[Evaluating the efficiency of endoscope-assisted septo-rhinoplasty via intranasal approach]

Objective: To observe the functional and esthetic results of endoscope-assisted septo-rhinoplasty via intranasal approach. Methods: The clinical data of 12 patients with septal deviation and nasal deformity in the University of Hong Kong-Shenzhen Hospital from June 2021 to June 2022 were analyzed, including 8 males and 4 females, aging 28 to 58 years. All patients were operated under general anesthesia. The septal deviation was corrected by hemitransfixion incision, combined with intercartilaginous incision and other intranasal or extranasal incisions to perform osteotomy, hump resection and saddle nose correction. Patient satisfaction with postoperative functional and aesthetic improvements was assessed through Nasal Obstruction Symptom Evaluation (NOSE), Rhinoplasty Outcome Evaluation (ROE), and Visual Analogue Scale (VAS).SPSS 25 software was used for statistical analysis. Results: The correction of nasal septum deviation was satisfactory in all 12 patients. Nasal obstruction was relieved, with NOSE score and VAS score of nasal ventilation decreased [(21.67±10.30) vs (70.83±14.12), (1.83±1.03) vs (8.33±0.89), t value was 9.49 and 16.30, respectively, both P<0.05]. The nasal appearance of 10 patients with crooked nose deformity was improved, with ROE score and VAS score of nasal appearance increased [(21.30±2.31) vs (8.10±3.31), (8.90±0.99) vs (3.80±1.62), t value was -11.85 and -9.33, respectively, both P<0.05];The nasal vestibule morphology of 2 patients with abnormal nasal vestibule was improved. During the follow-up of 12 to 24 months, no postoperative complication such as nasal septum perforation, nasal cavity adhesion or nasal dorsal collapse occurred in all patients. Conclusion: Endoscope-assisted septo-rhinoplasty via intranasal approach can resolve both functional and esthetic problems at the same time, improving outcomes while reducing surgical trauma.

Glutamine addiction promotes glucose oxidation in triple-negative breast cancer

Glutamine is a conditionally essential nutrient for many cancer cells, but it remains unclear how consuming glutamine in excess of growth requirements confers greater fitness to glutamine-addicted cancers. By contrasting two breast cancer subtypes with distinct glutamine dependencies, we show that glutamine-indispensable triple-negative breast cancer (TNBC) cells rely on a non-canonical glutamine-to-glutamate overflow, with glutamine carbon routed once through the TCA cycle. Importantly, this single-pass glutaminolysis increases TCA cycle fluxes and replenishes TCA cycle intermediates in TNBC cells, a process that achieves net oxidation of glucose but not glutamine. The coupling of glucose and glutamine catabolism appears hard-wired via a distinct TNBC gene expression profile biased to strip and then sequester glutamine nitrogen, but hampers the ability of TNBC cells to oxidise glucose when glutamine is limiting. Our results provide a new understanding of how metabolically rigid TNBC cells are sensitive to glutamine deprivation and a way to select vulnerable TNBC subtypes that may be responsive to metabolic-targeted therapies.

Cancer-Associated Fibroblasts in Pancreatic Ductal Adenocarcinoma Determine Response to SLC7A11 Inhibition

Cancer-associated fibroblasts (CAF) are major contributors to pancreatic ductal adenocarcinoma (PDAC) progression through protumor signaling and the generation of fibrosis, the latter of which creates a physical barrier to drugs. CAF inhibition is thus an ideal component of any therapeutic approach for PDAC. SLC7A11 is a cystine transporter that has been identified as a potential therapeutic target in PDAC cells. However, no prior study has evaluated the role of SLC7A11 in PDAC tumor stroma and its prognostic significance. Here we show that high expression of SLC7A11 in human PDAC tumor stroma, but not tumor cells, is independently prognostic of poorer overall survival. Orthogonal approaches showed that PDAC-derived CAFs are highly dependent on SLC7A11 for cystine uptake and glutathione synthesis and that SLC7A11 inhibition significantly decreases CAF proliferation, reduces their resistance to oxidative stress, and inhibits their ability to remodel collagen and support PDAC cell growth. Importantly, specific ablation of SLC7A11 from the tumor compartment of transgenic mouse PDAC tumors did not affect tumor growth, suggesting the stroma can substantially influence PDAC tumor response to SLC7A11 inhibition. In a mouse orthotopic PDAC model utilizing human PDAC cells and CAFs, stable knockdown of SLC7A11 was required in both cell types to reduce tumor growth, metastatic spread, and intratumoral fibrosis, demonstrating the importance of targeting SLC7A11 in both compartments. Finally, treatment with a nanoparticle gene-silencing drug against SLC7A11, developed by our laboratory, reduced PDAC tumor growth, incidence of metastases, CAF activation, and fibrosis in orthotopic PDAC tumors. Overall, these findings identify an important role of SLC7A11 in PDAC-derived CAFs in supporting tumor growth. SIGNIFICANCE: This study demonstrates that SLC7A11 in PDAC stromal cells is important for the tumor-promoting activity of CAFs and validates a clinically translatable nanomedicine for therapeutic SLC7A11 inhibition in PDAC.

RB/E2F1 as a Master Regulator of Cancer Cell Metabolism in Advanced Disease

Loss of the retinoblastoma (RB) tumor suppressor protein is a critical step in reprogramming biological networks that drive cancer progression, although mechanistic insight has been largely limited to the impact of RB loss on cell-cycle regulation. Here, isogenic modeling of RB loss identified disease stage-specific rewiring of E2F1 function, providing the first-in-field mapping of the E2F1 cistrome and transcriptome after RB loss across disease progression. Biochemical and functional assessment using both in vitro and in vivo models identified an unexpected, prominent role for E2F1 in regulation of redox metabolism after RB loss, driving an increase in the synthesis of the antioxidant glutathione, specific to advanced disease. These E2F1-dependent events resulted in protection from reactive oxygen species in response to therapeutic intervention. On balance, these findings reveal novel pathways through which RB loss promotes cancer progression and highlight potentially new nodes of intervention for treating RB-deficient cancers. SIGNIFICANCE: This study identifies stage-specific consequences of RB loss across cancer progression that have a direct impact on tumor response to clinically utilized therapeutics. The study herein is the first to investigate the effect of RB loss on global metabolic regulation and link RB/E2F1 to redox control in multiple advanced diseases.This article is highlighted in the In This Issue feature, p. 2113.

[Analysis of the feasibility and prognostic value of circulating tumor DNA in detecting gene mutations in small cell lung cancer]

Objective: To investigate the feasibility of circulating tumor DNA (ctDNA) in detecting small cell lung cancer (SCLC) gene mutations and its prognostic value in chemotherapy and/or radiotherapy for SCLC patients. Methods: A total of 77 SCLC patients who were admitted to the Department of Thoracic Medical Oncology and the Department of Thoracic Radiation Oncology of Zhejiang Cancer Hospital from July 2016 to November 2019 were included. There were 66 males and 11 females, with a median age of 60 years. Among them, 42 cases were in limited stage (LS) and 35 cases were in extensive stage (ES). Next-generation sequencing (NGS) of patients' plasma ctDNA was performed before treatment. The differences of mutated genes and signaling pathways between LS and ES patients were analyzed and compared. Blood-based tumor mutation burden (bTMB) was calculated according to detected somatic cell mutations. Patients were divided into the high bTMB and the low bTMB groups according to the optimal threshold calculated by R software. Log-rank tests were used to compare progression-free survival (PFS) between the high bTMB and the low bTMB groups. Results: Among the 77 patients, 76 patients had gene mutations detected in their plasma, and the positive rate of ctDNA test was 98%. Among the 76 patients, the genes with the highest mutation frequency were TP53 (89%), RB1 (70%), LRP1B (34%), CREBBP (21%), MLL3 (21%), MLL2 (16%), NOTCH1 (13%), ROS1 (13%), BRCA2 (12%), and PTPRD (12%). The most common mutated genes in LS patients were TP53 (90%), RB1 (68%), LRP1B (24%), MLL2 (22%), and BRCA2 (17%); the most common mutated genes in ES patients were TP53 (89%), RB1 (71%), LRP1B (46%), CREBBP (31%), and MLL3 (29%). The mutation rates of NOTCH1 and CREBBP genes were significantly higher in ES patients (31.4% and 22.9%) than those in LS patients (11.9% and 4.8%) (both P<0.05). Signaling pathway analysis showed that there were more NOTCH pathway gene variations in ES patients. Among LS patients, patients in the high bTMB group (≥ 6.96 mutations/Mb) had a longer PFS than that in the low bTMB group (<6.96 mutations/Mb) (P=0.033); but no such difference was noted in ES patients. Conclusion: Plasma ctDNA sequencing detected SCLC gene mutation profiles similar to those reported in previous literature, thus ctDNA could be used as a tool to study SCLC genomics; the mutation spectra of ES-SCLC and LS-SCLC were different. bTMB has potential prognostic value in LS-SCLCs treated with chemoradiotherapy.

Molecular underpinnings of RB status as a biomarker of poor outcome in advanced prostate cancer

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Background: There is emergent and compelling evidence to support RB status as a biomarker in advanced prostate cancer. RB loss is strongly associated with poor progression-free, disease-specific, and overall survival in prostate cancer (PCa). Preclinical studies in PCa have revealed RB positive tumors are more responsive to CDK4/6 inhibitors. An ongoing randomized Phase IB/II study of enzalutamide with and without ribociclib in patients with metastatic castration-resistant, chemotherapy naïve PCa has become a pioneer trial to include a positive RB status as inclusion criteria in a PCa study (NCT02555189). Beyond CDK4/6 inhibitors, therapeutic agents that target tumor metabolism have been introduced in the clinic. Current data suggests that RB status may be crucial to understand and predict therapeutic response to these agents within tumors. Methods: The biological significance of RB loss was studied utilizing isogenic model systems and human tumor xenografts of castration resistant prostate cancer (CRPC) with and without RB deletion. The mechanism that drives aggressive tumor phenotypes was identified through comprehensive transcriptomic, cistromic, and metabolomic analysis. Novel functions of RB were identified and the response to clinically-relevant therapeutics was examined. Results: Exclusively in CRPC, RB loss results in significant rewiring of cancer cell metabolism. Functional investigation revealed a causative link between RB loss and antioxidant production sufficient to alter responsiveness to genomic insult and selected chemotherapeutics. Observed changes in response to therapeutic intervention were attributed to RB-dependent modulation of intracellular reactive oxygen species. Conclusions: RB loss is strongly associated with poor outcome in advanced PCa. Molecular investigation identified RB-dependent rewiring of cancer cell metabolism as a significant consequence of RB loss, sufficient to alter response in model systems to therapeutic strategies of clinical relevance. These studies significantly advance understanding of the means by which RB loss enhances lethal tumor phenotypes, and are of relevance for development of RB status as a clinically actionable biomarker.

Genomic origin and EGFR-TKI treatments of pulmonary adenosquamous carcinoma

BACKGROUND

Adenosquamous carcinoma (ASC) of the lung is a heterogeneous disease that is composed of both adenocarcinoma components (ACC) and squamous cell carcinoma components (SCCC). Their genomic profile, genetic origin, and clinical management remain controversial.

PATIENTS AND METHODS

Resected ASC and metastatic tumor in regional lymph nodes (LNs) were collected. The ACC and SCCC were separated by microdissection of primary tumor. The 1021 cancer-related genes were evaluated by next-generation sequencing independently in ACC and SCCC and LNs. Shared and private alterations in the two components were investigated. In addition, genomic profiles of independent cohorts of adenocarcinomas and squamous cell carcinomas were examined for comparison. We have also carried out a retrospective study of ASCs with known EGFR mutation status from 11 hospitals in China for their clinical outcomes.

RESULTS

The most frequent alterations in 28 surgically resected ASCs include EGFR (79%), TP53 (68%), MAP3K1 (14%) mutations, EGFR amplifications (32%), and MDM2 amplifications (18%). Twenty-seven patients (96%) had shared variations between ACC and SCCC, and pure SCCC metastases were not found in metastatic LNs among these patients. Only one patient with geographically separated ACC and SCCC had no shared mutations. Inter-component heterogeneity was a common genetic event of ACC and SCCC. The genomic profile of ASC was similar to that of 170 adenocarcinomas, but different from that of 62 squamous cell carcinomas. The incidence of EGFR mutations in the retrospective analysis of 517 ASCs was 51.8%. Among the 129 EGFR-positive patients who received EGFR-TKIs, the objective response rate was 56.6% and the median progression-free survival was 10.1 months (95% confidence interval: 9.0-11.2).

CONCLUSIONS

The ACC and SCCC share a monoclonal origin, a majority with genetically inter-component heterogeneity. ASC may represent a subtype of adenocarcinoma with EGFR mutation being the most common genomic anomaly and sharing similar efficacy to EGFR TKI.

Recognizing basal cell carcinoma on smartphone-captured digital histopathology images with a deep neural network

BACKGROUND

Pioneering effort has been made to facilitate the recognition of pathology in malignancies based on whole-slide images (WSIs) through deep learning approaches. It remains unclear whether we can accurately detect and locate basal cell carcinoma (BCC) using smartphone-captured images.

OBJECTIVES

To develop deep neural network frameworks for accurate BCC recognition and segmentation based on smartphone-captured microscopic ocular images (MOIs).

METHODS

We collected a total of 8046 MOIs, 6610 of which had binary classification labels and the other 1436 had pixelwise annotations. Meanwhile, 128 WSIs were collected for comparison. Two deep learning frameworks were created. The 'cascade' framework had a classification model for identifying hard cases (images with low prediction confidence) and a segmentation model for further in-depth analysis of the hard cases. The 'segmentation' framework directly segmented and classified all images. Sensitivity, specificity and area under the curve (AUC) were used to evaluate the overall performance of BCC recognition.

RESULTS

The MOI- and WSI-based models achieved comparable AUCs around 0·95. The 'cascade' framework achieved 0·93 sensitivity and 0·91 specificity. The 'segmentation' framework was more accurate but required more computational resources, achieving 0·97 sensitivity, 0·94 specificity and 0·987 AUC. The runtime of the 'segmentation' framework was 15·3 ± 3·9 s per image, whereas the 'cascade' framework took 4·1 ± 1·4 s. Additionally, the 'segmentation' framework achieved 0·863 mean intersection over union.

CONCLUSIONS

Based on the accessible MOIs via smartphone photography, we developed two deep learning frameworks for recognizing BCC pathology with high sensitivity and specificity. This work opens a new avenue for automatic BCC diagnosis in different clinical scenarios. What's already known about this topic? The diagnosis of basal cell carcinoma (BCC) is labour intensive due to the large number of images to be examined, especially when consecutive slide reading is needed in Mohs surgery. Deep learning approaches have demonstrated promising results on pathological image-related diagnostic tasks. Previous studies have focused on whole-slide images (WSIs) and leveraged classification on image patches for detecting and localizing breast cancer metastases. What does this study add? Instead of WSIs, microscopic ocular images (MOIs) photographed from microscope eyepieces using smartphone cameras were used to develop neural network models for recognizing BCC automatically. The MOI- and WSI-based models achieved comparable areas under the curve around 0·95. Two deep learning frameworks for recognizing BCC pathology were developed with high sensitivity and specificity. Recognizing BCC through a smartphone could be considered a future clinical choice.

[Relationship between upper airway volume and polysomnography parameters of patients with obstructive sleep apnea hypopnea syndrome]

Objective:To study the relationship among upper airway volume of naso-pharyngeal, yelo-pharyngeal,glosso-pharyngeal, hypo-pharyngeal area which measured by spiral computed tomography three-dimensional reconstruction technique, apnea hypopnea indexes, and the lowest oxygen saturation in patients with OSAHS.Method:①fifty-one patients with OSAHS were received polysomnography, and then were divided into groups by the AHI,LSaO₂ values. ②To measure upper airway volume at normal breath and Müller maneuver state using spiral computed tomography three-dimensional reconstruction technique of CT measurement, and to calculate volume change rate and observe the upper airway compliance. ③To analyses the relationship between upper airway volume and AHI,LSaO₂ values.Result:The smallest upper airway volume of OSAHS was at the velo-pharyngeal level; the volume of velo-pharyngeal level were negatively correlated with AHI during normal respiration and Müller's maneuver state and were positively correlated with LSaO₂; the volume of hypo-pharyngeal were negatively correlated with AHI during normal respiration; the volume of glosso-pharyngeal were positively correlated with LSaO₂ during Müller's maneuver state.Conclusion:①The volume of velo-pharyngeal level with OSAHS patients can reflect the severity of AHI,LSaO₂. ②The measurement of upper airway volume using spiral computed tomography three-dimensional reconstruction technique is good method to evaluate the upper airway compliance of OSAHS patients.

Benzylserine inhibits breast cancer cell growth by disrupting intracellular amino acid homeostasis and triggering amino acid response pathways

Background

Cancer cells require increased levels of nutrients such as amino acids to sustain their rapid growth. In particular, leucine and glutamine have been shown to be important for growth and proliferation of some breast cancers, and therefore targeting the primary cell-surface transporters that mediate their uptake, L-type amino acid transporter 1 (LAT1) and alanine, serine, cysteine-preferring transporter 2 (ASCT2), is a potential therapeutic strategy.

Methods

The ASCT2 inhibitor, benzylserine (BenSer), is also able to block LAT1 activity, thus inhibiting both leucine and glutamine uptake. We therefore aimed to investigate the effects of BenSer in breast cancer cell lines to determine whether combined LAT1 and ASCT2 inhibition could inhibit cell growth and proliferation.

Results

BenSer treatment significantly inhibited both leucine and glutamine uptake in MCF-7, HCC1806 and MDA-MB-231 breast cancer cells, causing decreased cell viability and cell cycle progression. These effects were not primarily leucine-mediated, as BenSer was more cytostatic than the LAT family inhibitor, BCH. Oocyte uptake assays with ectopically expressed amino acid transporters identified four additional targets of BenSer, and gas chromatography-mass spectrometry (GCMS) analysis of intracellular amino acid concentrations revealed that this BenSer-mediated inhibition of amino acid uptake was sufficient to disrupt multiple pathways of amino acid metabolism, causing reduced lactate production and activation of an amino acid response (AAR) through activating transcription factor 4 (ATF4).

Conclusions

Together these data showed that BenSer blockade inhibited breast cancer cell growth and viability through disruption of intracellular amino acid homeostasis and inhibition of downstream metabolic and growth pathways.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4599-8) contains supplementary material, which is available to authorized users.

Functional Mutations Form at CTCF-Cohesin Binding Sites in Melanoma Due to Uneven Nucleotide Excision Repair across the Motif

CTCF binding sites are frequently mutated in cancer, but how these mutations accumulate and whether they broadly perturb CTCF binding are not well understood. Here, we report that skin cancers exhibit a highly specific asymmetric mutation pattern within CTCF motifs attributable to ultraviolet irradiation and differential nucleotide excision repair (NER). CTCF binding site mutations form independently of replication timing and are enriched at sites of CTCF/cohesin complex binding, suggesting a role for cohesin in stabilizing CTCF-DNA binding and impairing NER. Performing CTCF ChIP-seq in a melanoma cell line, we show CTCF binding site mutations to be functional by demonstrating allele-specific reduction of CTCF binding to mutant alleles. While topologically associating domains with mutated CTCF anchors in melanoma contain differentially expressed cancer-associated genes, CTCF motif mutations appear generally under neutral selection. However, the frequency and potential functional impact of such mutations in melanoma highlights the need to consider their impact on cellular phenotype in individual genomes.

Estrogen/ERR-α signaling axis is associated with fiber-type conversion of upper airway muscles in patients with obstructive sleep apnea hypopnea syndrome

Estrogen is related with the low morbidity associated with obstructive sleep apnea hypopnea syndrome (OSAS) in women, but the underlying mechanisms remain largely unknown. In this study, we examined the relationship between OSAS and estrogen related receptor-α (ERR-α). We found that the expression levels of ERR-α and Myh7 were both downregulated in palatopharyngeal tissues from OSAS patients. In addition, we report that ERR-α is dynamically expressed during differentiation of C2C12 myoblasts. Knockdown of ERR-α via instant siRNA resulted in reduced expression of Myh7, but not Myh4. Furthermore, differentiation of C2C12 cells under 3% chronic intermittent hypoxia, a model resembling human OSAS, was impaired and accompanied by a obvious reduction in Myh7 expression levels. Moreover, activation of ERR-α with 17β-estradiol (E2) increased the expression of Myh7, whereas pretreatment with the ERR-α antagonist XCT790 reversed the E2-induced slow fiber-type switch. A rat ovariectomy model also demonstrated the switch to fast fiber type. Collectively, our findings suggest that ERR-α is involved in estrogen-mediated OSAS by regulating Myhc-slow expression. The present study illustrates an important role of the estrogen/ERR-α axis in the pathogenesis of OSAS, and may represent an attractive therapeutic target, especially in postmenopausal women.

Pulsed laser dewetting of nickel catalyst for carbon nanofiber growth

We present a pulsed laser dewetting technique that produces single nickel catalyst particles from lithographically patterned disks for subsequent carbon nanofiber growth through plasma enhanced chemical vapor deposition. Unlike the case for standard heat treated Ni catalyst disks, for which multiple nickel particles and consequently multiple carbon nanofibers (CNFs) are observed, single vertically aligned CNFs could be obtained from the laser dewetted catalyst. Different laser dewetting parameters were tested in this study, such as the laser energy density and the laser processing time measured by the total number of laser pulses. Various nickel disk radii and thicknesses were attempted and the resultant number of carbon nanofibers was found to be a function of the initial disk dimension and the number of laser pulses.

Synthesis and alignment of Zn and ZnO nanoparticles by laser-assisted chemical vapor deposition

A simple, versatile, and fast laser-assisted chemical vapor deposition (LCVD) technique that produces linear arrays of Zn and ZnO nanoparticles on a silicon substrate, covering an extended region, is described. A series of consecutive steps is involved in the synthesis and alignment of Zn/ZnO nanoparticles. First, a Lloyd's mirror arrangement is employed to produce two types of periodic nanostructure, i.e., nanoripples and nanoprotrusions. Next, the nanostructured substrate is laser irradiated at a fluence of 60 mJ cm(-2) in the presence of the metall-organic (MO) precursor gas diethylzinc (DEZn). The evolution of the Zn nanocrystals by LCVD processing was studied as a function of precursor gas pressure and laser fluence by ex situ high-resolution scanning electron microscopy (SEM). Laser irradiation fulfills a double role: it decomposes the adsorbed precursor and causes the evolution of resulting Zn into aligned aggregates of zinc nanoparticles. The Zn nanoparticles react with oxygen upon high-temperature thermal annealing to yield aligned assemblies of ZnO nanoparticles. The production of ZnO was confirmed by x-ray diffraction (XRD) and photoluminescence spectra. This technique is general and could be used in a large number of substrate/precursor combinations.

[Laser-induced fluorescence detection in micro-column separation]

Laser-induced fluorescence detection (LIFD) has been used extensively in micro-column separation due to its high sensitivity and selectivity. A review is presented on the present status and the trends of development of LIF detector with 52 references cited. The detection cells of the LIFD are mainly discussed.

Alterations in lipoxygenase and cyclooxygenase-2 catalytic activity and mRNA expression in prostate carcinoma

Recent studies in prostate tissues and especially cell lines have suggested roles for arachidonic acid (AA) metabolizing enzymes in prostate adenocarcinoma (Pca) development or progression. The goal of this study was to more fully characterize lipoxygenase (LOX) and cyclooxygenase-2 (COX-2) gene expression and AA metabolism in benign and malignant prostate using snap-frozen tissues obtained intraoperatively and mRNA analyses and enzyme assays. Formation of 15-hydroxyeicosatetraenoic acid (15-HETE) was detected in 23/29 benign samples and 15-LOX-2 mRNA was detected in 21/25 benign samples. In pairs of pure benign and Pca from the same patients, 15-HETE production and 15-LOX-2 mRNA were reduced in Pca versus benign in 9/14 (P=.04) and 14/17 (P=.002), respectively. Under the same conditions, neither 5-HETE nor 12-HETE formation was detectable in 29 benign and 24 tumor samples; with a more sensitive assay, traces were detected in some samples, but there was no clear association with tumor tissue. COX-2 mRNA was detected by nuclease protection assay in 7/16 benign samples and 5/16 tumors. In benign and tumor pairs from 10 patients, COX-2 was higher in tumor versus benign in only 2, with similar results by in situ hybridization. Paraffin immunoperoxidase for COX-2 was performed in whole mount sections from 87 additional radical prostatectomy specimens, with strong expression in ejaculatory duct as a positive control and corroboration with in situ hybridization. No immunostaining was detected in benign prostate or tumor in 45% of cases. Greater immunostaining in tumor versus benign was present in only 17% of cases, and correlated with high tumor grade (Gleason score 8 and 9 vs. 5 to 7). In conclusion, reduced 15-LOX-2 expression and 15-HETE formation is the most characteristic alteration of AA metabolism in Pca. Increased 12-HETE and 5-HETE formation in Pca were not discernible. Increased COX-2 expression is not a typical abnormality in Pca in general, but occurs in high-grade tumors.

[Preparation and evaluation of wide-bore stainless-steel packed capillary liquid chromatographic columns]

A zero-dead volume column end and a conical shaped slurry reservoir for wide-bore stainless-steel packed capillary liquid chromatographic columns were designed and evaluated. A detailed procedure for the preparation of reversed-phase stainless-steel packed capillary columns with 0.5 mm-1.0 mm i.d. is described. The influences of the column length and the packing material on the column performance have been studied. Columns were evaluated by the reduced plate height vs reduced velocity curve and the peak asymmetric factor. Experimental results showed that the column efficiency and the reproducibility were better than 75% of theoretical value and 6% RSD, respectively. Separations of antiepileptic drugs and chlorinated benzenes are demonstrated.

[Analysis of group composit of crude oil by on-line coupling of capillary HPLC-HTGC]

The group composition of crude oil was analyzed by on-line coupled capillary HPLC-HTGC. After removal of asphaltenes, the oil sample was separated by capillary HPLC into aliphatics, aromatics and resins. The interface cut and stored each fraction, and transfered them into GC sequentially. The group contents of oil were determined by FID. The error of reproducibility(RSD) was less than 3%. The method is accurate, time saving, and easy for operation. It is very important for quality control and development of new and better products in crude oil.

[Enantioseparation of twelve pharmaceutical racemates with high performance capillary electrophoresis using L-leucine as chiral selector]

A rapid enantiomeric separation method using L-leucine as chiral selector was established. Capillary zone electrophoresis (CZE) has been used for the enantiomeric separation of twelve pharmaceutical racemates with bare fused silica capillary and employing L-leucine as chiral selector. The enantiomeric resolution was influenced by L-leucine concentration and pH of background electrolyte (BGE). The effects of the BGE types and concentrations on the enantiomeric separation were also investigated. The results showed that in the solution containing 50 mmol/L borax and 70 mmol/L L-leucine (pH 9.0), all the twelve drugs were on baseline separated in less than 11 minutes.

[Dynamic pre-concentration method of gas sample]

By utilizing the combination of frontal chromatography at ambient temperature, back-flushing and temperature gradient thermal desorption, a prototype of a dynamic pre-concentration system has been designed and evaluated. It realized the enrichment for gas samples of boiling point higher than - 103 degrees C without cryogenic facilities. To reduce the sample volume and enhance enrichment factor, the technique of momentarily non-steady state produced at the beginning of back-flushing, and the negative temperature gradient generated during thermal desorption were utilized, resulting a very sharp desorption band. Standard samples were tested to demonstrate the applicability of the method. At 10 mL sample volume, the enrichment factor was 100.

[Conical column end for wide bore packed capillary liquid chromatographic column]

Wide bore (> or = 0.5 mm i.d.) packed capillary liquid chromatographic columns with conical end were designed and evaluated. It was found that the column efficiency was 30%-50% higher than that of the packed capillary columns with conventional end connection at optimal flow rate, and was twice as much as that at reduced flow rate of 10-15. The chromatographic peak symmetry and the van Deemter curve of the novel shape column were also improved substantially. Fast analysis of PAHs is demonstrated.

Expression of peroxisome proliferator-activated receptor gamma (PPARgamma) in human transitional bladder cancer and its role in inducing cell death

The present study examined the expression and role of the thiazolidinedione (TZD)-activated transcription factor, peroxisome proliferator-activated receptor gamma (PPARgamma), in human bladder cancers. In situ hybridization shows that PPARgamma mRNA is highly expressed in all human transitional epithelial cell cancers (TCCa's) studied (n=11). PPARgamma was also expressed in five TCCa cell lines as determined by RNase protection assays and immunoblot. Retinoid X receptor alpha (RXRalpha), a 9-cis-retinoic acid stimulated (9-cis-RA) heterodimeric partner of PPARgamma, was also co-expressed in all TCCa tissues and cell lines. Treatment of the T24 bladder cancer cells with the TZD PPARgamma agonist troglitazone, dramatically inhibited 3H-thymidine incorporation and induced cell death. Addition of the RXRalpha ligands, 9-cis-RA or LG100268, sensitized T24 bladder cancer cells to the lethal effect of troglitazone and two other PPAR- activators, ciglitazone and 15-deoxy-delta(12,14)-PGJ2 (15dPGJ(2)). Troglitazone treatment increased expression of two cyclin-dependent kinase inhibitors, p21(WAF1/CIP1) and p16(INK4), and reduced cyclin D1 expression, consistent with G1 arrest. Troglitazone also induced an endogenous PPARgamma target gene in T24 cells, adipocyte-type fatty acid binding protein (A-FABP), the expression of which correlates with bladder cancer differentiation. In situ hybridization shows that A-FABP expression is localized to normal uroepithelial cells as well as some TCCa's. Taken together, these results demonstrate that PPARgamma is expressed in human TCCa where it may play a role in regulating TCCa differentiation and survival, thereby providing a potential target for therapy of uroepithelial cancers.

Regulation of renal function by prostaglandin E receptors

Prostaglandin E2 is the major cyclooxygenase product of arachidonic acid metabolism produced along the nephron. This autacoid interacts with four distinct, G-protein-coupled E-prostanoid receptors designated EP1-EP4. The intrarenal distribution of each receptor has been mapped and the consequences of receptor activation examined. EP3 receptor mRNA is expressed highly in the medullary thick ascending limb (mTAL) and collecting duct (CD). EP3 receptor activation inhibits cAMP generation via Gi, thus inhibiting vasopressin-stimulated water reabsorption in the CD. EP3 receptor activation also may contribute to PGE2-mediated inhibition of NaCl absorption in the mTAL. The EP1 receptor is coupled to increased cell [Ca2+]. EP1 mRNA expression is restricted to the CD, and receptor activation inhibits Na+ absorption. PGE2 also increases cAMP generation in the cortical thick ascending limb and CD; this may be due to EP4 receptor activation. EP4 mRNA is readily detected in the CD with little detectable EP2 expression. The EP4 receptor appears to be expressed both on luminal and basolateral membranes. EP4 receptor activation also may contribute to the regulation of renin release by the juxtaglomerular apparatus. The consequences of renal EP-receptor activation for salt and water balance may be determined by the relative renal expression of each of these receptors.

Prevention of myocardial reperfusion injury with free radical scavengers. An experimental study

The changes in endogenous superoxide dismutase (ESOD) during myocardial ischemia and reperfusion and the efficacy of oxygen free radical scavengers in myocardial protection were investigated in an isolated heart model connected with the recirculating nonpulsatile perfusion circuit. Subjected to a 2-hour period of global ischemia (27 C), the heart was reperfused with 37 C oxygen diluted auto-blood for 60 minutes. Superoxide dismutase plus catalase was added into the cardioplegic solution and reperfusates. ESOD activity was measured by pyrogallol method. The results of the experiment showed that ESOD activity after ischemia and reperfusion was decreased and the addition of oxygen free radical scavengers (SOD and CAT) to the cardioplegic solution and the reperfusates greatly reduced the leakage of myocardial enzymes, coronary vascular resistance, and the ultrastructural damages of the myocardium. These results suggest that the use of SOD and CAT may inhibit myocardial reperfusion injury by scavenging oxygen-derived free radicals.