Bilateral accessory head of the adductor longus muscle: an anatomical case study.

The adductor longus muscle, with its proximal origin at the pubic bone and distal at the linea aspera, is reported to be one of the most frequently injured groin muscles in contact sports, namely football or ice hockey. Notwithstanding, there is a scarcity of published works regarding the accessory heads of the adductor longus muscle in the existing literature, let alone the clinical significance of the said variant. The following study is a case report describing bilateral accessory heads of the adductor longus muscle in a 97-year-old female cadaver. A routine cadaveric dissection revealed two accessory heads on the right thigh and one on the left thigh of a donor with no known structural or pathological abnormalities of the proximal lower extremity. The anterior division of the obturator nerve provided nerve supply to the variants on both sides. The deep femoral, superficial external pudendal, femoral vessels were responsible for the vascular supply to the accessory heads of the adductor longus. Undoubtedly, extensive knowledge regarding the variant anatomy of the hip adductor muscles is of immense importance to physiotherapists and orthopaedists treating patients for their injury or complete tears. Nonetheless, there is little information regarding the accessory heads of the adductor longus in the existing literature (originating mostly from cadaveric studies) that requires further evaluation in vivo to assess whether this variant might have an impact on a patient's everyday life.

A three-headed piriformis muscle: an anatomical case study and narrative review of literature.

The piriformis muscle (PM) is found in the gluteal region, exiting the pelvis through the greater sciatic foramen and dividing it into the suprapiriform and infrapiriform foramina. The piriformis works as part of the hip external rotator muscle group, and is responsible for rotation of the femur upon hip extension and abduction of the femur during flexion of the hip joint. The aim of the present report is to describe a very rare case of the primary three-headed PM. To the best knowledge of the authors, the said variant has not yet been described in the existing literature. The 71-year-old male formalin-fixed cadaver was subjected to routine dissection. After careful removal of the connecting tissue, three separate, primary heads of the PM were identified. The lower head of the PM arose from the middle part of the sacral bone; 87.56 mm long and 9.73 mm wide. The medial head was attached to the internal part of the posterior inferior iliac spine; 121.6 mm long and 20.97 mm wide. The upper head was attached to the external part of the posterior inferior iliac spine; 78.89 mm long and 23.94 mm wide. All heads converged into a common tendon which inserted onto the greater trochanter. The clinical importance of this work comes down to the fact that the aberrant PM may be the reason behind the piriformis syndrome and its associated symptoms. Moreover, knowledge regarding the variant anatomy of the PM is of immense importance to, e.g. anaesthesiologists performing computed tomography- or ultrasound-guided sciatic nerve injection for local anaesthesia, radiologists interpreting imaging studies, and surgeons, especially during posterior approaches to the hip and pelvis.

Kinetics and dynamics of sematilide.

Sematilide HCl is a novel class III antiarrhythmic drug. The goals of this study in volunteers were to determine the pharmacokinetics, effect (QTc interval), and tolerability after intravenous and oral administration of 25 mg of the drug. Plasma and urine concentrations were measured by a specific high-performance liquid chromatography method. Pharmacokinetic data analysis used a compartment model independent approach. An effect on QTc was observed only after intravenous administration, and its relationship to the plasma concentration showed a counterclockwise hysteresis. A semiparametric approach was used to collapse the hysteresis and then evaluate the effect-site-concentration-to-effect relationship. After intravenous and oral administration, 75.1 (6.5)% (mean +/- SD) and 36.0 (11.5)% of the dose was excreted unchanged in urine, respectively. The respective renal clearances were 250 (41) ml.min-1 and 222 (44) ml.min-1. The bioavailability of sematilide was 0.47 (0.15). A maximum percent effect on QTc of 12 (1)% occurred with a delay of 14 min after termination of an intravenous infusion of 10 min. After collapsing the hysteresis, the pharmacokinetic-pharmacodynamic data could be fitted appropriately by a linear model in four subjects and by an Emax model in two subjects. Sematilide HCl was well tolerated.

Comparative kinetics of sematilide in four species.

The goals of this retrospective study with the novel class III antiarrhythmic sematilide HCI were to investigate: a) whether there existed interspecies correlations and b) whether reliable animal-to-human predictions were possible for the main pharmacokinetics parameters. Information on plasma concentrations after intravenous administration was available in rats, rabbits, dogs, and humans. Except for the rabbit, data on the urinary amounts of drug excreted were also available in these species. The drug concentrations in plasma and urine were assayed by a specific HPLC method with UV or electrochemical detection or liquid scintillation spectrometry. In the interspecies correlations and in the animal-to-human predictions, an allometric approach was used with log-log linear regressions of the pharmacokinetic parameters steady-state volume of distribution (Vss), total clearance (CL), mean residence time (t), and terminal disposition half life (t1/2 lambda z), on body weight. The results showed that significant interspecies correlations exist for the tested in vivo pharmacokinetic parameters for sematilide. Reliable animal-to-human predictions with errors < 60% were found for Vss, CL, t1/2 lambda z, and t. In rats, dogs, and humans, sematilide's renal elimination includes glomerular filtration and net tubular secretion. The relative contributions of the renal mechanisms are similar in all three species studied. There were no important species differences observed in the in vitro determined parameters, fraction unbound in plasma, and blood-to-plasma concentration ratio between rats, dogs, and humans.

Determination of sematilide in plasma by high-performance liquid chromatography.

A method for the determination of sematilide levels in human plasma is described. After the addition of an internal standard, plasma samples are adjusted to pH 8.5 and extracted with a solution of 7.5% isopropanol in methylene chloride. Separation from co-extracted matrix constituents is performed by reversed-phase HPLC followed by UV detection at 254 nm. The assay is linear in the concentration range 12-2400 ng/mL when 0.5-mL aliquots of plasma are extracted. Application of the method to the analysis of samples obtained from eight healthy volunteers given an oral dose of 100 mg of sematilide hydrochloride is shown.

Pharmacokinetics of iloprost in patients with hepatic dysfunction.

In the present experiment the pharmacokinetics of iloprost was studied in eight hospitalized patients suffering from liver cirrhosis (mean age: 56 years, 3 females, 5 males, child-classification: A [n = 1], B [n = 5], C [n = 2]/mean 14C-aminopyrine breath test: 3.9% dose/2 h). Iloprost was administered as a 1 h-i.v. infusion with 1 ng/kg/min to all the test subjects. Steady state plasma levels of 93 +/- 31 pg/ml were observed at the end of infusion. The terminal half-life of iloprost was 28 +/- 24 min. From AUC values of 126 +/- 60 pg.h/ml a total clearance of 10 +/- 5 ml/min/kg was calculated. The study demonstrated that iloprost clearance was reduced by a factor of 2 in patients suffering from hepatic dysfunction compared with healthy subjects. Individual dose titration is the recommended dose regimen for iloprost therapy in all patients. Therefore, apart from a reduction of the starting dose (of approximately 50%) for titration, special recommendations are not necessary for patients with impaired liver function.

Pharmacokinetics of iloprost in patients with chronic renal failure and on maintenance haemodialysis.

Iloprost is a potent, chemically stable prostacyclin-mimetic for which therapeutic efficacy has been proven in patients with peripheral arterial occlusive disease (PAOD) and in those suffering from Raynaud's phenomenon. In volunteers and PAOD-patients the pharmacokinetics of iloprost after intravenous (i.v.) infusion treatment was characterized by dose-dependent steady-state plasma levels, a terminal half-life of approximately 20-30 min, and a total clearance of 15-20 ml/min/kg. Bioinactivation was mainly due to beta-oxidation. In the present study the pharmacokinetics of iloprost was investigated in 21 patients suffering from renal insufficiency, which either required haemodialysis or not. They were treated by one hour i.v. infusion with 1 ng/kg/min and blood samples were taken during and after the end of infusion. Due to technical sampling problems iloprost pharmacokinetics could only be calculated for seven dialysis and eight non-dialysis patients. In the dialysis patients steady-state levels were 114 to 320 pg/ml as compared to 36 to 70 pg/ml in the non-dialysis group. Half-lives were similar in both groups: alpha-phase: 0.05 h and beta-phase: 0.5 h. The total clearance was 2.6 to 8.0 ml/min/kg (dialysis patients) and 13.2 to 25.8 ml/min/kg (non-dialysis patients). The present study demonstrated that the pharmacokinetic profile of iloprost in patients with renal failure (not subject to haemodialysis) was similar to that observed in PAOD-patients and volunteers. In patients on maintenance haemodialysis, iloprost clearance was reduced by a factor of four. The iloprost dose regimen required in general (due to interindividual variability in response) a careful dose titration.

Sensitivity and specificity of a modified agar gel precipitation test and its application to the diagnosis of enzootic bovine leukosis.

Sensitivity and specificity of a modified agar gel immuno-diffusion (AGID) test for the diagnosis of enzootic bovine leukosis was compared in 609 sera using the standard method, the modified test, and ELISA. The modifications concerned the composition of agar gel (1.8% Bacto-agar Difco), addition of polyethylene glycol (PEG 6000, 4%) and enlarging the diameters of the wells from 6 to 10 mm for sera. The change in well diameters and the addition of PEG 6000 increased the sensitivity of the test by about 60-100%, favourably influenced the proper interpretation of the results, especially with weak positive sera. ELISA proved to be more sensitive either than the modified (by 4.1%) or standard AGID (by 5.25%) tests. The modified AGID test may find wide application in laboratory practice, especially when a more sensitive technique is not available.

Determination of trace levels of steroids in blood plasma by liquid chromatography with peroxyoxalate chemiluminescence detection.

A highly sensitive and specific liquid chromatographic procedure with peroxyoxalate chemiluminescence detection has been developed for the determination of fluocortin butyl, a 3 alpha-ketocorticosteroid, in blood plasma. The technique employs dansylation of the steroid to provide a highly chemiluminescent derivative. After separation by reversed-phase liquid chromatography, reagents necessary for chemiluminescence are added, followed by detection in a conventional fluorimetric detector in which the excitation source is deactivated. The precision is 2.5% relative standard deviation at the 10 ng/ml level, and the response is linear up to at least 4 ng injected steroid. The procedure requires only 1 ml blood plasma and has a limit of detection of 100 pg/ml or 7.5 pg injected steroid. The system is reliably used for routine pharmacokinetic studies and with modifications, is applicable to other steroids as well.

Ion-pair liquid chromatographic assay of decongestants and antihistamines.

The quantitative determinations of combinations of antihistamine and decongestant drugs including phenylephrine, dl-ephedrine, psi-ephedrine, phenylpropanolamine, pyrilamine, pheniramine, l-ephedrine, chlorpheniramine, brompheniramine, oxymetazoline, naphazoline, and antazoline contained in solid and liquid dosage forms are described. All active ingredients except the ephedrine optical isomers were separated from other ingredients with ion-paired high-pressure liquid chromatography. Manipulation of the mobile phase either by changing the hydroalcoholic ratio or by changing the alkyl chain length of the counterion (sulfonic acid) for achieving optimum separations is discussed. The method is simple, short, accurate, and precise.

Rapid determination of quinidine in human plasma by high-performance liquid chromatography.

A sensitive and specific method for the determination of quinidine in plasma is described. Quinidine is extracted with chloroform, the extract is evaporated and reconstituted with methanol and the methanol extract is analyzed by high-performance liquid chromatography using a silica gel column. The recovery of quinidine from plasma varied between 93.0 to 100%. Quinidine levels as low as 12 ng/ml can be detected by this method.