Aerodynamic drag is not the major determinant of performance during giant slalom skiing at the elite level.

This investigation was designed to (a) develop an individualized mechanical model for measuring aerodynamic drag (F(d) ) while ski racing through multiple gates, (b) estimate energy dissipation (E(d) ) caused by F(d) and compare this to the total energy loss (E(t) ), and (c) investigate the relative contribution of E(d) /E(t) to performance during giant slalom skiing (GS). Nine elite skiers were monitored in different positions and with different wind velocities in a wind tunnel, as well as during GS and straight downhill skiing employing a Global Navigation Satellite System. On the basis of the wind tunnel measurements, a linear regression model of drag coefficient multiplied by cross-sectional area as a function of shoulder height was established for each skier (r > 0.94, all P < 0.001). Skiing velocity, F(d) , E(t) , and E(d) per GS turn were 15-21 m/s, 20-60 N, -11 to -5 kJ, and -2.3 to -0.5 kJ, respectively. E(d) /E(t) ranged from ∼5% to 28% and the relationship between E(t) /v(in) and E(d) was r = -0.12 (all NS). In conclusion, (a) F(d) during alpine skiing was calculated by mechanical modeling, (b) E(d) made a relatively small contribution to E(t) , and (c) higher relative E(d) was correlated to better performance in elite GS skiers, suggesting that reducing ski-snow friction can improve this performance.

Validated HPLC-MS/MS method for determination of quetiapine in human plasma.

A validated, highly sensitive and selective high-pressure liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the quantitative determination of quetiapine (QUE) in human Na2EDTA plasma with mass spectrometry (MS) detection. Clozapine (CLO) was employed as an internal standard. Samples were extracted using solid phase extraction (SPE). Oasis HLB cartridges and the concentration of quetiapine was determined by isocratic HPLC-MS/MS. The SRM mode was used for MS/MS detection. The method was validated over a concentration range of 1.0-382.2 ng/mL. Inter- and intra-day precision and accuracy of the proposed method were characterized by relative standard deviation (R.S.D.) and the percentage of deviation, respectively; both were lower than 8%. The developed method was employed in the pharmacokinetic study of quetiapine.

Validated HPLC-MS-MS method for simultaneous determination of atorvastatin and 2-hydroxyatorvastatin in human plasma-pharmacokinetic study.

Cholesterol-reducing statin drugs are the most frequently prescribed agents for reducing morbidity and mortality related to coronary heart disease. In this publication a validated, highly sensitive, and selective isocratic HPLC method is reported for quantitative determination of the major statin drug atorvastatin (ATV) and its metabolite 2-hydroxyatorvastatin (HATV). Detection was performed with an electrospray ionization triple-quadrupole mass spectrometer equipped with an ESI interface operating in positive-ionization mode. Multiple reaction monitoring (MRM) was used for MS-MS detection. The calibration plot was linear in the concentration range 0.10-40.00 ng mL(-1) for both ATV and HATV. Inter-day and intra-day precision and accuracy of the proposed method were characterized by measurement of relative standard deviation (RSD) and percentage deviation, respectively; both were less than 8% for both analytes. The limit of quantitation was 0.02 ng mL(-1) for ATV and 0.07 ng mL(-1) for HATV. The method was used for pharmacokinetic study of ATV and HATV. Pharmacokinetic data for all analytes are also reported.

Validated HPLC-MS/MS method for simultaneous determination of simvastatin and simvastatin hydroxy acid in human plasma.

Cholesterol lowering statin drugs are the most frequently prescribed agents for reducing morbidity and mortality related to coronary heart disease. This publication presents a validated, highly sensitive and selective isocratic HPLC method for the quantitative determination of the major statin drug simvastatin (SIM) and its metabolite simvastatin hydroxy acid (SIMA). Detection was performed on an electrospray ionization triple quadrupole mass spectrometer equipped with an ESI interface operated in positive and negative ionization mode. The multiple reaction-monitoring mode (MRM) was used to provide MS/MS detection. The linearity for the calibration curve in the concentration range of 0.10-16.00 ng/mL for SIM and 0.10-16.00 ng/mL for SIMA is presented. Inter- and intra-day precision and accuracy of the proposed method were characterized by relative standard deviation (R.S.D.) and percentage deviation, respectively; with both lower than 7% for all analytes. The limit of quantitation was 0.03 ng/mL for SIM and 0.02 ng/mL for SIMA. The devised method was employed in the pharmacokinetic study of SIM and the pharmacokinetic parameters of all analytes are also presented.

Validated HPLC-MS-MS method for determination of azithromycin in human plasma.

A validated, highly sensitive, and selective HPLC method with MS-MS detection has been developed for quantitative determination of azithromycin (AZI) in human Na2EDTA plasma. Roxithromycin (ROX) was used as internal standard. Human plasma containing AZI and internal standard was ultrafiltered through Centrifree Micropartition devices and the concentration of AZI was determined by isocratic HPLC-MS-MS. Multiple reaction monitoring mode (MRM) was used for MS-MS detection. The calibration plot was linear in the concentration range 2.55-551.43 ng mL(-1). Inter-day and Intra-day precision and accuracy of the proposed method were characterized by R.S.D and percentage deviation, respectively; both were less than 8%. Limit of quantification was 2.55 ng mL(-1). The proposed method was used to determine the pharmacokinetic profile of AZI (250-mg tablets).

War wounds to the foot.

Thirty-nine patients with foot injuries were admitted to the Clinic for Orthopedic Surgery in Lovran during the war against Croatia. All of them were soldiers wounded by antipersonnel mines. All of the patients were treated using the same protocol. Primary wound care included debridement, necrectomy, and three-dimensional external fixation with or without Kirschner wires. External fixation facilitated postoperative wound care, prevented vicious contracture position, and made fracture healing possible with early weight bearing.

Femoral neck anteversion: values, development, measurement, common problems.

The femoral neck anteversion angle is an important factor for hip stability and normal walking. It is multifactoral result of evolution, heredity, fetal development, intrauterine position, and mechanical forces. Abnormal FNA sometimes can be associated with many clinical problems ranging from harmless intoeing gait in the early childhood, to disabling osteoarthritis of the hip and the knee in the adults. In most cases is associated with minor functional problems in children during growth, but cause a concern in parents for children future. The child must be examined carefully and an accurate diagnosis must be established. The most important part of care is observation of the children. If abnormal femoral neck anteversion produces severe functional disability, derotational osteotomy should be done, but delayed until late childhood.

Comparison in regression of femoral neck anteversion in children with normal, intoeing and outtoeing gait--prospective study.

We studied the 950 children for spontaneous regression of femoral neck anteversion (FNA) angle. The children were divided in three groups. The first group comprised children with normal gait, second group comprised children with intoeing gait and the third group children with outtoeing gait. All children were seen first time at age seven. Second examination was performed at age 10 and the third at age 14. The FNA was measured using ultrasound techniques. The mean FNA angle in the first group was 24 degrees, and decreased during examined period for average 1 degree per year. The FNA angle in the second group was on average 42 degrees at age 7 and decreased average 1.6 degrees per year. FNA angle in group of children with outtoeing gait was average 13 degrees and did not significantly change during all three examinations. We found that medial and lateral rotation in the extended hip correlate with FNA angle as well as differences between medical and lateral rotation. On the third examination percentage of children with intoeing gait decreased from 12.8% to 1%, while number of children with outtoeing gait did not change significantly during examined period.

Femoral anteversion related to side differences in hip rotation. Passive rotation in 1,140 children aged 8-9 years.

We assessed whether the range of passive hip motion is reliable for predicting abnormal femoral anteversion. We measured the passive medial and lateral rotation in extension in both hips of 1,140 children between 8 and 9 years of age. The children were divided into 3 groups: group 1: difference between lateral and medial rotation less than 10 degrees; group 2: medial rotation more than 10 degrees greater than the lateral; group 3: lateral rotation more than 10 degrees greater than the medial. Group 1 comprised 90% of the children, whereas 8% belonged to group 2 and 2% to group 3. The angle of femoral neck anteversion was measured in 57 children from the first group, in 67 from the second and in 24 children from the third group, using biplane radiography. The mean anteversion angles in the 3 groups were 24 degrees, 36 degrees and 14 degrees, respectively. To predict an abnormally high anteversion angle (above mean +2SD), the difference between medial and lateral rotation must be 45 degrees or more, whereas an abnormally low anteversion angle (lower than mean -2SD) could be predicted when the lateral rotation was at least 50 degrees higher than the medial rotation.

[Arthroscopic treatment of lateral meniscal cyst by intraarticular dekompression.]. / Artroskopické lécení cysty laterálního menisku pomocí intraartikulární dekomprese.

47 cases of lateral meniscal cyst treated by arthroscopy are presented. Average follow up was 44 months, with a range of 14 to 63 months. 43 out of 47 knees had lateral meniscus tear. Torn menisci were arthroscopically partially resected and the cyst was evacuated inside the joint. Although the tear did not extend up to the insertion of the meniscus, a curved central resection was performed. Thereafter the palpation hook was inserted into the cyst and was manipulated in order to evacuate its content. The same procedure was applied in all 43 cases. With one exception there was neither cyst recurrence nor evidence of meniscal instability. In the remaining 4 cases with no evident meniscal tear, only extraarticular cyst extirpation was done. Key words: lateral meniscus cysts, arthroscopy of the knee joint.