Corrigendum: Development of a Scrub Typhus Diagnostic Platform Incorporating Cell-Surface Display Technology

[This corrects the article DOI: 10.3389/fimmu.2021.761136.].

Development of a Scrub Typhus Diagnostic Platform Incorporating Cell-Surface Display Technology

Scrub typhus (ST), also known as tsutsugamushi disease and caused by rickettsia Orientia tsutsugamushi, is an underestimated fatal epidemic in the Asia-Pacific region, resulting in a million human infections each year. ST is easily misdiagnosed as clinical diagnosis is based on non-specific skin eschar and flu-like symptoms. Thus, the lack of accurate, convenient, and low-cost detection methods for ST poses a global health threat. To address this problem, we adopted baculovirus surface-display technology to express three variants of TSA56, the major membrane antigen of O. tsutsugamushi, as well as the passenger domain of ScaC (ScaC-PD), on insect Sf21 cell surfaces rather than biosafety level 3 bacteria in an enzyme-linked immunosorbent assay (ELISA). Recombinant TSA56 and ScaC-PD were all properly expressed and displayed on Sf21 cells. Our cell-based ELISA comprising the four antigen-displaying cell types interacted with monoclonal antibodies as well as serum samples from ST-positive field-caught rats. This cell-based ELISA presented high accuracy (96.3%), sensitivity (98.6%), and specificity (84.6%) when tested against the ST-positive rat sera. Results of a pilot study using human sera were also highly consistent with the results of immunofluorescence analyses. By adopting this approach, we circumvented complex purification and refolding processes required to generate recombinant O. tsutsugamushi antigens and reduced the need for expensive equipment and extensively trained operators. Thus, our system has the potential to become a widely used serological platform for diagnosing ST.

[The treatment strategy and outcome of pregnancy complicated with Stanford type A aortic dissection]

To summarize the clinical characteristics and surgical treatment experience of pregnant women with acute Stanford type A aortic dissection.We collected the clinical data of 12 cases with acute aortic dissection during pregnancy and puerperal period from June 2010 to July 2020 in Beijing Anzhen Hospital and analyzed retrospectively, and summarize the clinical characteristics, treatment and outcomes for both mother and fetus. The age of these patients was(29±5)years old, and the onset time was from 16 weeks of gestation and 1 month after delivery. All the 12 patients underwent surgical treatment. The patients in the puerperium received aortic surgery after delivery. Four of them received the aortic surgery and continued pregnancy. Five of them underwent aortic repair and cesarean section simultaneously. Surgical treatment should be actively considered in pregnancy complicated with acute Stanford type A aortic dissection. Multi-disciplinary team cooperation can effectively improve the safety of the patients and fetus.

Combined Chibby and β-Catenin Predicts Clinical Outcomes in Patients with Hepatocellular Carcinoma

Chibby is an antagonist of β-catenin and is considered a potential tumor suppressor protein, but the role of Chibby in hepatocellular carcinoma (HCC) has not been characterized. The expression patterns of Chibby and β-catenin in HCC specimens and paired adjacent noncancerous tissues were measured by Western blotting and immunohistochemistry. The correlations between Chibby expression and clinicopathological parameters were analyzed. Then the biological functions of Chibby were analyzed in vitro. The Chibby protein was significantly downexpressed in human primary HCC tissues compared to that in matched adjacent normal liver tissue and is a risk factor for HCC recurrence and shorter survival. Furthermore, we found that in HCC tissues the high expression of β-catenin with low expression of Chibby in the nuclei was an independent predictor for disease-free survival (DFS) (p = 0.012) and overall survival (OS) (p = 0.005). Subsequent genetic manipulation in vitro studies revealed that Chibby knockdown induced the expression of β-catenin and C-myc, cyclin D1 protein, which promoted cell proliferation and invasiveness. In contrast, overexpression of Chibby decreased β-catenin expression and inhibited the cell proliferation and invasiveness. Our results suggest that low expression of Chibby was associated with advanced tumor-node-metastasis (TNM) stage and poor differentiation. Furthermore, the combination of Chibby and β-catenin can predict poor prognosis in patients with HCC. Chibby inhibited HCC progression by blocking β-catenin signaling in vitro. Chibby is a biomarker and may be a potential therapeutic target for HCC.

Oct4 upregulates osteopontin via Egr1 and is associated with poor outcome in human lung cancer

Background

Roles of cancer stem cells and early growth response gene 1 (Egr1) in carcinogenesis have been extensively studied in lung cancer. However, the role of Egr1 in the metastasis of lung cancer remains undetermined, especially in regard to stem cell-related pathways.

Methods

Egr1, osteopontin (OPN) and Oct4 expression in human lung cancer was determined by performing immunohistochemistry. Immunoblotting, ELISA, luciferase reporter assay, chromatin immunoprecipitation assay and RT-PCR were performed to validate the regulation of Oct4-Egr1-OPN axis. Moreover, the effect of Oct4-Egr1-OPN axis on lung cancer progression was evaluated by cell migration assay and mice study.

Results

We detected Oct4, Egr1, and OPN expression in clinical specimens from 79 lung cancer patients, including 72 adenocarcinomas and 7 squamous cell carcinomas. High expression of Oct4, Egr1, and OPN accounted for 53, 51, and 57% of the patients, respectively. All of the three biomarkers were positively correlated in clinical human lung cancer. Patients with high expression of OPN were significantly associated with shorter disease-free survivals than those with low expression of OPN (p < 0.05). In lung cancer cells, Oct4 transactivated the Egr1 promoter and upregulated Egr1 expression. In a human lung cancer xenograft model, Oct4-overexpressing tumors expressed elevated levels of Egr1. Furthermore, overexpression of Oct4 in lung cancer cells increased the metastatic potential.

Conclusions

Egr1 exerts a promoting effect on cancer metastasis in Oct4-overexpressing lung cancer. Thus, therapeutic strategies targeting the Oct4/Egr1/OPN axis may be further explored for the treatment of lung cancer, especially when lung cancer is refractory to conventional treatment due to cancer stem cells.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-6014-5) contains supplementary material, which is available to authorized users.

BMP-2 restoration aids in recovery from liver fibrosis by attenuating TGF-β1 signaling

Transforming growth factor-β (TGF-β) plays a central role in hepatic fibrogenesis. This study investigated the function and mechanism of bone morphogenetic protein-2 (BMP-2) in regulation of hepatic fibrogenesis. BMP-2 expression in fibrotic liver was measured in human tissue microarray and mouse models of liver fibrosis induced by bile duct ligation surgery or carbon tetrachloride administration. Adenovirus-mediated BMP-2 gene delivery was used to test the prophylactic effect on liver fibrosis. Primary hepatic stellate cells (HSC), HSC-T6 and clone-9 cell lines were used to study the interplay between BMP-2 and TGF-β1. Hepatic BMP-2 was localized in parenchymal hepatocytes and activated HSCs and significantly decreased in human and mouse fibrotic livers, showing an opposite pattern of hepatic TGF-β1 contents. BMP-2 gene delivery alleviated the elevations of serum hepatic enzymes, cholangiocyte marker CK19, HSC activation markers, and liver fibrosis in both models. Mechanistically, exogenous TGF-β1 dose dependently reduced BMP-2 expression, whereas BMP-2 significantly suppressed expression of TGF-β and its cognate type I and II receptor peptides, as well as the induced Smad3 phosphorylation levels in primary mouse HSCs. Aside from its suppressive effects on cell proliferation and migration, BMP-2 treatment prominently attenuated the TGF-β1-stimulated α-SMA and fibronectin expression, and reversed the TGF-β1-modulated epithelial-to-mesenchymal transition marker expression in mouse HSCs. The mutual regulation between BMP-2 and TGF-β1 signaling axes may constitute the anti-fibrogenic mechanism of BMP-2 in the pathogenesis of liver fibrosis. BMP-2 may potentially serve as a novel therapeutic target for treatment of liver fibrosis.

MiR-30a-5p Inhibits Epithelial-to-Mesenchymal Transition and Upregulates Expression of Tight Junction Protein Claudin-5 in Human Upper Tract Urothelial Carcinoma Cells

The involvement of microRNAs (miRNAs) in cancer development and their potential as prognostic biomarkers are becoming increasingly known. However, the signature of miRNAs and their regulatory roles in tumorigenesis of upper tract urothelial carcinoma (UTUC) remain to be elucidated. This study aimed to profile the miRNA expression pattern in UTUC tumor tissues and identify candidate miRNAs with prognostic and/or therapeutic functions. Methods and Results: We collected 22 UTUC tissue and adjacent normal tissues samples from patients who underwent nephroureterectomy. The miRNAs signatures of three selected UTUC samples using next-generation sequencing showed that miR-30a-5p was significantly downregulated in UTUC tumors compared to adjacent normal tissues. The differentially-expressed miRNAs were specifically validated by quantitative real-time polymerase chain reaction. In addition, the miRNA expression signatures were analyzed with the transcriptome profile characterized by microarray. Further in vitro studies indicated that overexpression of miR-30a-5p significantly suppressed proliferation, migration, and epithelial-to-mesenchymal transition (EMT) in cultured BFTC-909 UTUC cells. As a potential target gene of miR-30a-5p in the tight junction pathway suggested by the pathway enrichment analysis, the reduced expression of tight junction protein claudin-5 in UTUC cells was demonstrated to be upregulated by miR-30a-5p genetic delivery. Conclusions: Taken together, our findings demonstrated that miR-30a-5p inhibits proliferation, metastasis, and EMT, and upregulates the expression of tight junction claudin-5 in UTUC cells. Thus, miR-30a-5p may provide a promising therapeutic strategy for UTUC treatment.

Involvement of phosphatase and tensin homolog deleted from chromosome 10 in rodent model of neuropathic pain

Background

Many cancer research studies have extensively examined the phosphatase and tensin homolog deleted from chromosome 10 (PTEN) pathway. There are only few reports that suggest that PTEN might affect pain; however, there is still a lack of evidence to show the role of PTEN for modulating pain. Here, we report a role for PTEN in a rodent model of neuropathic pain.

Results

We found that chronic constriction injury (CCI) surgery in rats could elicit downregulation of spinal PTEN as well as upregulation of phosphorylated PTEN (phospho-PTEN) and phosphorylated mammalian target of rapamycin (phospho-mTOR). After examining such changes in endogenous PTEN in neuropathic rats, we explored the effects of modulating the spinal PTEN pathway on nociceptive behaviors. The normal rats exhibited mechanical allodynia after intrathecal (i.t.) injection of adenovirus-mediated PTEN antisense oligonucleotide (Ad-antisense PTEN). These data indicate the importance of downregulation of spinal PTEN for nociception. Moreover, upregulation of spinal PTEN by i.t. adenovirus-mediated PTEN (Ad-PTEN) significantly prevented CCI-induced development of nociceptive sensitization, thermal hyperalgesia, mechanical allodynia, cold allodynia, and weight-bearing deficits in neuropathic rats. Furthermore, upregulation of spinal PTEN by i.t. Ad-PTEN significantly attenuated CCI-induced microglia and astrocyte activation, upregulation of tumor necrosis factor-α (TNF-α) and phospho-mTOR, and downregulation of PTEN in neuropathic rats 14 days post injury.

Conclusions

These findings demonstrate that PTEN plays a key, beneficial role in a rodent model of neuropathic pain.

Field assessment of Orientia tsutsugamushi infection in small mammals and its association with the occurrence of human scrub typhus in Taiwan

We conducted an extensive study in Taiwan of Orientia tsutsugamushi (OT) infection in small wild mammals. Field trapping was carried out at six districts in eastern and western Taiwan as well as various offshore islands during the period 2006-2010. A total of 1061 specimens representing 11 rodent species were captured. The presence of OT infection was assessed by indirect immunofluorescence assay and polymerase chain reaction assays of 56-kDa type-specific antigen gene. The chigger infestation rate among the animals was 35% (371/1061). Among these, OT was detected in 64% (238/371) of the chiggers from the infested animals and in the spleens from 273 (34.3%) of 797 animals. Excluding animals in the Suncus murinus group, the antibody positive rate of scrub typhus was 69.1% (477 of 690 of serum samples). The prevalence of OT infection in animals from areas with a low incidence of human cases of scrub typhus was significantly lower than that in rodents obtained from regions with a high incidence of human cases of the disease (44.4%±4.0% vs. 71.2%±9.7%, p<0.001). In Taiwan, the prevalence of OT infection in wild rodents is considerably high and appears to correlate positively with the occurrence of scrub typhus in humans.

Inhibition of cartilage damage by pro-opiomelanocortin prohormone overexpression in a rat model of osteoarthritis

Pro-opiomelanocortin (POMC) is a precursor of various neuropeptides. POMC-derived neuropeptides are potent inflammation inhibitors and immunosuppressants. Evidence that osteoarthritis (OA) is an inflammatory disease is accumulating. We assessed whether intra-articular gene delivery of POMC ameliorates experimentally induced OA in a rat model. OA was induced in Wistar rats by anterior cruciate ligament-transection (ACLT) in the knee of one hind limb. Adenoviral vector encoding human POMC (AdPOMC) was injected intra-articularly into the knee joints after ACLT. The transgene expression and the inflammatory responses were evaluated using immunoblotting, immunohistochemistry and enzyme-linked immunosorbent assay. The treated joints were assessed histologically for manifestations of the disease. Human POMC was expressed in the chondrocytes and synovial membrane after the intra-articular injection. POMC gene transfer reduced nuclear factor- κB activity and the levels of interleukin-1 β in HTB-94 chondrosarcoma cells and Raw 264.7 macrophages; it also reduced microvessel density in the synovium. Histological examination showed that symptoms of OA in AdPOMC-treated rats were less severe than in rats treated with either empty adenoviral vector (AdNull) or normal saline. Intra-articular injection of adenoviral vectors expressing POMC significantly suppressed the progression and severity of OA, and reduced inflammatory responses and angiogenesis. POMC gene delivery may offer novel therapeutic approach for treating OA.

Realization and manipulation of ZnO nanorod arrays on sapphire substrates using a catalyst-free metalorganic chemical vapor deposition technique

Single-crystalline ZnO nanorod arrays (ZNRs) were grown by metalorganic chemical vapor deposition on ZnO buffer/sapphire substrate without using any metal catalyst. The density of vertically aligned ZNRs was found to govern by the morphology and thickness of buffer layer. That is to say, the ZnO buffer layer can be used as the nucleation template to control the growth direction and density of the ZNRs. In addition, by controlling the diethyl zinc flow rate, we can manipulate the size, crystal, and optical quality of ZNRs. Finally, the possible growth mechanism of ZNRs was discussed in detail.

Effects of Growth Conditions on Structural Properties of ZnO Nanostructures on Sapphire Substrate by Metal-Organic Chemical Vapor Deposition

ZnO was grown on sapphire substrate by metal-organic chemical vapor deposition using the diethylzinc (DEZn) and oxygen (O(2)) as source chemicals at 500 degrees C. Influences of the chamber pressure and O(2)/DEZn ratio on the ZnO structural properties were discussed. It was found that the chamber pressure has significant effects on the morphology of ZnO and could result in various structures of ZnO including pyramid-like, worm-like, and columnar grain. When the chamber pressure was kept at 10 Torr, the lowest full width at half-maximum of ZnO (002) of 175 arc second can be obtained. On the other hand, by lowering the DEZn flow rate, the crystal quality of ZnO can be improved. Under high DEZn flow rate, the ZnO nanowall-network structures were found to grow vertically on the sapphire substrate without using any metal catalysts. It suggests that higher DEZn flow rate promotes three-dimensional growth mode resulting in increased surface roughness. Therefore, some tip on the ZnO surface could act as nucleation site. In this work, the growth process of our ZnO nanowall networks is said to follow the self-catalyzed growth mechanism under high-DEZn flow rate.

Characteristics of ZnO nanowall structures grown on GaN template using organometallic chemical vapor deposition

Uniformly distributed ZnO nanowall network structures were grown at 550 degrees C by organometallic chemical vapor deposition technique on the GaN/sapphire substrate without using any catalysts. In this research, we discussed the nanostructures and optical properties of ZnO samples grown under the same conditions but on different underlying materials (GaN/sapphire and sapphire). By adjusting the growth parameters, ZnO nanowall networks with a honeycomb-like pattern without using any metal catalysts were successfully fabricated on the GaN/sapphire and sapphire substrates. Since the lattice mismatch between ZnO and GaN is only about 1.8% while the lattice mismatch between ZnO and sapphire is about 18.4%. Lattice mismatch may not be the decisive factor in the formation process of ZnO nanowall networks. The ZnO grown on GaN epilayer had smaller full width at half maximum value than that of ZnO grown under the same growth condition on the sapphire substrate, indicating a higher crystal quality in the sample of ZnO on GaN. The room temperature PL measurement of both ZnO nanostructures grown on GaN and sapphire show strong ultraviolet peak intensity and high intensity ratio of the near band emission to the deep-level emission in a PL spectrum.

Molecular detection and characterization of spotted fever group rickettsiae in Taiwan

Rickettsioses are emerging infectious diseases caused by rickettsiae in association with arthropods. We report the detection of spotted fever group rickettsiae (SFGR) in Taiwan using molecular methods. Phylogenetic analyses of the 17-kd protein and citrate synthase (gltA) genes showed that SFGR TwKM01 detected in Rhipicephalus haemaphysaloides ticks was most similar to Rickettsia rhipicephali. Three TwKM01 isolates were obtained from three individual R. haemaphysaloides ticks. Small, intracellular, coccobacillary bacteria were found in infected L929 cells using immunofluorescence antibody testing and transmission electron microscopy. Two other SFGRs, TwKM02 and TwKM03, identified in Leptotrombidium chigger mites, were closely related to R. australis and R. felis URRWXCal(2), respectively. The TwKM03 strain was also detected in Ixodes granulatus ticks and widely distributed in Hualien, Kinmen, and Lienchiang counties in Taiwan. The endonucleases MaeII and HhaI selected for restriction fragment length polymorphism analysis of the gltA and 17-kd polymerase chain reaction products, respectively, were useful for genotyping Rickettsia species TwKM01, TwKM02, TwKM03, and other SFGRs. Although their infectivity and pathogenicity for vertebrates are unknown, the finding of SFGRs raises the possibility that bacteria other than Orientia tsutsugamushi, Coxiella burnetii, and R. typhi may be involved in rickettsial diseases in Taiwan.

Low-Dose Etoposide Enhances Telomerase-Dependent Adenovirus-Mediated Cytosine Deaminase Gene Therapy through Augmentation of Adenoviral Infection and Transgene Expression in a Syngeneic Bladder Tumor Model

The human telomerase reverse transcriptase (hTERT) promoter can selectively drive transgene expression in many telomerase-positive human cancer cells. Here we evaluated combination therapy of adenoviral vector Ad-hTERT-CD encoding E. coli cytosine deaminase (CD) driven by the hTERT promoter and low-dose etoposide (0.1 microg/mL) for treating bladder cancer. Ad-hTERT-CD conferred sensitivity to 5-fluorocytosine (5-FC) in bladder cancer cells, which could be enhanced by etoposide treatment, but not in normal cells. Such effect was correlated with up-regulation of hypoxia-inducible factor (HIF)-1alpha expression. By contrast, etoposide activated p53 and down-regulated hTERT promoter activity in normal cells. Etoposide also increased adenoviral infection via enhancement of coxsackie-adenovirus receptor expression on bladder cancer and normal cells. Combination index analysis revealed that combined therapy of Ad-hTERT-CD (10(9) plaque-forming units)/5-FC (200 mg/kg) with etoposide (2 mg/kg) synergistically suppressed tumor growth and prolonged survival in mice bearing syngeneic MBT-2 bladder tumors. This combination therapy regimen induced complete tumor regression and generated antitumor immunity in 75% of tumor-bearing mice. Furthermore, increased infiltrating CD4(+) and CD8(+) T cells and necrosis within tumors were found in mice receiving combination therapy of Ad-hTERT-CD and etoposide compared with those treated with either treatment alone. Thus, the potential high therapeutic index of the combination therapy may be an appealing therapeutic intervention for bladder cancer. Furthermore, because a majority of human tumors exhibit high telomerase activity, adenovirus-mediated CD gene therapy driven by the hTERT promoter in combination with low-dose etoposide may be applicable to a broad spectrum of cancers.

Blockade of endothelin-1 release contributes to the anti-angiogenic effect by pro-opiomelanocortin overexpression in endothelial cells

Pro-opiomelanocortin (POMC) is the precursor of several neuropeptides, such as corticotropin (ACTH), alpha-melanocyte-stimulating hormone (MSH), and the endogenous opioid, beta-endorphin (EP). ACTH-dependent Cushing's syndrome is characterized by ACTH overproduction and is associated with an increased risk of cardiovascular disease. Endothelial dysfunction has been recognized as an early marker of cardiovascular disease. However, the mechanism underlying endothelial dysfunction by ACTH overexpression in Cushing's patients remains elusive. Endothelial cells, the primary cells producing endothelin (ET)-1, are both the source and target of POMC-derived peptides. In the present study, we generated adenovirus vectors (Ad) encoding POMC (Ad-POMC) and green fluorescent protein (GFP; Ad-GFP) to investigate whether POMC gene transfer altered the ET-1 homeostasis and angiogenic functions in human EA.hy926 endothelial cells. Via adenovirus gene delivery, the POMC-transduced EA.hy926 cells released significantly elevated ACTH and beta-EP levels (P < 0.001). In addition, POMC gene delivery significantly decreased the ET-1 release (P < 0.001) without affecting the ET-1 messenger RNA (mRNA) level. Despite no effect on the secretion of matrix metalloproteinases (MMPs) and cell proliferation, POMC gene delivery significantly inhibited the migration (P < 0.01) and tube-forming capability (P < 0.01) of endothelial cells. Moreover, the POMC-induced inhibition of tube formation could be partially reversed by adding exogenous ET-1 (P < 0.05). In summary, the attenuated ET-1 release and angiogenic processes by POMC overexpression may contribute to endothelial dysfunction, thereby providing a link between Cushing's syndrome and cardiovascular diseases.

Suppression of choroidal neovascularization by intramuscular polymer-based gene delivery of vasostatin

The purpose of this study was to evaluate the efficacy of gene delivery of angiogenesis inhibitor, vasostatin (VS), in suppressing experimental model of choroidal neovascularization (CNV). A mammalian expression vector carrying VS, pCMV3-VS, was constructed and evaluated for its ability to produce VS in transfected cells using western blot analysis and a cell viability assay. CNV was induced in Brown Norway rats by fundus argon laser photocoagulation and evaluated by fundus fluorescein angiography (FAG). Ten days post-laser treatment, gene delivery was achieved by intramuscular (IM) injection of poly-(N-vinyl pyrrolidone) (PVP) polymer conjugated with pCMV3-VS (PVP-VS) or a control vector (PVP-vector). Systemic VS expression was analysed by western blot analysis and enzyme linked immunosorbent assay (ELISA), and the extent of CNV was monitored by FAG analysis at different time intervals post-PVP treatment. Transfection of pCMV3-VS into muscle cells resulted in increased production and release of exogenous VS, which specifically inhibited the proliferation of endothelial cells. Besides, IM injection of PVP-VS, but not PVP-vector, led to elevated VS level in plasma for 30 days. After laser photocoagulation, rats injected with PVP-VS exhibited significantly lower incidence of CNV comparing with animals of control groups (P < 0.01) for at least 42 days. Moreover, rats treated with PVP-VS also showed a significant reduction in the CNV lesions compared with control groups (P < 0.001) for at least 42 days. Above all, no overt adverse effects were observed in rats received PVP-VS. These results demonstrate the potential of IM VS gene delivery for CNV treatment.

Increased endostatin/collagen XVIII expression correlates with elevated VEGF level and poor prognosis in hepatocellular carcinoma

Liver is the primary source for collagen XVIII, the precursor of angiogenesis inhibitor, endostatin. However, the role of endostatin/collagen XVIII expression during liver carcinogenesis remains elusive. Therefore, we studied its expression in five hepatoma cell lines and 105 hepatocellular carcinoma specimens. The poorly differentiated hepatoma cell lines exhibited increased endostatin/collagen XVIII levels compared with the well-differentiated ones. In hepatoma tissues, endostatin/collagen XVIII expression was detected in various types of liver cells and was significantly stronger in adjacent nontumor tissues than that in tumors (P<0.001). Endostatin/collagen XVIII expression in nontumor tissues correlated with tumor stages (P=0.014) and expression of vascular endothelial growth factor (P=0.007), but not the stages of hepatic fibrosis (P>0.05). Kaplan-Meier analysis showed that patients with higher endostatin/collagen XVIII expression had significantly shorter overall survival (P=0.011) and disease-free survival (P=0.0034). Moreover, endostatin/collagen XVIII level was an independent prognostic factor for tumor recurrence (P=0.034) by multivariate analysis. In conclusion, increased endostatin/collagen XVIII expression correlated with hepatoma progression and predicted poor prognosis for patients with hepatocellular carcinoma.

Inhibition of corneal angiogenesis by local application of vasostatin

PURPOSE

This study was designed to investigate the effects of the locally supplied endogenous angiogenesis inhibitor vasostatin (VS) on corneal angiogenesis.

METHODS

Recombinant VS was expressed and purified. The effects of VS on the proliferation of endothelial cells were investigated using the methyl thiazolyl tetrazolium (MTT) assay in the absence or presence of angiogenic factors such as basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF). Corneal neovascularization was induced by implantation of hydron pellets containing bFGF in rat corneal micropockets. The potency of VS to inhibit corneal angiogenesis was investigated by incorporation of VS with bFGF in hydron pellets or topical application of VS containing eye drops to rat eyes implanted with bFGF pellets. The extent of corneal neovascularization was evaluated by microscopic and histological analyses.

RESULTS

VS potently inhibited the growth of endothelial cells in the absence or presence of angiogenic factors such as bFGF or VEGF. In the rat corneal micropocket assay, concurrent incorporation of VS abolished the bFGF induced neovascularization. When formulated in a methylcellulose eye drop, VS remained intact and functional in a 4 degrees C solution for more than 7 days. Topical application of VS eye drops potently inhibited bFGF induced neovascularization in rat corneas.

CONCLUSIONS

The present study effectively demonstrated the potential feasibility of local application of VS for treatment of corneal angiogenesis.

Expression of hepatoma-derived growth factor in hepatocellular carcinoma

BACKGROUND

Hepatoma-derived growth factor (HDGF) is a novel growth factor derived from a hepatoma cell line. The current study was designed to elucidate the role of HDGF expression during the pathogenesis of hepatocellular carcinoma (HCC).

METHODS

HDGF expression in hepatoma cell lines was analyzed using the reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot analysis, and immunofluorescence analysis. Immunohistochemical studies were performed to examine the intensity and spatial distribution of HDGF immunostaining in 105 HCC specimens. To evaluate its prognostic value, the labeling index of HDGF immunostaining was analyzed for potential correlations with the clinicopathologic characteristics of HCC.

RESULTS

RT-PCR and Western blot analysis detected increased HDGF expression in malignant hepatoma cell lines. In resected HCC specimens, HDGF immunostaining was detected in the nuclei and cytoplasm of hepatocytes and hepatoma cells. HDGF levels in hepatoma tissue samples were significantly higher than in adjacent nontumor tissue samples (P < 0.05). Elevated nuclear HDGF levels were found to be correlated with loss of differentiation features (P < 0.05), absence of tumor capsules (P < 0.01), high alpha-fetoprotein levels (P < 0.05), and overexpression of proliferating cell nuclear antigen (P < 0.001). Kaplan-Meier analysis indicated that patients with higher nuclear HDGF levels had a shorter duration of survival and a higher incidence of recurrence (P < 0.001). Multivariate analysis indicated that for patients with HCC, the nuclear HDGF level is an independent prognostic factor for overall and disease-free survival.

CONCLUSIONS

Increased HDGF expression is correlated with the proliferating states of HCC and represents a novel prognostic factor for patients with HCC who have undergone surgery.

Expression and prognostic role of tumor suppressor gene PTEN/MMAC1/TEP1 in hepatocellular carcinoma

BACKGROUND

Inactivation of the tumor suppressor gene PTEN/MMAC1/TEP1, located on chromosome 10q23, is a common event in advanced stages of diverse human malignancies. However, the prognostic role of PTEN expression in patients with hepatocellular carcinoma (HCC) has not been characterized.

METHODS

One hundred five resected specimens were collected from patients with HCC. Expression levels of PTEN and p53 in clinical samples were analyzed by immunohistochemistry.

RESULTS

Immunohistochemical analysis of 105 HCC tissue specimens revealed that decreased or absence of PTEN immunostaining was found in 43 specimens (40.9%). Reduced PTEN expression levels were correlated with increased tumor grade (P = 0.017), advanced disease stage (P = 0.016), and elevated serum alpha-fetoprotein (alphaFP) levels (P = 0.001). Kaplan-Meier analysis indicated that patients with reduced PTEN levels had shorter overall survival (P = 0.001) and higher recurrence rates (P = 0.0007) compared with patients who had intact PTEN expression. Examining p53 expression unveiled an inverse correlation between p53 overexpression and reduced PTEN expression in patients with HCC (P = 0.004). In addition, patients with p53 overexpression had shorter overall survival compared with patients who were without p53 overexpression (P = 0.0014). Univariate and multivariate analyses revealed that reduced PTEN expression was an independent prognostic factor for survival in patients with HCC.

CONCLUSIONS

The current study demonstrated that reduced PTEN expression levels are involved in the pathogenesis of HCC. Moreover, decreased PTEN expression was correlated with tumor progression, high alphaFP levels, p53 overexpression, and poor prognosis in patients with HCC.

Retrovirus-mediated transfer of prothymosin gene inhibits tumor growth and prolongs survival in murine bladder cancer

To explore the potential use of prothymosin alpha(ProT), a putative thymic hormone, in gene therapy for bladder cancer, we generated a replication-defective recombinant retroviral vector encoding ProT and tested its antitumor effect on the MBT-2 murine bladder cancer. C3H/HeN mice injected with MBT-2 cells in conjunction with retroviruses encoding ProT exhibited smaller tumor mass, lower tumor incidence and higher survival rate, as well as higher antitumor cytotoxic activities compared with those injected with control viruses. However, such effects were not observed in severe combined immunodeficiency mice, suggesting that ProT exerts antitumor effects through its immunomodulatory activities. Cell growth in monolayer culture and colony formation in soft agar were enhanced in ProT gene-modified MBT-2 clones, and such growth-promoting activities of ProT could be reversed if its nuclear localization signal (NLS) was deleted. To circumvent the proliferation-promoting effect of ProT on tumor cells, a retroviral vector encoding ProT lacking NLS was constructed. Our results showed that retroviruses encoding NLS-deleted ProT was more efficacious than those encoding wild-type ProT in prolonging survival of tumor-bearing mice. This is the first report indicating that ProT, in particular NLS-deleted ProT, delivered by retroviral vectors may be further explored for the treatment of bladder cancer.

Current status of human parasitic infections in Taiwan

The eradication of the 2 mosquito-borne parasitic diseases, malaria and lymphatic filariasis, is one of the greatest achievements of the parasite control campaigns in Taiwan. Most of the soil-transmitted nematode infections, with the exception of pinworm infection, are currently well controlled and limited to some aboriginal areas. Food-borne parasitic zoonosis such as infections with Angiostrongylus cantonensis, Clonorchis sinensis, and Taenia saginata asiatica are not rare, but the former is seasonal and the latter 2 are ethnically and geographically associated. Intestinal protozoal infections with Giardia lamblia and Cryptosporidium parvum are at low levels but may be widely distributed. Opportunistic protozoal infections among patients with acquired immunodeficiency syndrome, which included amebic colitis, Pneumocystis carinii pneumonia, and cerebral toxoplasmosis, are becoming increasingly important. The rapid increase in international travel and the introduction of large numbers of foreign workers from other countries in Southeast Asia may change the epidemiological patterns of parasitic infections in Taiwan.

A case study of cytokine profiles in acute human babesiosis

The immune response in a patient with acute babesiosis was determined by measurements of lymphocyte subpopulations, serum levels of cytokines, and adhesion molecules. The ratio of CD4+:CD8+ lymphocytes was reduced early in the infection, but returned to a normal value after treatment with azithromycin and quinine. Natural killer (NK) cells markedly increased in the acute phase but progressively decreased and to the normal range in the convalescent phase. Serum levels of tumor necrosis factor-alpha, interferon-gamma, interleukin-2 (IL-2), IL-6, E-selectin, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1 were highly elevated in the acute phase while normal levels of these mediators were observed one month after treatment. These results suggest that CD8+ T cells and NK cells may be involved in the host defense mechanisms against acute babesiosis.

Colorimetric one-tube nested PCR for detection of Trichomonas vaginalis in vaginal discharge

A colorimetric one-tube nested PCR was developed for the detection of Trichomonas vaginalis in clinical vaginal discharge specimens. A family of 650-bp specific DNA repeats from the T. vaginalis genome was targeted. There was no cross-reaction with human DNA or other infectious agents, including Pentatrichomonas hominis and Giardia lamblia. The colorimetric assay was applied as an adjunct to nested PCR for semiquantitative determination of T. vaginalis DNA at levels corresponding to 1 to 1,000 parasites. PCR of samples prepared by a rapid boiling method was as sensitive and specific as PCR of samples prepared by the standard DNA extraction method: the equivalent of one T. vaginalis organism in 20 microliters of vaginal discharge could be detected. The colorimetric nested PCR was compared with wet mount and culture for the detection of T. vaginalis. A total of 378 clinical vaginal discharge specimens from symptomatic patients were examined; 31 patients were positive for T. vaginalis both by culture and by nested PCR. However, only 17 of these 31 patients were positive by wet mount examination. In addition, of 113 asymptomatic patients, 9 were positive for T. vaginalis by nested PCR. Of these nine PCR-positive patients, only two were also positive both by wet mount and by culture, four patients were positive by culture but negative by wet mount, and three patients were negative both by wet mount and by culture. No specimens negative by nested PCR were positive by wet mount or by culture. The three asymptomatic patients with PCR-positive but wet mount- and culture-negative samples were subsequently found to have T. vaginalis infection after repeated and prolonged culture was performed. This colorimetric nested PCR was very sensitive compared with culture for the diagnosis of vaginal trichomoniasis, especially asymptomatic T. vaginalis infection. It is also simple, specific, rapid, and semiquantitative.

One-tube, nested-PCR assay for the detection of Trichomonas vaginalis in vaginal discharges

To shorten the time and improve the accuracy of diagnosis of vaginal trichomoniasis, a novel, one-tube, nested PCR, which targets a family of 650-bp specific DNA repeats from the Trichomonas vaginalis genome, has been developed. Samples were prepared by a rapid boiling method and the PCR products analysed by gel electrophoresis. A 290-bp DNA fragment was observed in all positive cases. No cross-reaction with any other pathogens, including the Pentatrichomonas hominis and Giardia lamblia used as controls, was found. Using the assay, one genome-equivalent of T. vaginalis in 20 microliters vaginal discharge can be detected and diagnosis can be made within 6 h. When 165 clinical specimens were examined by wet amount, culture and the PCR assay, 16 were found positive for T. vaginalis by both culture and PCR, whereas only nine of these 16 cases were found to be positive by examination of wet mounts. No PCR-negative cases were positive by wet mount or culture. This new assay appears to be a simple, rapid, accurate and sensitive method for the diagnosis of vaginal trichomoniasis.

Silicone intubation with tissue glue anastomosis in the treatment of congenital nasolacrimal duct obstruction

BACKGROUND AND OBJECTIVE

To evaluate the advantages of tissue glue application for the anastomosis of silicone intubation in congenital nasolacrimal duct obstruction.

PATIENTS AND METHODS

Patients with congenital nasolacrimal duct obstruction were treated with silicone intubation with the aid of tissue glue for end-to-end anastomosis. The recurrence rate, complications, and the need for general anesthesia at tube removal were recorded.

RESULTS

The silicone tubes for all 18 eyes studied were removed smoothly on an outpatient basis. Early extrusion was noted in 3 eyes. No recurrence of epiphora was noted in any eye after more than 6 months of follow-up.

CONCLUSION

Tissue glue anastomosis is a beneficial modification that avoids the need for general anesthesia during stent removal in children and allows removal to be easily performed in an outpatient clinic.

Generation of interleukin-8 from human monocytes in response to Trichomonas vaginalis stimulation

Neutrophils are the predominant inflammatory cells found in the vaginal discharges of patients with Trichomonas vaginalis infection. We have investigated the possible role of interleukin-8 (IL-8) in the inflammatory response elicited by T. vaginalis infection. This study has shown that T. vaginalis induces blood monocytes to produce large amounts of bioactive IL-8, mainly by membrane components of T. vaginalis (MTV). Monocyte-derived IL-8 induced by MTV was dose and time dependent. The peak level of IL-8 was 102 +/- 11 ng/ml of conditioned media (mean +/- standard error; n = 5) obtained from MTV-stimulated monocytes (MTVCM) at 36 h of cultivation. With a multichamber chemotactic assay, we found an optimal neutrophil chemotaxis (177 +/- 14 migrated cells) induced by MTVCM collected at 16 h of cultivation when the level of IL-8 was 42 +/- 8 ng/ml. A neutralizing monoclonal antibody directed against IL-8, but not the irrelevant antibodies, significantly blocked the neutrophil chemotactic activity (decreased from 153 +/- 6 to 23 +/- 3 migrated cells; n = 3 [P < 0.001]) induced by MTVCM. Moreover, the maximum increase of the IL-8 mRNA level from MTV-treated monocytes was observed after a 5-h cultivation and decreased thereafter. Monocytes cocultured with MTV in the presence of a neutralizing monoclonal antibody directed against tumor necrosis factor alpha, but not against IL-1 beta, decreased IL-8 production by 25% (P < 0.05), indicating that the release of IL-8 in MTV-stimulated monocytes is partially dependent on tumor necrosis factor alpha. The capacity of MTV-induced monocytes to synthesize IL-8 suggests that these cells can contribute to the induction of the acute inflammatory response seen in T. vaginalis infection.

Influence of humoral immunity on leukotriene B4 production by neutrophils in response to Trichomonas vaginalis stimulation

Neutrophils are the predominant inflammatory cells found in vaginal discharges from patients with Trichomonas vaginalis infection. In this study, we investigated the effect of humoral immunity on leukotriene B4 (LTB4) generation by neutrophils in the inflammatory response of vaginal trichomoniasis. As quantitated by a radioimmunoassay, no release of LTB4 was detected from neutrophils (5 x 10(6)/ml) interacted with trichomonads (1 x 10(6)/ml). However, specific immunoglobulin G(IgG) but not F(ab')2, at a titre of 1:256 directed against T. vaginalis, augmented LTB4 production (1.4 +/- 0.4 ng/ml, n = 5) by neutrophils, suggesting that this enhancement is Fc gamma receptor-mediated. Moreover, addition of the specific IgG (1 mg/ml) to C2-deficient serum or Factor B-deficient serum, but not C5-deficient serum, significantly increased LTB4 production by neutrophils in response to trichomonad stimulation. This indicates that the complement common pathway activation is crucial for the amplification of host defence mechanisms against T. vaginalis. An LTB4 receptor antagonist, SC-41930, completely abolished neutrophil chemotactic activity induced by LTB4. Taken together, these results indicate that humoral immunity could promote the interaction of neutrophils with T. vaginalis and augment the inflammatory response through the amplification of LTB4 production.

A study on the in vitro susceptibility of Trichomonas vaginalis to metronidazole

The susceptibility of 32 clinical isolates of Trichomonas vaginalis to metronidazole has been studied under aerobic and anaerobic conditions. Of 32 patients with vaginal trichomoniasis, 27 (84%) were cured by a standard metronidazole treatment regimen (200 mg thrice daily for seven days). The geometric means of minimum inhibitory concentration (MIC) under aerobic and anaerobic conditions for these isolates were 2.0 and 0.4 micrograms/ml, respectively; the geometric means of minimum lethal concentration (MLC) under aerobic and anaerobic conditions were 7.4 and 2.0 micrograms/ml, respectively. However, for those five patients with treatment failure, the geometric means of MIC for these isolates under aerobic and anaerobic conditions were 6.8 and 1.1 micrograms/ml, respectively; the geometric means of MLC under aerobic and anaerobic conditions were 18 and 5.5 micrograms/ml, respectively. Trichomonads reisolated from patients after treatment failure had similar susceptibility to metronidazole as before treatment. However, all five women were cured by a second course of metronidazole treatment. Although primary treatment failure was common when isolates of T. vaginalis had aerobic MLC values of > 18 micrograms/ml or anaerobic MLC values > 5.5 micrograms/ml, two cases with isolates having high MLC values (aerobic: 20 micrograms/ml, anaerobic: 5 micrograms/ml) responded well to the standard treatment. It was evident that no metronidazole-resistant trichomonads were found in this study.

Killing of Trichomonas vaginalis by complement-mediated lysis is not associated with the presence of Trichomonas vaginalis virus

We have examined the possible relationship between trichomonad killing by human serum and the presence of virus-encoded double-stranded ribonucleic acid in T. vaginalis (TVV). Indirect immunofluorescence assay revealed that non-immune serum (NIS) and T. vaginalis-immune serum (TVIS) had immunoglobulin G (IgG) antibody titres of 1:8 and 1:256, respectively, against T. vaginalis. Among the 12 isolates of T. vaginalis examined, 9 were infected with TVV. Upon long-term (> 9 months) culture, of the 9 infected isolates, 3 isolates lost the virus during the passage process. Five of 9 TVV-infected isolates were completely killed by 10% NIS while the other 4 TVV-infected isolates had viability over the range 22-81%. Three fresh non-TVV-infected isolates had viability over the range 12-89%. On the other hand, no trichomonads survived in the presence of 10% TVIS. Viability of the virus-lost isolates during long-term culture was not altered when compared with that of their corresponding fresh isolates. Heat-inactivated-NIS and -TVIS had no killing effect on trichomonads while absorbed-NIS and -TVIS (ATVIS) had a similar killing effect to NIS. Further studies on the role of antibody and complement in the killing of trichomonads by serum revealed no significant difference in trichomonad viability between treatments of Mg2+-ethylene glycol-bis-(beta-aminoethyl ether)- N,N,N1,N1- tetraacetic acid (Mg(2+)-EGTA)-TVIS and of Mg(2+)-EGTA-ATVIS. Zymosan-treated ATVIS did not kill trichomonads but zymosan-treated TVIS had a marked killing effect.(ABSTRACT TRUNCATED AT 250 WORDS)

A novel neutrophil-activating factor released by Trichomonas vaginalis

We have investigated the effects of a novel neutrophil-activating factor released by Trichomonas vaginalis (TV-NAF) on neutrophil chemotaxis. TV-NAF was present in the supernatant from 10(7) T. vaginalis (STV) cultured in 1 ml of serum-free Hanks' balanced salt solution (HBSS) at 37 degrees C for 30 min. With a multichamber chemotactic assay, we found that there were 112 +/- 15 migrated neutrophils (mean +/- standard deviation, n = 7) for STV and 11 +/- 4 for HBSS per high-power field (x 400). STV was also able to induce neutrophil actin assembly (increased 1.5-fold), enhance expression of complement receptor type 3 (increased 5-fold), and promote intracellular calcium mobilization (increased 2.5-fold). There was no chemotactic activity in the preparation of STV from killed trichomonads. The fact that heating up to 100 degrees C or deproteinization by treatment with proteinase K at 65 degrees C for 1 h did not abolish its chemotactic activity suggests that the TV-NAF involved was not a protein. The chemotactic activity of TV-NAF was associated with the fraction containing small molecules of less than 3,000 Da. Therefore, the possibility that eicosanoid production by trichomonads is responsible for neutrophil activation was investigated. Leukotriene B4 (LTB4; 500 pg/ml) but not thromboxane B2 (< 20 pg/ml) or prostaglandin E2 (< 8 pg/ml) was found in the STV by radioimmunoassay. Production of LTB4 by trichomonads was time dependent and increased twofold when arachidonic acid (100 microM) was added but was not decreased when eicosanoid inhibitors were present. Evidence for the presence of LTB4 in STV was further provided by the fact that rabbit anti-LTB4 antiserum could abolish the chemotactic activity of STV. These studies suggest that the spontaneous release of TV-NAF, which is most likely LTB4, may activate neutrophils, presumably through a different arachidonate metabolic pathway than that in mammalian cells.

The role of immunoglobulin and complement in enhancing the respiratory burst of neutrophils against Trichomonas vaginalis

Human neutrophils, alone, did not kill Trichomonas vaginalis. More than 90% of T. vaginalis (10(5)/ml) survived in the presence of 10% normal human serum (NHS) while 90% of these organisms were killed in the presence of a combination of neutrophils (10(6)/ml) and 10% NHS. Mechanisms responsible for this serum-mediated neutrophil killing of T. vaginalis were demonstrated through a process of lucigenin-amplified neutrophil chemiluminescence. As evidenced by indirect immunofluorescence, NHS showed specific immunoglobulin G (IgG) titre of 1:8 for T. vaginalis. Purified IgG, at 1.6 mg/ml, showed no direct opsonizing or lytic effect on this organism. Formalin-fixed trichomonads opsonized by C2 deficient human serum promote 4 times more neutrophil chemiluminescence than those opsonized by Factor B deficient human serum. With the addition of purified IgG (5 mg/ml) neutrophil chemiluminescence was increased by 4 times and further improved trichomonal killing by neutrophils (from 5 +/- 4% to 78 +/- 16%) via activation of the classical complement pathway, but did not alter that due to activation of the alternative complement pathway. These studies indicate that both an IgG-enhanced classical complement pathway activation and an antibody-independent alternative complement pathway activation provide opsonin (C3) for T. vaginalis to facilitate the neutrophil killing mechanism.