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.     

Clinicopathological and tissue indicators of para-aminophenol nephrotoxicity in sprague-dawley rats

A model of para-aminophenol (PAP) nephrotoxicity in Sprague-Dawley rats was utilized to characterize potential indicators of toxicity in the kidney and in biofluids, and to chronicle the progression of acute renal injury. Rats were administered PAP at a low or high dose and examined terminally at 6, 24 and 48 hours (4 animals/group with matching controls). Acute tubular necrosis was observed in the medullary rays (low and high doses) and the outer stripe of outer medulla (high dose only) as early as 6 hours postdosing. Starting at 24 hours, regeneration of the tubular epithelium was evident in both low and high dose studies. Associated with the tubular lesions, we observed elevation of urinary alpha -glutathione S-transferase levels, an indicator of proximal tubular injury. By immunohistochemistry of the kidney, decreased gamma -glutamylcysteine synthetase expression correlated with tubular injury, especially at high dose, whereas elevation of vimentin, osteopontin, and Ki-67 expression was concurrent with tubular regeneration. Clusterin and kidney injury molecule-1 displayed expression patterns characteristic of both renal injury and regeneration. Taken together, this study provided insight into the progression of nephrotoxicity, and allowed the evaluation of potential urinary and tissue protein biomarkers that could complement the early detection of acute tubular injury.     

Identification of the lactococcal exonuclease/recombinase and its modulation by the putative Chi sequence

Studies of RecBCD–Chi interactions in Escherichia coli have served as a model to understand recombination events in bacteria. However, the existence of similar interactions has not been demonstrated in bacteria unrelated to E. coli. We developed an in vivo model to examine components of dsDNA break repair in various microorganisms. Here, we identify the major exonuclease in Lactococcus lactis, a Gram-positive organism evolutionarily distant from E. coli, and provide evidence for exonuclease–Chi interactions. Insertional mutants of L. lactis, screened as exonuclease-deficient, affected a single locus and resulted in UV sensitivity and recombination deficiency. The cloned lactococcal genes (called rexAB) restored UV resistance, recombination proficiency, and the capacity to degrade linear DNA, to an E. coli recBCD mutant. In this context, DNA degradation is specifically blocked by the putative lactococcal Chi site (5′-GCGCGTG-3′), but not by the E. coli Chi (5′-GCTGGTGG-3′) site. RexAB-mediated recombination was shown to be stimulated ≈27-fold by lactococcal Chi. Our results reveal that RexAB fulfills the biological roles of RecBCD and indicate that its activity is modulated by a short DNA sequence. We speculate that exonuclease/recombinase enzymes whose activities are modulated by short DNA sequences are widespread among bacteria.     

Concomitant Reconstruction of Arch Vessels during Repair of Aortic Dissection

Surgery for acute aortic dissection is challenging, especially in cases of cerebral malperfusion. Should we perform only the aortic repair, or should we also reconstruct the arch vessels when they are severely affected by the disease process? Here we present a case of acute aortic dissection with multiple tears that involved the brachiocephalic artery and caused cerebral and right upper-extremity malperfusion. The patient successfully underwent complete replacement of the brachiocephalic artery and the aortic arch during deep hypothermic circulatory arrest, with antegrade cerebral protection. We have found this technique to be safe and reproducible for use in this group of patients.     

Good reasons to implement quality assurance in nationwide breast cancer screening programs in Croatia and Serbia: Results from a pilot study

The purpose of this study is to investigate the need for and the possible achievements of a comprehensive QA programme and to look at effects of simple corrective actions on image quality in Croatia and in Serbia. The paper focuses on activities related to the technical and radiological aspects of QA. The methodology consisted of two phases. The aim of the first phase was the initial assessment of mammography practice in terms of image quality, patient dose and equipment performance in selected number of mammography units in Croatia and Serbia. Subsequently, corrective actions were suggested and implemented. Then the same parameters were re-assessed. Most of the suggested corrective actions were simple, low-cost and possible to implement immediately, as these were related to working habits in mammography units, such as film processing and darkroom conditions. It has been demonstrated how simple quantitative assessment of image quality can be used for optimisation purposes. Analysis of image quality parameters as OD, gradient and contrast demonstrated general similarities between mammography practices in Croatia and Serbia. The applied methodology should be expanded to larger number of hospitals and applied on a regular basis.     

Effects of beta-adrenoceptor blockade on the phenotypic characteristics of thymocytes and peripheral blood lymphocytes

The study revealed that beta-adrenoceptor blockade with propranolol (0.40 mg/100 g/day, s.c.) in adult male DA rats: (i) increased the thymocyte proliferation and apoptosis, (ii) caused disturbances in kinetics of T cell differentiation leading to distinguishable changes in relative proportion of thymocytes at distinct maturational steps and to an expansion of the most mature single positive (CD4+, CD8+) thymocyte pool, (iii) affected the relative proportion of neither CD4+ nor CD8+ peripheral blood lymphocytes (PBL), and (iv) augmented the relative number of CD8+CD25+ cells. Thus, the results suggest the role of beta-adrenoceptors in fine-tuning of T cell maturation, and, possibly, distribution and activation of distinct PBL subsets.     

Necrotizing fasciitis caused by group A streptococcus

The first case of the confirmed necrotizing fasciitis caused by Group A Streptococcus in Yugoslavia was presented. Male patient, aged 28, in good health, suddenly developed symptoms and signs of severe infective syndrome and intensive pain in the axillary region. Parenteral antibiotic, substitutional and supportive therapy was conducted along with the radical surgical excision of the necrotizing tissue. The patient did not develop streptococcal toxic shock syndrome thanks to the early established diagnosis and timely applied aggressive treatment. He was released from the hospital as completely cured two months after the admission.     

Exposure to forced swim stress alters morphofunctional characteristics of the rat thymus

The aim of this study was to investigate whether chronic stress, induced by repeated daily swimming during 21 days, alters the morphofunctional parameters in the thymus of adult rats. Our results showed that chronic stress reduced thymus mass, total number of thymocytes, volume of the thymus compartments and numerical density of thymocytes within thymus inner cortex and medulla. However, the percentage of apoptotic cells and the level of corticosterone were significantly increased. The percentages of CD4-CD8-TCRβ^low/high and CD4-CD8+TCRβ^-thymocytes were significantly increased, while the percentage of the least mature CD4+CD8-SP TCRβ⁻ thymocytes was significantly decreased.

These results show that recurred swimming procedure induces thymus hypotrophy and elevated percentage of DN TCRβ⁺ cells.