Identifying SARS-CoV-2 main protease inhibitors by applying the computer screening of a large database of molecules

The outbreak of coronavirus disease 2019 (COVID-19) at the end of 2019 affected global health. Its infection agent was called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Wearing a mask, maintaining social distance, and vaccination are effective ways to prevent infection of SARS-CoV-2, but none of them help infected people. Targeting the enzymes of SARS-CoV-2 is an effective way to stop the replication of the virus in infected people and treat COVID-19 patients. SARS-CoV-2 main protease is a therapeutic target which the inhibition of its enzymatic activity prevents from the replication of SARS-CoV-2. A large database of molecules has been searched to identify new inhibitors for SARS-CoV-2 main protease enzyme. At the first step, ligand screening based on similarity search was used to select similar compounds to known SARS-CoV-2 main protease inhibitors. Then molecules with better predicted pharmacokinetic properties were selected. Structure-based virtual screening based on the application of molecular docking and molecular dynamics simulation methods was used to select more effective inhibitors among selected molecules in previous step. Finally two compounds were considered as SARS-CoV-2 main protease inhibitors.

The apoptotic effects of progesterone on breast cancer (MCF-7) and human osteosarcoma (MG-636) cells

Purpose

Progesterone has been reported to inhibit the proliferation of breast cancer and osteosarcoma cells; however, its inhibitory mechanism has not yet been clarified. The aim of the present study was to clarify the effects of progesterone on apoptosis in breast cancer (MCF-7) and human osteosarcoma (MG-63) cells.

Materials and methods

In this experimental study the cytotoxic effect of progesterone was measured in MCF-7 and MG-63 cells exposed to different concentrations of progesterone using MTT assay, and effective concentrations were identified. The expression levels of the Bax, P53 and Bcl-2 genes were evaluated by real-time PCR, and caspase-3, 8 and 9 activity levels were determined using a colorimetric method. Hoechst staining and flow cytometry were used to confirm apoptosis. The data were statistically analyzed using one-way analysis of variance (ANOVA) and independent-samples t-test.

Results

Compared to the control group, we observed a significant increase in the expression levels of the Bax and P53 genes and the activity levels of caspase-3 and 9, and a significant decrease in the expression level of the Bcl-2 gene in MCF-7 and MG-63 treated with effective concentration of progesterone. The caspase-8 activity level did not change significantly in treated MG-63 but increased in treated MCF-7 cells. Hoechst staining and flow cytometry results confirmed apoptosis in the cells exposed to effective concentration of progesterone.

Conclusions

The cytotoxic effect of progesterone on breast cancer and osteosarcoma cells was mediated by apoptotic pathways. In this context, progesterone triggers the extrinsic and intrinsic apoptotic pathways in MCF-7 cells and induces the intrinsic apoptotic pathway in MG-63 cells.

A new approach to dispersing and stabilizing graphene in aqueous nanofluids of enhanced efficiency of energy-systems

Owing to its severe hydrophobicity, graphene (G) as on dispersed in a fluid usually deposits therein after a short interval of time. Understanding the G-behavior and the factors affecting its deposition could pave a way for creating a substantially stable nanofluid (NF). In this work, a novel method of stabilizing a G-NF is described with selective examples. The results can be extended to develop the science and technology of G-NFs in general. Electrohydrodynamic forces are used as a controlling factor in the presence of magnetic nanoparticles (MNPs). Contrary to common chemical methods employed for preparing G-NFs, which depend on establishing bonds between the components, the physical method introduced in this article could be used as a novel approach not only to dispersing G in a fluid carrier but also to resolve the common problems originating from utilizing such chemical methods as increasing thermal resistance through adding various types of surfactants. The effects of various factors on the stability of the G-NFs are described. By increasing 50%, 100% and 170% of G, the G sitting rate increased by 43%, 82%, and 109%, respectively. With the addition of one, two and three layers to a G-monolayer, the G sitting rate grew by 77%, 153%, and 263%, respectively. Further, the G-behavior in the presence of MNPs and varied intensive electric fields were studied to optimize an electric field that could stabilize a single-layer G sheet in aqueous NFs. Adding MNPs promptly stabilizes a water/ethylene glycol/G NF in an applied electric field of 0.05 V/Å.

Deep eutectic-water binary solvent associations investigated by vibrational spectroscopy and chemometrics

Investigation of the behaviour of deep eutectic solvents (DESs) as novel green solvents in the presence of other solvents is of great interest. In this study the behaviour of a common natural DES, namely choline chloride-glycerol deep eutectic solvent (GDES), was studied in the presence of water. A detailed study of the association of the two solvents was performed by integration of two vibrational spectroscopic methods (FTIR and Raman spectroscopy) followed by multivariate analysis. Moreover, a binary mixture of glycerol (Gly) as one of the liquid constituents of GDES and water was explored under the same conditions. A quintuplet and ternary systems were resolved for GDES-water and Gly-water probes, respectively, using multivariate analysis of global data (multi-technique and multi-experiment data arrangements). The results confirmed that in the presence of water the GDES showed different behaviour from its components. Therefore, a DES can be introduced as an independent solvent with its unique properties. Also, different H-bond interaction energies of GDES and its pure components in the presence of water were shown by theoretical calculations based on a density functional theory framework. To investigate the effects of water on the structure of GDES, molecular dynamics (MD) simulations of GDES-water liquid mixtures were performed at 0.9 mole fraction of water.

Platelet Deposition at Angioplasty Sites and Platelet Survival Time After PTA in lliac and Femoral Arteries: Investigations with Indium-111-Oxine Labelled Platelets in Patients with ASA (1.0 g/Day)-Therapy

In this study we have assessed the deposition of 111-In-oxine-labelled platelets - using a dual radiotracer method - at angioplasty sites of the lower extremities in 20 patients (14 male, 6 female; median age: 60 years) with ASA (1.0 g/day)-therapy. The platelet survival time (PST) - using the multiple hit model -was evaluated before and after percutaneous transluminal angio-plasry, and we also measured the plasma levels of β-thrombo-globulin (β TG) and platelet fuetui 4 (PF 4) before and after PTA.

Before PTA, scintigraphy was positive in only one patient, while 24 hours after PTA a positive scintigraphic result was observed in 16/20 patients. The median target/non target-ratio was 1.0 (0.66-1.3) before PTA, and this ratio increased significantly (p <0.0005) to 1.53 (1.0-3.3) after PTA.

The median PST decreased significantly (185.0 hours before PTA → 145.2 hours after PTA; p <0.001), while the median platelet turnover increased from 34,000/μl/day to 47,900/μl/day(p<0.01).

The median plasma levels of the platelet specific proteins increased significantly immediately after PTA (p <0.001), but one day later they were not significantly different from the pretreatment values.

The quantitative methods used in this study seem a valuable tool to evaluate the effects of different therapeutical - especially antiplatelet - interventions after PTA in humans, thus helping to find the best antithrombotic regimen for this widely used therapeutical procedure.

How do educators in one New Zealand undergraduate Bachelor of Oral Health course teach and nurture professionalism?

INTRODUCTION

Research on integrated dental hygiene and dental therapy courses is scarce; studies reporting on how staff in these combined scope courses teach professionalism are even more scarce. This study aimed to partially fill these research gaps.

METHOD AND MATERIALS

In 2016, online surveys were sent to 34 staff members who taught into the integrated Bachelor of Oral Health (BOH) course at the University of Otago's Faculty of Dentistry; 13 were returned. Two focus groups were conducted with six BOH educators.

RESULTS

Aspects of professionalism were taught and nurtured in the formal curriculum, the clinic and the informal curriculum. In the formal curriculum, policies outlining the professional standards of behaviour expected of oral health practitioners and students in New Zealand and the Faculty were discussed. In the clinic, educators taught professionalism through modelling clinical skills, assessing students' performance and commenting on their reflective logbooks. In the informal curriculum, BOH teachers nurtured professionalism through discussions about standards of behaviour outside of the university. Role modelling was the most common method that participants reported they taught or nurtured professionalism in their students.

DISCUSSION

Professionalism is a complex concept that is taught and nurtured in a number of ways over all aspects of the course.

CONCLUSION

Oral Health educators need to maintain a high standard of professionalism when interacting with students and patients, as well as in public spaces, in order to model professionalism to their students.

Relationship between pain coping strategies with mental disorders symptoms in patients referring to dental clinics

Introduction

The study aimed to assess the relationship between mental disorders symptoms with pain coping strategies in dentistry clinics.

Method

One hundred and twenty people with dental pain that attended in dentistry clinics were randomly selected and responded to Rosenstein and Keefe's Pain Coping Strategies Questionnaire (PCSQ) and Derogatis's Symptom Checklist (SCL-90-R). PCSQ assesses six pain coping strategies: diverting attention, reinterpretation pain sensation, self-negotiation, ignoring pain, disastrous thought, hope–praying, and SCL-90 measures nine dimensions: somatization, obsessive compulsive, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism. The data were analysed with Pearson correlation coefficient and independent t-test.

Results

Findings showed positive and significant relationship between disastrous thought with all mental disorders symptoms; and reinterpretation pain sensation with depression and anxiety. Also there is negative significant relationship between ignoring pain with obsessive compulsive, interpersonal sensitivity and somatization; and hope – praying with interpersonal sensitivity, depression, anxiety, paranoid ideation and psychoticism. Meanwhile there were significant differences in males and females. Females got more scores in ignoring pain than males, and males got more scores in anxiety, hostility and paranoid ideation tan females.

Discussion

With regard to findings, it is recommended that in addition to drug treatment, for changing the attitudes and thinking in patients with dental pain, psychiatrists and psychologists apply psychological treatments specially cognitive-behavior therapy to reduce abnormal thinking level about pain so that the length during of treatment declines, and as a results reduce the personality and health problems that is related with dental pain before and in during of drug treatment.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Resin Infiltration of Caries in Primary Molars in a Community Setting: 24-Month Randomized Controlled Trial Findings

This study aimed to assess whether resin infiltration of primary molar proximal lesions is more effective than noninvasive measures in radiographically controlling carious lesion progression into the dentin. A split-mouth randomized controlled trial included 90 children, each with 2 proximal lesions confined to the inner half of the enamel or ≤0.5 mm into the dentin. For each child, lesions were randomly allocated to test (infiltration: DMG Icon preproduct and fluoride varnish) or control (fluoride varnish) status. The primary outcome measure was 24-mo radiographic lesion progression. Placement of a restoration during the study period was counted as lesion progression. Proportions of teeth with progressed lesions were compared using the McNemar test. Children also reported on the treatment's acceptability to them. Children (46% female) ranged in age from 6 to 9 y. Their mean number of decayed, missing, and filled teeth (d₃mft) was 2.8 (SD 2.6). At baseline, 58% and 42% of children were at moderate and low risk, respectively. Test and control lesions presented with similar radiographic lesions at baseline. At the 24-mo follow-up, 6 children had moved and 30 teeth had exfoliated. In the test and control groups, 15 of 66 lesions (22.7%) and 30 of 69 lesions (43.5%) had progressed, respectively (P < 0.05). The 2-y therapeutic effect (based on pairwise radiographic readings) of infiltration over fluoride varnish was 20.8% (95% confidence interval, 10.6%-30.2%). Nearly all children (96.7%) had enjoyed their visit to the clinic, and more than two-thirds (72.2%) were not worried about returning for treatment. Infiltration is more efficacious than fluoride varnish for controlling carious lesion progression in proximal lesions in primary molars, and most children find the treatment acceptable (Australian New Zealand Clinical Trials Registry ANZCTR.org.au ACTRN12611000827932). Knowledge Transfer Statement: These study findings can help clinicians decide which caries management approach they wish to use to prevent progression of proximal lesions in primary molars. With consideration of cost and patient preference, this information could lead to more appropriate therapeutic decisions.

ASSOCIATION OF TESTOSTERONE WITH COLORECTAL CANCER (HT29), HUMAN GLIOBLASTOMA (A172) AND HUMAN EMBRYONIC KIDNEY (HEK293) CELLS PROLIFERATION

Testosterone influences cancer development. This in vitro experiment was exerted to determine the association of testosterone with human colorectal cancer(HT29), glioblastoma (A172) and human embryonic kidney(HEK293) cells proliferation. HT-29, A172 and HEK293 cell lines were cultured in standard growth medium, then randomly divided into control group (not exposed to testosterone) and groups exposed to 1, 10, 100 and 1000 μg/mL of testosterone. Cell viability was quantified by MTT assay. Statistical analysis was performed using ANOVA. Viability of HEK293 cells significantly increased in groups exposed to 1 μg/mL and decreased in groups exposed to 100 and 1000 μg/mL of testosterone compared to control group (P<0.05, P<0.05 and P<0.001, respectively). Viability of HT29 cells significantly increased in groups exposed to 10 and 100 μg/mL of testosterone and significantly decreased when exposed to 1000 μg/mL of testosterone compared to control group (P<0.05, P<0.001 and P<0.001, respectively). Viability of A172 cells significantly decreased in groups exposed to 100 and 1000 μg/mL of testosterone compared to control group (P<0.001). In conclusion, different doses of testosterone have enhancing or suppressive effects on HEK293, HT29 and A172 cells proliferation; according to which, considering clinical use of testosterone therapy for cancer treatment is a highly controversial issue.

Helicobacter pylori infection and iron deficiency in patients with coronary artery disease

The aim of this study was to investigate whether impact of the seropositivity to Helicobacter pylori (H pylori) infection on ferritin and iron levels is an independent risk factor for atherosclerosis in patients with cardiovascular disease. The anti H pylori IgG, IgA levels, serum ferritin and iron concentration of 86 patients with cardiovascular disease and 64 participants free of cardiovascular disease as control subjects were determined by ELISA assay. The results of present study showed that seropositivity to H pylori IgG and IgA levels of coronary artery disease (CAD) patients was higher than controls and CAD patients with negative anti H pylori IgG and IgA significantly. A significant negative correlation was found between seropositivity to H pylori IgG and IgA, ferritin and iron levels of CAD patients with seronegativity and seronegativity to H pylori IgG and IgA in comparison with controls. The achieved results from present study suggest that the involvement of H pylori infection in atherosclerosis process is based on the chronic inflammation which might facilitate the CAD-related pathologies. Moreover, impact of the presence of H pylori infection on reduction of the ferritin and iron levels of CAD patients as a risk factor independent of other classic factors including lipid profiles and inflammatory factors was remarkable.

Job satisfaction and its influential factors in dental academic members in tehran, iran

Background:

Assessment of job satisfaction of the faculty members and its underlying factors may increase career fulfillment and raise the educational and research productivity, leading to higher quality of dental services at the community level, ultimately improving public oral health status.

Aim:

This study assessed job satisfaction and its influential factors in dental academic members in Tehran.

Subjects and Methods:

The job satisfaction level of 203 faculty members was assessed using a Likert scale questionnaire from 0 to 4, with 4 representing very satisfied and 0 not at all satisfied. The analysis of variance was used to compare the responses among dental faculty members of three different universities. The impact of age, gender, academic rank, employment status and the date of employment on the overall faculty job satisfaction was identified by multiple linear regression analysis.

Results:

The mean professional satisfaction score among faculty members was 1.5 (0.5) out of four. Among the studied underlying factors, only the date of employment was seen to have a statistically significant impact on the faculties’ overall job satisfaction (P= 0.05). There was no difference in job compensation observed between the three dental faculties. Dissatisfying aspects of the academic work included educational and research policies, monetary strategies, quality of leadership and administration, promotion and tenure policies, job security, educational environment, equipments, and facilities. The only satisfying factor was the interaction between faculty colleagues and students.

Conclusion:

Faculty members of Tehran Dental Schools are dissatisfied with their work environments in Tehran Dental Schools. Issues such as salary and remuneration, facilities, equipments, promotion and tenure policies are strongly believed to account for the dissatisfaction.

Antiglioma activity of GoPI-sugar, a novel gold(I)-phosphole inhibitor: chemical synthesis, mechanistic studies, and effectiveness in vivo

Glioblastoma, an aggressive brain tumor, has a poor prognosis and a high risk of recurrence. An improved chemotherapeutic approach is required to complement radiation therapy. Gold(I) complexes bearing phosphole ligands are promising agents in the treatment of cancer and disturb the redox balance and proliferation of cancer cells by inhibiting disulfide reductases. Here, we report on the antitumor properties of the gold(I) complex 1-phenyl-bis(2-pyridyl)phosphole gold chloride thio-β-d-glucose tetraacetate (GoPI-sugar), which exhibits antiproliferative effects on human (NCH82, NCH89) and rat (C6) glioma cell lines. Compared to carmustine (BCNU), an established nitrosourea compound for the treatment of glioblastomas that inhibits the proliferation of these glioma cell lines with an IC50 of 430μM, GoPI-sugar is more effective by two orders of magnitude. Moreover, GoPI-sugar inhibits malignant glioma growth in vivo in a C6 glioma rat model and significantly reduces tumor volume while being well tolerated. Both the gold(I) chloro- and thiosugar-substituted phospholes interact with DNA albeit more weakly for the latter. Furthermore, GoPI-sugar irreversibly and potently inhibits thioredoxin reductase (IC50 4.3nM) and human glutathione reductase (IC50 88.5nM). However, treatment with GoPI-sugar did not significantly alter redox parameters in the brain tissue of treated animals. This might be due to compensatory upregulation of redox-related enzymes but might also indicate that the antiproliferative effects of GoPI-sugar in vivo are rather based on DNA interaction and inhibition of topoisomerase I than on the disturbance of redox equilibrium. Since GoPI-sugar is highly effective against glioblastomas and well tolerated, it represents a most promising lead for drug development. This article is part of a Special Issue entitled: Thiol-Based Redox Processes.

Synergistic effects of BuChE non-UU phenotype and paraoxonase (PON1) 55 M allele on the risk of systemic lupus erythematosus: influence on lipid and lipoprotein metabolism and oxidative stress, preliminary report

There is some evidence indicating lipid peroxidation can affect progression of atherosclerosis, cardiovascular diseases (CVDs) and glomerulonephritis in systemic lupus erythematosus (SLE) patients. Human butyrylcholinesterase (BuChE) and paraoxonase-1 (PON1) are two major bioscavenger enzymes that are associated with inflammation, oxidative stress and lipid metabolism. Hyperlipidemia, increase in lipid oxidation reactions and defects in antioxidant status may lead to increased oxidative stress and high frequency of CVDs in SLE. It has also been suggested that deficiency in the function of the antioxidant system and an increase in reactive oxygen release (ROS) may play an important role in the pathogenesis of SLE. This study is the first investigation to examine the association of BuChE phenotypes, PON1 (L55M; PON-55-M) polymorphism, the levels of malondialdehyde (MDA), neopterin, lipid-lipoprotein and activities of BuChE and arylesterase activity (ARE) of PON with severity of SLE.

The present case-control study consisted of 109 SLE patients and 101 gender- and age-matched, unrelated healthy control subjects from the population of west Iran. We found that the PON-55-M allele and BuChE non-UU act synergistically to increase the risk of SLE by 2.5 times (1.03–6.7, p = 0.044). There was a significant negative correlation between severity of SLE with serum BuChE activity ( R = −0.31, p < 0.001) and positive correlation with serum neopterin level. The SLE patients with the PON-55-M (M/L + M/M) allele or with BuChE non-UU phenotype had significantly lower serum ARE and BuChE activities than those with PON-55-L/L or BuChE-UU phenotypes, respectively. In addition, their serum levels of MDA, neopterin and LDL-C were significantly elevated, suggesting that these individuals are more susceptible to CVD. However, further studies are needed to shed more light on the contribution of the M allele of PON1 and non-UU phenotypes of BuChE in the development of SLE in different ethnicities.

Effect of intrahippocampal ghrelin agonist administration on passive avoidance learning and anxiety in rats

Hippocampus, amygdala and dorsal raphe nucleus are the cerebral main structures involved in learning, memory and anxiety. Ghrelin increases the level of several hormones in these structures and affects learning, memory and anxiety-like behaviors. This study was performed to investigate the effect of ghrelin agonist on passive avoidance learning and anxiety in adult female rats in the presence and absence of ovary hormones. Five groups of rats, including control group with no injections, ovariectomized groups; one group receiving normal saline and other group receiving ghrelin agonist solution, surgery shocked (sham operated) groups; one group receiving saline and other group ghrelin agonist solution, were tested. Inside stereotaxis apparatus, two sided CA1 cannulae were used and 1 microL of saline or ghrelin agonist solution, at 3 nmol microL(-1) concentration, was injected into each cannula. Passive avoidance learning was measured by using shuttle box and anxiety by elevated plus- maze. Ghrelin agonist increased the level of learning in surgery shocked group in comparison with control group. Anxiety-like behavior was seen in both ovariectomized and surgery shocked groups. Ghrelin agonist binds its own receptors in the hippocampus, thereby increases learning capability and induces anxiety-like behaviors. Proper management of these behaviors might be useful in controlling some forms of nervous system diseases in humans.

Effect of high water fluoride concentration on the intellectual development of children in makoo/iran

OBJECTIVE

Prolonged excessive intake of fluoride during child's growth and development stages has been associated with mental and physical problems. The aim of this study was to investigate the effect of excessive fluoride intake on the intelligence quotient (IQ) of children living in five rural areas in Makoo/Iran.

MATERIALS AND METHODS

In this cross-sectional study, 293 children aged 6-11 years were selected from five villages in Makoo with normal fluoride (0.8±0.3 ppm), medium fluoride (3.1±0.9 ppm) and high fluoride (5.2±1.1 ppm) in their water supplies. The IQ of each child was measured by the Raven's test. Educational and residential information and the medical history of each child was recorded by a questionnaire completed by the parents. Data were analyzed by ANOVA test with a significance level of 0.05.

RESULTS

The mean IQ scores decreased from 97.77±18.91 for the normal fluoride group to 89.03±12.99 for the medium fluoride group and to 88.58±16.01 for the high fluoride group (P=0.001).

CONCLUSION

Children residing in areas with higher than normal water fluoride levels demonstrated more impaired development of intelligence. Thus, children's intelligence may be affected by high water fluoride levels.

Oro-dental health status and salivary characteristics in children with chronic renal failure

Children suffering from decreased renal function may demand unique considerations regarding special oral and dental conditions they are encountered to. It is mentioned that renal function deterioration may affect the hard or soft tissues of the mouth. Having knowledge about the high prevalence of dental defects, calculus, gingival hyperplasia, modified salivary composition and tissue responses to the dental plaque may aid the physician and the dentist to help nurture the patient with chronic renal failure through the crisis, with an aesthetically satisfying and functioning dentition.

Enhanced attachment, growth and migration of smooth muscle cells on microcarriers produced using thermally induced phase separation

Microcarriers are widely used for the expansion of cells in vitro, but also offer an approach for combining cell transplantation and tissue bulking for regenerative medicine in a minimally invasive manner. This could be beneficial in conditions associated with muscle damage or atrophy, such as faecal incontinence, where the use of bulking materials or cell transplantation alone has proven to be ineffective. Microcarriers currently available have not been designed for this purpose and are likely to be suboptimal due to their physical and biochemical properties. The aim of this study was to investigate macroporous microspheres of polylactide-co-glycolide (PLGA), prepared using a thermally induced phase separation technique, for their suitability as cell microcarriers for the transplantation of smooth muscle cells. Cell attachment, growth and migration were studied and compared with commercially available porcine gelatin microcarriers (Cultispher-S) in suspension culture. Smooth muscle cells attached more rapidly to the PLGA microcarriers, which also significantly enhanced the rate of cell growth compared with Cultispher-S microcarriers. The majority of smooth muscle cells attached to the PLGA microcarriers in suspension culture were able to migrate away over a 15 day period of static culture, unlike Cultispher-S microcarriers which retained the majority of cells. The ability of PLGA microcarriers to enhance cell growth combined with their capacity to release cells at the sites of delivery are features that make them ideally suited for use as a cell transplantation delivery device in tissue engineering and regenerative medicine.

Molecular cloning of gluconobacter oxydans DSM 2003 xylitol dehydrogenase gene

Due to the widespread applications of xylitol dehydrogenase, an enzyme used for the production of xylitol, the present study was designed for the cloning of xylitol dehydrogenase gene from Glcunobacter oxydans DSM 2003. After extraction of genomic DNA from this bacterium, xylitol dehydrogenase gene was replicated using polymerase chain reaction (PCR). The amplified product was entered into pTZ57R cloning vector by T/A cloning method and transformation was performed by heat shocking of the E. coli XL1-blue competent cells. Following plasmid preparation, the cloned gene was digested out and ligated into the expression vector pET-22b(+). Electrophoresis of PCR product showed a 789 bp band. Recombinant plasmid (rpTZ57R) was then constructed. This plasmid was double digested with XhoI and EcoRI resulting in 800 bp and 2900 bp bands. The obtained insert was ligated into pET-22b(+) vector and its orientation was confirmed with XhoI and BamHI restriction enzymes. In conclusion, in the present study the recombinant expression vector containing xylitol dehydrogenase gene has been constructed and can be used for the production of this enzyme in high quantities.

Critical care management of potential organ donors: our current standard

Caring for a brain dead potential organ donor requires a shift in critical care from the extensive treatment of increased intracranial pressure towards strategies to maintain donor organ function. Suboptimal, unstandardized critical care management of organ donors, however, is one of the main reasons for insufficient organ procurement. The pathophysiological changes following brain death entail a high incidence of complications including hemodynamic instability, endocrine and metabolic disturbances, and disruption of internal homeostasis that jeopardize potentially transplantable organs. Strategies for the management of organ donors exist and consist of the normalization of donor physiology. This has resulted in standardized efforts to improve the critical care delivered to potential organ donors, increasing not only the number, but also the quality of suitable organs and aiming at an optimal outcome for the recipients. In this review, we discuss the pathophysiological changes associated with brain death and present the current guidelines at our department, which are optimized based on available literature.

Effects of ovariectomy or orchidectomy and estradiol valerate or testosterone enanthate replacement on serum insulin in rats

Various clinical observations and experimental data from in vitro studies suggest that insulin and sex hormones interact. The main purpose of the present study was to examine the effects of testosterone and estradiol on serum insulin in rats. Seven week old male and female albino (Wistar) rats were used in our study. Testosterone enanthate (50 mg kg(-1) day(-1)) or estradiol valerate (200 microg kg(-1) day(-l)) were injected intraperiotenally or subcutaneously in orchidectomised or ovariectomised rats, respectively. In orchidectomised rats, serum insulin was decreased compared with control animals (p < 0.01), on the other hand, decreasing of serum insulin was prevented by testosterone replacement (p < 0.001). In ovariectomised rats, serum insulin was also decreased compared with control group (p < 0.01) and decreasing of serum insulin was prevented by estradiol replacement (p < 0.05). Conclusively, present findings indicated that testosterone or estradiol were serum insulin enhancer hormones in male or female rats, respectively.

Neuropsychological Outcome 6 Months after Unilateral Carotid Stenting

Percutaneous transluminal angioplasty with stenting (PTAS) has become a treatment option for severe carotid stenosis. The goal of our study was to determine prospectively neurocognitive outcome 6 months after unilateral stent-protected carotid angioplasty. Twenty consecutive patients who underwent stent-protected angioplasty for symptomatic (n=9) or asymptomatic (n=11) high-grade carotid stenosis were investigated and compared to an age and disease matched control group. Patients were administered preprocedurally and 6 months postprocedurally a battery of neuropsychological tests. We used reliable change indices methodology in order to control for practice and statistical effects unrelated to intervention. We found no cognitive change in approximately 90% of patients and cognitive improvement in approximately 10% of patients for concentration and attention variables. We further found no cognitive change in 61% of patients, cognitive improvement in 11% of patients and cognitive deterioration in 28% of patients for psychomotor speed. No cognitive change in 94% of patients and cognitive deterioration in 6% of patients was found for sustained attention; no cognitive change in 80% of patients, cognitive improvement in 15% of patients and cognitive deterioration in 5% of patients was found for verbal fluency; no cognitive change in 100% of patients was found for interference (Stroop test): no cognitive change in 95% of patients, cognitive improvement in 5% of patients was found for interference (c.I. test), respectively. Our study showed that 6 months after PTAS cognitive functioning did not change in most patients significantly. For some patients, however, significant improvement or deterioration in single neurocognitive domains can be expected. The reasons for these changes are unclear but may depend on variable type; magnitude of microemboli production; right vs. left cerebral vasculature, respectively.

[Pseudonormalization of diffusion weighted images: magnetic resonance imaging in an animal model (C6-glioma)]

PURPOSE

Previous studies on intracranial tumors indicate that a high apparent diffusion coefficient (ADC) is due to low cellularity and that lower values indicate a dense, highly cellular tumor. Diffusion is affected by three major factors: cell density, existence and distribution of vasogenic edema, and hypoxic tissue. Therefore, we studied the characteristics of diffusion-weighted magnetic resonance imaging (DWI) in a rat brain C6 glioma during tumor progression.

MATERIALS AND METHODS

In male Wistar rats, C6 gliomas were implanted in the caudoputamen. At day 9, 11, 13 and 15 after tumor inoculation, conventional DWI was performed on a 2.35 Tesla small bore MRI unit (Biospec 24/40, BRUKER Medizintechnik, Ettlingen, Germany).

RESULTS

On conventional T2-weighted and contrast-enhanced T1-weighted images, all tumors could well be delineated from the surrounding brain tissue and showed significant progression. On DWI, the tumors were isointense or slightly hypointense compared to the surrounding brain. On the ADC maps, the tumors could be well visualized due to increasing ADC values from day 9 to 15. The mean ADC of brain tumor tissue was 0.76 +/- 0.4 x 10 ( - 3) mm (2)/s at day 9 and 0.91 +/- 0.03 x 10 ( - 3) mm (2)/s at day 15. The mean ADC of the normal contralateral caudoputamen was 0.59 +/- 0.007 x 10 ( - 3)mm (2)/s.

CONCLUSION

T2 prolongation and increased water diffusion can be balanced on DWI in C6 gliomas, resulting in isointensity on DWI (T2 shine-through washout phenomenon). ADC maps are indispensable for the correct interpretation of tumor tissue diffusion behavior.

Recurrent low-grade gliomas: the role of fractionated stereotactic re-irradiation

PURPOSE

To assess the effectiveness of re-irradiation in recurrent low-grade gliomas (LGG).

PATIENTS AND METHODS

Sixty-three patients were treated with fractionated stereotactic re-irradiation in the case of recurrent gliomas. At primary diagnosis of the tumor, the histology was grade II astrocytoma, oligodendroglioma or oligoastrocytoma. Fifty-two (82.5%) recurrences were in-field, three (4.8%) were localized at the field border, and eight (12.7%) tumors were localized completely out-field of the former RT field, respectively. Using three to four irregular non-coplanar fields formed with a multi-leaf-collimator, we applied a median total dose of 36 Gy (range 15-62 Gy)with a weekly fractionation of 5 x 2 Gy/week depending on the size and the location of the lesion. No concomitant chemotherapy was applied.

RESULTS

Radiation was well tolerated by all patients. No severe side effects occurred. Median overall survival was 111 months (range 12-240 months). Extent of neurosurgical resection significantly influenced overall survival (P = 0.02). Median interval between the first radiation therapy and re-irradiation was 50 months (range 5-204 months). From the time point of re-irradiation, median survival was 23 months. Median progression-free survival from the time point of re-irradiation was 12 months (range 2-63 months). No prognosticators could be identified for survival from re-irradiation and progression free survival.

CONCLUSION

Our retrospective data suggest that stereotactically guided fractionated re-irradiation in recurrent glioma represents an effective treatment option with good results and few complications. However, further investigation is warranted to consolidate these results and to combine radiation with chemotherapy in the case of recurrent LGG.

Supratentorial malignant ependymoma in childhood: 16 years without relapse after hemispherectomy

INTRODUCTION

Malignant intracranial ependymomas in childhood have a poor prognosis, supratentorial ependymomas have the poorest clinical course with a survival rate after 5 years of 45%. The most important prognostic factor in these cases is a radical operation, which cannot usually, however, prevent relapse.

CASE REPORT

We demonstrate the case of a large malignant ependymoma of the left cerebral hemisphere in a child who has so far lived for 16 years without relapse after an extensive but uncomplicated left-sided hemispherectomy. The patient has also shown an improvement in her preoperative neurologic deficits. Her epilepsy, which was difficult to manage preoperatively, has been completely eliminated. She went to a special school for handicapped children and now works there. She does not need any help in handling everyday activities.

CONCLUSION

This case shows the significance of complete tumor resection in malignant ependymomas, which may, under certain circumstances, lead to lasting tumor control.

Neointimal proliferation within carotid stents is more pronounced in diabetic patients with initial poor glycaemic state

AIMS/HYPOTHESIS

We studied the influence of initial hyperglycaemia on neointimal proliferation within carotid Wallstents.

METHODS

A total of 112 patients were followed by duplex sonography after carotid stenting for 24 months. Patients were assigned to three groups: non-diabetic subjects (group A) and diabetic patients, who were assigned according to their baseline HbA(1)c values, to group B1(HbA(1)c<or=6.5%) or group B2 (HbA(1)c>6.5%).

RESULTS

At baseline the groups did not differ with respect to other vascular risk factors and residual stenosis on angiograms. The maximal thickness of the layer between the stent and the perfused lumen was measured at the duplex follow-ups. At 3 months the typical ultrasonic structure of the neointima was clearly discernible. From this point on, group B2 differed significantly ( p<0.001) compared with B1 and A with respect to the maximal thickness of neointima and the time course of its ingrowth: group A vs B1 vs B2 was 0.51+/-0.39 vs 0.52+/-0.33 vs 0.56+/-0.35 at 3 months, 0.91+/-0.27 vs 0.90+/-0.38 vs 1.14+/-0.48 at 6 months, 1.02+/-0.24 vs 0.97+/-0.34 vs 1.21+/-0.44 at 12 months and 1.09+/-0.23 vs 1.10+/-0.31 vs 1.23+/-0.37 at 24 months.

CONCLUSION/INTERPRETATION

Initial hyperglycaemia seems to be a predictor of more pronounced neointimal proliferation after carotid stenting independent of diabetes. As intimal hyperplasia is known to be responsible for stent restenosis, strict optimisation of the hyperglycaemic state should be aimed at before elective carotid artery stenting.

Outcome of Conservative Therapy of Patients with Severe Intermittent Claudication

BACKGROUND

Intermittent claudication due to peripheral artery disease (PAD) can be treated conservatively, or by revascularization.

OBJECTIVES

To assess the short-term outcome of conservatively-treated claudicants, and determine predictors for clinical improvement. Design. A retrospective cohort study.

METHODS

We evaluated Fontaine stage, walking distance and ankle brachial index (ABI) at baseline and after median 9 months (interquartile range (IQR) 6-24) in 181 patients with severe claudication.

RESULTS

We found clinical improvement by at least one Fontaine stage in 38 patients (21%) with an increased walking distance from baseline median 100 m (IQR 50-150) to follow-up median 650 m (IQR 300 to unlimited; p<0.001), but without changes in ABI (median 0.57, IQR 0.48-0.73 vs. median 0.54, IQR 0.45-0.81; p=0.10). One hundred and thirty-eight patients (76%) remained clinically and hemodynamically stable. A worsening of the clinical stage but without amputation was recorded in five patients (3%). Female gender (hazard ratio (HR) 0.51, p=0.052), diabetes (HR 0.35, p=0.020), and baseline ABI below 0.44 (HR 0.31, p=0.019) were associated with a reduced probability of clinical improvement.

CONCLUSION

Certain patients with intermittent claudication show substantial clinical improvement with conservative medical therapy, despite any lack of hemodynamic improvement. Given the low number of patients with clinical deterioration in the short term, primarily conservative therapy should be the preferred initial option for most claudicants.

Reduction in renal function after renal arteriography and after renal artery angioplasty

OBJECTIVE

To investigate the incidence and risk factors for renal function deterioration after renal angiography and angioplasty or stenting.

METHODS

A retrospective study of 85 consecutive patients undergoing selective renal artery arteriography (n = 53) or renal artery angioplasty % (PTRA) stenting (n = 32) for renal artery stenosis. Multivariate logistic regression analysis was used to determine independent predictors of deterioration of renal function, defined as an increase of serum creatinine by at least one third within 24 h.

RESULTS

Deterioration of renal function occurred in 13 patients (15%), [8/53 (15%) after angiography and 5/32 (16%) after PTRA/stenting]. Only pre-existing renal impairment (se-creatinine > or = 177 mumol/l) (Odds ratio: 40; 95% confidence interval 1.2-72, p = 0.02) and administered dosage of contrast agent (more than 225 ml) (OR 67; 95% CI 11.8-100, p = 0.02) were independently associated with renal function deterioration.

CONCLUSION

Transient renal dysfunction after renal artery angiography or PTRA/stenting occurs in about 15% of patients, but persistent renal failure is uncommon. Pre-existing renal impairment and amount of contrast agent are independent risk factors. Endovascular treatment of renal artery stenosis is not associated with a higher risk of renal deterioration compared to selective renal angiography.

Clinical outcome and prognostic factors for ischaemic ulcers treated with PTA in lower limbs

OBJECTIVE

To analyse the clinical outcome of patients with ischaemic ulcers (Fontaine stage IV) undergoing percutaneous transluminal angioplasty (PTA).

METHODS AND DESIGN

Retrospective cohort study of 40 patients (21 males) treated between January 1998 and December 1998. Cardiovascular risk factors, co-morbid, baseline laboratory, angiographic data and technical success were recorded. Patients were followed for a median of 20 (inter quartile range (IQR) 8-26) months.

RESULTS

Cumulative ulcer healing rates at 3, 6, 12, and 24 months were 15, 40, 54 and 81%, respectively. The median time to healing was 5 (IQR 2-7) months. Cumulative restenosis at 1, 3, 6 and 12 months was 3, 10, 29 and 52%, respectively. Nine patients (22%) suffered ulcer reappearance. Lipoprotein (a) serum levels > 30 mg/dl (HR 0.2, 95% CI 0.05-1.0, p = 0.05) and diabetes mellitus (HR 0.2, 95% CI 0.5-0.7, p = 0.01) were associated with delayed ulcer healing.

CONCLUSION

PTA leads to ulcer healing in the majority of patients. Elevated lipoprotein (a) levels > 30 mg/dl and diabetes mellitus are independently associated with ulcer persistence.

Experimental monitoring of hepatic glucose, lactate, and glutamate metabolism by microdialysis during surgical preparation of the liver hilus

Mechanical liver manipulation can lead to hepatic microcirculation (MC) impairment. The pathobiochemical relevance of this phenomenon is not fully understood. Microdialysis (MD) allows a quantification of metabolic products in interstitial fluid, thus enabling analysis of the hepatic metabolic state during changes of liver perfusion. The aim of the study was to quantify the functional effects of standardized surgical liver preparation both on liver metabolism and microperfusion. Two groups of animals (pigs, n = 25) were formed: In the trial group (TG; n = 13) the liver was mobilized, followed by hilar preparation. In the control group (CG; n = 12) mobilization of the liver without hilar dissection was performed. Surgical manipulation was followed by an observation in both groups. Hepatic interstitial glucose, lactate, and glutamate concentrations were detected by MD and liver MC by thermodiffusion. During liver mobilization MC decreased significantly in both groups (TG; 86.7 +/- 2.0 to 73.4 +/- 2.3 ml/100 g min; and CG; 88.3 +/- 3.1 to 71.9 +/- 2.2 ml/100 g/min). In the trial group levels decreased further during hilar preparation reaching minimal values of 65.6 +/- 2.8. After preparation MC recovered to baseline. Glucose, lactate, and glutamate concentrations increased significantly during liver mobilization in the trial (glucose; 0.52 +/- 0.13 to 0.88 +/- 0.19 mmol/L; lactate; 0.34 +/- 0.07 to 0.54 +/- 0.07 mmol/L; glutamate; 34.5 +/- 3.6 to 52.6 +/- 8.0 micromol/L) and control group (glucose; 0.58 +/- 0.06 to 0.95 +/- 0.13 mmol/L; lactate; 0.30 +/- 0.06 to 0.49 +/- 0.07 mmol/L; glutamate; 32.9 +/- 2.36 to 56.1 +/- 5.12 micromol/L). Throughout hilus preparation maximum values could be measured in TG (glucose; 1.69 +/- 0.34; lactate; 0.90 +/- 0.18; glutamate; 63.5 +/- 7.2). After termination of mobilization or preparation baseline concentrations were reached again. MD allows monitoring of metabolic changes in hepatic parenchyma. Surgical liver preparation leads to changes of intrahepatic glucose, lactate, and glutamate levels (without alterations of parameters in systemic plasma) along with hepatic MC impairment. Reconstitution of hepatic MC was accompanied by rapid normalization of metabolic parameters. By measuring specific parameters, MD could prove to be of use for functional assessment of metabolic effects due to MC disturbances.

Influence of lipoprotein(a) on restenosis after femoropopliteal percutaneous transluminal angioplasty in Type 2 diabetic patients

OBJECTIVE

The influence of vascular morphology and metabolic parameters including lipoprotein(a) (Lp(a)) on restenosis after peripheral angioplasty has been compared in Type 2 diabetes (DM) vs. non-diabetic patients (ND).

RESEARCH DESIGN AND METHODS

The clinical course and risk profile of 132 (54 DM vs. 78 ND) patients with peripheral arterial occlusive disease (PAD) were observed prospectively following femoropopliteal angioplasty (PTA). Clinical examination, oscillometry, ankle brachial blood pressure index (ABI) and the toe systolic blood pressure index (TSPI) were used during follow-up. Duplex sonography and reangiography were also used to verify suspected restenosis or reocclusion.

RESULTS

At the time of intervention patients with DM had a lower median Lp(a) of 9 vs. 15 mg/dl (P < 0.01) in patients without diabetes. Recurrence within 1 year after PTA occurred in 25 diabetic (= 46%, Lp(a) 12 mg/dl) and 30 non-diabetic (= 38%, Lp(a) 48 mg/dl) patients. DM patients with 1 year's patency had a median Lp(a) of 7 vs. 11 mg/dl in non-diabetic patients (P < 0.05). However, 12 months after angioplasty Lp(a) correlated negatively with the ABI (r = -0.44, P < 0.01) in diabetic and in non-diabetic patients (r = -0.20, P < 0.05). The probability of recurrence after PTA continuously increased with higher levels of Lp(a) in each subgroup of patients.

CONCLUSIONS

Our data indicate that Lp(a) is generally lower in those with peripheral arterial occlusive disease and Type 2 diabetes than in non-diabetic individuals. The increased risk for restenosis with rising levels of Lp(a) is set at a lower Lp(a) in diabetes and may be more harmful for diabetic patients.

Clinical long-term results of percutaneous transluminal angioplasty in patients with peripheral arterial occlusive disease

BACKGROUND

We investigated the long-term clinical results of percutaneous transluminal angioplasty (PTA) in patients with peripheral arterial occlusive disease (PAOD) and the influence of different parameters on the primary success rate, the rate of complications and the long-term outcome.

PATIENTS AND METHODS

We reviewed clinical and hemodynamic follow-up data of 166 consecutive patients treated with PTA in 1987 in our department.

RESULTS

PTA improved the clinical situation in 79.4% of patients with iliac lesions and in 88.3% of patients with femoro-popliteal lesions. The clinical stage and ankle brachial index (ABI) post-interventional could be improved significantly (each P < 0.001), the same results were observed at the end of follow-up (each P < 0.001). Major complications occurred in 11 patients (6.6%). The rate of primary clinical long-term success for suprainguinal lesions was 55% and 38% after 5 and 10 years (femoro-popliteal 44% and 33%), respectively, the corresponding data for secondary clinical long-term success were 63% and 56% (60% and 55%). Older age (P = 0.017) and lower ABI pre-interventional (P = 0.019) significantly deteriorated primary clinical long-term success for suprainguinal lesions, while no factor could be identified influencing the outcome of femoro-popliteal lesions significantly.

CONCLUSION

Besides an acceptable success rate with a low rate of severe complications, our results demonstrate favourable long-term clinical results of PTA in patients with PAOD.

Risk stratification for subclavian artery angioplasty: is there an increased rate of restenosis after stent implantation?

PURPOSE

To compare long-term patency after balloon angioplasty of stenotic or occluded subclavian arteries with and without adjunctive stenting and to identify independent risk factors for restenosis after balloon angioplasty.

METHODS

In a retrospective cohort study, 115 consecutive patients (65 women; mean age 60 years, interquartile range 53-68) who underwent PTA for atherosclerotic subclavian artery obstruction within a 15-year period were included. Among these, 26 (23%) consecutive patients had Palmaz stents routinely implanted since 1996. Follow-up investigation was performed in the year 2000. Patency during the median 44-month follow-up period (interquartile range 18-69 months, minimum 12) was evaluated by oscillography, blood pressure measurement, and color-coded duplex sonography. The predictive value of possible risk factors for restenosis was assessed in a multivariate model controlling for cardiovascular comorbidities and angiographic data.

RESULTS

PTA success was achieved in 98 (85%) patients, 72 (81%) of 89 undergoing angioplasty alone and all 26 with stents. Complete occlusion of the vessel and long lesions (> or = 2 cm) correlated with a lower success rate. One-year patency was 76% in unstented arteries and 95% in stented lesions due to better primary technical success, but at 4 years, the patency rates were 59% in arteries with stents and 68% in arteries without. Long lesions, residual stenosis after PTA, and stent implantation were independent predictors for restenosis after successful intervention.

CONCLUSIONS

Subclavian arterial stent implantation is associated with better 1-year patency than PTA due to improved technical success, but intermediate and long-term outcomes are less favorable, as instent restenosis frequently occurs.

Carotid artery stenting: effect of learning curve and intermediate-term morphological outcome

PURPOSE

To assess the impact of learning on the rate of success and complications of carotid stenting in a single-center, one-operator series and prospectively follow a patient cohort with regard to restenosis.

METHODS

In 303 patients (mean age 70 +/- 8.8 years), 320 internal carotid arteries (ICA) were treated with carotid stenting for stenoses > or = 70%. Four groups of 80 consecutive interventions were compared with regard to primary technical success and periprocedural complications. Stent patency in follow-up was assessed using duplex scanning.

RESULTS

Stenting was successful in 298 (93%) arteries. The combined neurological complications (transient ischemic attacks and all strokes) and 30-day death rate was 8.2% (n = 25), but the all stroke and 30-day death rate was 3.0% (n = 9). A significant reduction in the frequency of neurological complications after the initial 80 interventions was observed (p = 0.03), but technical success was not appreciably improved with increasing experience thereafter. Over a median 12 months (interquartile range 6 to 24), cumulative patency rates were 91%, 90%, and 91% at 6, 12, and 36 months, respectively.

CONCLUSIONS

Elective carotid stenting can be performed with excellent technical success, an acceptable frequency of periprocedural complications, and good intermediate-term patency. However, our findings suggest that a larger number of interventions should be performed to overcome the negative effects of the initial learning phase.

Predicting renal failure after balloon angioplasty in high-risk patients

PURPOSE

To assess the incidence and predictors of acute renal failure after percutaneous transluminal angioplasty (PTA) in a cohort of patients with generalized atherosclerosis.

METHODS

A retrospective review of 213 consecutive patients (127 men; median age 71 years, interquartile range 63-77) undergoing femoropopliteal PTA was undertaken. Renal function was measured by creatinine clearance at baseline and 24 hours after the intervention; acute renal dysfunction was defined as > or = 20% decrease of creatinine clearance. The predictive value of potential risk factors was determined in a multivariate model adjusting for comorbidities, pre-existing renal impairment, and angiographic data.

RESULTS

Overall serum creatinine values and creatinine clearance remained stable within 24 hours after PTA. Acute renal dysfunction occurred in 25 (12%) patients. Two (1%) patients developed oliguria; one required transient hemodialysis and developed persistent renal failure. Pre-existing impaired renal function (OR 12.2, p < 0.0001) and contrast dosage (OR 1.1, p = 0.03) were independent predictors of acute renal failure; hypertension (OR 7.9, p = 0.06) and congestive heart failure (OR 4.5, p = 0.06) were associated factors.

CONCLUSIONS

While transient acute renal dysfunction occurs in approximately 10% of patients with peripheral artery disease within 24 hours after angioplasty, persistent renal failure or end-stage renal disease is rare.