Is routine gastrointestinal endoscopy required in every woman with mucinous ovarian cancer? An analysis of survival rates and metastatic tumours in a cancer centre

INTRODUCTION

Mucinous ovarian cancer (MOC) represents a rare entity of ovarian malignant neoplasms. The true incidence could be as low as 3% of all ovarian cancers. The aim of this study is to compare and understand the clinicopathological characteristics of patients with mucinous ovarian cancer, report on the survival rates and evaluate the role of gastrointestinal (GI) endoscopy as part of the peri-operative investigations and the impact it has on the survival rates.

METHODOLOGY

This is a retrospective data collection on patients with MOC operated in Nottingham gynaecological oncology centre over a 10-year period. Data were analysed using SPSS software.

RESULTS

43 cases were included in the final analysis. The median maximal tumour diameter was 180 mm. 32 (74.5 %) and 11 (25.5 %) women presented with unilateral and bilateral tumours respectively. 30 patients (69.7 %) presented with stage 1 disease, 1 (2.3 %) presented with stage 2 disease, 7 women (16.4 %) had stage 3 disease and 1 woman (11.6 %) had stage 4 disease. 41 women had staging surgical procedures and 2 women had limited surgery due to poor performance status. After final histology, 5 cases found to have metastatic disease to the ovary rather than primary MOC. 14 women had GI endoscopy as part of their investigation. The total estimated cost of the endoscopies that have been performed is £5635. Primary GI cancer was diagnosed in 1 case during the endoscopy (1 case of gastric cancer). The 5-year overall survival of the women included in this study is 62.8 %. The 5-year overall survival of the women in the endoscopy and non-endoscopy groups was 60 % and 64.3 % respectively (p-value: 0.767).

CONCLUSION

The findings of this study show that the survival rates of patients treated for mucinous ovarian cancer in our centre are similar to other published studies. Our findings do not support the routine use of GI endoscopy in the peri-operative investigations of every patient with MOC due to the non-statistically significant difference in the overall survival.

Pyruvate carboxylase deficiency type C; variable presentation and beneficial effect of triheptanoin

Pyruvate carboxylase is a mitochondrial enzyme essential for the tricarboxylic acid cycle (TCA), gluconeogenesis and fatty-acid synthesis. Pyruvate carboxylase deficiency (PCD) mostly presents with life-limiting encephalopathy (types A/B). A milder type C presentation is rare, with a comparatively favourable prognosis. Therapies remain essentially supportive. Triheptanoin is an odd-chain triglyceride, with the potential to replenish TCA intermediates (anaplerosis), and its metabolites cross the blood-brain-barrier. Outcomes of triheptanoin treatment in PCD types A/B have been disappointing, but have not been reported in type C. Here, we present two new patients with PCD type C, and report the response to treatment with triheptanoin in one. Patient 1 (P1) presented with neonatal-onset lactic acidosis and recurrent symptomatic lactic acidosis following exercise and during illnesses, with frequent hospitalisations. Speech development was delayed. MRI-brain showed delayed cerebral myelination. Patient 2 (P2) presented with episodic ketoacidosis, hyperlactataemia and hypoglycaemia at 2 years of age, with gross motor delay and mild global volume loss on MRI brain. Treatment with triheptanoin was commenced in P1 at 3 years of age with up-titration to 35 mL/day (25% of daily energy intake) over 6 months, due to transient diarrhoea. Dietary long-chain triglycerides were restricted, with fat-soluble vitamin supplementation. Subsequently, hospitalisations during intercurrent illnesses decreased, post-exertional hyperlactataemia resolved and exercise tolerance improved. Continued developmental progress was observed, and repeat MRI 18 months after initiation showed improved myelination. Triheptanoin was well-tolerated and appeared efficacious during 2 years' follow-up, and has potential to restore energy homeostasis and myelin synthesis in PCD type C.

[Eriocitrin suppresses proliferation and migration of hepatocellular carcinoma SMMC-7721 cells by promoting ROS production and activating the MAPK pathway]

OBJECTIVE

To investigate the role of the ROS/MAPK signaling axis in mediating the inhibitory effect of eriocitrin on proliferation and migration of hepatocellular carcinoma SMMC-7721 cells.

METHODS

SMMC-7721 cells were treated with different concentrations of eriocitrin for 24 h, and the changes in cell viability were detected with CCK-8 assay. The migration and invasion abilities of the treated cells were evaluated using Transwell and scratch healing assays, the cell proliferation was assessed with colony-forming assay, and changes in nuclear morphology were observed with DAPI staining. Western blotting was performed to examine the changes in the expressions of E-cadherin, N-cadherin, MMP-2, MMP-9, PARP, Pro-caspase 3, pJNK, p-P38, and p-ERK. The effect of eriocitrin on PARP cleavage in SMMC-7721 cells pretreated with ERK, JNK and P38 inhibitors (U0126, SB203580 and SP600125, respectively) was detected using Western blotting. The effect of treatment with Nacetyl-cysteine (NAC, 30 μmol/L) and eriocitrin (100, 200, and 300 μg/mL), alone or in combination, on reactive oxygen species (ROS) levels in the cells was examined using a DCFH-DA fluorescent probe.

RESULTS

Eriocitrin below 50 μg/mL did not produce significant effect on the viability of SMMC-7721 cells (P>0.05). Treatment with eriocitrin significantly inhibited scratch healing, migration, and colony formation of the cells (P < 0.01), reduced the protein expressions of N-cadherin, MMP-2, and MMP-9 (P < 0.01), and up-regulated E-cadherin protein expression (P < 0.05). Eriocitrin-treated SMMC-7721 cells showed obvious apoptotic morphologies with decreased Procaspase 3 expression and increased PARP cleavage (P < 0.01) and phosphorylation levels of JNK, P38, and ERK (P < 0.01); Eriocitrin-induced PAPR cleavage was obviously enhanced by U0126 and SB203580 but attenuated by SP600125. Treatment with 300 μg/mL eriocitrin for 30 min significantly increased ROS level in the cells, and this effect was obviously suppressed by NAC.

CONCLUSION

Eriocitrin can suppress the proliferation and migration and promote apoptosis of hepatocellular carcinoma SMMC-7721 cells by promoting ROS production and activating the MAPKs signaling pathway.

Left distal ureter leiomyosarcoma: a case report

Primary leiomyosarcoma of the ureter is an extremely rare, aggressive malignancy of the urinary tract. This report describes a case of primary leiomyosarcoma of the distal left ureter in a middle-aged male, with no tumor recurrence achieved following resection and end-to-end ureteroureterostomy.

582 Transperineal Prostate Biopsies: Complication Rates and Predictors of Significant Malignancy

Aim

To ascertain the risks of undergoing a transperineal biopsy. To investigate the relationship between assessment tools and biopsy result.

Method

100 consecutive patients who received a transperineal biopsy between January and June 2021 in Lister Hospital completed a questionnaire. Their investigation results were recorded, and data analysed.

Results

Complication rates revealed 10% sustained heavy bleeding, 2% went into urinary retention, and 2% were treated with antibiotics for suspected urinary tract infection.

Erectile dysfunction was not included on the questionnaire, however 4% raised this as a concern.

Average number of cores appeared to be higher in those with complications compared to the whole sample.

Pain score generally decreased with age, over 75s averaged 3.9/10 whilst under 65s averaged as 5.4/10.

High PSA density and high PIRADS scores are well correlated with risk of positive biopsy

PIRADS 2 was an exception to this trend, showing 14% had Gleason &gt;6 compared with 9% in PIRADS 3. Not all PIRADS 2 patients will routinely receive a biopsy and therefore this could be down to preselection bias.

All Gleason &gt;6 cases in PIRADS 2 and PIRADS 3 had PSA density &gt;0.15.

Conclusions

Overall complication rate is low with no readmissions. The procedure is tolerated reasonably well and 85% would be willing to have the procedure again. Possible correlation between number of cores and complications. High PSA density and high PIRADS scores are well correlated with risk of positive biopsy. PIRADS 3 with low PSA density have a low proportion of positive biopsy.

[Mechanism of PI3K/AKT/mTOR signaling pathway for mediating anti-inflammatory and anti-oxidant effects of chrysin: a protein microarray-based study]

OBJECTIVE

To investigate the mechanism of PI3K/AKT/mTOR signaling pathway for mediating the anti-inflammatory and anti-oxidant effects of chrysin.

METHODS

RAW264.7 cells were treated with different concentrations of chrysin for 24 h, and the changes in cell viability were detected using CCK-8 method. The cells with or without chrysin pretreatment for 2 h were stimulated with lipopolysaccharide (LPS) for different lengths of time, and the related signal molecules were screened using protein chip technique. In cells pretreated with chrysin for 2 h followed by LPS stimulation for 18 h, the release of IL-6, MCP-1 and TNF-α by the cells was detected with ELISA, and NO production was examined using Griess method, and ROS level was determined using DCFH-DA. The effects of chrysin, LPS, and their combination on the mRNA expressions of iNOS and COX-2 were detected using RT-PCR; Western blotting was performed to examine the changes in cellular expressions of p-AKT, p-PRAS40, p-mTOR, mTOR, p-P70S6k, p-S6RP and S6RP following the treatments with LPS, N-Acetyl-L-cysteine, and chrysin, alone or in combinations.

RESULTS

Chrysin below 60 μg/mL did not significantly affect the viability of RAW264.7 cells (P>0.05). Chrysin treatment significantly reduced the release of IL-6, MCP-1, and TNF-α and the level of NO (P < 0.01), and inhibited the mRNA and protein expressions of iNOS and COX-2 (P < 0.01) in the cells. The results of protein chip screening suggested that LPS could activate the AKT/mTOR pathway, which was significantly inhibited by chrysin pretreatment, and the results were verified by Western blotting (P < 0.01). Chrysin treatment significantly reduced the generation of endogenous ROS, and treatment with N-Acetyl-L-cysteine to eliminate intracellular ROS obviously reduced the expressions of iNOS and COX-2 (P < 0.05) and blocked the AKT/mTOR pathway (P < 0.05).

CONCLUSION

Chrysin can inhibit the synthesis of the upstream signaling molecule ROS to inhibit the activation of AKT/mTOR signaling pathway, regulate the translation process of ribosomes, down-regulate the synthesis and release of pro-inflammatory cytokines and inflammatory mediators, and thus produce anti-inflammatory effects.

AFM detects the effects of acidic condition on the size and biomechanical properties of native/oxidized low-density lipoprotein

Solution acidification exists under some physiological conditions (e.g. lysosomes in cells) and diseases (e.g. atherosclerosis, tumors, etc.). It is poorly understood whether and how acidification influences the size and biomechanical (stiffness and stickiness) properties of native Low-density lipoprotein (LDL) and its oxidized form (oxLDL) which plays a vital role in atherogenesis and tumorigenesis. Atomic force microscopy (AFM) evaluated that gradient acidification from pH 7.4 to pH 4.4 caused an expanding-first-and-then-shrinking decrease in size and a dramatic decrease in stiffness (but no statistically significant changes in stickiness) of LDL/oxLDL particles by influencing secondary/tertiary structures and lipid release detected by infrared spectral analysis and cholesterol detection, respectively. The smaller and softer characteristics of LDL/oxLDL at acidic conditions versus at the neutral pH partially explains the atherogenic role of acidification. The data may provide important information for a better understanding of LDL/oxLDL and some diseases (e.g. atherosclerosis and tumors).

[A multicenter randomized controlled study of bismuth-containing quadruple therapy followed by Jing-Hua-Wei-Kang in the treatment of patients newly diagnosed with Helicobacter pylori infection and dyspepsia]

Objective: To investigate the Helicobacter pylori (H. pylori) eradication rate and improvement of dyspepsia in patients who were newly diagnosed with H. pylori infection and dyspepsia and treated by bismuth-containing quadruple therapy followed by Jing-Hua-Wei-Kang(JHWK). Methods: Patients who were newly diagnosed with dyspepsia and H. pylori infection and treated in 16 medical centers in China between December 1, 2017 and September 30, 2019 were randomly divided into two groups. The experimental group received bismuth-containing quadruple therapy (esomeprazole+amoxicillin+furazolidone+colloidal bismuth pectin capsule, 14 days), followed by JHWK (30 days), and the course of treatment was 44 days in total. In the control group, the administration regimen was bismuth-containing quadruple therapy (esomeprazole+amoxicillin+furazolidone+colloidal bismuth pectin capsule, 14 days). The main outcome measure was H. pylori eradication rate, while the secondary outcome measures were dyspepsia symptom changes and adverse events during the treatment and the 1st month after treatment. Results: A total of 1 054 patients were included in the study. There were 522 cases enrolled in the experimental group, including 224(42.91%) men and 298(57.09%) women, and the age was 53(26, 73) years old; 532 cases enrolled in the control group, including 221(41.54%) men and 311(58.46%) women, and the age was 46(22, 71) years old. Based on PP analysis, it was found that the H. pylori eradication rate in the experimental group was significantly higher than those in the control group (93.85% vs 87.88%, P=0.001). In the group of all enrolled patients, the symptom dyspepsia after H. pylori eradication was significantly improved compared with that before treatment [4(4, 7) vs 15(10, 22), P<0.001], so was the superior and middle abdominal pain [1(1, 4) vs 4(1, 8), P<0.001], the postprandial fullness [1(1, 4) vs 4(4, 9), P<0.001], the early satiety [1(1, 1) vs 4(1, 4), P<0.001], and the heartburn [1(1, 1) vs 1(1, 4), P<0.001]. The symptom dyspepsia after treatment was significantly improved compared with that before treatment in the experimental, the control groups, the successful and the unsuccessful H. pylori eradication groups. The superior and middle abdominal pain after treatment was signifcantly improved than that before treatment [1(1, 2) vs 1(1, 4), P<0.001], so were the postprandial fullness [1(1, 3) vs 1(1, 4), P=0.002] and the dyspepsia[4(4, 7) VS 7(4, 10), P<0.001]. There was no statistically significant difference in the incidence of adverse events between the experimental group and the control group (1.34% vs 0.38%, P=0.09). Conclusions: Compared with bismuth-containing quadruple therapy, bismuth-containing quadruple therapy followed by JHWK significantly improves the H. pylori eradication rate without increasing the incidence of adverse events. H. pylori eradication therapy can improve symptoms of patients with H. pylori infection and dyspepsia.

Notoginsenoside R1 protects hypoxia-reoxygenation deprivation-induced injury by upregulation of miR-132 in H9c2 cells

BACKGROUND

Myocardial ischemia/reperfusion injury (IRI) is a common perioperative complication of heart and great vessels surgery, aggravating the original myocardial damage and seriously affecting the postoperative recovery of cardiac function. The aim of this study was to reveal the functional effects and potential mechanisms of notoginsenoside R1 (NG-R1) in myocardial cells injured by hypoxia-reoxygenation (H/R).

METHODS

The rat cardiomyocyte line H9c2 was subjected to H/R with or without NG-R1 treatment. The levels of miR-132 and HBEGF in the cell were altered by microRNA or short-hairpin RNA transfection. Cell viability, apoptosis, lactate dehydrogenase (LDH) and malondialdehyde (MDA) were monitored. Dual luciferin was used to detect the relationship between miR-132 and HBEGF.

RESULTS

NG-R1 (20 μM) had no impact on H9c2 cells, but cell viability was significantly reduced at 80 μM. NG-R1 (20 μM) protected H9c2 cells against H/R-induced cell damage, accompanied by increased cell viability, reduced cell apoptosis, and downregulation of LDH and MDA. Furthermore, the level of miR-132 was decreased in response to H/R exposure but then increased after NG-R1 treatment. When miR-132 was overexpressed, H/R-induced cell damage could be recovered. Downregulation of miR-132 limited the protective effect of NG-R1 on H/R damage. We also found that HBEGF was a direct target of miR-132. The expression of HBEGF was increased upon H/R damage, and this increase was reversed after NG-R1 treatment.

CONCLUSIONS

This study demonstrated that NG-R1 markedly protected H9c2 cells against H/R-induced damage via upregulation of miR-132 and downregulation of its target protein HBEGF.

Attitudes towards risk-reducing early salpingectomy with delayed oophorectomy for ovarian cancer prevention: a cohort study

OBJECTIVE

To determine risk-reducing early salpingectomy and delayed oophorectomy (RRESDO) acceptability and effect of surgical prevention on menopausal sequelae/satisfaction/regret in women at increased ovarian cancer (OC) risk.

DESIGN

Multicentre, cohort, questionnaire study (IRSCTN:12310993).

SETTING

United Kingdom (UK).

POPULATION

UK women without OC ≥18 years, at increased OC risk, with/without previous RRSO, ascertained through specialist familial cancer/genetic clinics and BRCA support groups.

METHODS

Participants completed a 39-item questionnaire. Baseline characteristics were described using descriptive statistics. Logistic/linear regression models analysed the impact of variables on RRESDO acceptability and health outcomes.

MAIN OUTCOMES

RRESDO acceptability, menopausal sequelae, satisfaction/regret.

RESULTS

In all, 346 of 683 participants underwent risk-reducing salpingo-oophorectomy (RRSO). Of premenopausal women who had not undergone RRSO, 69.1% (181/262) found it acceptable to participate in a research study offering RRESDO. Premenopausal women concerned about sexual dysfunction were more likely to find RRESDO acceptable (odds ratio [OR] = 2.9, 95% CI 1.2-7.7, P = 0.025). Women experiencing sexual dysfunction after premenopausal RRSO were more likely to find RRESDO acceptable in retrospect (OR = 5.3, 95% CI 1.2-27.5, P < 0.031). In all, 88.8% (143/161) premenopausal and 95.2% (80/84) postmenopausal women who underwent RRSO, respectively, were satisfied with their decision, whereas 9.4% (15/160) premenopausal and 1.2% (1/81) postmenopausal women who underwent RRSO regretted their decision. HRT uptake in premenopausal individuals without breast cancer (BC) was 74.1% (80/108). HRT use did not significantly affect satisfaction/regret levels but did reduce symptoms of vaginal dryness (OR = 0.4, 95% CI 0.2-0.9, P = 0.025).

CONCLUSION

Data show high RRESDO acceptability, particularly in women concerned about sexual dysfunction. Although RRSO satisfaction remains high, regret rates are much higher for premenopausal women than for postmenopausal women. HRT use following premenopausal RRSO does not increase satisfaction but does reduce vaginal dryness.

TWEETABLE ABSTRACT

RRESDO has high acceptability among premenopausal women at increased ovarian cancer risk, particularly those concerned about sexual dysfunction.

Study on molecular mechanism of MiRNA-29a in promoting proliferation and invasion of non-small-cell lung cancer by inhibiting MTSS1

OBJECTIVE

To investigate the biological role of micro-ribonucleic acid (miR)-29a in non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

55 cases of NSCLC tissue specimens and paired normal lung tissue specimens collected in the Department II of Oncology, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine from July 2012 to April 2015 were randomly included. The fluorescent quantitative polymerase chain reaction, Western blotting, and immunohistochemistry were performed to detect the expression levels of miR-29a and metastasis suppressor 1 (MTSS1). Pearson correlation analysis was utilized to investigate the relationship between miR-29a expression and MTSS1 expression in NSCLC tissues, and the Kaplan-Meier survival curves were constructed to analyze the association of miR-29a expression with the survival time of NSCLC patients. A54 proliferation and invasion abilities were measured by means of plate clone formation assay, and transwell assay after the miR-29a was suppressed by miRNA inhibitor. Luciferase assay was used to detect the target gene of miR-29a.

RESULTS

In NSCLC tissues, the miR-29a expression level was higher than that in normal lung tissues (p<0.05), while the expression level of MTSS1 protein was remarkably lower than that in normal lung tissues (p<0.05). The median survival time of the patients was 15.1 months in high miR-29a expression group and 18.3 months in low miR-29a expression group (p<0.05). The miR-29a expression was negatively correlated with the expression level of MTSS1 protein in NSCLC tissues (r=-0.762, p<0.05). Luciferase results suggest that miR-29a binds to the promoter region of MTSS1 and inhibits its transcription level. The expression of MTSS1 protein was up-regulated notably after miR-29a knockdown by an inhibitor. It was revealed in the results of transwell assay and plate clone formation assay that the proliferative and invasive capacity of A549 cells was significantly decreased after knockdown of miR-29a.

CONCLUSIONS

The transcribed miR-29a down-regulates the protein level of MTSS1, suppressor of tumor proliferation and invasion, thereby promoting the proliferative and invasive capacity of NSCLC cells. Both miR-29a and MTSS1 are expected to become potential therapeutic targets for NSCLC.

A prospective clinical, cost and environmental analysis of a clinician-led virtual urology clinic

INTRODUCTION

A virtual clinic is a form of telemedicine where contact between clinical teams and patients occur without face-to-face consultation. Our study aims to quantify the clinical, financial and environmental benefits of our virtual urology clinic.

MATERIAL AND METHODS

We collected data prospectively from our weekly follow-up virtual clinic over a continuous four-month period between July and September 2017.

RESULTS

In total, we reviewed 409 patients. Following virtual clinic consultation, 68.5% of our patients were discharged from further follow-up. The majority of our patients (male 57.7%, female 55.5%) were of working age. The satisfaction scores were high, at 90.1%, and there were no reported adverse events as a result of using the virtual clinic. Our calculated cost savings were £18,744, with a predicted 12-month cost saving of £56,232. The creation of additional face-to-face clinic capacity has created an estimated 12-month increase in tariff generation for our unit of £72,072. In total, 4623 travel miles were avoided by patients using the virtual clinic, with an estimated avoided carbon footprint of 0.35-1.45 metric tonnes of CO2e, depending on mode of transport. Our predicted 12-month avoided carbon footprint is 1.04-4.04 metric tonnes of CO2e.

CONCLUSIONS

Our virtual clinic model has demonstrated a trifecta of positive outcomes, namely, clinical, financial and environmental benefits. The environmental importance and benefits of a virtual clinic should be promoted as a social enterprise value when engaging stakeholders in setting up such a urological service. We propose the adoption of our virtual clinic model in those urological units considering this method of telemedicine.

Comparative investigation on the sizes and scavenger receptor binding of human native and modified lipoprotein particles with atomic force microscopy

BACKGROUND

The size and receptor-binding abilities of plasma lipoproteins are closely related with their structure/functions. Presently, the sizes of native lipoproteins have been measured by various methods including atomic force microscopy (AFM) whereas the sizes of modified lipoproteins are poorly determined and the receptor-binding ability of lipoproteins is less detected and compared at the nanoscale.

METHODS

Here, AFM was utilized to detect/compare the size and scavenger receptor-binding properties of three native human lipoproteins including high-density lipoprotein, low-density lipoprotein (LDL), and very low-density lipoprotein, and two modified human lipoproteins including oxidized and acetylated LDL, as well as bovine serum albumin and their antibodies as negative and positive controls, respectively.

RESULTS

AFM detected that the sizes of these lipoproteins are close to the commonly known values and the previously-reported AFM-detected sizes and that native and modified LDL have different height/size. AFM also revealed that the CD36-binding abilities of the five lipoproteins are different from one another and from their SR-B1-binding abilities and that the anti-CD36/SR-B1 antibodies as positive controls have strong CD36/SR-B1-binding abilities.

CONCLUSIONS

The data provide important information on lipoproteins for better understanding their structures/functions. Moreover, the data certify that besides size measurement AFM also can visualize receptor-lipoprotein binding at the nanoscale, as well as antigen-antibody (scavenger receptors and their antibodies) binding.

Subunit Vaccines Consisting of Antigens from Dormant and Replicating Bacteria Show Promising Therapeutic Effect against Mycobacterium Bovis BCG Latent Infection

To screen effective antigens as therapeutic subunit vaccines against Mycobacterium latent infection, we did bioinformatics analysis and literature review to identify effective antigens and evaluated the immunogenicity of five antigens highly expressed in dormant bacteria, which included Rv2031c (HspX), Rv2626c (Hrp1), Rv2007c (FdxA), Rv1738 and Rv3130c. Then, several fusion proteins such as Rv2007c-Rv2626c (F6), Rv2031c-Rv1738-Rv1733c (H83), ESAT6-Rv1738-Rv2626c (LT40), ESAT6-Ag85B-MPT64_<190-198> -Mtb8.4 (EAMM), and EAMM-Rv2626c (LT70) were constructed and their therapeutic effects were evaluated in pulmonary Mycobacterium bovis Bacilli Calmette-Guérin (BCG) - latently infected rabbit or mouse models. The results showed that EAMM and F6 plus H83 had therapeutic effect against BCG latent infection in the rabbit model, respectively, and that the combination of EAMM with F6 plus H83 significantly reduced the bacterial load. In addition, the fusion proteins LT40 and LT70 consisting of multistage antigens showed promising therapeutic effects in the mouse model. We conclude that subunit vaccines consisting of both latency and replicating-associated antigens show promising therapeutic effects in BCG latent infection animal models.

In situ AFM imaging of apolipoprotein A-I directly derived from plasma HDL

BACKGROUND AND AIMS

The major apolipoproteins of plasma lipoproteins play vital roles in the structural integrity and physiological functions of lipoproteins. More than ten structural models of apolipoprotein A-I (apoA-I), the major apolipoprotein of high-density lipoprotein (HDL), have been developed successively. In these models, apoA-I was supposed to organize in a ring-shaped form. To date, however, there is no direct evidence under physiological condition.

METHODS

Here, atomic force microscopy (AFM) was used to in situ visualize the organization of apoA-I, which was exposed via depletion of the lipid component of plasma HDL pre-immobilized on functionalized mica sheets.

RESULTS

For the first time, the ring-shaped coarse structure and three detailed structures (crescent-shaped, gapped "O"-shaped, and parentheses-shaped structures, respectively) of apoA-I in plasma HDL, which have the ability of binding scavenger receptors, were directly observed and quantitatively measured by AFM. The three detailed structures probably represent the different extents to which the lipid component of HDL was depleted. Data on lipid depletion of HDL may provide clues to understand lipid insertion of HDL.

CONCLUSIONS

These data provide important information for the understanding of the structure/maturation of plasma HDL. Moreover, they suggest a powerful method for directly visualizing the major apolipoproteins of plasma lipoproteins or the protein component of lipoprotein-like lipid-protein complexes.

Effects of cyclodextrins on the structure of LDL and its susceptibility to copper-induced oxidation

Cyclodextrins (CDs) have long been widely used as drug/food carriers and were recently developed as drugs for the treatment of diseases (e.g. Niemann-Pick C1 and cancers). It is unknown whether cyclodextrins may influence the structure of low-density lipoprotein (LDL), its susceptibility to oxidation, and atherogenesis. In this study, four widely used cyclodextrins including α-CD, γ-CD, and two derivatives of β-CD (HPβCD and MβCD) were recruited. Interestingly, agarose gel electrophoresis (staining lipid and protein components of LDL with Sudan Black B and Coomassie brilliant blue, respectively but simultaneously) shows that cyclodextrins at relatively high concentrations caused disappearance of the LDL band and/or appearance of an additional protein-free lipid band, implying that cyclodextrins at relatively high concentrations can induce significant electrophoresis-detectable lipid depletion of LDL. Atomic force microscopy (AFM) detected that MβCD (as a representative of cyclodextrins) induced size decrease of LDL particles in a dose-dependent manner, further confirming the lipid depletion effects of cyclodextrins. Moreover, the data from agarose gel electrophoresis, conjugated diene formation, MDA production, and amino group blockage of copper-oxidized LDL show that cyclodextrins can impair LDL susceptibility to oxidation. It implies that cyclodextrins probably help to inhibit atherogenesis by lowering LDL oxidation.

Effects of membrane lipid composition and antibacterial drugs on the rigidity of Escherichia coli: Different contributions of various bacterial substructures

The rigidity/stiffness is an important biomechanical property of bacteria and potentially correlated with many bacterial activities. While the rigidity or fluidity of the bacterial membrane has been extensively studied, the contributions of different bacterial substructures to the bacterial rigidity are less investigated. Here, we utilized four Escherichia coli (E. coli) strains with different membrane lipid compositions and three antibacterial drugs (EDTA, lysozyme, and streptomycin) to specifically alter bacterial substructures. By using atomic force microscopy (AFM), we found that the average height and Young's modulus of phosphatidylethanolamine (PE)-deficient E. coli strains were larger than those of PE(+) strains and that EDTA, EDTA plus lysozyme instead of lysozyme alone, and streptomycin all caused significant decreases in height and Young's modulus of the four E. coli strains. Our data imply that membrane lipid composition, the integrated outer membrane, the cell wall, and the cytoplasmic content are all responsible for bacterial rigidity but to different extents.

Imaging and force measurement of LDL and HDL by AFM in air and liquid

The size and biomechanical properties of lipoproteins are tightly correlated with their structures/functions. While atomic force microscopy (AFM) has been used to image lipoproteins the force measurement of these nano-sized particles is missing. We detected that the sizes of LDL and HDL in liquid are close to the commonly known values. The Young's modulus of LDL or HDL is ∼0.4 GPa which is similar to that of some viral capsids or nanovesicles but greatly larger than that of various liposomes. The adhesive force of LDL or HDL is small (∼200 pN). The comparison of AFM detection in air and liquid was also performed which is currently lacking. Our data may provide useful information for better understanding and AFM detection of lipoproteins.

Tolerant T cells inhibit natural killer cells function in antigen-presenting cells in an independent fashion

Understanding the relationships among immune cells in the setting of immunologic tolerance is imperative to maintain organ and tissue transplants. T cells and natural killer (NK) cells are responsible for both immune tolerance and immune rejection; however, there is only limited knowledge about the relevance of T and NK cells in tolerance. To address this issue, we explored the possible actions of tolerant T cells on NK cells by the means of mixed lymphocyte co-cultures and NK cytotoxicity assays. We showed that tolerant T cell-induced blockade of the co-stimulatory pathway significantly inhibited NK cell function in vitro regarding antigen-presenting cells. This action was cell-cell-contact dependent. We argue that tolerant T cells and NK cells impart synergistic cooperation to maintain transplant tolerance.

[High performance gel chromatographic behaviour of sodium alginate and determination of its molecular weight parameters]

The molecular weight parameters of sodium alginate were determined by high performance gel chromatography with Waters Bondagel E-High A column. The differences in high performance gel chromatographic behaviours between the sodium alginate and the non-polar standard Dextran T500 were compared. The influences of the sample concentration and the sample volume on the results were discussed. The high performance gel chromatographic behaviour of sodium alginate is different from that of Dextran T500, and is also different from those on Sepharose or Sephadex columns. The peak shifted toward full osmotic side under in crease of ionic strength. The elution volumn didn't tend toward stable, even though at the high concentration of 0.5mol/L NaCl. A change of the sample concentration at stable sample volume or the sample volume at stable sample concentration would cause tailing peaks. It was showed that the sample size of sodium alginate would be less than 25microg, and the relative standard deviations of Mn, Mw and d were 0.95%, 4.04% and 4.70%.

[Investigation on HBV-M among hospital workers and observation on the efficacy of vaccination against type B hepatitis]

An epidemiological study on HBV infection among 315 staff of PUMC Hospital was carried out with detection of HBsAg, anti-HBs and anti-HBc by ELISA. The results showed that 138 persons had one or more markers of HBV infection and an overall HBV prevalence rate 43.8%. The positive rates of HBsAg anti-HBs, anti-HBc were 6.3%, 28.9% and 8.6%, respectively. This indicates that HBV infection is a risk factor for medical staff, but there was no significant difference among medical, surgical and other members. In 1992, 177 workers whose HBV markers were negative received 3 doses of HB vaccine at 0, 1 and 6 months, respectively. 91.3 percent of them showed an anti-HBs response one month after the last inoculation. The result shows that our national made HB vaccine is safe and immunogenic.

Contact lenses affect corneal stromal pH

Recent studies suggest that corneal acidosis may alter corneal structure and function. We determined whether the range of oxygen transmissibility (Dk/L) provided by a hydrogel lens could affect corneal stromal pH. Stromal pH was measured using a noninvasive fluorometric technique under both open- and closed-eye conditions on subjects who wore hydrogel lenses made of the same material but with different lens powers. Under closed-eye lens wearing conditions, central stromal pH was reduced substantially and there was no relation between degree of acidosis and lens Dk/L. Under open-eye lens wearing conditions, central stromal pH was also reduced but the degree of acidosis was dependent on lens Dk/L. These results suggest extended wear of hydrogel lenses can produce marked decreases in stromal pH which could remain reduced even after the eyes are opened.