Preliminary inter-port study of the quality of environments using physiological responses of invertebrates exposed to chronic trace element and organic contamination in Corsica (Mediterranean Sea)

Port areas are socio-ecosystems impacted by chronic mixture pollution. Some marine species benefit from living there and may be studied to define the ecological state of such environments. In this study, the risks of chronic chemical contamination and its consequences on three marine molluscs were evaluated in North Corsica (France) port areas. Mediterranean mussel Mytilus galloprovincialis, tubular sea cucumber Holothuria tubulosa and Mediterranean limpet Patella sp. were sampled in three port areas and a reference location. A set of biomarkers was analysed to evaluate oxidative stress, detoxification, energetic metabolism, neurotoxicity, immunity and bioaccumulation (metallic trace elements and organic pollutants). The objectives were to assess pollution-induced effects in organisms, to determine the best bioindicator species for the selected locations and to validate a "pool" sampling technique (when the analysis is done on a single pool of samples and not on individual samples). The results validate the sampling techniques as "pool" for management purposes. St-Florent was demonstrated as the most contaminated location. All the other locations present a low contamination, below the recommended threshold values (for metallic trace elements and organic pollutants). Finally, the limpet appears to be the best bioindicator for the selected locations. Mussel and sea cucumber are inappropriate due to their absence in this oligotrophic region and the lack of responses observed, respectively.

Hybrid telerehabilitation in patients with hypertrophic cardiomyopathy without left ventricular outflow tract obstruction and preserved left ventricular ejection fraction-the randomised clinical trial

Background

Hypertrophic cardiomyopathy (HCM) is the most common hereditary heart disease, and its diagnosis is often associated with limited physical activity. Little is known about cardiac rehabilitation programs for patients with HCM. Therefore the novel hybrid cardiac telerehabilitation (HCTR) model consisting of hospital-based rehabilitation and home-based telemonitored rehabilitation might be an option to improve physical capacity in patients with HCM.

Purpose

To evaluate the safety, effectiveness and adherence to HCTR in patients with HCM without the left ventricle (LV) outflow tract obstruction and preserved LV ejection fraction.

Methods

The study group comprised 60 patients with HCM (51.1±13.3 years; NYHA II-III; LV ejection fraction 66.1±6.9%). Patients were randomised (1:1) to either HCTR program (hospital-based rehabilitation [1 month] based on cycloergometer training and home-based telemonitored rehabilitation [2 months] based on Nordic walking, five times a week, at 40–70% of maximal estimated heart rate) - training group (TG), or to a control group (CG). All patients had implantable cardioverter-defibrillator. In order to perform home-based telemonitored rehabilitation, a special device was used which enabled patients to: (1) do Nordic walking training according to a preprogrammed plan, (2) record and send electrocardiograms (ECGs) via mobile phone network to the monitoring centre. The moments of automatic ECGs registration were pre-set and coordinated with exercise training. The effectiveness of HCTR was assessed by changes - delta (Δ) in duration (t) of the workload, peak oxygen consumption (pVO2) in cardiopulmonary exercise test, 6-minute walking test distance (6-MWT) as a result of comparing t (s), pVO2 (ml/kg/min), 6-MWT (m) from the beginning and the end of the program.

Results

Safety of HCTR. Neither death nor other serious adverse events occurred during HCTR. We did not observe any ICDs intervention during the HCTR.

Effectiveness of HCTR: Within-group analysis: t, pVO2, 6-MWT increased significantly in TG: t 657±183 vs 766±181 (p<0.001), pVO2 19.2±5.0 vs 20.6±4.9 (p=0.007), 6-MWT 445±88 vs 551±77 (p<0.001). In the untrained CG, the unfavourable results were observed: 695±198 vs 717±187 (p=0.114), pVO2 21.2±5.1 vs 21.1±5.6 (p=0.723), 6-MWT 512±83 vs 536±84 (p=0.061).

Between-group analysis: The differences between TG and CG were statistically significant: in Δt (p<0.001); ΔpVO2 (p=0.012); Δ6-MWT (p<0.001).

Adherence to HCTR: In TG 28 patients (93%) completed the HCTR program. Two patients did no undergo HCTR because of personal issues.

Conclusion

Hybrid cardiac telerehabilitation in patients with HCM without the left ventricle (LV) outflow tract obstruction and preserved LV ejection fraction is safe and effective. The adherence to HCTR is high.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Statutory work in The Cardinal Stefan Wyszyński National Institute of Cardiology in Warsaw, Poland

Intravascular ultrasound for valve frame expansion and orifice area measurement as well as paravalvular leak assessment during transcatheter aortic valve replacement

Introduction

Valve frame expansion (measured outer valve frame area/nominal valve dimension), but not oversizing (nominal valve dimension/annulus area, %) determines pattern of restored blood flow after transcatheter aortic valve replacement (TAVR). There is no online measure of frame expansion, and error in current echocardiographic assessment of effective orifice area (EOA) and paravalvular leak (PVL) are common.

Purpose

To evaluate large imaging field intravascular ultrasound (IVUS) during TAVR for measuring valve geometry [frame expansion, minimal geometric orifice area (min GOA), and mechanism of PVL] with transthoracic echo and angio-CT serving for comparative measures, along with the nominal EOA as established by Hahn et al.

Methods

After successful TAVR either a 10MHz Vision PV 0.035" (60mm imaging field) or 20MHz Vision PV 0.018" (24mm imaging field plus Chr omaFlo) IVUS catheter (Philips) was slowly pulled from the left ventricle outflow (LVOT) to the aorta with continuous imaging of the aortic root.

Results

There were 16 pts (80.8±7.1 yrs, 8 female) treated for de novo aortic stenosis (n=15) or failed bioprosthesis (n=1), 7 of whom were treated with balloon-expandable TAVR. PV 0.35" catheters were used in 8 pts (including valve-in-valve) and allowed complete geometry assessment of 26.6±2.7mm nominal prosthesis Ø (Figure 1A) whereas PV 0.018" allowed complete geometry assessment in only 4 of 8 pts with nominal prosthesis Ø of 26.1±2.8mm (Figure 1B). Actual % valve inflow expansion (IVUS outer frame/valve nominal dimension) was significantly smaller than % valve oversizing (80%±19% vs 125±19%, p=0.005). Min GOA was substantially bigger than corresponding nominal EOA and EOA calculated using the post-procedural LVOT diameter (272±84mm2 vs 174±25mm2 vs 181±59mm2, p=0.001 correspondingly). However, min GOA was similar to EOA calculated using baseline LVOT area (272±84mm2 vs 230±90mm2; r=0.713, p=0.009). IVUS and angio-CT measurements of outer prosthesis frame area were similar for inflow, coaptation site, and outflow (460±143mm2 vs 454±134mm2 and 455±134mm2 vs 447±114mm2 and 722±174mm2 vs 725±180; p≤0.001 for all paired correlations). Inflow expansion (IVUS outer frame/baseline CT annulus area) tended to be smaller among valves with ≥mild vs no PVL (95±14% vs 107±11%, p=0.156), with clear ChromaFlo signal seen in the space between the aortic annulus wall and outer-valve frame surface (Figure 1C).

Conclusions

Large imaging field IVUS during TAVR allows for peri-procedural assessment of actual valve geometry that differs substantially from nominal. IVUS offers online tomographic perspective and highest accuracy in anatomy evaluation corresponding with valve function.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Illness experience and adjustment to treatment in hypertrophic cardiomyopathy patients undergoing cardiac rehabilitation: qualitative study

Funding Acknowledgements

Study No. 2.1/I/17, Sadowski, K. MD

Background. Hypertrophic cardiomyopathy (HCM) is an hereditary disease in which the heart muscle becomes abnormally thick, which makes it harder for the heart to pump blood. Some people with HCM experience medical complications, including heart failure or sudden cardiac death (SCD). Due to lack of efficient causal treatment, the goal of HCM treatment is to relieve symptoms, slow down disease development and prevent SCD. For many years one of the major lifestyle recommendations for HCM patients was to refrain from excessive physical activity and stressful situations. At the same time, there is multiple scientific evidence that cardiac rehabilitation and regular physical activity can be beneficial in terms of treatment outcome and survival in cardiac patients. Nevertheless, data on adjustment and physical activity among HCM patients are scarce.

Purpose. The presented study is a part of research on the effectiveness and safety of cardiac rehabilitation in HCM patients. This part aims to assess illness perception and adjustment to treatment among patients with HCM.

Method. The study is an experimental randomized control trial (RCT). In part related to adjustment and mental health there are quantitative and qualitative measures used: questionnaires related to general health, illness perception, level of stress, adherence to treatment, and semi-structured interviews performed to assess patients’ concerns regarding illness identity, the impact of HCM on everyday life, and expectations of themselves and the medical team. The entire study population consists of 60 participants with HCM (cardiac rehabilitation/telerehabilitation vs usual care). Quantitative data will be analysed using appropriate tests (e.g. t-Student, regression analysis) and qualitative data will be analysed using Interpretative Phenomenological Analysis.

Results. Preliminary results evaluate adjustment to treatment based on patients" experience and illness perception. The group for the qualitative study consists of 20 participants (M = 51,70; SD = 11,07; 13 F/ 5 M). Starting the treatment often led to intense distress because 70% of them have been diagnosed accidentally (20% after diagnosis or death of a family member). 20% of participants describe HCM using negative terms, and patients’ identity of HCM fall along a continuum from "curse"/"nightmare" to "value"/"relief". Patients’ adjustment is influenced the most by "being a role model for relatives struggling with HCM" and „adapting to barriers", and the most important expectation toward medical professionals was to be "approachable" and „attentive", which strenghtened the sense of security in threatening medical situations.

Conclusions. Although many patients identify HCM as a burden, their adjustment to illness is mostly related to their need for being a positive role model for relatives with HCM. A therapeutic alliance with the medical team and experiencing kindness were the most important for the sense of security and being well treated.

Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment: DUNE Collaboration

The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.

Impact of annular and cusps calcification on occurrence of paravalvular leak after transcatheter aortic valve replacement with intra- versus supra-annular devices

Introduction

Severe annular and valve cusps calcification is frequent among patients treated with transcatheter aortic valve replacement (TAVR). Severe annular calcification increases the risk of paravalvular leak (PVL) and was associated with worse outcomes. Whether it is accompanied by an independent effect of calcifications localized on cusps and whether the impact of cusps/annular calcification depends on supra vs intra-annular valve design is unknown.

Purpose

To assess the impact of cusps/annular calcifications on occurrence of moderate PVL after successful TAVR with devices of either intra- or supra-annular design.

Methods

282 consecutive patients (80.3±7.6 yrs, 63% female) with baseline 384-slice CT scan were successfully treated with TAVR between Jul 2012 and Oct 2017, either with intra-annular or supra-annular devices. Severe annular calcification (clear protrusion) and severe cusps calcification (Rosenhek 4 score) were identified using a Syngo Via.

Results

138 (48.9%) patients were treated with intra-annular and 144 (51.15) with supra-annular devices. Whereas severe annular calcification was similar (23.9% vs 20.1%), there was more severe cusps calcification among intra-annular valves (52.9% vs 41.7%, p=0.073). Intra-annular devices were used less frequently among bicuspid aortic valves, were also of smaller diameter, less frequently deployed after pre-dilation, and less frequently post-dilated. Post-procedure mean aortic gradient tended to be higher among intra-annular devices. Moderate PVL was less frequent among intra- vs supra-annular valves (14.5% vs 34.0%, p<0.001). However, PVL occurrence was higher (30.3%) among those (33/138, 23.9%) treated with an intra-annular valve who had severe annular calcification vs 9.5% in pts treated with an intra-annular TAVR who did not have severe annular calcification (p=0.008) unlike in patients treated with a supra-annular valve who had a high frequency of PVL with or without severe annular calcium (37.9% vs 33.0%). After excluding patients with severe annular calcium (n=62, 22%), moderate PVL was similar between those with vs without severe cusp calcification whether treated with intra- or supra-annular valves (11.8% vs 7.4% and 29.3% vs 35.1%, respectively). Combined VARC-2 safety endpoints plus 2-yr mortality occurrence were lower for intra- vs supra-annular devices (30.4% vs 43.8%, p=0.026).

Conclusions

Moderate PVL after intra-annular TAVR device deployment occurs in 30% of patients with protruding annular calcification. Severe cusps calcification unaccompanied by annular calcium was not associated with PVL occurrence. Higher frequency of moderate PVL (34%) seen after supra-annular valve deployment appears to be related to other parameters rather than presence of severe annular or cusps calcification.

Funding Acknowledgement

Type of funding source: None

P3738Clinical outcomes after early vs new generation TAVR device deployment

Background

Whether newer generation devices influence early and long-term outcomes post-TAVR in a real life setting is unknown.

Aim

To assess impact of an early vs a new generation transcatheter heart valves (THV) on clinical outcomes (30-day and -years) in a real life scenario.

Methods

Out of 445 consecutive pts treated between 8/2009 and 10/2017 within the single-center, prospective TAVR Registry, there were 432 [median 83.0 years of age, 63.4% female] with device success (97.1%) as per VARC-2. Early generation THV included: CoreValve; Edwards SAPIEN or SAPIEN XT. Newer generation devices included: Evolut-R/-Pro; Acurate neo; Engager, SAPIEN 3; or Lotus Edge Aortic Valve System.

Results

Median follow-up was 29.3 (15.8–53.1) months with 100% 1-year follow-up. Early generation devices were deployed in 60.6% (n=262) and new devices in 39.4% (n=170). Pts treated with newer devices had more peripheral arterial disease (PAD) and more frequent PCI history (17.1% vs 8.8%, p=0.015, and 35.3% vs 26.7%, p=0.068 respectively); other demographic and clinical data were alike. Baseline aortic valve area and LV ejection fraction were similar between early and newer devices. Pre-dilation was less frequent with newer devices (41.8% vs 70.6%, p<0.001), whereas THV size, contrast volume, fluoroscopy time, radiation dose, and post-procedure aortic valve gradients were similar. Moderate PVL assessed early post-TAVR was recognized with same frequency between earlier vs newer devices (28.2% vs 28.6%). An VARC-2 safety endpoint was recognized more often among pts treated with early vs new devices (30.5% vs 21.8%, p=0.028, respectively), with more frequent: 30-day death (3.8% vs 1.8%, p=0.177), life-threatening or disabling bleeding (8.4% vs 5.3%, p=0.181), major vascular complications (20.2% vs 15.3%, p=0.121), and new permanent pacemaker implantation (22.9% vs 10.0%, p=0.001) with early devices, but similar frequencies of stroke and acute kidney injury (1.9% vs 1.8% and 3.8% vs 5.9%, respectively). The 1-year mortality rates were similar (13.4% vs 13.5%, respectively), with similar estimated midterm (1–2 years) prognosis, but worse estimated very long-term follow-up for newer THV devices (fig 1).

Figure 1

Conclusions

Newer TAVR devices with smaller delivery system size, although deployed in pts with more PAD and PCI history, are associated with less frequent occurrence of an VARC-2 safety endpoint and less frequent permanent pacemaker implantation. The 1-year and midterm (1–2 years) prognosis are similar for early and newer devices, whereas the longer follow-up could have been influenced by intrinsic pt characteristics (more frequent PAD and history of PCI).

P1610The genetic background of the disease in a group of patients with severe course of hypertrophic cardiomyopathy

Background

End-stage hypertrophic cardiomyopathy (esHCM) indicates the most progressive form of HCM with progression to left ventricle remodeling and systolic dysfunction and is common indication to heart transplant. It affects 2.4–15.7% of HCM cases and is associated with a poor prognosis (mortality in this group of patients reaches 11%).

Purpose

In this study patients with esHCM were investigated using next generation sequencing in order to examine the genetic causes of the most severe course of the disease. Despite huge amount of data from many studies, a clear genotype-phenotype correlation is still lacking and predictive value of genetic testing is sometimes undermined. However, there is an ongoing need for a prediction factors in HCM patients.

Methods

Fifty seven patients (21 male, 36.8%) with esHCM were genetically investigated with next generation sequencing of a TruSight Cardio panel by Illumina that provides coverage of 174 genes with known associations to cardiac conditions including cardiomyopathies (n=52) or custom panel of 35 cardiomyopathies genes (n=5).

Results

Disease-causing variants where found in 47 probands (82.5%). Thirty-two probands (77.2%) had a single pathogenic or potentially pathogenic mutation in one of the sarcomeric genes: MYBPC3 (13, 22.8%), MYH7 (11, 19.3%), TNNT2 (3, 5.3%), TNNI3 (3, 5.3%), MYL3 (1, 1.8), TPM1 (1, 1.8%). In 13 (22.8%) probands we found a double mutation: in 7 (12.3) both variants sarcomeric (MYBPC3 and TNNT2 with MYH7, MYBPC3 and ACTA1) and in 5 (8.8%) one sarcomeric and the second non-sarcomeric cardiomyopathy variant (BAG3, ILK, PRKAG2, RBM20, SCN5A). In 3 (5.3%) probands we identified mutations or potentially disease-causing variants in genes associated Danon disease (LAMP2), glycogen storage disease of heart (PRKAG2) and double mutation FHL1 + PTPN11 (myopathy/Emery-Dreifuss muscular dystrophy and Noonan syndrome). In 10 (17.5%) patients, genetic examination did not reveal a candidate for disease-causing mutation. Surprisingly, a half of them had documented familial history of the disease. The majority of mutations in MYBPC3 were truncating variants (14/18, 78%). Thirty-three probands (57.9%) had a heart transplant or qualification to the procedure.

Conclusion

Despite a similar background of typical HCM and esHCM and still ambiguous genotype-phenotype correlation, results may indicate that certain mutations (and not genes) may determine a more severe course of the disease. The majority of truncating variants in MYBPC3 gene may suggest their very strong impact on the course of the disease. Also, 3 neighboring variants in TNNT2 gene indicate a hot spot region for esHCM in our population. As expected, in single cases esHCM was related to specific non-sarcomeric genes (LAMP2, PRKAG2, FHL1). 17.5% of unsolved cases suggests that in such cases whole exome/genome sequencing might be needed to recognize the disease-causing mutation, especially when disease is familial.

Acknowledgement/Funding

This work was supported by a grant 2.7/II/17 from the Institute of Cardiology, Warsaw, Poland.

P1855Multiple and posterior location of moderate paravalvular leaks are associated with worse long-term outcome after successful TAVR

Background

Posterior location of a paravalvular leak (PVL) affects left ventricle fluid dynamics in a more unfavorable way than leaks of the other locations.

Purpose

To assess impact of the PVL location and its grade on subsequent long term mortality after successful TAVR.

Methods

Out of 445 consecutive patients treated between 8/2009 and 10/2017 within the single-center, prospective TAVR Registry, there were 432 pts [median 83.0 years of age, 63.4% female] with device success (97.1%) as per VARC-2. Post-procedural TTE studies done within 7 days post-TAVR were analyzed for PVL location (anterior vs posterior vs medial vs lateral) and grade (none/trace/mild vs moderate). Long-term mortality was assessed.

Results

Median follow-up was 29.3 (15.8–53.1) months with 1-year follow-up in all pts. The 30-day and 1-year mortality rates were 3.0% (n=13) and 13.4% (n=58) with an estimated 4-year mortality of 35.5%. Moderate PVL was reported in 28.5% (n=123) of pts, with 12.0% (n=52) having multiple locations (>1 PVL). Among moderate PVLs (n=184), most were of anterior (33.2%), 29.3% were posterior, 25.2% were lateral, and the least common location was medial (12.0%). Whereas moderate PVL alone was not associated with worse long-term outcome, the 1-year mortality rates tended to be higher for pts with PVL found at multiple or posterior locations (19.2% vs 12.6% among the rest of the subjects, p=0.20, and 18.5% vs 12.7%, p=0.28, respectively). The KM curves suggest mid-term clinical importance of multiple or posterior PVLs (Fig 1A and 1B).

Figure 1

Conclusions

Moderate PVL found in multiple locations or recognized in the posterior location tend to be associated with worse midterm (1–2 years) prognosis after successful TAVR.

The role of sentinel node mapping with indocyanine green and endoscopic near-infrared fluorescence imaging in endometrial and cervical cancer

INTRODUCTION

Endometrial and cervical carcinoma are common neoplasms in gynecological oncology. The prognosis and treatment depend on the stage of the cancer according to the FIGO staging system. Stage IAl may be treated by hysterectomy or even local surgical procedures. For Stage IA2, radical hysterectomy and lymphadenectomy must be performed. Lymph node metastasis is an important prognostic factor in both cancers, however lymphadenectomy is associated with long-term complications. Thanks to the sentinel lymph node biopsy (SLNB), we can more accurately discover the staging of the primary tumor, and in case of sentinel lymph node (SLN) negative patients, can resign regional lymphadenectomy. Some researchers claim that new techniques such as indocyanine green (ICG) and endoscopic near-infrared fluorescence imaging for sentinel node mapping can be used instead of the traditional techniques.

AIM

To establish the role of sentinel node mapping technique in endometrial and cervical cancer.

MATERIAL AND METHODS

A retrospective study of medical records of five patients with cervical cancer (first group) Stage I and nine patients (second group) who underwent laparoscopic radical hysterectomy and SLNB or group of lymph nodes. These procedures were performed at Gynecology Department of the District Hospital in Garwolin.

RESULTS

All lymph nodes were clear of metastases. All patients after histopathological diagnosis were finally referred to the Cancer Centre and Institute of Oncology due to consultation or for further treatment.

CONCLUSION

Based on the present first results and literature review, intracervical ICG injection with fluorescence imaging seems to be the best SLN mapping technique, because of its simplicity, safety, and overall lower cost. More data is required to determine if the nodes identified with this technique are able to predict metastatic disease.

Stochastic Properties of the Solution Vector of Parameters for the Model of the Partially Mobile Adsorption of a Single Gas on an Energetically Heterogeneous Microporous Adsorbent

For the previously formulated model of single gas adsorption on energetically heterogeneous microporous solids, two adsorption isotherms were generated — one for each distribution function of the localization energy dividing two neighbouring adsorption sites. Using numeric methods, a mass measurement error was ascribed to each point generated for both adsorption isotherms and an analysis of the influence of the normal distribution of this error on the type of distribution of the optimized parameter values was undertaken. The hypothesis regarding the agreement of the distributions of the parameter values for both energy distribution functions was verified. The work described was carried out for three arbitrary assumed values of the variation coefficients of the adsorbate mass measurement error.

A Non-Analytical Solution of the Description of Single Gas Adsorption on a Microporous Adsorbent

Two distribution functions for the energy of localization dividing two neighbouring adsorption sites were suggested for the model of partially mobile adsorption on energetically heterogeneous microporous solids. The experimental isotherms of ethane adsorption on NaX-type zeolite derivatives cationized by Li+, K+, Rb+, Ca2+, Sr2+ ions as well as isotherms of ethane, ethene and n-pentane adsorption on NaX-type zeolite were described by the relationships of the proposed adsorption model.

Analysis of expression and structure of the TSG101 gene in cervical cancer cells

Human papillomavirus (HPV)-mediated transformation of human epithelial cells has been recognized as a multi-step process in which additional unknown factors and (epi)genetic events are required. The tumor susceptibility gene 101 (TSG101) was discovered in mouse NIH3T3 fibroblast cells as a gene whose functional knockout leads to transformation. TSG101 protein is involved in a variety of important biological functions, such as ubiquitination, transcriptional regulation, endosomal trafficking, virus budding, proliferation and cell survival. It is suggested that TSG101 is an important factor for maintaining cellular homeostasis and that perturbation of TSG101 functions leads to cell transformation. Interestingly, a recent report showed up- or down-regulation of TSG101 in several human malignancies. At present, the role of TSG101 in cervical tumorigenesis is unexplained. TSG101 expression in tumors, where carcinogenesis is connected with viral infection, and a mechanism of TSG101 expression regulation in cancer cells are also unknown. The aim of our study was to estimate the TSG101 mRNA and protein level in cervical cancer and non-tumor epithelial cells. We also analyzed the TSG101 coding and promoter sequence using the PCR-SSCP technique and methylation pattern of the TSG101 promoter. Our real-time PCR and Western blot analysis showed decreased TSG101 mRNA and protein level in cervical cancer tissue in comparison to normal (non-tumor) HPV(-) and HPV16(+) epithelial cells. Our results suggest that TSG101 down-regulation in cervical cancer cells is not regulated by genetic or epigenetic events. However, we detected novel single nucleotide polymorphisms in the promoter of this gene.

Syphilitic cervical lymphadenopathy: return of an old foe

We present the case of a 38-year-old man who presented to the ENT clinic with cervical lymphadenopathy, oral ulceration, and generalized rash. He was diagnosed with syphilis after serologic testing. After years of decline, the incidence of syphilis is now increasing. It is unusual for patients to present to the otolaryngologist, but the recent marked increase in the incidence of syphilis in the UK is likely to translate into a greater incidence of pathology in the head and neck region. Knowledge of the condition, along with its head and neck manifestations, remains central to the diagnosis of this treatable infection. This article provides a summary of syphilis in the head and neck, for the latest generation of otorhinolaryngologist.

Transient receptor potential vanilloid 1 and xenobiotics

Over the last couple of years, transient receptor potential vanilloid 1(TRPV1) channels have been a hot topic in ion channel research. Since this research field is still rather new, there is not much known about the working mechanism of TRPV1 and its ligands. Nevertheless, the important physiological role and therapeutic potential are promising. Therefore, extensive research is going on and a lot of natural as well as synthetic compounds are already described. In this review, we briefly give an overview of capsaicin's history and the current knowledge of its working mechanism and physiological role. We discuss the best known plant molecules acting on TRPV1 and highlight the latest discovery in TRPV1 research: animal venoms and toxins acting on TRPV1 channels. In an effort to give the complete image of TRPV1 ligands known today, the most promising synthetic compounds are presented. Finally, we present a novel pharmacophore model describing putative ligand binding domains.

Chorionic mRNA expression and N-glycodiversity of pregnancy-associated glycoprotein family (PAG) of the European bison (Bison bonasus)

Placental PAG mRNA expression and N-glycodiversity of multiple PAG proteins secreted in vitro by trophectoderm (chorion epithelium) of wild pecoran Bovidae taxons was not examined previously. The study on European bison (Eb) aimed: (1) to determine placental PAG mRNA expression by in situ hybridisation; (2) to identify a profile of pecoran PAG protein family secreted in vitro by cotyledonary (CT) explants; (3) to examine N-glycodiversity of the PAG proteins in this wild taxon. In addition, we compared (4) a profile and N-glycodiversity of the PAG protein family secreted in vitro by CT and interCT-trophectoderm (intCT-TRD) explants of domestic ruminants. Cotyledonary sections of the Eb were used for in situ hybridisation (ISH) with (35)S-labelled probes produced with porcine PAG cDNA as templates. Various CT and intCT-TRD explants were long-term cultured in vitro. Chorionic proteins were isolated from media, ultra-filtrated (>10 kDa MWCO) and analysed by PAGE-Western blotting with various polyclonal anti-PAG sera. Protein samples with or without enzymatic deglycosylation were examined after different times of explant cultures. Released chorionic proteins were deglycosylated by N-glycanase F (PNGase F+) and compared to glycosylated forms (PNGase F-). This is the first paper demonstrating the PAG-like mRNA transcript expression (by ISH) and N-glycodiversity of immuno-reactive PAG-like proteins (produced in vitro by chorionic explants) of European bison. Various PAG proteins of Eb (EbPAG) were secreted by CT explants during long-term in vitro studies. Major approximately 78, approximately 67 and approximately 65 kDa EbPAG-like proteins were reduced by enzymatic deglycosylation (at least by 10 kDa). Considerably smaller amounts of approximately 45 kDa EbPAG-like proteins were also observed. In addition, we have found that various PAG proteins (30-73 kDa) were secreted by bovine CT explants, during long-term in vitro cultures. Corresponding amounts of PAG proteins, similar in M(r), were also secreted by intCT-TRD explants, whose tissues were not utilised for PAG protein extraction during other scientists' previous studies. It seems that the M(r)-heterogeneity and N-glycodiversity of the PAG protein family can play very important role during feto-placental interactions in Bovidae species.

Potent and selective activation of the pancreatic beta-cell type K(ATP) channel by two novel diazoxide analogues

AIMS/HYPOTHESIS

We investigated the pharmacological properties of two novel ATP sensitive potassium (K(ATP)) channel openers, 6-Chloro-3-isopropylamino-4 H-thieno[3,2- e]-1,2,4-thiadiazine 1,1-dioxide (NNC 55-0118) and 6-chloro-3-(1-methylcyclopropyl)amino-4 H-thieno[3,2-e]-1,2,4-thiadiazine 1,1-dioxide (NN414), on the cloned cardiac (Kir6.2/SUR2A), smooth muscle (Kir6.2/SUR2B) and pancreatic beta cell (Kir6.2/SUR1) types of K(ATP) channel.

METHODS

We studied the effects of these compounds on whole-cell currents through cloned K(ATP) channels expressed in Xenopus oocytes or mammalian cells (HEK293). We also used inside-out macropatches excised from Xenopus oocytes.

RESULTS

In HEK 293 cells, NNC 55-0118 and NN414 activated Kir6.2/SUR1 currents with EC(50) values of 0.33 micromol/l and 0.45 micromol/l, respectively, compared with that of 31 micro mol/l for diazoxide. Neither compound activated Kir6.2/SUR2A or Kir6.2/SUR2B channels expressed in oocytes, nor did they activate Kir6.2 expressed in the absence of SUR. Current activation was dependent on the presence of intracellular MgATP, but was not supported by MgADP.

CONCLUSION/INTERPRETATION

Both NNC 55-0118 and NN414 selectively stimulate the pancreatic beta-cell type of K(ATP) channel with a higher potency than diazoxide, by interaction with the SUR1 subunit. The high selectivity and efficacy of the compounds could prove useful for treatment of disease states where inhibition of insulin secretion is beneficial.

Acute and 3-month treatment effects of candesartan cilexetil on hemodynamics, neurohormones, and clinical symptoms in patients with congestive heart failure

BACKGROUND

This study evaluated the short-term and long-term effects of the angiotensin II type 1 receptor antagonist candesartan cilexetil on hemodynamics, neurohormones, and clinical symptoms in patients with congestive heart failure (CHF).

METHODS

In this multicenter, double-blind, parallel-group study, 218 patients with CHF (New York Heart Association class II or III) with impaired left ventricular function (ejection fraction < or =40%) and pulmonary capillary wedge pressure > or =13 mm Hg were randomly assigned to 12 weeks of treatment with placebo (n = 44) or candesartan cilexetil (2 mg [n = 45], 4 mg [n = 46], 8 mg [n = 39], or 16 mg [n = 44]) once daily after a 2-week placebo run-in period. Hemodynamic measurements were performed by right heart catheterization over a 24-hour period after single (day 1) and repeated (3-month) treatment with the study drug.

RESULTS

On regression analysis of the time-response curves, single and multiple doses of candesartan cilexetil produced sustained, significant, and dose-dependent reductions in pulmonary capillary wedge pressure (short-term effect P =.036, long-term effect P =.035) and mean pulmonary arterial pressure (short-term effect P =.031, long-term effect P =.042). Systemic vascular resistance showed a trend toward decreasing with dose on short-term and long-term treatments. No consistent changes were seen in cardiac index. Compensatory increases in plasma renin activity and angiotensin II levels with decreases in aldosterone and atrial natriuretic peptide were dose-dependent and significant. Candesartan cilexetil improved clinical symptoms, stabilized patient New York Heart Association status compared with placebo, and was judged to be an efficacious treatment by the investigators. More patients receiving placebo stopped the trial prematurely because of an adverse event than in any candesartan cilexetil group, and there was no excess of deaths in any treatment group. Candesartan was safe and well tolerated at all dosages.

CONCLUSIONS

Candesartan cilexetil demonstrated significant short-term and long-term improvements in hemodynamic, neurohormonal, and symptomatic status and was well tolerated in patients with CHF.

Characterisation of new KATP-channel mutations associated with congenital hyperinsulinism in the Finnish population

AIMS/HYPOTHESIS

ATP-sensitive potassium (K(ATP)) channels are crucial for the regulation of insulin secretion from pancreatic beta cells and mutations in either the Kir6.2 or SUR1 subunit of this channel can cause congenital hyperinsulinism (CHI). The aim of this study was to analyse the functional consequences of four CHI mutations (A1457T, V1550D and L1551V in SUR1, and K67N in Kir6.2) recently identified in the Finnish population.

METHODS

Wild type or mutant Kir6.2 and SUR1 subunits were coexpressed in Xenopus oocytes. The functional properties of the channels were examined by measuring currents in intact oocytes or giant inside-out membrane patches. Surface expression was measured by enzyme-linked immunosorbance assay, using HA-epitope-tagged subunits.

RESULTS

Two mutations (A1457T and V1550D) prevented trafficking of the channel to the plasma membrane. The L1551V mutation reduced surface expression 40-fold, and caused loss of MgADP and diazoxide activation. Both these factors will contribute to the lack of K(ATP) current activation observed in response to metabolic inhibition in intact oocytes. The L1551V mutation also increased the channel open probability, thereby producing a reduction in ATP-sensitivity (from 10 micro mol/l to 120 micro mol/l). The fourth mutation (K67N mutation in Kir6.2) did not affect surface expression nor alter the properties of K(ATP) channels in excised patches, but resulted in a reduced K(ATP) current amplitude in intact cells on metabolic inhibition, through an unidentified mechanism.

CONCLUSION/INTERPRETATION

The four CHI mutations disrupted K(ATP) channel activity by different mechanisms. Our results are discussed in relation to the CHI phenotype observed in patients with these mutations.

Effect of repaglinide on cloned beta cell, cardiac and smooth muscle types of ATP-sensitive potassium channels

AIMS/HYPOTHESIS

The carbamoylbenzoic acid derivative repaglinide is a potent short-acting insulin secretagogue that acts by closing ATP-sensitive potassium (KATP) channels in the plasma membrane of the pancreatic beta cell. In this paper we investigated. the specificity of repaglinide for three types of cloned (KATP) channel composed of the inwardly rectifying potassium channel Kir6.2 and either the sulphonylurea receptor SUR1, SUR2A or SUR2B, corresponding to the beta cell, cardiac and either smooth muscle types of KATP channel, respectively.

METHODS

The action of the drug was studied by whole-cell current recordings of KATP channels expressed either in Xenopus oocytes or mammalian cells (HEK293). We also used inside-out macropatches excised from Xenopus oocytes for detailed analysis of repaglinide action.

RESULTS

The drug blocked all three types of KATP channel with similar potency, by interacting with a low-affinity site on the pore-forming subunit of the channel (Kir6.2: half-maximal inhibition 230 micromol/l) and with a high-affinity site on the regulatory subunit, the sulphonylurea receptor (SUR: half-maximal inhibition 2-8 nmol/l). There was no difference in potency between channels containing SUR1, SUR2A or SUR2B. MgADP potentiated the inhibitory effect of repaglinide on Kir6.2/SUR1 and (to a lesser extent) Kir6.2/SUR2B, but not on Kir6.2/SUR2A.

CONCLUSION/INTERPRETATION

Repaglinide interacts with a site common to all three types of sulphonylurea receptor leading to inhibition of the KATP channel. The fact that MgADP potentiated this effect in the case of the beta cell, but not cardiac, type of channel could help explain why the drug shows no adverse cardiovascular side-effects in vivo.

Different mechanisms of positive chronotropic actions of isoprenaline and noradrenaline on isolated guinea pig right atria revealed by pretreatment with rilmakalim

In this study we tested the influence of activation of ATP-sensitive K+ channels (KATP) on the changes in automatism induced by isoprenaline, noradrenaline and phenylephrine. Experiments were performed on the spontaneously beating right atria isolated from guinea pig. The rate of spontaneously beating preparations was measured under different experimental conditions. Rilmakalim (formerly HOE 234) was used as an activator of KATP channels. Isoprenaline induced significant, concentration-dependent positive inotropic action. This effect was strongly attenuated only in the presence of selective blockers of beta1- (metoprolol), but not beta2-adrenoceptor subtype (ICI 11855). Pretreatment with 4 microM rilmakalim resulted in a significant increase in the described effects of isoprenaline on automatism of isolated right atria. Phenylephrine (1 to 100 microM) in the presence of 1 microM propranolol, did not cause any changes in automatism of guinea pig right atria. Slight but significant positive chronotropic action induced by noradrenaline at lower concentrations (0.1 to 10 microM) in the presence of 1 microM propranolol was significantly decreased by pretreatment with rilmakalim. However, the effects obtained at higher concentrations (30 and 100 microM) of noradrenaline were enhanced. Interactions mentioned above were prevented by addition of 3 microM glibenclamide. The results imply that positive chronotropic effect of noradrenaline in the presence of propranolol is mediated by adrenoceptor subtype different from alpha1-, beta1- and beta2-adrenoceptors.

[Elevated levels of homocysteine in plasma as a risk factor for coronary artery disease]

This study was performed to assess the significance of association between coronary artery disease (CAD) and circulating homocysteine concentrations. 100 consecutive CAD patients (78 men and 22 women, aged 31 to 79 years) qualified for PTCA were investigated. At the time of PTCA, the risk factors for CAD and plasma for homocysteine and vitamins were obtained. The controls were without clinical evidence of coronary artery disease and hypertension (90 men and 30 women aged 32 to 81 years). Homocysteine was assayed using ELISA test. Red cell folate and plasma vitamin B12 were assayed by immunofluoroscency (Delphia test). Homocysteine concentrations were higher in patients than in controls (13.61 +/- 4.5 vs 10.99 +/- 4.49 mumol/L, p < 0.001, adjusted for age). Male patients had nonsignificantly higher homocysteine levels than females (13.94 +/- 5.21 vs 11.46 +/- 5.16 mumol/L, p = 0.05, adjusted for age). Elevated homocysteine level--defined as one in the top fifth of the control distribution > or = 12.83 mumol/L--was seen in 46% of the patients compared with 20% of the control group (p = 0.001). The odds ratio (OR) for CAD in persons with elevated homocysteine level was 3.1 (95% Cl 1.6-5.8, p < 0.001, adjusted for age). The OR for CAD of 5 mumol/L increment in homocysteine level was 2.1 (95% Cl 1.4-3.1 p < 0.001, adjusted for age). After adjustment for conventional risk factors (age, smoking, hypertension, family history of CAD, hyperlipidemia), elevated homocysteine level remained independent risk factor for CAD (OR 2.88, 95% Cl 1.1-7.8, p < 0.05). We observed inverse correlation between homocysteine and folate level (r = -0.32, p = 0.005) and between homocysteine and vitamin B12 concentrations (r = -0.24, p = 0.03), especially in men. Patients with elevated homocysteine level had lower levels of folate (629.6 +/- 241.2 nmol/L vs 735.1 +/- 252.4 nmol/L, p < 0.05), and vitamin B12 (213.6 +/- 64.4 pmol/L vs 246.6 +/- 62.3 pmol/L, p < 0.05) than patients with normal level of homocysteine. Elevated plasma homocysteine level is a strong risk factor for coronary artery disease. A 5 mumol/L increment in total homocysteine level may be associated with twofold increase of risk for the disease.

The presence of Chlamydia pneumoniae in atherosclerotic plaques--a report of three cases of ischaemic heart disease

The report presents three cases of ischaemic heart disease in which Chlamydia pneumoniae infections were detected first serologically, later the bacteria were shown in atherosclerotic plaques with electron microscopy, and finally C. pneumoniae strains were isolated from the tissues.

Light and electron microscopic picture of atherosclerotic plaque in stable and unstable angina

By presenting this series of 127 cases of coronary atherectomy the authors join the workers who study morphological differences between the atherosclerotic plaques in stable and unstable angina. Routine staining of formalin-fixed, paraffin-embedded material was completed by the detection of T lymphocytes, macrophages, mast cells, smooth myocytes and grown-in capillaries using monoclonal antibodies (DAKO), as well as by the immunofluorescent demonstration of fibrinogen in the plaques. The plaques derived from patients with unstable angina showed a higher incidence of mast cells (significant) and macrophages (insignificant). These cells render the plaque more susceptible to rupture or fissuring. There was also significantly more frequent and quantitatively more abundant permeation of the plaque by fibrinogen that raises the chance of thrombosis. These findings support the view that unstable angina correlates with the phenomena that favour the rupture of the plaque and thrombosis. Electron microscopy has not been used so far to study coronary atherosclerotic plaques. This material includes 15 plaques from stable and 18 plaques from unstable angina. A cover of fibrin and blood platelets is a regular formation on the surface and in the superficial layer of the plaque from unstable angina. It contributes to the "thrombotic proneness" of the coronary artery. These plaques also show abundant elastic fibres. This pattern corresponds to myo-elastic intimal hyperplasia ("intimal thickening") where the production of intimal elastin constitutes an essential phenomenon. Intimal thickening is interpreted as a preatherosclerotic event. The presence of elastin reflects an early stage of the development of the plaque. The plaque from stable angina shows abundant collagen fibres, which aggravate the lesion.

Protection patterns of tRNAs do not change during ribosomal translocation

The translocation reaction of two tRNAs on the ribosome during elongation of the nascent peptide chain is one of the most puzzling reactions of protein biosynthesis. We show here that the ribosomal contact patterns of the two tRNAs at A and P sites, although strikingly different from each other, hardly change during the translocation reaction to the P and E sites, respectively. The results imply that the ribosomal micro-environment of the tRNAs remains the same before and after translocation and thus suggest that a movable ribosomal domain exists that tightly binds two tRNAs and carries them together with the mRNA during the translocation reaction from the A-P region to the P-E region. These findings lead to a new explanation for the translocation reaction.

Differential RNA display identifies novel genes associated with decreased vitamin D receptor expression

To characterize further the function of the intracellular vitamin D receptor (VDR), we have developed stable transfectant variants of a vitamin D-responsive cell line (U937) which express either decreased or increased numbers of VDR. In this study we have analyzed changes in gene expression associated with this variable VDR expression. Initial experiments indicated that a 50% decrease in VDR levels was associated with a 2-fold increase in cell proliferation and a similar rise in c-myc mRNA expression. Further studies were carried out using differential RNA display (DD). Sequence analysis of DD products revealed two cDNAs with identity to known gene products: the catalytic sub-unit of DNA-protein kinase (DNA-PK(CS)), and the peroxisomal enzyme 17beta-hydroxysteroid dehydrogenase type IV (17beta-HSD IV). Northern analysis confirmed that expression of both mRNAs was reduced in cells with decreased numbers of VDR. Down-regulation of 17beta-HSD IV mRNA expression was associated with enhanced estradiol inactivation by U937 cells, suggesting a link between estrogenic pathways and cell proliferation. Further Northern analyses indicated that there was no significant change in 17beta-HSD IV or DNA-PK(CS) mRNA levels following treatment with 1,25(OH)2D3, although expression of both genes varied with changes in cell proliferation. These data suggest that, in addition to its established role as a hormone-dependent trans-activator, VDR may influence gene expression by ligand-independent mechanisms.

Kainate-evoked modulation of gene expression in rat brain

Kainate is a glutamate analog that produces neuronal excitation resulting in seizures within hours following its intraperitoneal injection into adult rats. Then, at 2-3 days after the treatment, neurodegeneration of apoptotic character can be observed in limbic system. As a consequence, plastic reorganization and glial reactivation phenomena occur. These physiological and pathological responses are reflected by specific changes in gene expression, that can be dissected according to their spatio-temporal patterns. The early phase of gene expression observed in all hippocampal subfields appears to reflect a sudden burst of spiking activity. Changes in mRNA levels restricted to dentate gyrus are suggestive of a link to neuronal plasticity. The late gene expression response implies its correlation either to neuronal cell death or glial reactivation, depending on cellular localization of gene products. Thus analysis of the temporal and spatial gene expression pattern in the hippocampus after kainate treatment may provide clues revealing specific phenomena to which gene expression could be attributed.

[Liver abscess in the course of ulcerative colitis]

The case of 19 year old female patient treated because of the ulcerative colitis. The abscess of the liver has appeared in this patient. This kind of complication has been never described in medical literature.

Kainate-evoked modulation of gene expression in rat brain

Kainate is a glutamate analog that produces neuronal excitation resulting in seizures within hours following its intraperitoneal injection into adult rats. Then, at 2-3 days after the treatment, neurodegeneration of apoptotic character can be observed in limbic system. As a consequence, plastic reorganization and glial reactivation phenomena occur. These physiological and pathological responses are reflected by specific changes in gene expression, that can be dissected according to their spatio-temporal patterns. The early phase of gene expression observed in all hippocampal subfields appears to reflect a sudden burst of spiking activity. Changes in mRNA levels restricted to dentate gyrus are suggestive of a link to neuronal plasticity. The late gene expression response implies its correlation either to neuronal cell death or glial reactivation, depending on cellular localization of gene products. Thus analysis of the temporal and spatial gene expression pattern in the hippocampus after kainate treatment may provide clues revealing specific phenomena to which gene expression could be attributed.

A novel class of RanGTP binding proteins

The importin-alpha/beta complex and the GTPase Ran mediate nuclear import of proteins with a classical nuclear localization signal. Although Ran has been implicated also in a variety of other processes, such as cell cycle progression, a direct function of Ran has so far only been demonstrated for importin-mediated nuclear import. We have now identified an entire class of approximately 20 potential Ran targets that share a sequence motif related to the Ran-binding site of importin-beta. We have confirmed specific RanGTP binding for some of them, namely for two novel factors, RanBP7 and RanBP8, for CAS, Pse1p, and Msn5p, and for the cell cycle regulator Cse1p from Saccharomyces cerevisiae. We have studied RanBP7 in more detail. Similar to importin-beta, it prevents the activation of Ran's GTPase by RanGAP1 and inhibits nucleotide exchange on RanGTP. RanBP7 binds directly to nuclear pore complexes where it competes for binding sites with importin-beta, transportin, and apparently also with the mediators of mRNA and U snRNA export. Furthermore, we provide evidence for a Ran-dependent transport cycle of RanBP7 and demonstrate that RanBP7 can cross the nuclear envelope rapidly and in both directions. On the basis of these results, we propose that RanBP7 might represent a nuclear transport factor that carries an as yet unknown cargo, which could apply as well for this entire class of related RanGTP-binding proteins.

[Phosphate sites of RNA-ligands interacting with ribosome at different stages of translation. Thiophosphate method of analysis]

A novel footprinting method was recently developed which identifies phosphate groups of RNA involved in strong RNA-RNA and RNA-protein interactions. The method is based on iodine-dependent RNA cleavage at phosphothioate groups as long as these groups are not protected from iodine. Our recent studies of mRNA and tRNA regions protected in active ribosomes are summarized; initiation state of ribosomes as well as two elongation states in pre- and post-translocational states were analyzed. Only one phosphate group of mRNA, which was two positions upstream of the decoding codons, was weakly protected in longation complexes, whereas this group and the phosphate groups in the Shine-Dalgarno sequence were protected in the initiation complex. No protection was observed downstream of the decoding codons. On the contrary, numerous phosphate residues of tRNA were protected by the ribosome. The tRNA protection patterns significantly varied between two tRNAs simultaneously bound to the ribosome. The protection pattern of an individual tRNA was not significantly affected by translocation. The data indicate that both tRNA molecules are tightly bound to the ribosome, whereas mRNA is fixed predominantly by two tRNAs via codon-anticodon interaction. A possible translocation mechanism is suggested.

[Early and long-term outcome after coronary artery patency]

The role of percutaneous transluminal coronary angioplasty (PTCA) in the management of chronically occluded coronary arteries is still controversial. Percutaneous transluminal coronary angioplasty of chronic total occlusion is associated with relatively low success rates and a high incidence of restenosis. The purpose of this analysis was to determine, from the records of our institution, the efficacy and long-term outcome of angioplasty performed for chronic total occlusion defined as complete occlusion (Thrombolysis in Myocardial Infraction [TIMI] grade 0). PTCA was performed in 212 consecutive patients with chronically occluded coronary arteries and was successful in 125 (59%) patients. Complications were not observed. Successful initial PTCA was related to the clinical duration of occlusion and the type of guidewire (the primary success rate with the conventional guidewire was 49 (48%) versus 76 (69.1%) with Magnum Meier System p < 0.01). Repeat angiography was performed for 65 (52.0%) consecutive patients with successful initial PTCA and demonstrated restenosis in 34 (52.3%). 17 patients were successfully treated by a second PTCA. Restenosis or reocclusion was not clearly related to the residual stenosis post PTCA. In addition, the grade of collateral supply was not different in the vessels with and without restenosis.

Antisense inhibition of vitamin D receptor expression induces apoptosis in monoblastoid U937 cells

The active vitamin D3 metabolite 1,25-dihydroxycholecalciferol (1,25(OH)2D3) acts as an antiproliferative and differentiating agent for the monoblastoid cell line U937 and as an important immunologic mediator implicated particularly in the function of cells belonging to the monocyte/macrophage lineage. These effects are controlled by the vitamin D receptor (VDR), a member of the steroid hormone receptor family. The objective of this study was to develop U937 transfectants expressing antisense VDR mRNA, and to use these to examine the role of 1,25(OH)2D3-VDR interaction in this lineage. A 2-kb VDR cDNA insert (including the complete VDR coding region) was cloned in an antisense orientation into the EBV episomal vector pMEP4 under the control of an inducible promoter and transfected into U937. The resultant cell line, DH42, was hygromycin resistant, contained VDR cDNA, expressed fewer VDRs than controls, and showed a substantial decrease in antiproliferative response to 1,25(OH)2D3. However, 1,25(OH)2D3 increased the number of cells expressing macrophage cell surface Ags, including CD14 and CD11b. A subpopulation of smaller cells did not express the differentiation markers after cadmium stimulation. Cell cycle analysis showed shifts in the distribution of cells from G1 to S phase, which were more pronounced after cadmium treatment. A considerable proportion of cells were outside the cycle and DNA fragmentation confirmed apoptosis. Thus, the functional outcome of the VDR antisense transfection suggests that in the myelomonocytic lineage, VDR expression may act as a protective mechanism against programmed cell death.

Antisense inhibition of vitamin D receptor expression induces apoptosis in monoblastoid U937 cells

The active vitamin D3 metabolite 1,25-dihydroxycholecalciferol (1,25(OH)2D3) acts as an antiproliferative and differentiating agent for the monoblastoid cell line U937 and as an important immunologic mediator implicated particularly in the function of cells belonging to the monocyte/macrophage lineage. These effects are controlled by the vitamin D receptor (VDR), a member of the steroid hormone receptor family. The objective of this study was to develop U937 transfectants expressing antisense VDR mRNA, and to use these to examine the role of 1,25(OH)2D3-VDR interaction in this lineage. A 2-kb VDR cDNA insert (including the complete VDR coding region) was cloned in an antisense orientation into the EBV episomal vector pMEP4 under the control of an inducible promoter and transfected into U937. The resultant cell line, DH42, was hygromycin resistant, contained VDR cDNA, expressed fewer VDRs than controls, and showed a substantial decrease in antiproliferative response to 1,25(OH)2D3. However, 1,25(OH)2D3 increased the number of cells expressing macrophage cell surface Ags, including CD14 and CD11b. A subpopulation of smaller cells did not express the differentiation markers after cadmium stimulation. Cell cycle analysis showed shifts in the distribution of cells from G1 to S phase, which were more pronounced after cadmium treatment. A considerable proportion of cells were outside the cycle and DNA fragmentation confirmed apoptosis. Thus, the functional outcome of the VDR antisense transfection suggests that in the myelomonocytic lineage, VDR expression may act as a protective mechanism against programmed cell death.

The elongating ribosome: structural and functional aspects

We determined the positions and arrangements of RNA ligands within the ribosome with a new neutron-scattering technique, the proton-spin contrast-variation. Two tRNAs were bound to the ribosome in the pre-translocational and the post-translocational state. The mass centre of gravity of both tRNAs resides at the subunit interface of the body of the 30S subunit. Both tRNAs are separated by an angle of 50-55 degrees, and their mutual arrangement does not change during translocation. The mass centre of gravity moves by 13 +/- 3 A (1A = 0.1 nm) during translocation, corresponding well with the length of one codon. Using an RNase-digestion technique, the length of the mRNA sequence covered by the ribosome was determined to be 39 +/- 3 nucleotides before and after translocation. The ribosome moves like a rigid frame along the mRNA during translocation. In contrast, both tRNAs seem to be located on a movable ribosomal domain, which carries the tRNAs before, during, and after translocation, leaving the microtopography of the tRNAs with the ribosome unaltered. This conclusion was derived from an analysis of the contract patterns of thioated tRNAs on the ribosome. The results have led to a new model of the elongation cycle, which reinterprets the features of the previous "allosteric three-sites model" in a surprisingly simple fashion. Finally, a mutational analysis has identified a single nucleotide of the 23S rRNA essential for the peptidyltransferase activity.

Interaction of tRNAs with the ribosome at the A and P sites

In vitro transcribed tRNA(Phe) analogues from Escherichia coli containing up to four randomly distributed A, G, U or C phosphorothioated nucleotides were used to investigate contact patterns with the ribosome in the A and P sites. The tRNAs were biologically active. Molecular iodine (I2) can trigger a break in the sugar-phosphate backbone at phosphorothioated positions of the ribosomal bound tRNAs if contacts with ribosomal components do not prevent access of the iodine. Highly differentiated protection patterns were found which were strikingly different in the A and P sites, respectively. Strong protections accumulated in the T psi C loop and no protection was seen in the extra-arm region in both sites, whereas the phosphates in the anticodon loop are more strongly protected in the A site. Strong common protections in both the A and P sites were found neighbouring universally or semi-universally conserved bases in prominent regions of the tertiary structure of tRNAs: Y11, Y32, U33, psi55, C56, A58 and Y60. These bases are therefore candidates for 'identity elements' in ribosomal tRNA recognition. The data further indicate that tRNAs change their conformations upon binding to either ribosomal site.

Self-coded 3'-extension of run-off transcripts produces aberrant products during in vitro transcription with T7 RNA polymerase

More than 70% of the RNA synthesized by T7 RNA polymerase during run-off transcription in vitro can be incorrect products, up to twice as long as the expected transcripts. Transcriptions with model templates indicate that false transcription is mainly observed when the correct product cannot form stable secondary structures at the 3'-end. Therefore, the following hypothesis is tested: after leaving the DNA template, the polymerase can bind a transcript to the template site and the 3'-end of the transcript to the product site and extend it, if the 3'-end is not part of a stable secondary structure. Indeed, incubation of purified transcripts with the polymerase in transcription conditions triggers a 3'-end prolongation of the RNA. When two RNAs of different lengths are added to the transcription mix, both generate distinct and specific patterns of prolonged RNA products without any interference, demonstrating the self-coding nature of the prolongation process. Furthermore, sequencing of the high molecular weight transcripts demonstrates that their 5'-ends are precisely defined in sequence, whereas the 3'-ends contain size-variable extensions which show complementarity to the correct transcript. Surprisingly, a reduction of the UTP concentration to 0.2-1.0 mM in the presence of 3.5-4.0 mM of the other NTPs leads to faithful transcription and good yields, irrespective of the nucleotide composition of the template.

Transfection of vitamin D receptor cDNA into the monoblastoid cell line U937. The role of vitamin D3 in homotypic macrophage adhesion

A 2-kB cDNA for the vitamin D receptor (VDR) was cloned in sense orientation into the plasmid pMEP4 (containing a cadmium-inducible metallothionein II promoter and a hygromycin-resistance selection gene) and transfected into monoblastoid U937 cells. The resultant cell line, DH39, expressed two species of VDR mRNA: 4.6-kb wild-type mRNA (present in native U937 cells or cells transfected with pMEP4 alone) and 2-kb transfected mRNA, which increased with cadmium treatment. Binding studies (using the active vitamin D metabolite, 1,25-dihydroxycholecalciferol (1,25-DHCC)) showed that DH39 cells contained five times more VDR per cell than controls, and ten times more after cadmium treatment. DH39 were sensitive to 1,25-DHCC: adding cadmium with 100 nM 1,25-DHCC for 72 h completely inhibited proliferation and induced concomitant differentiation. Unlike control cells, differentiation of DH39 by 1,25-DHCC led to homotypic cell-cell adhesion and formation of macrophage clusters. FACS analysis showed that 1,25-DHCC increased the number of cells expressing CD11b in both DH39 and controls, and the number of cells expressing CD11c in DH39. There was a quantitative increase in mean fluorescence intensity of expression of CD11a and CD18 in DH39. Northern blotting showed increased CD11a and CD18 mRNA in DH39. Ab inhibition of 1,25-DHCC-induced homotypic adhesion showed that CD11a/18 mediated the cell-cell clustering. CD50 expression was decreased on DH39, but the CD11a/18 ligand implicated was CD54. DH39 provides a model system not only for investigating the VDR role in 1,25-DHCC anti-proliferative effects, but also for regulation of homotypic macrophage adhesion mechanisms that are important in disease pathogenesis.