Computed tomography of cystic lung diseases

A cystic lesion in the lung is defined as a well-demarcated epithel-lined cavity, that can be mostly filled with air, water, as well as solid material content. This definition includes a wide variety of diseases such as bronchogenic cyst, abscess formation, lymphangioleiomyomatosis, Langerhans cell histiocytosis, emphysema, bronchiectasis, and pneumatoceles. Despite the difficulties in differential diagnosis, there are some diagnostic criteria for CT-scanning helping the radiologist to differentiate between these cystic entities. Moreover, clinical informations are extremely important. The most important clinical parameters include age, sex, clinical history and symptoms. Thus, a better understanding of classic CT appearance of cystic lung disease will allow more definitive diagnosis and could, in some cases, avoid biopsy.     

Fasciocutaneous flaps in the treatment of soft tissue defects of the lower leg caused by explosive war injuries

The use of fasciocutaneous flaps for the reconstruction of lower leg soft-tissue defects inflicted during the bombing of our country is presented in this case report. The experience with 9 patients with soft-tissue defects of the lower leg is presented with the aim of examining the possibilities of war-wound reconstruction. The results of the earlier use of fasciocutaneous flaps in the lower leg reconstruction as well as the those obtained during the reconstruction of the lower leg soft-tissue defects in war wounds was proven to be safe and reliable method of the reconstructions of severe lower leg injuries, particularly of its distal segment and the malleolus region.     

Ran's C-terminal,basic patch,and nucleotide exchange mechanisms in light of a canonical structure for Rab,Rho, Ras,and Ran GTPases

Proteins comprising the core of the eukaryotic cellular machinery are often highly conserved, presumably due to selective constraints maintaining important structural features. We have developed statistical procedures to decompose these constraints into distinct categories and to pinpoint critical structural features within each category. When applied to P-loop GTPases, this revealed within Rab, Rho, Ras, and Ran a canonical network of molecular interactions centered on bound nucleotide. This network presumably performs a crucial structural and/or mechanistic role considering that it has persisted for more than a billion years after the divergence of these families. We call these 'FY-pivot' GTPases after their most distinguishing feature, a phenylalanine or tyrosine that functions as a pivot within this network. Specific families deviate somewhat from canonical features in interesting ways, presumably reflecting their functional specialization during evolution. We illustrate this here for Ran GTPases, within which two highly conserved histidines, His30 and His139, strikingly diverge from their canonical counterparts. These, along with other residues specifically conserved in Ran, such as Tyr98, Lys99, and Phe138, appear to work in conjunction with FY-pivot canonical residues to facilitate alternative conformations in which these histidines are strategically positioned to couple Ran's basic patch and C-terminal switch to nucleotide exchange and effector binding. Other core components of the cellular machinery are likewise amenable to this approach, which we term Contrast Hierarchical Alignment and Interaction Network (CHAIN) analysis.     

The enhancement of riboflavin-mediated photo-oxidation of doxorubicin by histidine and urocanic acid

PURPOSE: Previously we have shown that doxorubicin (Adriamycin, ADR) can be inactivated by light-excited riboflavin. The inactivation of the drug results from its direct oxidation by the excited triplet riboflavin in a type I photosensitization reaction, and 3-methoxysalicyclic acid is an ADR breakdown product. In the present study, we investigated the enhancement of this process by histidine and some other imidazole analogs. METHODS: ADR solutions containing various concentrations of riboflavin and other agents were exposed to 365 nm light for various time periods and then the absorbance spectrum of ADR was measured by a double beam spectrophotometer. These measurement were used to calculate the half-time of the ADR degradation process. The degraded ADR solutions were analyzed by HPLC. RESULTS: The rate of bleaching of ADR by light-excited riboflavin was enhanced in the presence of histidine in a concentration-dependent manner. This enhancement was more pronounced at higher riboflavin concentrations. Histidine also enhanced the riboflavin-mediated photobleaching of N,N-dimethyl-4-nitrosoaniline (RNO), a compound known to be resistant to oxidation by singlet oxygen but sensitive to oxidation by the trans-annular peroxide of histidine. RNO was found to block the histidine enhancement of the riboflavin-mediated photobleaching of ADR in a competitive manner. Among the imidazole analogs of histidine tested, urocanic acid was found to be the most efficient enhancer of the riboflavin-mediated photobleaching of ADR. Superoxide anion radicals which retard the oxidation of ADR were quenched by urocanic acid but not by histidine. It was shown that the oxidation of ADR by the trans-annular peroxide of histidine resulted in the formation of 3-methoxysalicylic acid. CONCLUSIONS: In contrast to singlet oxygen, the trans-annular peroxide, formed by the interaction of histidine and the singlet oxygen produced by photoexcited riboflavin, is an efficient oxidizer of ADR. The enhancement of the riboflavin-mediated photobleaching of ADR by histidine analogs depends on the rate of their conversion to a trans-annular peroxide and on the efficiency of these products in oxidizing ADR. However, for some analogs of histidine, as shown for urocanic acid, other mechanisms could also be involved. The presence of urocanic acid in the skin suggests that significant degradation of ADR could occur in the presence of biologically relevant concentrations of riboflavin if patients treated with ADR are exposed to sunlight. The finding that histidine also enhanced the degradation of ADR to 3-methoxysalicylic acid, suggests that the process of ADR oxidation by the trans-annular peroxides is similar to the direct oxidation of ADR by excited triplet riboflavin.     

Advantages and limitations of the autofluorescent diagnostics of the laryngeal cancer and precancerosis

Any endoscopic diagnostic procedure that is capable of giving exact information on laryngeal lesions without damaging the tissue has essential advantages over standard biopsy. Tissue autofluorescence is defined as a natural ability of tissue to fluoresce when exposed to a certain light wavelength. This feature is a consequence of the presence of fluorophores in the tissues, which are activated by a narrow wavelength range. However, due to their biochemical and biophysical characteristics, laryngeal precancerosis and cancer do not fluoresce when exposed to blue light. In the present study, we used Pentax’s System of Autofluorescent Endoscopy (SAFE 1000) to detect autofluorescence disturbances from laryngeal mucosa. Diagnostic parameters (sensitivity and specificity) of the microlaryngoscopy (MLS) and SAFE 1000 in the diagnosis of laryngeal precancerosis and carcinoma were compared and discussed. We have found that SAFE had a better sensitivity with regard to mentioned laryngeal pathology, but MLS had better specificity than SAFE. The overall diagnostic sensitivity in the diagnostics of laryngeal atypical hyperplasia and cancer with SAFE was 89%, as opposed to 73% with MLS. Diagnostic specificity of SAFE for all cases of laryngeal carcinomas and atypical hyperplasia was 78%. The specificity of MLS in diagnostics of laryngeal carcinomas cases was 98%, while that for cases of atypical hyperplasia was 100%. Many other conditions that have impact on autofluorescent features of laryngeal mucosa were also discussed.     

Surgical Treatment of Coronary Artery-Pulmonary Artery Fistula with Coronary Artery Disease

Abstract   Coronary arteriovenous fistulae present rare clinical finding with the incidence of about 0.002% in the general population. Usually they are asymptomatic, but sometimes they can mimic other cardiac diseases, most commonly heart failure, myocardial ischemia, and endocarditis. Coronary arteriovenous fistulae have been reported to arise more commonly from the right coronary artery. Most of these fistulae are congenital, and only a small fraction acquired. In this report we present successful surgical treatment of coronary artery to pulmonary artery fistula combined with myocardial revascularization.     

The calcified ascending aorta in aortocoronary bypass

Heavily calcified ascending aorta significantly increased morbidity and lethality during open-heart surgery. Cannulation and clamping (partial or total) of severely atherosclerotic ascending aorta can easily cause damage and rupture of aortic wall, with consequential distal (often fatal) embolization with atheromatous debris (brain, myocardium). From June 1998. until June 2000, 11 of 2,136 (0.5%) patients who underwent coronary artery bypass grafting were with the severe atheromatous ascending aorta. The site of cannulation was in the aortic arch in three patients (aorta was occluded with Foley catheter in one case, and single clamp technique was used in the other two cases). The femoral artery was the cannulation site in other five cases. Profound hypothermia, ventricular fibrillation, and circulatory arrest, with no cross-clamping or cardioplegia, were used in three patients. Two patients were operated on with extracorporeal circulation, one in normothermia, on the beating heart, the other in moderate hypothermia, on fibrillating heart. In three patients myocardial revascularization was performed on the beating heart, in normothermia, without extracorporeal circulation. Postoperative course was uneventful in all 11 patients. Neither atheroembolism in the peripheral organs, nor atheroembolism of the extremities occurred. The proposed surgical approaches have the potential to reduce the prevalence of stroke and systemic embolization associated with coronary artery bypass grafting in patients with heavily calcified ascending aorta. This result was achieved due to the applied modifications of standard cardiosurgical technique.     

Palladium(II) Complexes with N‐Heteroaromatic Bidentate Hydrazone Ligands: The Effect of the Chelate Ring Size and Lipophilicity on in vitro Cytotoxic Activity

Novel Pd(II) complex with N‐heteroaromatic Schiff base ligand, derived from 8‐quinolinecarboxaldehyde (q8a) and ethyl hydrazinoacetate (haOEt), was synthesized and characterized by analytical and spectroscopy methods. The structure of novel complex, as well as structures of its quinoline and pyridine analogues, was optimized by density functional theory calculations, and theoretical data show good agreement with experimental results. A cytotoxic action of the complexes was evaluated on cultures of human promyelocytic leukemia (HL‐60), human glioma (U251), rat glioma (C6), and mouse fibrosarcoma (L929) cell lines. Among investigated compounds, only complexes with quinoline‐based ligands reduce the cell numbers in a dose‐dependent manner in investigated cell lines. The observed cytotoxic effect of two isomeric quinoline‐based complexes is predominantly mediated through the induction of apoptotic cell death in HL‐60 cell line. The cytotoxicity of most efficient novel Pd(II) complex is comparable to the activity of cisplatin, in all cell lines investigated.     

Biological evaluation of selected 3,4‐dihydro‐2(1H)‐quinoxalinones and 3,4‐dihydro‐1,4‐benzoxazin‐2‐ones: Molecular docking study

In order to investigate new potential therapeutically active agents, we investigated the biological properties of two small libraries of quinoxalinones and 1,4‐benzoxazin‐2‐ones. The results obtained showed that compounds 5 , 9–11 have good cytotoxic activity against HeLa cells where the lowest IC₅₀ value (10.46 ± 0.82 μM/mL) was measured for compound 10 . Additionally, the most active compounds ( 5 , 9 – 11 ) showed much better selectivity for MRC‐5 cells (up to 17.4) compared to cisplatin. In vitro evaluation of the inhibition of the enzyme α‐glucosidase showed that compounds 10 and 11 exert significant inhibition of the enzyme at 52.54 ± 0.09 and 40.09 ± 0.49 μM, respectively. Competitive experiments with ethidium bromide (EB) indicated that all tested compounds have affinity to displace EB from the EB‐DNA complex through intercalation, suggesting good competition with EB (K_sv = (3.1 ± 0.2), (5.1 ± 0.1), (5.6 ± 0.2), and (6.3 ± 0.2) × 10³ M^?1). A molecular docking study was also performed to better understand the binding modes and to conclude the structure–activity relationships of the synthesized compounds.