from Conus textile, a marine molluscivorous snail collected from the South China Sea, on neural electrophysiological activity in insect, molluscan and mammalian species. Our results demonstrate that the venom reversibly blocks the cholinergic synaptic transmission of cockroach Periplaneta americana central nervous system, partially blocks Na(+) currents in rat hippocampal CA(1) pyramidal neurons, and enhances the excitability and spontaneous activity of the giant neurons of garden snail Achatina fulica.

Chronic tuberculous epididymitis: color Doppler US findings with histopathologic correlation

BACKGROUND

The aim of this study was to determine the color Doppler features of tuberculous epididymitis and to correlate these findings with histopathologic findings.

METHODS

Color Doppler ultrasound (US) findings of 12 histopathologically proven tuberculous epididymitis and tuberculous epididymo-orchitis in 11 consecutive patients were retrospectively analyzed. Color Doppler US findings of tuberculous epididymitis were correlated with histopathologic findings.

RESULTS

Color Doppler US findings of tuberculous epididymitis demonstrated no blood flow in the epididymal lesions except for focal linear or spotty flow signals in the peripheral portion. These findings correlated well with pathologic findings; the central portion of the epididymal lesions demonstrated granulomas with caseation necrosis, and the peripheral portion of the epididymal lesions had several medium to small vessels.

CONCLUSIONS

Color Doppler US may be helpful for differential diagnosis of tuberculous epididymitis and non-tuberculous epididymitis.

Intrarenal pseudoaneurysms complicating renal choriocarcinoma metastases: treatment with coil embolization

Most intrarenal pseudoaneurysms result from a laceration of the renal artery or its branches. However, tumor-induced renal pseudoaneurysm is very rare. We report a case in which embolization of an intrarenal pseudoaneurysm complicating renal metastases resulting from a choriocarcinoma was successful.

PIK3CA as an oncogene in cervical cancer

Amplification of chromosome arm 3q is the most consistent aberration in cervical cancer, and is implicated in the progression of dysplastic uterine cervical cells into invasive cancer. The present study employed the 'positional candidate gene' strategy to determine the contribution of PIK3CA, which is located in 3q26.3, in cervical tumorigenesis. PIK3CA is known to be involved in the PI 3-kinase/AKT signaling pathway, which plays an important role in regulating cell growth and apoptosis. The results of comparative genomic hybridization show that the 3q26.3 amplification was the most consistent chromosomal aberration in primary tissues of cervical carcinoma, and a positive correlation between an increased copy number of PIK3CA (detected by competitive PCR) and 3q26.3 amplification was found in tumor tissues and in cervical cancer cell lines. In cervical cancer cell lines harboring amplified PIK3CA, the expression of gene product (p110alpha) of PIK3CA was increased, and was subsequently associated with high kinase activity. In addition, transformation phenotypes in these lines, including increased cell growth and decreased apoptosis, were found to be significantly affected by the treatment of specific PI 3-kinase inhibitor, suggesting that increased expression of PIK3CA in cervical cancer may result in promoting cell proliferation and reducing apoptosis. These evidences support that PIK3CA is an oncogene in cervical cancer and PIK3CA amplification may be linked to cervical tumorigenesis. Oncogene (2000).

Depressed cytolytic activity of peripheral blood mononuclear cells in unusually high paclitaxel concentrations: reversal by IL-2 and IL-12

BACKGROUND

Human lymphocyte function was inhibited by high concentrations of paclitaxel and the effect was reversed by interleukin (IL)-2. However, there was no parallel study determining the relationship between paclitaxel concentrations in the lymphocyte cultures and pharmacokinetic analysis in human patients, nor was there any study on the reversal by cytokines, other than IL-2, of the paclitaxel-induced suppression of lymphocyte cytotoxicity.

METHODS

We tested the effect of different doses of paclitaxel with various incubation times on the cytolytic activity of peripheral blood mononuclear cells (PBMNCs) against K-562 target cells.

RESULTS

Our results showed that using a schedule similar to that for treating patients with tolerable doses of paclitaxel, no inhibition of cytolytic activity of PBMNCs was seen. When the paclitaxel concentration was increased 10-fold, the cytolytic activity of PBMNCs was significantly reduced. This suppression was reversed by the simultaneous addition of a low dose (10 U/ml) of IL-2 or IL-12. Addition of granulocyte macrophage-colony stimulating factor (10 U/ml) did not affect the cytolytic activity of PBMNCs, whereas addition of IL-4 reduced it. Time kinetic studies revealed that, with the addition of IL-2 or IL-12, most of the mononuclear cellular cytolytic activity recovered within 48 to 72 hours.

CONCLUSIONS

These findings suggested that, to reduce the toxicity on mononuclear cellular function when high-dose paclitaxel treatment is elected in clinical practice, paclitaxel should be infused over a longer duration of time, or the treatment should be combined with the administration of a low dose of IL-2 or IL-12.

Chronic levothyroxin treatment is associated with ion channel abnormalities in cardiac and neuronal cells

1. We investigated the ion currents responsible for repolarization of guinea-pig isolated myocytes (ICa) and rat hippocampal CA1 neurons (IA and IK) by means of the whole-cell holding technique. 2. The rat hypertrophied heart, induced by levothyroxin, caused exaggerated cardiac arrhythmias after coronary ischaemia-reperfusion. 3. We found an enhanced ICa in guinea-pig isolated myocytes and decreased IA and IK in rat hippocampal CA1 neurons following levothyroxin treatment. Blockade of the outward K+ current and an increment in inward Ca2+ current by chronic levothyroxin treatment contributed to the delayed repolarization and aggravated cardiac arrhythmias. 4. Animals treated with chronic levothyroxin may serve as pathological models for the investigation of the pattern of ion channel disorders with regard to impaired repolarization and aggravated cardiac arrhythmias.

Bepridil inhibition of sodium current in rat hippocampal CA1 neurons

AIM

To study the effects of bepridil on sodium current in rat hippocampal neurons.

METHODS

All experiments were performed on acutely isolated hippocampal pyramidal neurons by means of whole-cell patch-clamp techniques. Recording media contained ion channel blockers to allow the selective activation of voltage-dependent sodium currents.

RESULTS

Bepridil reduced the amplitudes of sodium current in time- and concentration-dependent manners. The half-blocking time was about 10 min in bepridil 10 micromol.L-1, and IC50 was 2.6 (2.3-2.9) micromol.L-1. Bepridil 10 micromol.L-1 shifted the maximal activation of sodium current from -50 mV to -40 mV, and the characteristic voltage of inactivation from -71 mV to -89 mV without changing the slope factor.

CONCLUSION

Bepridil blocked voltage-dependent sodium current of hippocampal CA1 neurons and might have therapeutic actions for ischemia-induced brain damage.

Modulation of dopamine transporter activity by nicotinic acetylcholine receptors and membrane depolarization in rat pheochromocytoma PC12 cells

To elucidate the regulation of the rat dopamine transporter (rDAT), we established several PC12 variants overexpressing the rDAT. Treating these cells with a nicotinic agonist (1,1-dimethyl-4-phenylpiperazinium iodide, 30 microM) depolarized the plasma membrane potential from -31 +/- 2 to 43 +/- 5 mV and inhibited rDAT activity significantly in a calcium- and protein kinase C-independent manner. Membrane depolarization by a high external K+ concentration or two K+ channel blockers (tetraethylammonium hydroxide and BaCl2) also resulted in a marked inhibition of rDAT activity. Such inhibition of dopamine uptake is due to a reduction in Vmax, with no marked effect on the Km for dopamine. The potency of cocaine in inhibiting dopamine uptake was not significantly altered, whereas that of amphetamine was slightly enhanced by membrane depolarization. Removing extracellular Ca2+ or blocking the voltage-sensitive L-type calcium channels using nifedipine did not exert any significant effect on the inhibition of rDAT activity by depolarization. These data confirm that calcium influx on depolarization is not required for inhibition of the rDAT. Collectively, our data suggest that rDAT activity can be altered by a neurotransmitter that modulates the membrane potential, thus suggesting an exquisite mechanism for the fine-tuning of dopamine levels in the synapse.

Involvement of Fas (CD95/APO-1) and Fas ligand in apoptosis induced by ganciclovir treatment of tumor cells transduced with herpes simplex virus thymidine kinase

Transduction of cancer cells with herpes simplex virus thymidine kinase gene (HSVtk) followed by prodrug ganciclovir (GCV) treatment has been shown to induce apoptosis. In this study, four murine tumors including B16F10 melanoma, NG4TL4 sarcoma, H6 hepatoma and 1MEA 7R.1 hepatoma were found to vary in sensitivity to this gene therapy strategy in vitro but, at effective doses of GCV, the HSVtk-transduced cells of all four tumors showed similar kinetics of early rise in p53 protein levels, then cell cycle S-/G2-phase arrest and finally signs of apoptosis. Immunoblot analyses revealed that Fas (CD95/APO-1), Fas ligand (FasL) and two downstream mediators, RIP and caspase-3, (CPP32, YAMA, Apopain) were increased in GCV-treated HSVtk-transduced tumor cells the cell cycle arrest and before apoptosis. Increased expression of FasL could also be observed in vivo in HSVtk-transduced tumors induced to regress by GCV treatment. Enzyme measurements using specific substrate showed that the caspase-3 activation followed kinetically the FasL expression. More than half of the HSVtk/GCV-induced cell death could be abrogated by addition to the cell culture medium of a specific antisense oligonucleotide to block FasL synthesis, a recombinant Fas/Fc chimeric protein to compete with Fas receptor for FasL binding, or cell-permeable specific tetrapeptide inhibitors of caspase-3 or caspase-8.

S- and G2-phase cell cycle arrests and apoptosis induced by ganciclovir in murine melanoma cells transduced with herpes simplex virus thymidine kinase

Mechanism of cell killing by transfer of Herpes simplex virus type-1 thymidine kinase (HSVtk) and subsequent ganciclovir (GCV) treatment was examined in B16F10 murine melanoma model. While parental B16F10 melanoma cells were resistant to GCV at 100 microM or higher, HSVtk-transduced B16F10 melanoma cell clones became susceptible to GCV with IC50 of 0.1 to 0.3 microM. By means of various parameters including characteristic morphological changes, in situ DNA end-labeling, DNA ladder pattern, flow cytometric detection of sub-G1 DNA content, and annexin V binding of inverted cell surface phosphatidylserine, apoptosis was shown to be associated with the cell killing of ganciclovir on HSVtk-transduced melanoma B16F10 cells. Kinetic analysis showed that the signs of apoptosis were observed not until 60 h of continued GCV treatment and preceded first by a rise in p53 protein level in 12 h and then by S-phase/G2-phase cell cycle arrest associated with corresponding increases in the level of cyclin B1 protein but no apparent change in protein level of Bax or Cdc2. These results suggest that apoptosis occurred as a result of ganciclovir-induced cell cycle arrests rather than direct chemical effect on HSVtk-transduced B16F10 melanoma cells.

Paradoxical effect of GM-CSF gene transfer on the tumorigenicity and immunogenicity of murine tumors

The effect of granulocyte/macrophage colony-stimulating factor (GM-CSF) gene transfer on the tumorigenicity and immunogenicity of 2 different murine tumor lines was determined. Transduction of B16 melanoma cells with the GM-CSF gene rendered the cells more immunogenic. In contrast, transduction of NG4TL4 fibrosarcoma in FVB/N mice (NG) with the GM-CSF gene showed increased tumorigenicity in a high producer line (NG-MGh). The parent NG or NG-MG cells induced the same level of cytotoxic T-lymphocyte (CTL) response and the same magnitude of tumor transplantation immunity. However, the proliferation of the NG-MGh cells was increased 2- to 10-fold. There was no increase in apoptosis in the NG cells and there was no increase of NG-MGh cells in S-phase, hence the increase of the proliferative activity appeared to be indeed inherent to the cells. Mixing the splenocytes from the NG-MGh tumor bearers with the NG tumor cells did not increase tumorigenicity but totally inhibited the growth of the NG tumor, indicating that suppressor cells were not present. Mixing 10,000 rad X-irradiated NG-MGh cells with viable NG tumor cells resulted in 3- to 10-fold increased NG tumor growth rate. The in vitro proliferation of NG cells was increased by adding both GM-CSFs and macrophages and not by either one alone, suggesting that interaction between macrophages and GM-CSFs resulted in the production of tumor growth enhancing factor(s). Our findings suggest that transduction of NG tumor cells with the GM-CSF gene increases tumorigenicity, which is attributed both to an increased inherent proliferative ability of the tumor cells and to the in vivo production of a tumor growth enhancing factor(s) at the tumor site.

Cross regulation by IL-10 and IL-2/IL-12 of the helper T cells and the cytolytic activity of lymphocytes from malignant effusions of lung cancer patients

STUDY OBJECTIVE

Our previous report demonstrated that there was impairment of local cellular immunity with elevated interleukin-10 (IL-10) and undetectable IL-12 in neoplastic pleural effusion. These findings suggest that the local immune reactions favor the T-helper type 2 (Th2) pathway instead of Th1 pathway. The present study was designed to examine whether local cellular immunity could be manipulated by IL-2 and/or IL-12 treatment, and to determine their effect on the helper T-cell pathways and the cytolytic activity of the effusion-associated lymphocytes (EALs).

DESIGN

Using malignant pleural effusions obtained from four patients suffering from adenocarcinoma of lung, we separated the tumor cells from the EALs with Ficol-Hypaque centrifugation, followed by Percoll density centrifugation. To test whether the cytolytic function of lymphocytes could be enhanced by culturing with IL-2 and/or IL-12, lymphocytes were incubated with recombinant IL-2 with/without IL-12 for 6 days. Following this, the tumoricidal activity was assessed in an overnight 5'chromium-release assay. Autologous tumor cells for measuring specific antitumor activity, Daudi cells susceptible to lymphokine-activated killer cells, and NK-susceptible K562 cells were used as target cells.

MEASUREMENTS AND RESULTS

After treatment in vitro with IL-2, IL-12, or IL-2 plus IL-12, the Th pathway shifted from Th2 to Th1 type (increased gamma-interferon production). To further study the effect of cytokine treatment on the cytolytic activity of EALs, it was found that after 6-day culturing, the EALs failed to kill any of the three tumor targets, whereas the 6-day cultured peripheral blood lymphocytes (PBLs) gave low level of cytotoxicity against all three tumor targets. Stimulation with IL-2 alone partially restored the immunocompetence of EALs to kill the tumor targets. Stimulation with IL-12 alone showed no significant effect on their cytolytic activity. However, IL-12 synergized with IL-2 to increase the cytolytic activity of EALs and PBLs against autologous tumor targets. This synergistic effect was not found for Daudi cells and K562 cells.

CONCLUSIONS

These results suggest that EALs activated with IL-12 in the presence of a low concentration of IL-2, which converted the EALs from Th2 pathway to Th1 pathway, could be an alternative source of antitumor effectors for adoptive immunotherapy of cancer.

Restoration of the immunocompetence by IL-2 activation and TCR-CD3 engagement of the in vivo anergized tumor-specific CTL from lung cancer patients

The present study investigates the nature of the immunosuppressed state of the lymphocytes obtained from the malignant pleural effusion (effusion associated lymphocytes, EAL) of lung cancer patients. The immunocompetence of EAL from 13 patients was assessed by determining their T-helper cell phenotype, proliferative response to alpha CD3-activation, and their cytolytic activity against three tumor targets: the autologous tumor, Daudi, and K562. Flow cytometry analysis showed that the lymphocytes in EAL were predominantly T cells with < 1% natural killer cells. The T-helper cell phenotype was found to be predominantly of Th2 type, but could be readily converted to Th1 type by culturing the EAL in vitro, and this conversion was augmented by interleukin-2 (IL-2) or IL-2 plus alpha CD3. To test the cytolytic activity of EAL, it was found that after 6-day culturing, the EAL remained in an immunosuppressed state so that they failed to kill any of the three tumor targets. Stimulation with IL-2 partially restored the immunocompetence of EAL. Further engagement of TCR-CD3 by alpha CD3 fully restored the cytolytic activity of the EAL to kill the autologous tumor target but not Daudi or K562 tumor cells, and thus seemed to be tumor specific. The specificity was further confirmed by testing the activated EAL and normal donor peripheral blood lymphocytes against a variety of tumor targets and control targets. Furthermore, the killing by EAL against the autologous tumor target seemed to be major histocompatibility complex-restricted and was inhibited by anti-human leukocyte antigen class I antibody. The EAL from lung cancer patients also showed much reduced responsiveness to the alpha CD3 stimulation to induce proliferation, and addition of IL-2 restored the responsiveness. These results suggest that, through close contact with tumor cells, anergy of cytotoxic T lymphocytes (CTLs) was induced in vivo at a localized site. IL-2 stimulation and TCR-CD3 engagement could reverse the anergic state and restored the full competence of CTLs in EAL to mediate the specific anti-tumor killing against the autologous tumor. Proper manipulation of EAL may prove useful as a source of anti-tumor effectors for cancer adoptive immunotherapy.

Formation of a whorl-like autophagosome by Golgi apparatus engulfing a ribosome-containing vacuole in corpora allata of the cockroach Diploptera punctata

Previously, we showed that synchronous autophagy occurred in the corpora allata during the declining phase of juvenile hormone synthesis in mated adult females of the cockroach Diploptera punctata. At the onset of this process, conspicuous whorl-like autophagosomes were often observed. Each consisted of a ribosome-containing vacuole at the center surrounded by about eight layers of double membranes. Labeling the cis-Golgi cisternae with hot osmium and histochemical detection of thiamine pyrophosphatase in the trans-Golgi cisternae were used to trace the autophagic process. We conclude that the membranes surrounding the whorl-like autophagosome are derived from the entire Golgi apparatus with its cis-cisternae forming the outermost layer and the trans-cisternae the innermost layer. The engulfing process is initiated through direct contact between trans-cisternae of the Golgi apparatus and the isolation membrane of the ribosome-containing vacuole. Formation of a whorl-like autophagosome appears to be a highly regulated process specific to ribosome-containing vacuoles since it occurs only on day 5 and the Golgi apparatus does not recognize membranes of other types of autophagic vesicles or of functional organelles. This novel behavior of the Golgi apparatus in the corpora allata should play an important role in the long-term inhibition of juvenile hormone synthesis (e.g., during gestation) since it results in the depletion of cellular machinery for juvenile hormone synthesis.

Blockade of neuromuscular transmission by huwentoxin-I, purified from the venom of the Chinese bird spider Selenocosmia huwena

Huwentoxin-I (HWTX-I) is a neurotoxic peptide purified from the venom of the Chinese bird spider Selenocosmia huwena. The effects of HWTX-I on neuromuscular transmission of vertebrate skeletal muscle have been investigated by means of twitch tension and electrophysiological techniques. On isolated mouse phrenic nerve-hemidiaphragm preparations, HWTX-I blocked the twitch responses to indirect, but not to direct, muscle stimulation. The time needed for complete block of the neuromuscular transmission was dose dependent. The transmission could be mostly restored by prolonged repeated washing with Tyrode's solution. If the preparation was pretreated with D-tubocurarine and then immersed in a mixed solution of D-tubocurarine and HWTX-I, the washout time necessary to restore the neuromuscular transmission was significantly decreased. Intracellular recording at the end-plate region of frog sartorius muscle revealed that HWTX-I could synchronously reduce the amplitude of the acetylcholine potential induced by ionophoretic application of acetylcholine as well as the amplitude of the end-plate potential evoked by nerve stimulation. Both of these effects eventually disappeared; however, both could be restored by prolonged washing. Experiments on Xenopus embryonic myocytes indicated that HWTX-I reduced the open probability of acetylcholine-induced channel activity, and finally blocked the channel. All of these results demonstrated that HWTX-I was a peptide neurotoxin and the postsynaptic nicotinic acetylcholine receptor was its site of action.

Two new iridolactones and their glycosides from the roots of Patrinia scabra

Investigation of the roots of Patrinia scabra afforded two new iridolactones, patriscabrol and isopatriscabrol. Their structures have been established by extensive analysis of their NMR spectra and an X-ray crystallographic analysis of patriscabrol. Four monoglucosides of each iridolactone were also isolated together with an apioside of glucosidic patriscabrol.

Carbon tetrachloride induction of rapid changes in liver nuclear protein factors capable of sequence-specific binding to regulatory elements in the long terminal repeat of polytropic-class endogenous murine leukemia virus-related proviruses

Treatment of mice with hepatic carcinogens, including CCl4, has been shown to rapidly enhance the transcription of endogenous murine leukemia virus-related proviral sequences in the liver. To understand the mechanism for this transcriptional stimulation, we used nuclear protein preparations from mouse livers to perform DNase I protection analyses and identified nuclear protein binding on approximately 20 individual sequences within the regulatory regions of the long terminal repeat (LTR) of a polytropic-class endogenous provirus clone. From 3 to 144 h after treatment with CCl4, the livers of FVB/N mice were analyzed for specific nuclear protein binding to the LTR DNA. Three to nine hours after CCl4 treatment, decreased protection was seen at potential regulatory cis-elements throughout the LTR, including specific sites within the putative negative regulatory element (located 5' of the consensus enhancer sequences) and the 3' terminal portion of the polytropic class-specific enhancer-like inserted sequence element and around the CCAA(C/T) box in the promoter region. In addition, by 3-6 h after treatment, a transient increase in protection activity for the transcription initiation site occurred. The loss of cis-element protection expanded to other binding sites and became most marked by 48 h after treatment. As the regenerating liver recovered, the nuclear protein binding activities for these LTR sequences also recovered, but protection at the TATAA and transcription initiation sites remained deprotected at 144 h after treatment. Nuclear protein protection of other sites, particularly in the conserved LTR enhancer sequences, was minimally affected by CCl4 treatment. Three nuclear protein binding sites that showed rapid CCl4-induced kinetic changes were homologous to the consensus sequence for the binding of the transcription factor families MEF-2, HNF-1, and C/EBP. The complex kinetic changes in factors that may contribute to the rapid and transient induction of endogenous retroviral gene expression in the liver after CCl4 exposure are discussed.

Effects of qinghaosu (artemisinin) and its derivatives on experimental cutaneous leishmaniasis

We have investigated the effect of qinghaosu (QHS, artemisinin) and its derivatives on Leishmania major replication in vitro and on the disease development in mice infected with L. major. Artemisinin is effective against promastigotes in vitro, with an ED50 (50% effective dose) at 7.5 x 10(-7) M. Both artemisinin and artemether are leishmanicidal for amastigotes in infected murine macrophages in vitro, with ED50 at 3 x 10(-5) M and 3 x 10(-6) M respectively. These compounds have no effect on the viability of macrophages or on the phytohaemaglutinin-induced proliferation of normal spleen cells, even at 10(-4) M. BALB/c mice infected in the footpad with L. major developed significantly smaller lesions and parasite loads when treated with the compounds. Intra-lesion injection of the compounds was the most effective route. The intramuscular and oral routes were also effective; however, intravenous injection with artesunate was not effective.

Comparison of polymerase chain reaction, monoclonal antibody based enzyme immunoassay, and cell culture for detection of Chlamydia trachomatis in genital specimens

An enzyme immunoassay (EIA; AntigEnz Chlamydia; Northumbria Biologicals, Northumberland, United Kingdom) and a polymerase chain reaction (PCR) assay (Genemed Biotechnologies, San Francisco, CA) were evaluated for the detection of Chlamydia trachomatis in urogenital specimens. Of 324 specimens, 23 were positive by cycloheximide-treated McCoy's cell culture method. Of 23 culture-positive specimens, 20 and 22 were found to be positive by EIA and PCR, respectively. Among 301 culture-negative samples, 4 were found to be positive by both PCR and EIA, 2 were PCR-positive and EIA-negative, and 3 PCR-negative and culture-negative specimens were found to be positive by EIA. In comparing nonculture methods with cell culture technique, combined sensitivities of 87.0% (90.9% in men and 83.3% in women) and 95.6% (90.9% in men and 100% in women), and specificities of 97.7% (99.4% in men and 95.7% in women) and 98.0% (99.4% in men and 96.5% in women) are achieved by EIA and PCR, respectively. The PCR proved to be the more sensitive of these two nonculture methods, and it can be used for the rapid diagnosis of C. trachomatis urogenital infection.

TNF-alpha reverses the disease-exacerbating effect of subcutaneous immunization against murine cutaneous leishmaniasis

Earlier studies have demonstrated that mice injected subcutaneously or intramuscularly with leishmanial antigens develop significantly exacerbated disease compared with unimmunized controls when challenged with the cutaneous protozoan parasites Leishmania major. We report here that this disease enhancement can be prevented, and protective immunity induced, by the incorporation of recombinant tumour necrosis factor (TNF-alpha) in the immunizing inoculum. This effect of TNF-alpha is dose-dependent and is not evident when TNF-alpha and the antigens are injected into separate sites. Furthermore, TNF-alpha injected together with p183, a peptide known to preferentially stimulate Th2 cells and disease exacerbation in H-2d mice, activates spleen and lymph node cells secreting more interferon-gamma (IFN-gamma) and less interleukin-4 (IL-4) and induces a modest but significant degree of resistance against L. major infection in highly susceptible BALB/c mice.

Identification and characterization of host-protective T-cell epitopes of a major surface glycoprotein (gp63) from Leishmania major

By using a series of overlapping synthetic peptides that cover more than 75% of the amino acid sequence of the major surface glycoprotein (gp63) from Leishmania major, 11 T-cell epitopes in CBA and BALB/c mice have been identified. Six of the peptides were recognized by T cells of CBA mice recovered from L. major infection, while one was recognized by the T cells from BALB/c mice recovered from the infection following sublethal doses of gamma-irradiation. Lymph node cells from mice immunized with the peptides also responded to a number of the same peptides (seven in CBA and one in BALB/c). Peptide p10-28 induced proliferative T-cell responses in both CBA and BALB/c mice. Five of the peptides (p10-28, p22-40, p289-309, p459-471 and p467-482) induced vigorous T-cell response in CBA mice but were not recognized by T cells from recovered mice. Four other peptides (p321-336, p364-476, p372-385 and p378-396) were recognized by T cells from recovered CBA mice but could not induce a T-cell response in normal CBA mice. Three peptides (p146-171, p289-309 and p395-414) were both able to induce a T-cell response and were recognized by T cells from recovered mice. However, only two peptides (p146-171 and p467-482) were able to activate T cells, which also recognized epitopes expressed by antigen-presenting cells infected with promastigotes. T cells induced by p146-171 and p467-171 or a mixture of these two peptides were mainly CD4+ and produced interleukin (IL-2) and interferon-gamma (IFN-gamma) but not IL-4 upon antigen stimulation in vitro. These two peptides also induced a classical delayed type hypersensitivity (DTH) response in CBA mice. Furthermore, CBA mice immunized with a mixture of the two peptides in Coryne parvum or entrapped in liposomes induced significant resistance against L. major infection. The implications of these results in terms of a synthetic vaccine against leishmaniasis and the mechanism of the induction of Th1 and Th2 cells are discussed.

Oral Salmonella typhimurium (AroA-) vaccine expressing a major leishmanial surface protein (gp63) preferentially induces T helper 1 cells and protective immunity against leishmaniasis

The gp63 gene of Leishmania major was transformed into the AroA- vaccine strain of Salmonella typhimurium (SL3261). The construct (SL3261-gp63), which stably expresses the gp63 Ag in vitro, was used to immunize CBA mice by the oral route. Spleen cells from mice inoculated with SL3261-gp63 developed antibody and proliferative T cell response to L. major. They did not express detectable delayed-type hypersensitivity reactivity. The activated T cells are mainly CD4+ and secrete IL-2 and IFN-gamma but no IL-4. The orally immunized mice developed significant resistance against a challenge L. major infection. We have, therefore, demonstrated the feasibility of oral vaccination against leishmaniasis and that the oral route of antigen delivery via the heterologous carrier may preferentially induce Th1 subsets of CD4+ cells.