Ileus is one of the most severe diagnoses of the group of acute abdomen events. Some patients with certain forms of bowel obstruction respond well to conservative therapy. However, the diagnosis of strangulation ileus can be delayed in some situations, resulting in high morbidity and mortality in such cases. Our paper presents the case of an 81-year-old female patient who developed an ileus shortly after ureteral stent placement due to obstructive hydroureteronephrosis. The strangulation of the small intestine was caused by an atypical position of the right ureter in the abdominal cavity.
- Klíčová slova
- case report, ileus, stents, ureter,
- MeSH
- břišní dutina * MeSH
- ileus * diagnostické zobrazování etiologie MeSH
- lidé MeSH
- senioři nad 80 let MeSH
- stenty škodlivé účinky MeSH
- střevní obstrukce * diagnostické zobrazování etiologie chirurgie MeSH
- tenké střevo MeSH
- ureter * MeSH
- Check Tag
- lidé MeSH
- senioři nad 80 let MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
PURPOSE OF THE STUDY The study analyses a cohort of patients with surgically treated ankle fractures who developed complete distal tibiofibular synostoses. It focuses on their occurrence and association with the extent of tibiotalar dislocation of the ankle joint on the trauma X-ray and its relation to the choice of surgery. MATERIAL AND METHODS The cohort of a total of 824 patients with type B and C fractures according to Weber classification was followed up for 9 years. The cohort consisted of 403 (48.9%) men and 421 (51.1%) women. The exclusion criteria included associated talus fractures, calcaneus fractures and fractures of the other bones of the foot. The studied data were obtained retrospectively from medical documentation and by evaluation of trauma X-rays and X-rays obtained during the postoperative checks. The ankle fractures were classified based on the Weber classification and the basic epidemiologic data (age and gender), type of fracture and extent of tibiotalar dislocation of ankle fractures on the trauma X-ray were evaluated. Posttraumatic ankle dislocation was divided into tibiotalar dislocation > 10 mm, tibiotalar dislocation < 10 mm and the group with regular ankle joint. When evaluating the treatment method, the cohort was divided into three groups: Group 1 with one-stage osteosynthesis, Group 2 with temporary K-wire transfixation or external fixation and subsequent secondary conversion to internal osteosynthesis, and Group 3 with definitive transfixation or external fixation of the ankle. The results were statistically evaluated using the Pearson s chi-square test, or the Fisher s exact test for low frequencies. A multivariant logistic regression model was created to identify statistically significant factors contributing to the development of synostosis. The results with the p-value < 0.05 were considered statistically significant. RESULTS In the whole cohort, the synostosis of distal tibiofibular joint was observed in a total of 131 (15.9%) patients. In men it was in 85 (21.1%) cases and in women in 46 (10.9%) cases, which was statistically significant (p < 0.0001). There was a statistically significant difference (p = 0.0020) between the mean age in the group of patients with synostosis (54.4 years) and the mean age in the group of patients without synostosis (49.1 years). Complete distal tibiofibular synostoses were found in 78 (12.7%) fractures classified as type B according to the Weber classification and in 53 (25.5%) type C fractures. When taking into account the gender, synostoses occurred more frequently in men in both types of fractures classified based on the Weber classification, only in type C fractures no statistical significance was established (p = 0.3026). Various size of posttraumatic tibiotalar dislocation was present in both types of fractures. The group with less severe type B ankle fractures showed a statistically significant dominance of synostosis development in cases with large tibiotalar dislocation of more than 10 mm (p<0.0001). In the group with type C fractures different results were obtained. The highest frequency of cases with synostosis was reported in the group with dislocation smaller than 10 mm (p = 0.0698). In the entire cohort, 615 (74.6%) one-stage osteosyntheses were performed and synostoses developed in 77 (12.5%) cases. In 165 (20.0%) patients, transfixation with K-wires or external fixation with subsequent conversion to secondary osteosynthesis were used and synostoses were identified in 50 (30.3%) cases (p < 0.0001). The open fractures showed an insignificantly smaller number of synostoses than the closed fractures (p = 0.5902). DISCUSSION Posttraumatic distal tibiofibular synostoses have varied morphology. A number of studies confirmed that they do not affect much the functional status of the ankle, even despite their extensive finding in the area of syndesmosis is evident on the Xray. Etiologically, a certain role in their development is reported to be played by posttraumatic hematoma in case of damage to deep soft and bony structures of the ankle. CONCLUSIONS A higher occurrence of synostoses was observed in male population, older age patients and also in type C fractures according to the Weber classification. Larger tibiotalar dislocation showed statistical significance in the development of synostoses in type B fractures according to the Weber classification, whereas in type C fractures it was not the main factor contributing to the development of synostosis. In cases where one-staged osteosynthesis was performed, the occurrence of synostoses was statistically significantly lower than in secondary osteosynthesis after temporary stabilisation. Key words: ankle fracture, distal tibiofibular synostosis, ankle joint dislocation, Weber classification, acute surgery, delayed surgery.
- MeSH
- fraktury kotníku * epidemiologie chirurgie MeSH
- hlezenní kloub diagnostické zobrazování chirurgie MeSH
- kotník MeSH
- lidé středního věku MeSH
- lidé MeSH
- retrospektivní studie MeSH
- rizikové faktory MeSH
- synostóza * epidemiologie etiologie MeSH
- vnitřní fixace fraktury metody MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE OF THE STUDY The aim of this retrospective study was to assess the subjective evaluation of treatment by patients with respect to their return to work and recreational sport following the fracture of clavicle diaphysis with posttraumatic shortening of 1.5 cm, or more, treated non-operatively and surgically. MATERIAL AND METHODS Our group of patients consisted of 51 patients (14 females, 37 males) aged between 18 and 89 years (average age 46 years). We concentrated on the parameters of sex, age, side of injury, extent of posttraumatic shortening, method of treatment, return to work or recreational sport, DASH score at one year post non-operative or surgical treatment. Patients who sustained a pathological fracture, fractures of the clavicle combined with an injury of the acromioclavicular joint or simultaneous fracture of the humerus or the ribs were excluded from the study. Patients with open fractures or re-fractures were excluded as well. The indication for treatment selection was based on pre-operative discussion of the doctor with the patient and the Informed Consent was signed. The patient was informed about different treatment options. A shorter period of fixation of the arm and post-operative physiotherapy was mentioned in connection with surgical treatment as well as potential surgical complications. A statistical analysis comparing the data in both groups was conducted using the Fisher exact test. The p-value of 0.05 or less was considered as statistically significant. RESULTS The right side was affected 26 times, the left side 25 times. The shortening ranged from 1.5 to 3.7 cm. 24 patients (8 females, 16 males) aged 21 to 89 years (average 54 years) were treated non-operatively. 27 patients (6 females, 21 males) aged 18 to 74 years (average 38 years) underwent surgery. The difference in sex distribution in both groups was not statistically significant (p = 0.5311). According to the Robinson classification, there were 17 patients with type 2A2 fractures, of whom 8 underwent surgery and 9 were treated non-operatively, 19 patients with type 2B1 fractures, of whom 9 underwent surgery and 10 were treated non-operatively, and 15 patients with type 2B2, of whom 10 underwent surgery and 5 were treated non-operatively. The surgically treated patients prevailed in type 2B2 only, but this difference was not statistically significant (p = 0.2350). In the non-operatively treated group, 23 out of 24 patients returned to pre-injury activities in 3 months on average. Ten patients (48%) reported reaching the same function as on the other side. In the DASH score evaluation, 11 patients reached the value of 0-3.3, five patients 3.4-10, six patients 10.1-30.0 and two reached the score of more than 30. In the evaluation of capacity to work, 15 out of 24 patients were able to work, 11 of them without any restrictions or difficulties. In the evaluation of the sport and playing musical instrument module, 9 out of 24 patients did not engage in sports activities or do not play any musical instruments. In the surgically treated group, 26 out of 27 patients returned to pre-injury activities within 6 weeks. 19 (70%) patients reported reaching the same function as on the other side. In the DASH score evaluation, 19 patients reached the value of 0-3.3, two patients 3.4-10, 5 patients 10.1-30.0 and one patient with nonunion 72.5. Comparison of the average values of the DASH score demonstrated slightly better results achieved by surgical treatment (9.03 vs 6.77). When assessing the work module, 24 out of 27 patients returned to work, 20 of them without any restrictions or difficulties. Out of 27 patients, 4 patients were no longer able to engage in sports activities or to play a musical instrument. Of the 23 remaining patients, 18 did not have any problems, 5 suffered from minimal problems. The group of patients treated non-operatively included one case of non-union and the same applies to the surgically treated group. In 3 patients the removal of hardware was performed, 3 patients underwent revision of the surgical wound because of infection. DISCUSSION The recommendation of the weight-bearing of the upper extremity was similar in both groups, 12 weeks post injury/surgery on average. It is clear that sooner return to work or sports activities in the surgically treated group was preferred by younger patients who expected quicker recovery. Younger patients were less patient and more eager to return to work and sports, while the older patients, on the other hand, were more cautious about possible complications of surgery. CONCLUSIONS The results of our study did not identify any correlation between the clavicle shortening and the indication for surgical treatment. Surgical treatment was preferred by younger patients, more frequently by males. The rationale was supported by the perspective of sooner return to work and favourite sports activities. Their decision was not affected by the known risks of surgical treatment. Evaluation of the DASH score at one year after injury/surgery showed similar results. A higher incidence of complications in the surgically treated group did not lead to negative evaluation of the selected treatment modality by the highly motivated group of patients either. Key words: fractures of the clavicle diaphysis, non-operative treatment, surgical treatment, return to work, return to sports activities, functional results at 1 year.
- MeSH
- diafýzy MeSH
- dospělí MeSH
- fraktury kostí * komplikace chirurgie MeSH
- klíční kost zranění MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- retrospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- sporty * MeSH
- vnitřní fixace fraktury metody MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE OF THE STUDY Lumbar spinal stenosis (LSS) is a serious and fairly frequent disorder with prevalence increasing with age which often results in a disability. The surgical procedures are often very risky due to the greater age of patients with severe stenosis and their comorbidities. The study aimed to assess the functional outcomes and complications in patients who underwent surgical treatment for LSS at one year postoperatively and to identify the differences in the functional outcomes, if any, in dependence on the number of operated segments. MATERIAL AND METHODS It was a prospective study which included 33 patients who underwent surgery at the authors department from 1 November 2015 to 1 October 2016 for LSS, the mean age of patients was 69.5 (43-83) years. The surgery was indicated based on the clinical examination, radiography and MR imaging and consisted in posterior decompression with or without stabilisation and fusion. Pre- and post-operatively, a neurological examination and evaluation of patient difficulties were performed by: VAS - particularly for low back pain (VAS-LB) and lower limb pain (VAS-LL), Oswestry Disability Index (ODI) and Swiss Spinal Stenosis Questionnaire (SSSQ). The evaluation was done at a half year and one year after the surgery. The authors made comparisons in dependence on the number of treated segments (1-2, 3-5 and Th-S stabilisation). RESULTS A significant improvement of all the followed-up parameters was reported at one year postoperatively. At one year after the surgery, the VAS-LB score showed a decrease by 2.39 (p = 0.001), the VAS-LL by 3.26 (p < 0.001), while a decrease by 2 or more points is considered clinically significant. When evaluating the SSSQ questionnaire, a decrease in subjective difficulties (SSSQ-S) was by 0.89 (p < 0.001), in physical function (SSSQ-F) by 0.87 (p < 0.001). In this questionnaire, the satisfaction rate with the surgery was 2 - i.e. somewhat satisfied. Altogether 76% of patients were very or somewhat satisfied, no one was very dissatisfied. When evaluating the ODI, an improvement by 20.6% (p < 0.001) was reported. The authors identified neither any significant differences in the outcomes at a one-year follow-up in dependence on the length of stabilisation, nor any significant differences between the six-months and one-year follow-up. Intraoperative complications occurred in 18%, early postoperative complications in 6% of patients. The ASD developed in 9% within one year. DISCUSSION The authors confirmed a significant improvement of the followed-up parameters (VAS-LB, VAS-LL, SSSQ, ODI) which corresponds with recent literature. The decrease in VAS and ODI in the authors study is more marked than the outcomes stated in literature. The authors outcomes clearly show that there is no correlation with the length of stabilisation and the number of decompressed segments. Conversely, the rate of complications was higher in this group than the rates stated in literature, but majority of complications had no consequences for the patients. CONCLUSIONS In the group of patients with a one-year follow-up the authors confirmed that surgical procedures will result in reduced subjective difficulties of patients, reduced pain and improvement of physical function. A significant improvement of all the followed-up parameters was reported. The authors did not confirm the correlation between the postoperative improvement and the number of treated segments. Key words:lumbar spinal stenosis, quality of life, post-operative outcomes, complications.
- MeSH
- bederní obratle chirurgie MeSH
- chirurgická dekomprese MeSH
- dospělí MeSH
- fúze páteře MeSH
- kvalita života MeSH
- lidé středního věku MeSH
- lidé MeSH
- následné studie MeSH
- obnova funkce MeSH
- posuzování pracovní neschopnosti MeSH
- prospektivní studie MeSH
- průzkumy a dotazníky MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- spinální stenóza diagnóza diagnostické zobrazování chirurgie MeSH
- spokojenost pacientů MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE OF THE STUDY Ankle fractures are characterised by a high variability of damage to bone and ligament structures which leads to diverse clinical conditions. This study aims to analyse a group of patients with surgically treated ankle fractures, with a focus on evaluating the outcomes of treatment of ankle joint medial structure injuries (medial malleolar fracture, ligament lesions). MATERIAL AND METHODS The analysed group included 186 patients (102 men and 84 women), in whom an ankle fracture surgery was performed in 2015 and 2016. The outcomes of the treatment were evaluated in 111 patients with type B and type C fractures, who underwent a follow-up examination at one year after the surgery consisting in subjective and objective assessment of the condition and an ankle radiograph. The obtained outcomes were processed using the techniques of descriptive statistics and subsequently evaluated through the Pearson´s chi-square test at 5% significance level, or the Fisher´s exact test for low frequencies. RESULTS The mean age of patients in the group was 48.6 years, while it was lower in men than in women (42.8 years compared to 53.9 years). According to Weber classification, 1 % of fractures were classified as a type A fracture, 68 % as a type B, 27 % as a type C. The group of isolated medial malleolar fractures represented 4 % of cases. The medial side of the ankle joint more frequently suffered a ligament lesion (56 %) than a medial malleolar fracture (44 %). The mean age of the patients with a medial malleolar fracture was 51.9 years, whereas the mean age of the patients with a ligament lesion on the medial side of the ankle was 44.2 years. When evaluating the outcomes using the OMA score at one year postoperatively, a statistically significant difference was found (p = 0.002) between the patients with a medial malleolar fracture (OMA 79.9) and the patients with a ligament lesion at the medial side of the ankle joint (OMA 91.2). DISCUSSION The aim of the study was to add more information on medial structures of ankle joint that are of major importance for ensuring stability of ankle fractures. In agreement with the literature, when managing the ankle fractures with an injury suffered on the medial side there is obviously a more uniform approach in cases with medial malleolar fractures. The situation is different in case of the deltoid ligament lesion, when historically there is a certain level of non-uniformity in indications for revision surgeries and treatment of the injured ligament structures. In our group, in the case of ligament lesion on the medial side of the ankle joint an emphasis is put on the fluoroscopy control of the symmetry of tibiotalar joint space before the beginning of the surgery and also after the fibular fracture stabilisation. The revision surgery was indicated in cases where asymmetry of ankle fork was found. The patients considered the treatment outcome better in cases with a ligament lesion than in cases with a medial malleolar fracture. CONCLUSIONS Proper treatment of medial structures of the ankle joint is important for ensuring the stability of ankle fractures. The patients with type B fractures reported better results at one year postoperatively compared to the patients with type C fracture according to the Weber classification. A statistically significantly better results after the ankle fracture surgery were achieved in patients with the presence of a medial ligament lesion compared to the patients with a medial malleolar fracture. Key words:ankle fracture, injury of medial structures, epidemiology, outcomes of treatment.
- MeSH
- dospělí MeSH
- fraktury kotníku epidemiologie chirurgie MeSH
- lidé středního věku MeSH
- lidé MeSH
- poranění kotníku epidemiologie chirurgie MeSH
- vnitřní fixace fraktury MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Research on brown adipose tissue and its hallmark protein, mitochondrial uncoupling protein UCP1, has been conducted for half a century and has been traditionally studied in the Institute of Physiology (AS CR, Prague), likewise UCP2 residing in multiple tissues for the last two decades. Our group has significantly contributed to the elucidation of UCP uncoupling mechanism, fully dependent on free fatty acids (FFAs) within the inner mitochondrial membrane. Now we review UCP2 physiological roles emphasizing its roles in pancreatic beta-cells, such as antioxidant role, possible tuning of redox homeostasis (consequently UCP2 participation in redox regulations), and fine regulation of glucose-stimulated insulin secretion (GSIS). For example, NADPH has been firmly established as being a modulator of GSIS and since UCP2 may influence redox homeostasis, it likely affects NADPH levels. We also point out the role of phospholipase iPLA2 isoform gamma in providing FFAs for the UCP2 antioxidant function. Such initiation of mild uncoupling hypothetically precedes lipotoxicity in pancreatic beta-cells until it reaches the pathological threshold, after which the antioxidant role of UCP2 can be no more cell-protective, for example due to oxidative stress-accumulated mutations in mtDNA. These mechanisms, together with impaired autocrine insulin function belong to important causes of Type 2 diabetes etiology.
- MeSH
- antioxidancia metabolismus MeSH
- beta-buňky metabolismus MeSH
- glukosa metabolismus MeSH
- inzulin biosyntéza MeSH
- iontové kanály metabolismus MeSH
- kultivované buňky MeSH
- lidé MeSH
- mitochondriální proteiny metabolismus MeSH
- mitochondrie metabolismus MeSH
- oxidace-redukce MeSH
- oxidační stres fyziologie MeSH
- reaktivní formy kyslíku metabolismus MeSH
- regulace genové exprese fyziologie MeSH
- uncoupling protein 2 MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- antioxidancia MeSH
- glukosa MeSH
- inzulin MeSH
- iontové kanály MeSH
- mitochondriální proteiny MeSH
- reaktivní formy kyslíku MeSH
- UCP2 protein, human MeSH Prohlížeč
- uncoupling protein 2 MeSH
Living microalgal cells differ from other cells that are used as objects for optical micromanipulation, in that they have strong light absorption in the visible range, and by the fact that their reaction centers are susceptible to photodamage. We trapped cells of the microalga Trachydiscus minutus using optical tweezers with laser wavelengths in the range from 735 nm to 1064 nm. The exposure to high photon flux density caused photodamage that was strongly wavelength dependent. The photochemical activity before and after exposure was assessed using a pulse amplitude modulation (PAM) technique. The photochemical activity was significantly and irreversibly suppressed by a 30s exposure to incident radiation at 735, 785, and 835 nm at a power of 25 mW. Irradiance at 885, 935 and 1064 nm had negligible effect at the same power. At a wavelength 1064 nm, a trapping power up to 218 mW caused no observable photodamage.
Synthetic study on cystinyl peptides using solution and solid phase methodology was carried out with the central hinge region of immunoglobulin IgG1. In the solid phase synthesis of hexadecapeptide 1c, the time necessary for the formation of disulfide bonds between linear precursors was shortened four times by the action of pure oxygen in buffered solution, in comparison with air oxidation. The product was thus obtained devoid of impurities from side reactions. In the preparation of the shortened bis-cystinyl analogs 2k and 3d of the natural hexadecapeptide 1c, both the classical and polyethylene glycol (PEG6000) solution methods were utilized using a disulfide synthon (Boc-Cys-OPfp)2 to obtain peptide chains in a natural parallel alignment. In the PEG6000 strategy, lysine as a linker on both sides of the polymer was attached to enhance the loading capacity. The leucine residue, instead of proline one, was introduced to the carboxy terminus to facilitate a specific enzymatic cleavage of the peptides from PEG6000 by thermolysine.
- MeSH
- imunoglobulin G chemie MeSH
- lidé MeSH
- molekulární sekvence - údaje MeSH
- organická chemie metody MeSH
- peptidy chemická syntéza chemie MeSH
- sekvence aminokyselin MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- Názvy látek
- imunoglobulin G MeSH
- peptidy MeSH
Homeostasis of reactive oxygen species (ROS) in cardiomyocytes is critical for elucidation of normal heart physiology and pathology. Mitochondrial phospholipases A2 (mt-PLA2) have been previously suggested to be activated by ROS. Therefore, we have attempted to elucidate physiological role of such activation. We have found that function of a specific i-isoform of mitochondrial phospholipase A2 (mt-iPLA2) is activated by tert-butylhydroperoxide in isolated rat heart mitochondria. Isoform specificity was judged from the inhibition by bromoenol lactone (BEL), a specific iPLA2 inhibitor. Concomitant uncoupling has been caused by free fatty acids, since it was inhibited by bovine serum albumin. The uncoupling was manifested as a respiration burst accompanied by a slight decrease in mitochondrial inner membrane potential. Since this uncoupling was sensitive to carboxyatractyloside and purine nucleotide di- and tri-phosphates, we conclude that it originated from the onset of fatty acid cycling mediated by the adenine nucleotide translocase (major contribution) and mitochondrial uncoupling protein(s) (minor contribution), respectively. Such a mild uncoupling may provide a feedback downregulation of oxidative stress, since it can further attenuate mitochondrial production of ROS. In conclusion, ROS-induced function of cardiac mt-iPLA2 may stand on a pro-survival side of ischemia-reperfusion injury.
- MeSH
- aktivace enzymů účinky léků fyziologie MeSH
- fosfolipasy A2, skupina VI metabolismus MeSH
- iontové kanály metabolismus MeSH
- krysa rodu Rattus MeSH
- mastné kyseliny metabolismus MeSH
- mitochondriální ADP/ATP-translokasy metabolismus MeSH
- mitochondriální proteiny metabolismus MeSH
- mitochondrie účinky léků enzymologie MeSH
- myokard enzymologie patologie MeSH
- oxidační stres účinky léků fyziologie MeSH
- oxidativní fosforylace MeSH
- potkani Wistar MeSH
- reaktivní formy kyslíku metabolismus MeSH
- reperfuzní poškození myokardu metabolismus patologie MeSH
- terc-butylhydroperoxid farmakologie MeSH
- uncoupling protein 1 MeSH
- viabilita buněk fyziologie MeSH
- zpětná vazba fyziologická fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- fosfolipasy A2, skupina VI MeSH
- iontové kanály MeSH
- mastné kyseliny MeSH
- mitochondriální ADP/ATP-translokasy MeSH
- mitochondriální proteiny MeSH
- Pla2g6 protein, rat MeSH Prohlížeč
- reaktivní formy kyslíku MeSH
- terc-butylhydroperoxid MeSH
- uncoupling protein 1 MeSH
Glycodendrimers bearing Tn (alpha-D-GalNAc-(1 --> O)-Ser/Thr), an identified tumor-associated carbohydrate antigen, hold promise in the post-surgery treatment of a variety of tumors such as metastatic breast cancer. We used molecular dynamics (MD) techniques to examine structural differences taking place during synthesis of two classes of tetravalent Multiple Antigen Glycopeptides (MAG) that differ only by the gamma-Abu insert in the structure of the oligolysine core. Each of the selected intermediates of the synthesis was modeled, subjected to the 2 ns run in N,N'-dimethylformamide (DMF) and geometrically characterized. We characterized: a) distances of free, or extended termini from the anchor, b) interatomic distances between free or substituted N termini, c) radius of gyration and d) spatial distribution of molecular density. A detailed conformational analysis of 16 glycodendrimers shows the distinct behavior of the inserted vs. non-inserted constructs already during the first steps of the modeled synthesis. It suggests that the character as well as the length of the insert has a major impact on the spatial characteristics and behavior of the dendritic molecules. The inserts can, in principle, increase a tendency of dendrimers to establish a high-density core, which is similar to the effect of a higher generation.
- MeSH
- antigeny sacharidové asociované s nádorem chemie MeSH
- dimethylformamid chemie MeSH
- GABA chemie metabolismus MeSH
- glykopeptidy chemie MeSH
- molekulární modely MeSH
- polylysin chemie MeSH
- polymery chemie MeSH
- reagencia zkříženě vázaná chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antigeny sacharidové asociované s nádorem MeSH
- dimethylformamid MeSH
- GABA MeSH
- glykopeptidy MeSH
- polylysin MeSH
- polymery MeSH
- reagencia zkříženě vázaná MeSH
- Tn antigen MeSH Prohlížeč