Impact of triple pelvic osteotomy on contact stress pressure distribution in the hip joint

Purpose

We studied changes of contact stress distribution in the hip joint after Tonnis triple pelvic osteotomy applied in the treatment of dysplasia and hip joint incongruence in adolescents.

Methods

In a group of 75 patients, 54 (72 %) female, who underwent surgery by triple pelvic osteotomy in adolescence for developmental disorder of the hip and avascular necrosis of the femoral head, a three-dimensional hip joint model was used based on the radiography of the pelvis with hips. The following biomechanical parameters were calculated: resultant hip force normalised to body weight (R/Wb), inclination of the resultant hip force (θ−R), the position of the stress pole (θ), peak contact hip stress (Pmax), and peak contact hip stress normalised to body weight (Pmax/Wb). Gait quality was also assessed.

Results

After surgery the Wiberg CE angle was increased by 17.85° (114 %), resultant hip force normalised to body weight (R/Wb) was decreased by 0.107 (3.3 %), the position of the stress pole was shifted medially by 27.59° (63.5 %), and peak contact hip stress normalised to body weight (Pmax/Wb) was decreased by 2249.74 (55.9 %). Waddling gait was reduced from 17 (23.9 %) to four cases (5.6 %). All changes were statistically highly significant (p<0.01).

Conclusions

The effect of Tonnis triple pelvic osteotomy lies in the improvement of stress distribution across the acetabular cartilage of the hip joint, thus slowing down the degenerative damage of the hip joint.     

Quantitative X-ray Computed Tomography Peritoneography in Malignant Peritoneal Mesothelioma Patients Receiving Intraperitoneal Chemotherapy

Background

Intraperitoneal chemotherapy is used to treat peritoneal surface-spreading malignancies. We sought to determine whether volume and surface area of the intraperitoneal chemotherapy compartments are associated with overall survival and posttreatment glomerular filtration rate (GFR) in malignant peritoneal mesothelioma (MPM) patients.

Methods

Thirty-eight MPM patients underwent X-ray computed tomography peritoneograms during outpatient intraperitoneal chemotherapy. We calculated volume and surface area of contrast-filled compartments by semiautomated computer algorithm. We tested whether these were associated with overall survival and posttreatment GFR.

Results

Decreased likelihood of mortality was associated with larger surface areas (p = 0.0201) and smaller contrast-filled compartment volumes (p = 0.0341), controlling for age, sex, histologic subtype, and presence of residual disease >0.5 cm postoperatively. Larger volumes were associated with higher posttreatment GFR, controlling for pretreatment GFR, body surface area, surface area, and the interaction between body surface area and volume (p = 0.0167).

Discussion

Computed tomography peritoneography is an appropriate modality to assess for maldistribution of intraperitoneal chemotherapy. In addition to identifying catheter failure and frank loculation, quantitative analysis of the contrast-filled compartment’s surface area and volume may predict overall survival and cisplatin-induced nephrotoxicity. Prospective studies should be undertaken to confirm and extend these findings to other diseases, including advanced ovarian carcinoma.

     

In-vivo measurement of LDOPA uptake,dopamine reserve and turnover in the rat brain using [18F]FDOPA PET

Longitudinal measurements of dopamine (DA) uptake and turnover in transgenic rodents may be critical when developing disease-modifying therapies for Parkinson''s disease (PD). We demonstrate methodology for such measurements using [¹⁸F]fluoro-3,4-dihydroxyphenyl-L-alanine ([¹⁸F]FDOPA) positron emission tomography (PET). The method was applied to 6-hydroxydopamine lesioned rats, providing the first PET-derived estimates of DA turnover for this species. Control (n=4) and unilaterally lesioned (n=11) rats were imaged multiple times. Kinetic modeling was performed using extended Patlak, incorporating a k_loss term for metabolite washout, and modified Logan methods. Dopaminergic terminal loss was measured via [¹¹C]-(+)-dihydrotetrabenazine (DTBZ) PET. Clear striatal [¹⁸F]FDOPA uptake was observed. In the lesioned striatum the effective DA turnover increased, shown by a reduced effective distribution volume ratio (EDVR) for [¹⁸F]FDOPA. Effective distribution volume ratio correlated (r>0.9) with the [¹¹C]DTBZ binding potential (BP_ND). The uptake and trapping rate (k_ref) decreased after lesioning, but relatively less so than [¹¹C]DTBZ BP_ND. For normal controls, striatal estimates were k_ref=0.037±0.005 per minute, EDVR=1.07±0.22 and k_loss=0.024±0.003 per minute (30 minutes turnover half-time), with repeatability (coefficient of variation) ≤11%. [¹⁸F]fluoro-3,4-dihydroxyphenyl-L-alanine PET enables measurements of DA turnover in the rat, which is useful for developing novel therapies for PD.     

Gastroprotective effects of amifostine in rats treated by T-2 toxin

Cytoprotector amifostine (AMI) was given in a dose of 50, 100 or 150?mg/kg ip in rats treated with several highly toxic doses of T-2 toxin. The best survival rate (24?h and 7?days after treatment) was obtained with AMI50 (50?mg/kg ip). After T-2 intoxication, a peak in the mean number of gastric lesions (petechiae and ulcerations) was reached on the third day (26.40?±?6.24). Administration of AMI50 reduced, almost completely, the total number of gastric lesions in rats acutely poisoned by 0.5 LD₅₀ T-2 (1.5?mg/kg sc), starting with day 1 after intoxication (5.60?±?3.42).     

Bioequivalence study of two formulations of itraconazole 100 mg capsules in healthy volunteers under fed conditions: a randomized,three-period,reference-replicated,crossover study

Background: The aim of the study was to evaluate the bioequivalence of two itraconazole 100 mg capsule formulations.

Research design and methods: The single-center, open-label, randomized, three-period, three-sequence, reference-replicated, cross-over study included 38 healthy subjects under fed conditions. In each study period (separated by a 14-day washout), a single oral dose of the test (T) or reference (R) product was administered. Blood samples were collected at pre-dose and up to 72.0 h after administration. The calculated pharmacokinetic parameters, based on the plasma concentrations of itraconazole and hydroxy itraconazole, were AUC_0-72h, AUC_0-∝, C_max, T_max, T_1/2 and K_el.

Results: The 90% CI for the test/reference geometric means ratio for the parent compound, itraconazole, was in the range from 85.29% to 116.07% for AUC_0-72h. Since the coefficient of variation (CV) for the reference product was 44.95% for C_max, the 90% CI for this parameter for itraconazole was 93.49–133.78%, which was within the proposed limits of the EMA for bioequivalence of 72.15–138.59%. During the study, 4 subjects encountered a total of 14 mild adverse events.

Conclusions: The use of the reference-scaling approach with 3-period design (TRR, RTR, and RRT) was an efficient way to demonstrate that two commercially available oral itraconazole formulations met the predetermined bioequivalence criteria.