Crescent sign in invasive pulmonary aspergillosis: frequency and related CT and clinical factors

PURPOSE

The aim of our study was to evaluate the frequency of the crescent sign on follow-up radiographs in patients with invasive pulmonary aspergillosis, correlated with initial CT and clinical findings.

METHOD

Retrospective analysis of serial chest radiographs was performed to see the frequency of the crescent sign in 21 consecutive patients with pathologically proved invasive pulmonary aspergillosis. The appearance of the crescent sign was correlated with the pattern of parenchymal lesions on initial CT scans, the presence and duration of neutropenia, and underlying diseases.

RESULTS

The crescent sign was seen in 10 of 21 patients (48%) on follow-up radiographic examinations. It was seen in patients with initially large [consolidation or mass; 9/11 (82%) patients] rather than small [nodule(s); 1/10 (10%) patients] parenchymal lesions (p = 0.002) on CT. The sign appeared in 7 of 17 (41%) patients with neutropenia 1-10 days after recovery from neutropenia. It appeared in three of four patients (75%) without neutropenia 4--8 days after treatment with amphotericin B. The appearance was not related to the duration (32 days in patients with crescent sign and 17 days without sign) of the neutropenic period (p > 0.05). The sign was seen in 8 of 15 (53%) patients with acute myelogenous leukemia and 2 of 6 (33%) patients with other diseases (p > 0.05).

CONCLUSION

The crescent sign appears in about half of patients with invasive pulmonary aspergillosis with recovery from neutropenia, especially when the initial lesion is a consolidation or mass on CT scans.

Malignant thymic epithelial tumors: CT-pathologic correlation

OBJECTIVE

The purpose of our study was to describe and compare the CT and pathologic findings of atypical thymoma and thymic carcinoma.

MATERIALS AND METHODS

Twenty-seven consecutive patients (14 men, 13 women ranging in age from 22 to 77 years [mean age, 52 years]) with pathologically proven atypical thymoma (n = 9) and thymic carcinoma (n = 18) constituted the study population. The chest CT findings in each of the 27 patients were reviewed retrospectively in consensus by two chest radiologists. These findings were correlated with pathologic findings.

RESULTS

The tumors were located in the anterior mediastinum, and most tumors had a lobulated margin (24/27, 89%). Atypical thymomas were significantly smaller (mean, 4.7 cm) than thymic carcinomas (mean, 7.2 cm) (p = 0.041) on CT. The findings of invasion of the great vessels, lymph node enlargement, extrathymic metastases, and phrenic nerve palsy were seen only in patients with thymic carcinoma. The frequencies of necrosis, intratumoral calcification, pleural effusion, pleural implants, pericardial effusion, and obliteration of the mediastinal fat plane were not significantly different between atypical thymomas and thymic carcinomas (p > 0.05). Various histologic subtypes were included in thymic carcinoma. The tumor necrosis and calcification seen on CT were confirmed at pathologic examination.

CONCLUSION

When a large thymic tumor appears with invasion of the great vessels, lymph node enlargement, phrenic nerve palsy, or extrathymic metastases on CT, thymic carcinoma rather than atypical thymoma should be considered.

Induction of in vivo resistance to Mycobacterium avium infection by intramuscular injection with DNA encoding interleukin-18

Interferon-gamma (IFN-gamma) is closely associated with the generation of cell-mediated immunity and resistance to intracellular parasites. Interleukin-18 (IL-18) was known to strongly induce IFN-gamma production by T cells and natural killer (NK) cells. In order to determine whether injection with DNA encoding IL-18 can stimulate the resistance to Mycobacterium avium complex (MAC) infection, the mature IL-18 cDNA with kappa leader sequence was cloned under control of the cytomegalovirus (CMV) promoter (TcCMVIL-18) and its effect on MAC infection was investigated in genetically susceptible BALB/c mice. Injection with the TcCMVIL-18 DNA during intranasal infection with MAC resulted in a significant decrease in bacterial load of lung during the entire 8-week observation period, while injection with the TcCMV control DNA did not. Lung cells in mice injected with the TcCMVIL-18 DNA showed persistent production of IFN-gamma throughout the 8-week period. Furthermore, immunization with the TcCMVIL-18 DNA induced and maintained significantly higher levels of cytotoxic activity and nitric oxide production by lung cells than immunization with the TcCMV control vector. This work suggests that IL-18 DNA vaccination may be useful in the immunotherapeutic or immunoprotection approaches of infections by intracellular parasites such as mycobacteria.

Long-term results of guided tissue regeneration therapy with non-resorbable and bioabsorbable barriers. I. Class II furcations

BACKGROUND

The aim of this 5-year follow-up study was to clinically and radiographically evaluate the long-term results after guided tissue regeneration (GTR) therapy of Class II furcation defects using non-resorbable and bioabsorbable barriers.

METHODS

Nine pairs of contralateral Class II furcation defects were treated in 9 patients with advanced periodontitis. Within each patient, one defect received a non-resorbable (expanded polytetrafluoroethylene [ePTFE]; control, C) barrier and the other a bioabsorbable (polyglactin 910; test, T) barrier by random assignment. At baseline, 6, and 60 +/- 3 months after surgery, clinical parameters and standardized radiographs were obtained. Gain of bone density within furcation areas was assessed using subtraction radiography.

RESULTS

Six and 60 months after GTR therapy, statistically significant (P <0.05) horizontal attachment (CAL-H) gain was observed in both groups (C6: 1.7 +/- 0.8 mm; C60: 1.6 +/- 1.2 mm; T6: 2.0 +/- 0.7 mm; T60: 2.2 +/- 0.9 mm). However, 1 furcation assessed as Class I six months after GTR therapy with a bioabsorbable barrier had progressed to Class III after 5 years, and in another patient, 5 years after placement of an ePTFE barrier, 1 furcation had lost all the CAL-H gain that had been observed at 6 months. Subtraction analysis revealed similar area gain in both groups 6 and 60 months postsurgically (C6: 0.3 +/- 0.5; C60 1.0 +/- 1.7; T6: 0.4 +/- 0.4; T60: 1.1 +/- 1.7).

CONCLUSIONS

CAL-H gain achieved after GTR therapy in Class II furcations was stable after 5 years in 16 of 18 defects. The study failed to show a statistically significant difference in stability of CAL-H gain between control and test groups 5 years after GTR therapy.

Inhibition of porcine reproductive and respiratory syndrome virus by interferon-gamma and recovery of virus replication with 2-aminopurine

Porcine reproductive and respiratory syndrome virus (PRRSV) belongs to a group of RNA viruses that establish persistent infections. A proposed strategy for evading immunity during persistent PRRSV infection is by preventing the induction of IFN activity in pigs and/or by blocking the activation of antiviral proteins in permissive cells. IFN-gamma mRNA expression was observed in the lymph nodes and lungs of pigs infected with wild-type PRRSV strain SDSU-23983. Pretreatment of MARC-145 cells with IFN-gamma inhibited wild-type (SDSU-23983 P6) and culture-adapted (SDSU-23983 P136) PRRS viruses in a dose-dependent manner and at relatively low concentrations. The effect of IFN-gamma on virus replication included reductions in the number of infected cells, virus yield, and RNA content in single cells. Virus replication was partially restored by the addition of 2-aminopurine (2-AP), an inhibitor of dsRNA inducible protein kinase (PKR). The addition of 2-AP also restored the viral RNA content per cell to near normal levels, suggesting that inhibition of viral RNA synthesis was through PKR. The principal difference between P6 and P136 isolates was the recovery of P136 replication with lower concentrations of 2-AP. Immunostaining with anti-PKR antibody showed a redistribution of PKR from the cytoplasm into nucleoli of infected cells.

Proliferating trichilemmal tumors: CT and MR imaging findings in two cases, one with malignant transformation

We report the imaging findings in two patients with proliferating trichilemmal tumors. In the first patient, the tumor arose on the lower lip, a very unusual location for this type of tumor, and showed malignant transformation with metastasis to a regional lymph node. It was seen as a poorly marginated soft-tissue mass with isointense signal on T1-weighted MR images and hyperintense signal on T2-weighted images. Large areas of high signal intensity caused by necrosis were also found within the tumor on T2-weighted images. After i.v. administration of contrast material, the mass showed significant enhancement, with considerable portions remaining unenhanced. In the second patient, the tumor originated from a preexisting trichilemmal cyst and occurred in the hair-bearing area of the posterior part of the neck. CT scans showed a well-encapsulated cystic mass that contained multiple speckled calcifications in a wall of variable thickness. There were several foci of smooth soft-tissue elevations from the inner wall of the mass, which corresponded histologically to proliferating portions of trichilemmal cyst.

Study on real time control of non-point pollutants discharged from urban areas during a storm event

In this research, we installed the storm water storage tank, which has three functions: pollutant control, flood control and water use, to the end pipe of a separate system. We examined the effect of real time control (RTC) introduction with the scenario selection in the study area in the catchment basin, which has measured data. As a result, a latter period centering-type case is satisfied with the pollutant reduction by the RTC and also at the water use tank, the best control settles COD concentration at about 0.45 mg/l. It was clarified how to use a RTC method as a measure of the discharge problem from an urban area during a storm event.

Identification and partial characterization of lacticin BH5, a bacteriocin produced by Lactococcus lactis BH5 isolated from Kimchi

Strain BH5 was isolated from naturally fermented Kimchi and identified as a bacteriocin producer that has bactericidal activity against Micrococcus flavus ATCC 10240. Strain BH5 was identified tentatively as Lactococcus lactis by API test. Lactococcus lactis BH5 showed a broad spectrum of activity against most of the nonpathogenic and pathogenic microorganisms tested by the modified deferred method. The activity of lacticin BH5, named tentatively as the bacteriocin produced by L. lactis BH5, was detected at the mid-log growth phase, reached its maximum during the early stationary phase, and decreased after the late stationary phase. Lacticin BH5 also showed a relatively broad spectrum of activity against nonpathogenic and pathogenic microorganisms as tested by the spot-on-lawn method. Its antimicrobial activity on sensitive indicator cells was completely destroyed by protease XIV. The inhibitory activities of lacticin BH5 were detected during treatments up to 100 degrees C for 30 min. Lacticin BH5 was very stable over a pH range of 2.0 to 9.0 and was stable with all the organic solvents examined. It demonstrated a typical bactericidal mode of inhibition against M. flavus ATCC 10240. The apparent molecular mass of lacticin BH5 was estimated to be in the region of 3 to 3.5 kDa, by the direct detection of bactericidal activity after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Overexpression of c-H-ras p21 is correlated with vascular endothelial growth factor expression and neovascularization in advanced gastric carcinoma

BACKGROUND AND AIMS

ras Gene and its product (p21) have been reported to be associated with vascular endothelial growth factor (VEGF), which is one of the most important angiogenic factors, and tumor-associated angiogenesis. We tried to evaluate the correlation between the expression of c-H-ras gene product p21 and angiogenesis in advanced gastric carcinoma.

METHODS

Immunohistochemical expression of c-H-ras p21 and VEGF was examined in 49 advanced gastric adenocarcinomas. In addition, double immunohistochemical staining was performed using anti-CD34 and anti-Ki-67 antibodies, and the intratumoral microvessel densities and their endothelial proliferative labeling indices were then counted to evaluate the degree of angiogenesis.

RESULTS

The expression of c-H-ras p21 was demonstrated in 43 out of 49 gastric adenocarcinomas (87.8%). It did not correlate with histologic type, depth of invasion or metastasis. However, the degree of c-H-ras p21 expression was correlated with VEGF. In addition, the degree of c-H-ras p21 expression was correlated with increased intratumoral microvascular density and endothelial proliferative activity.

CONCLUSIONS

We suggest that c-H-ras oncogene product p21 contributes to the upregulation of tumor-associated angiogenesis by the increased production of VEGF in advanced gastric carcinomas. Therefore, treatment involving the targeting of ras oncogene could inhibit solid tumor growth by suppressing tumor-associated angiogenesis.

[The life of Dr. John William Heron, the second superintendent of Chejungwon]

The purpose of this paper is to overview the life of John W. Heron, M. D. who was the first appointed medical missionary to Korea by the Presbyterian Church USA. Although he was a competent doctor as well as a devoted missionary, he is not well-known yet, because he died early after 5 years' service in Korea. Dr. Heron was born in Derbyshire, England on June 15, 1856. His father, Rev. E. S. Heron, was a Scotch Minister of Congregational Church. His family emigrated to America in 1870 when he was fourteen years old and settled in Knoxville, Tennessee. In 1881, he was admitted to the University of Tennessee Medical School and graduated with highest honors in 1883. After training in New York University Hospital, he refused the offer of professorship from the University of Tennessee to become a medical missionary to Korea. He arrived in Seoul on June 21, 1885 and began to work in Royal Government Hospital, Chejungwon, the predecessor of Severance Hospital. In 1887, he became the superintendent of the Hospital following Dr. Horace N. Allen. He also worked for the Royal family and sometimes traveled to the rural areas to care for the patients. He started Chejungwon Church which later became Namdaemoon Presbyterian Church. In 1887, Dr. Heron worked as a member of the Bible translation committee and in 1889, he was elected as the chairman of the Public Committee of the Presbyterian Churches. In 1890, he established 'The Korean Religious Tract Society (Chosunsyungkyoseohoi) with Underwood and Ohlinger. The society published and replenished Christian books, periodical magazines and booklets. In the Summer of 1890, Dr. Heron did his best to take care of the sick suffering from an epidemic dysentery and himself got infected because of the terrible overwork. He passed away on July 26th, 1890. On his deathbed, he told his soldier and native friends around him as follow: "Jesus loves you. He gave His life for you. Stand by Him!" The martyrdom of Dr. Heron should be remembered in the Korean history of mission, because he was the first victim among the foreign missionaries who had lived and worked in Seoul for Korean mission. Dr. Heron's mind of love, service and devotion should be remembered by the medical doctors working today in caring for the patients suffering from physical and spiritual illnesses.

Supradiaphragmatic ectopic adrenocorticotropic hormone-secreting adenoma

A 22-year-old woman with Cushing's syndrome, caused by an extremely rare suprasellar ectopic pituitary adenoma, is presented. Magnetic resonance imaging and computed tomography revealed a well-circumscribed mass in the right suprasellar region. Endocrinological tests showed elevated s-adrenocorticotropic hormone level and hypercortisolemia. The tumor was totally removed by right subfrontal approach. At the time of the operation, the tumor was in continuity with the distal pituitary stalk but not with the pituitary gland. The diaphragma sellae was intact. Histologic diagnosis of the tumor specimen was confirmed as a pituitary adenoma. After surgical removal of the tumor, continued improvement in the patient's laboratory results and disappearance of her endocrine symptoms strongly indicated the absence of adenoma cells in the pituitary gland or stalk. Six years post-surgery, there was no evidence of recurrence in the patient's clinical and laboratory examination. This tumor probably originated from aberrant anterior pituitary cells of the pituitary stalk.

Oxidized low density lipoprotein inhibits interleukin-12 production in lipopolysaccharide-activated mouse macrophages via direct interactions between peroxisome proliferator-activated receptor-gamma and nuclear factor-kappa B

Lipopolysaccharide (LPS) increases the production of interleukin-12 (IL-12) from mouse macrophages via a kappaB site within the IL-12 p40 promoter. In this study, we found that oxidized low density lipoprotein (oxLDL) inhibited this LPS-stimulated production of IL-12 in a dose-dependent manner while native LDL did not. OxLDL inhibited p40 promoter activation in monocytic RAW264.7 cells transiently transfected with p40 promoter/reporter constructs, and the repressive effect mapped to a region in the p40 promoter containing a binding site for nuclear factor-kappaB (NF-kappaB) (p40-kappaB). Activation of macrophages by LPS in the presence of oxLDL resulted in markedly reduced binding to the kappaB site, as demonstrated by the electrophoretic mobility shift assays. In contrast, native LDL did not inhibit the IL-12 p40 promoter activation and NF-kappaB binding to the kappaB sites, suggesting that oxidative modification of LDL was crucial for the inhibition of NF-kappaB-mediated IL-12 production. 9-Hydroxyoctadecadienoic acid, a major oxidized lipid component of oxLDL, significantly inhibited IL-12 production in LPS-stimulated mouse macrophages and also suppressed NF-kappaB-mediated activation in IL-12 p40 promoter. The NF-kappaB components p50 and p65 directly bound peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in vitro. In cotransfections of CV-1 and HeLa cells, PPAR-gamma inhibited the NF-kappaB transactivation in an oxLDL-dependent manner. From these results, we propose that oxLDL-mediated suppression of the IL-12 production from LPS-activated mouse macrophages may, at least in part, involve both inhibition of the NF-kappaB-DNA interactions and physical interactions between NF-kappaB and PPAR-gamma.

Digital chest radiography with a selenium-based flat-panel detector versus a storage phosphor system: comparison of soft-copy images

OBJECTIVE

We compared the soft-copy images produced by a digital chest radiography system that uses a flat-panel X-ray detector based on amorphous selenium with images produced by a storage phosphor radiography system for the visualization of anatomic regions of the chest.

MATERIALS AND METHODS

Two chest radiologists and two residents analyzed 46 pairs of posteroanterior chest radiographs on high-resolution video monitors (2560 x 2048 x 8 bits). In each pair, one radiograph was obtained with a storage phosphor radiography system, and the other radiograph was obtained with a selenium-based flat-panel detector radiography system. Each pair of radiographs was obtained at the same exposure settings. The interpreter rated the visibility and radiographic quality of 11 different anatomic regions. Each pair of images was ranked on a five-point scale (1 = prefer image A, 3 = no preference, 5 = prefer image B) for preference of technique. Statistical significance of preference was determined using the Wilcoxon's signed rank test.

RESULTS

The interpreters had a statistically significant preference for the selenium-based radiography system in six (unobscured lung, hilum, rib, minor fissure, heart border, and overall appearance) of 11 anatomic regions (p<0.001) and for the storage phosphor system in two regions (proximal airway and thoracic spine) (p<0.05). Chest radiologists strongly preferred selenium-based images in eight regions, and they did not prefer storage phosphor images in any region.

CONCLUSION

The soft-copy images produced by the selenium-based radiography system were perceived as equal or superior to those produced by the storage phosphor system in most but not all anatomic regions.

A case of epidermoid cyst of the intrapancreatic accessory spleen

A 54-year-old woman presented with a huge palpable mass on left upper quadrant of the abdomen. After preoperative work-up, a cystic disease of pancreatic tail or accessory spleen was initially suspected. We performed exploratory laparotomy and resected both the spleen and a 15 x 11 cm-sized huge cystic mass containing a part of solid component which extended continuously to the pancreatic tail. The solid component, comprising the upper portion of the resected cyst, was reddish brown and granular like as normal splenic tissue. The inner surface of the cyst was smooth and was filled with yellowish white material. Histologic examination showed an epidermoid cyst originating in the accessory spleen of the pancreatic tail lacking hair or skin appendages.

Transanally injected triamcinolone acetonide in levator syndrome

PURPOSE

Several treatments are used for the treatment of levator syndrome, such as rectal massage, biofeedback, and galvanic stimulation. But their effects are inconsistent, and multiple treatment sessions are usually required. Triamcinolone acetonide and lidocaine mixture was injected locally into the tenderest point in levator syndrome under the hypothesis that levator syndrome is caused by tendinitis of pelvic floor musculature.

METHODS

A mixture of 40 mg of triamcinolone acetonide and 1 ml of 2 percent lidocaine was injected into the tenderest point transanally in 104 patients (33 males; mean age, 51 years) with levator syndrome from December 1996 to May 1998 at Daehang Clinic. Additional injections were repeated at two-week intervals to a maximum of three injections in cases of poor response. Follow-up was performed prospectively concerning patient's perception of pain level using a visual analog scale. Depending on the response, the patients were classified into four groups: pain-free, good, fair, and no response. More than 50 percent pain reduction was classified as "good," and less than 49 percent reduction as "fair."

RESULTS

The injection regions, where the tenderest points were identified on digital rectal compression, were left anterior anal canal in 71.2 percent of patients, right anterior in 3.8 percent of patients, and posterior in 25 percent of patients. The results of treatment were as follows: at three months after injection, response was classified as pain-free in 36.8 percent of patients, good in 35 percent of patients, fair in 19.5 percent of patients, and no response in 8.7 percent of patients; at six months the response was pain-free in 30.1 percent of patients, good in 46.5 percent of patients, fair in 18.2 percent of patients, and no response in 5.2 percent of patients. Most patients, except 8.7 percent at three months and 5.2 percent at six months, experienced treatment benefits. There were no complications during the follow-up periods.

CONCLUSION

Transanal injection of triamcinolone acetonide and lidocaine mixture into the tenderest point is such a simple, safe, and very effective modality that it can be recommended as a primary therapy for levator syndrome.

Pulmonary tuberculosis: CT and pathologic correlation

Typical CT findings of active postprimary pulmonary tuberculosis include centrilobular nodules and branching linear structures (tree-in-bud appearance), lobular consolidation, cavitation, and bronchial wall thickening. The CT findings of inactive pulmonary tuberculosis include calcified nodules or consolidation, irregular linear opacity, parenchymal bands, and pericicatricial emphysema. The typical appearance of primary tuberculosis on CT scans is homogeneous, dense, well-defined segmental or lobar consolidation with enlargement of lymph nodes in the hilum or the mediastinum. Miliary nodules may be seen in primary and postprimary tuberculosis. On CT, tuberculomas appear as a nodule with surrounding satellite nodules and internal cavitation on CT. Atypical radiologic manifestations of tuberculosis, encountered in as many as one third of the cases of adult-onset tuberculosis, are single or multiple nodules or masses, basilar infiltrates, miliary tuberculosis with diffuse bilateral areas of ground-glass opacity, and reversible multiple cysts. Underlying histopathologic findings of typical and atypical CT findings of tuberculosis are caseating granulomas or pneumonia in the active phase and fibrosis and dystrophic calcification in the inactive phase.

Inhibition of interleukin-12 and interferon-gamma production in immune cells by tanshinones from Salvia miltiorrhiza

Pharmacological control of interleukin-12 (IL-12) and interferon-gamma (IFN-gamma) production may be a key therapeutic strategy for modulating immunological diseases dominated by Th1-derived cytokine responses. In this study, we investigated the effects of three different tanshinone pigments from Salvia miltiorrhiza (tanshinone I, dihydrotanshinone, and cryptotanshinone) on IL-12 production in mouse macrophages and on IFN-gamma production in lymph node cells. All tested tanshinones significantly inhibited IL-12 production in lipopolysaccharide (LPS)-activated macrophages and also IFN-gamma production in keyhole limpet hemocyanin (KLH)-primed lymph node cells in a dose-dependent manner. Dihydrotanshinone was more effective than tanshinone I or cryptotanshinone. Tanshinones significantly inhibited the expression of IL-12 p40 gene at the mRNA level. Furthermore, tanshinones potently inhibited the promoter activation of IL-12 p40 gene and nuclear factor (NF)-kappaB binding to the kappaB site, suggesting that tanshinones may negatively regulate IL-12 production at the transcription level. These results may explain some known biological activities of tanshinones including their anti-inflammatory effect, and suggest a possible use of tanshinones in the treatment of immunological diseases dominated by Th1-derived cytokine responses.

Low-dose, volumetric helical CT: image quality, radiation dose, and usefulness for evaluation of bronchiectasis

RATIONALE AND OBJECTIVES

The aim of our study was to assess the image quality, radiation dose, and clinical applicability of low-dose, volumetric helical CT in the evaluation of bronchiectasis.

METHODS

Volumetric helical CT scans (120 kVp, 3-mm collimation, pitch of 2, and reconstruction interval of 2 mm) were obtained through the thorax at four levels of tube current: 150, 100, 70, and 40 mA. There were a total of 12 patients who underwent CT scan either for suspected bronchiectasis or for lung cancer screening, with three patients allocated to each current level. Five radiologists assessed and compared image quality of the helical CT scans obtained at the various exposure levels. Radiation doses of helical CT performed with four different current settings and of high-resolution CT (120 kVp, 170 mA, 1-mm collimation, and 10-mm intervals) were measured. The diagnostic usefulness of the 40-mA helical CT images was compared with that of high-resolution CT by two observers in 52 patients with known or suspected airway diseases.

RESULTS

With helical CT, there was no significant difference in image quality among the four different levels of current (P > 0.05). Radiation doses associated with the 40-, 70-, 100-, and 150-mA helical techniques were 3.21 mGy (range, 3.02-3.57), 4.81 mGy (range, 3.89-5.93), 6.46 mGy (range, 6.01-7.31), and 10.4 mGy (range, 8.93-12.1), respectively, whereas that of high-resolution CT was 2.17 mGy (range, 1.90-2.67). Of 52 patients, 44.5 and 47 patients (the mean of positive interpretations by the five observers) were diagnosed with bronchiectasis at high-resolution and low-dose helical CT, respectively. Of 928 segments, bronchiectasis was seen in 152.5 segments on high-resolution CT and in 193.5 segments on helical CT. The interobserver agreement (k-values) was acceptable for both techniques.

CONCLUSIONS

With acceptable images and similar radiation dose, low-dose volumetric helical CT at 40 mA may offer more information than does high-resolution CT in the evaluation of bronchiectasis.

T1 lung cancer on CT: frequency of extrathoracic metastases

PURPOSE

To determine the frequency of extrathoracic metastases in T1 non-small-cell lung cancer.

METHOD

Ninety patients with T1 lung cancer identified on CT were included. Extrathoracic metastases were evaluated at the time of initial diagnosis and during a 1-year follow-up study. The frequency of metastases was compared in terms of cell type (squamous or nonsquamous), size (<2 cm or >2 cm), and the initial CT findings of the tumor.

RESULTS

Extrathoracic metastases were identified in 12 (13%) of 90 patients at the time of diagnosis and in 10 patients at the 1-year follow-up study (total, 22 of 90 [24%] patients). Tumors with ground-glass opacity on CT were associated with a significantly lower prevalence of metastases (p = 0.042). The area of ground-glass opacity was seen in 1 of 13 (85%) patients with bronchioloalveolar carcinoma and in 12 of 53 (23%) patients with adenocarcinoma other than bronchioloalveolar carcinoma (p < 0.001). There was no significant difference in the prevalence of metastases between squamous and nonsquamous cell carcinoma, between tumors smaller than 2 cm (n = 17) and larger than 2 cm in diameter (n = 73) and between tumors with or without mediastinal nodal metastases (p>0.05).

CONCLUSION

Extrathoracic metastases were apparent at the initial examination in 13% of patients and at the 1-year follow-up examination in 11% of patients. The prevalence is significantly lower in tumors with ground-glass opacity.

Purification and characterization of an extracellular serine proteinase from Acanthamoeba castellanii

An extracellular proteinase of Acanthamoeba castellanii was purified and its biochemical and pathological properties were characterized. The molecular mass of the purified enzyme was approximately 42 kDa as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Sephacryl S-200 HR gel-filtration chromatography. Therefore, its structure seemed to be monomeric with a single polypeptide. Its activity was inhibited by the serine proteinase inhibitors diisopropyl fluorophosphate and phenylmethanesulfonyl fluoride. Its activity was optimum at 30 to 50 degrees C with a maximum at 50 degrees C; optimal pH was 8.0. As much as 70% of the enzyme activity was maintained at 50 degrees C for at least 12 h but was rapidly inactivated thereafter. The purified enzyme degraded collagen and rabbit corneal extract. Furthermore, it exhibited strong cytopathic effects on human corneal epithelial cells and fibroblast cells. These suggest the possible role of this enzyme in the pathogenesis of Acanthamoeba.

The prediction of EEG signals using a feedback-structured adaptive rational function filter

In this article, we present a feedback-structured adaptive rational function filter based on a recursive modified Gram-Schmidt algorithm and apply it to the prediction of an EEG signal that has nonlinear and nonstationary characteristics. For the evaluation of the prediction performance, the proposed filter is compared with other methods, where a single-step prediction and a multi-step prediction are considered for a short-term prediction, and the prediction performance is assessed in normalized mean square error. The experimental results show that the proposed filter shows better performance than other methods considered for the short-term prediction of EEG signals.

Diffuse cerebrospinal gliomatosis with extensive leptomeningeal spread

A case of diffuse cerebrospinal gliomatosis with extensive leptomeningeal spread is presented. The patient, an 18-year-old girl, was admitted due to progressive weakness and paresthesia of both legs, following rapid neuropsychiatric deterioration. An initial magnetic resonance imaging (MRI) study of the T-spine showed diffuse high signal intensities from T9 to T12 spinal cords on a T2 sagittal image and diffuse cord bulging at T1WI. This suggested an inflammatory lesion such as tuberculosis or fungal meningoencephalitis. A limited autopsy was performed. A microscopic examination revealed multifocal GFAP-positive astrocytic proliferations that were low grade astrocytoma in the cerebral leptomeninges, parietal, occipital and temporal lobes and anaplastic astrocytoma in the spinal cord and spinal leptomeninges. The high proliferative indices of the spinal lesion and aneuploidy correspond to a diagnosis of malignant astrocytoma and a rapid fatal clinical course.

Therapeutic anti-tumor response induced with epitope-pulsed fibroblasts genetically engineered for B7.1 expression and IFN-gamma secretion

Mouse fibroblasts (H-2(b)) were genetically engineered to express a co-stimulatory B7.1 and an IFN-gamma (Fb/IFN-gamma/B7.1). The Fb/IFN-gamma/B7.1 cells were then pulsed with an ovalbumin epitope (amino acids 257-264, SIINFEKL, H-2K(b)-restricted) as a model antigen (Fb/IFN-gamma/B7.1/OVA) and tested for the induction of OVA-specific cytotoxic T lymphocytes (CTLs) in C57BL/6 mice (H-2(b)). Genetically engineered fibroblasts lacking either IFN-gamma or B7.1 were constructed and used as controls. Immunization with the Fb/IFN-gamma/B7.1/OVA cells induced strong cytotoxic activity against OVA-expressing EL4 (EG7) tumor cells but not against other H-2(b) tumor cells, such as EL4, C1498, and B16F1. The magnitude of the cytotoxic response in mice with the Fb/IFN-gamma/B7.1/OVA cells was significantly higher than that in mice immunized with any other cell construct. CD8(+) T cells with OVA-specific cytotoxic activity were predominant in mice immunized with Fb/IFN-gamma/B7.1/OVA cells. Furthermore, treatment with Fb/IFN-gamma/B7.1/OVA cells significantly prolonged the survival period of EG7 tumor-bearing mice. Anti-tumor CTL immunity by the Fb/IFN-gamma/B7.1/OVA cells could be induced without the help of host antigen-presenting cells, CD4(+) T cells, or NK1.1(+) cells. Our results suggest that fibroblasts can be genetically modified into efficient antigen-presenting cells for the induction of antigen-specific CTL response in cancer immunotherapy.

Molecular cloning and expression of Cu/Zn-containing superoxide dismutase from Fasciola hepatica

The cytosolic superoxide dismutase (SOD) of Fasciola hepatica, a causative agent of fascioliasis, was purified and characterized. The enzyme consists of two identical subunits, each with an apparent molecular mass of 17.5 kDa. An analysis of the enzyme's primary structure and inhibition studies revealed that the enzyme is a copper/zinc-containing SOD (Cu/Zn-SOD). The enzyme activity was relatively stable in a broad pH range, from pH 7.0 to 10.0, and the enzyme showed maximum activity at pH 7.5. This enzyme also displayed strong antigenicity against sera of bovine and human subjects with fascioliasis. The SOD gene fragment was amplified by PCR with degenerate oligonucleotide primers derived from amino acid sequences conserved in the Cu/Zn-SODs of other organisms. An F. hepatica cDNA library was screened with the SOD gene fragment as a probe. As a result, a complete gene encoding the Cu/Zn-SOD was identified, and its nucleotide sequence was determined. The gene had an open reading frame of 438 bp and 146 deduced amino acids. Comparison of the deduced amino acid sequence of the enzyme with previously reported Cu/Zn-SOD amino acid sequences revealed considerably high homologies. The coding region of the F. hepatica Cu/Zn-SOD was cloned and expressed in Escherichia coli. Staining of native polyacrylamide gel for SOD activity of the expressed protein revealed SOD activity that was inactivated by potassium cyanide and hydrogen peroxide but not by sodium azide. This means that the presence of the recombinant fusion protein is indicative of Cu/Zn-SOD. The expressed protein also reacted with sera of bovine and human subjects with fascioliasis, but it did not react with sera of uninfected bovine and human subjects.

Augmentation of antitumor immunity by genetically engineered fibroblast cells to express both B7.1 and interleukin-7

Mouse fibroblasts (H-2(b)) were genetically engineered to express a costimulatory B7.1 and an interleukin-7 (IL-7; Fb/B7.1/IL7). The Fb/B7.1/IL7 cells were then pulsed with an ovalbumin (OVA) epitope (amino acids 257-264, SIINFEKL, H-2 K(b) restricted; Fb/B7. 1/IL7/OVA) and tested for the induction of OVA-specific cytotoxic T lymphocytes (CTLs) in C57BL/6 mice (H-2(b)). The genetically engineered fibroblasts lacking either B7.1 or IL-7 were constructed and used as controls. Immunization with the Fb/B7.1/IL7/OVA cells induced strong cytotoxic activities against OVA-expressing EL4 (EG7) tumor cells. The magnitude of the cytotoxic response in mice with the Fb/B7.1/IL7/OVA cells was significantly higher than the response in mice immunized with any other cell constructs. CD8(+) T cells were a major effector cell-type of antitumor response in the immunized mice with the Fb/B7.1/IL7/OVA cells. Furthermore, immunization with the Fb/B7.1/IL7/OVA cells significantly prolonged the survival period of mice when the mice were injected with EG7 tumor cells one week after the immunization. These results suggest that fibroblasts can be genetically modified to an efficient cell vaccine for the induction of antitumor response.