New hydrazine and hydrazide quinoxaline 1,4-di-N-oxide derivatives: In silico ADMET, antiplasmodial and antileishmanial activity

We report the design (in silico ADMET criteria), synthesis, cytotoxicity studies (HepG-2 cells), and biological evaluation of 15 hydrazine/hydrazide quinoxaline 1,4-di-N-oxide derivatives against the 3D7 chloroquine sensitive strain and FCR-3 multidrug resistant strain of Plasmodium falciparum and Leishmania infantum (axenic amastigotes). Fourteen of derivatives are novel quinoxaline 1,4-di-N-oxide derivatives. Compounds 18 (3D7 IC₅₀=1.40μM, FCR-3 IC₅₀=2.56μM) and 19 (3D7 IC₅₀=0.24μM, FCR-3 IC₅₀=2.8μM) were identified as the most active against P. falciparum, and they were the least cytotoxic (CC₅₀-values>241μM) and most selective (SI>86). None of the compounds tested against L. infantum were considered to be active. Additionally, the functional role of the hydrazine and hydrazide structures were studied in the quinoxaline 1,4-di-N-oxide system.

New amide derivatives of quinoxaline 1,4-di-N-oxide with leishmanicidal and antiplasmodial activities

Malaria and leishmaniasis are two of the World's most important tropical parasitic diseases. Continuing with our efforts to identify new compounds active against malaria and leishmaniasis, twelve new 1,4-di-N-oxide quinoxaline derivatives were synthesized and evaluated for their in vitro antimalarial and antileishmanial activity against Plasmodium falciparum FCR-3 strain, Leishmania infantum and Leishmania amazonensis. Their toxicity against VERO cells (normal monkey kidney cells) was also assessed. The results obtained indicate that a cyclopentyl derivative had the best antiplasmodial activity (2.9 µM), while a cyclohexyl derivative (2.5 µM) showed the best activity against L. amazonensis, and a 3-chloropropyl derivative (0.7 µM) showed the best results against L. infantum. All these compounds also have a Cl substituent in the R⁷ position.

Influence of patient activity on femoral osteolysis at five and ten years following hybrid total hip replacement

We conducted a longitudinal study including patients with the same type of primary hybrid total hip replacement and evaluated patient activity and femoral osteolysis at either five or ten years post-operatively. Activity was measured using the University of California, Los Angeles scale. The primary outcome was the radiological assessment of femoral osteolysis. Secondary outcomes were revision of the femoral component for aseptic loosening and the patients' quality of life. Of 503 hip replacements in 433 patients with a mean age of 67.7 years (30 to 91), 241 (48%) were seen at five and 262 (52%) at ten years post-operatively. Osteolytic lesions were identified in nine of 166 total hip replacements (5.4%) in patients with low activity, 21 of 279 (7.5%) with moderate activity, and 14 of 58 (24.1%) patients with high activity. The risk of osteolysis increased with participation in a greater number of sporting activities. In multivariate logistic regression adjusting for age, gender, body mass index and the inclination angle of the acetabular component, the adjusted odds ratio for osteolysis comparing high vs moderate activity was 3.6 (95% confidence interval 1.6 to 8.3). Stratification for the cementing technique revealed that lower quality cementing increased the effect of high activity on osteolysis. Revision for aseptic loosening was most frequent with high activity. Patients with the highest activity had the best outcome and highest satisfaction. In conclusion, of patients engaged in high activity, 24% had developed femoral osteolysis five to ten years post-operatively.

Anatomy of the anterior cruciate ligament

The anterior cruciate ligament (ACL) is a band of dense connective tissue which courses from the femur to the tibia. The ACL is a key structure in the knee joint, as it resists anterior tibial translation and rotational loads. When the knee is extended, the ACL has a mean length of 32 mm and a width of 7-12 mm. There are two components of the ACL, the anteromedial bundle (AMB) and the posterolateral bundle (PLB). They are not isometric with the main change being lengthening of the AMB and shortening of the PLB during flexion. The ACL has a microstructure of collagen bundles of multiple types (mostly type I) and a matrix made of a network of proteins, glycoproteins, elastic systems, and glycosaminoglycans with multiple functional interactions. The complex ultrastructural organization and abundant elastic system of the ACL allow it to withstand multiaxial stresses and varying tensile strains. The ACL is innervated by posterior articular branches of the tibial nerve and is vascularized by branches of the middle genicular artery.

Anatomic variation of the mechanical properties of the glenoid

Finite element analysis modeling is an important tool in the design of total joint replacements. However, to use a finite element analysis the material properties of the studied bone must be known. The aim of the study was to measure the elastic properties of the glenoid bone in the axial, coronal, and sagittal planes with an ultrasound transmission technique. The relative density and Houndsfield computed tomography numbers were also assessed. Three pairs of scapulas were obtained from unembalmed human cadavers. Seventy-four cubic cancellous bone specimens of 6 mm were used for ultrasonic measurements. The study showed significant differences with anatomic location. Mechanical properties of cancellous bone were found to be higher near the direction of application of the resultant force, perpendicular to the articular surface of the glenoid. Mechanical properties were found to be significantly higher at the center and posterior edge of the glenoid (p < 0.01). Significant differences were also found in the three planes studied. The lateromedial Young's modulus (E1) was higher than the anteroposterior modulus (E2) and the superoinferior modulus (E3) (E1 = 372 +/- 164 MPa, E2 = 222 +/- 79 MPa, E3 = 198 +/- 75 MPa).