Topical tranexamic acid versus autotransfusion after total knee arthroplasty

PURPOSE

To compare the use of topical tranexamic acid (TXA) with postoperative autologous transfusion (PAT) in terms of blood loss, need for allogeneic blood transfusion, and cost-effectiveness.

METHODS

Records of 25 men and 125 women (mean age, 67 years) who underwent primary unilateral total knee arthroplasty (TKA) and were randomised to the PAT group (n=50), topical TXA group (n=50), or routine drainage group (control) [n=50] were reviewed. Pre- and post-operative haemoglobin level, total postoperative drainage volume, and the need for allogeneic blood transfusion were recorded.

RESULTS

The 3 groups were comparable in terms of age, gender, and preoperative haemoglobin level. The total postoperative drainage volume was lower in the TXA group than the PAT or routine drainage groups (174.48 vs. 735 vs. 760 ml, p<0.001). The postoperative haemoglobin level was lower in the routine drainage group than the PAT or TXA groups on day 1 (11.67 vs. 12.33 vs. 12.40 g/dl, p<0.001) and day 3 (9.9 vs. 10.7 vs. 11.14 g/dl, p<0.001). The number of patients who received allogeneic blood transfusion was higher in the routine drainage group (12 and 4 patients received 1 and 2 units of blood, respectively) than the PAT group (4 patients received 1 unit of blood) or the TXA group (none required transfusion) [p<0.001], and the respective total transfusion cost was $1200, $240, and $0. The total cost was lowest in the TXA group followed by the routine drainage group and PAT group ($200 vs. $1200 vs. $12 390). No patient developed acute infection, deep venous thrombosis, pulmonary embolism, myocardial infarction, or stroke.

CONCLUSION

Compared with PAT, topical TXA was more cost-effective and resulted in less total postoperative drainage volume and less need for allogeneic blood transfusion.

Amino substituted nitrogen heterocycle ureas as kinase insert domain containing receptor (KDR) inhibitors: Performance of structure–activity relationship approaches

A quantitative structure–activity relationship (QSAR) study was performed on a set of amino-substituted nitrogen heterocyclic urea derivatives. Two novel approaches were applied: (1) the simplified molecular input-line entry systems (SMILES) based optimal descriptors approach; and (2) the fragment-based simplex representation of molecular structure (SiRMS) approach. Comparison with the classic scheme of building up the model and balance of correlation (BC) for optimal descriptors approach shows that the BC scheme provides more robust predictions than the classic scheme for the considered pIC₅₀ of the heterocyclic urea derivatives. Comparison of the SMILES-based optimal descriptors and SiRMS approaches has confirmed good performance of both techniques in prediction of kinase insert domain containing receptor (KDR) inhibitory activity, expressed as a logarithm of inhibitory concentration (pIC50) of studied compounds.

Three-dimensional model of nonsteroidal estrogen receptor ligand binding/electron topological method

Three-dimensional quantitative structure-activity relationship (3D-QSAR) models have been obtained using the electron topological method (ETM) for estrogen (estrone, CAS 53-16-7) receptor (ER) affinities. This method was used to identify regions of the enzyme and inhibitors where steric and electrostatic effects correlate strongly with biological activity. Thirty compounds belong to a series of diethylstilbestrol (CAS 56-53-1, DES) and indenestrol (CAS 24643-94-5) analogues whose affinities for ER have been, theoretically, investigated. After energy minimizations and molecular dynamics calculations were performed to find the ground state conformer for each molecule, quantum chemical properties of each molecule were defined and in ETM their matrices were compared with those of the reference molecule. It is shown that the molecular fragments responsible for this affinity possess fixed electronic and geometric characteristics associated with a distinct arrangement and steric accessibility of an oxygen atom and a group of carbon atoms. Several parameters were modified in order to analyze their influence onto the correlation between binding affinities. The highest correlation coefficient (R2 = 0.930, SE = 0.403) was obtained with the structure of the active fragment and the orientation of aliphatic and phenolic substituents.

Study of the binding affinity for corticosteroid-binding globulin (CBG) using the electron topological method (ETM) as three-dimensional quantitative structure-activity relationship (3D QSAR)

The Electron Topological Method, called ETM, is a descriptor for predicting the biological activities of molecules based on three-dimensional quantitative structure-activity relations (3D QSAR). ETM uses a modified electron topological state index to substitute for electronic properties and a topological distance for the relative distance in the molecule. It is shown that the molecular fragments responsible for this activity possess fixed electronic and geometric characteristics associated with a distinct arrangement and the steric accessibility of an oxygen atom and a group of carbon atoms. After that, it is essential to employ a linear regression analysis technique to derive a 3D QSAR model relating the biological activities to the ETM. The ETM is used to study the 3D QSAR of the corticosteroid-binding globulin (CBG) binding affinity to 31 steroids, and resulting models have a comparable to current 3D methods such as CoMFA. Though the ETM is a descriptor based on 3D topological information obtained by quantum chemical derived descriptors, give the best answer for both the similarity analysis and the statistical fitting.

Investigation of antiulcer activities of imidazo[1,2-alpha]pyridinyl-2-alkylaminobenzoxazoles and 5,6,7,8-tetahydroimidazo[1,2-alpha]pyridinyl-benzoxazoles with electron-topological (ET) method

The study presents structure-activity considerations of a series of imidazo[1,2-alpha]pyridiny-2-alkylaminobenzoxazoles(I) and 5,6,7,8-tetahydroimidazo[1,2-alpha]pyridinylbenzoxazoles(II) investigated for anti-stress ulcer activity with the electron-topological method. A series of 39 compounds including 24 active and 15 weakly active was studied. It is shown that the fragment determined by the electron-topological method in an active molecule is responsible for anti-stress ulcer activity. Quantitative structure-activity relationships with electron topological approach of these compounds are discussed in terms of the statistical program STATGRAF-7.0.