External fixation reconstruction of the residual problems of benign bone tumours

The mechanical features of and biologic response to using distraction osteogenesis with the circular external fixator are the unique aspects of Ilizarov’s contribution that allows deformity correction and reconstruction of bone defects. We present a retrospective study of 20 patients who suffered from a variety of benign tumours for which external fixators (EF) were used to treat deformity, bone loss, and limb-length discrepancy. A total of 26 bony segments in twenty patients (10 males, 10 females; mean age 17 years; range 7–58 years) were treated with EF for residual problems from the tumour itself (primary treatment) in 8 patients and for complications related to the primary surgery (secondary treatment) in 12 patients. Histological diagnoses were Ollier’s disease (n = 4), Fibrous Dysplasia (n = 5), Congenital multiple exostosis (n = 5), giant cell tumour (n = 2) and one case for chondromyxoid fibroma, desmoid fibroma, chondroma and unicameral bone cyst. Various types of external fixators used to treat these problems. These were Ilizarov, unilateral fixator, multiaxial correction frame (Biomet, Parsippany, NJ), Taylor spatial frame (Memphis, TN) and smart correction multiaxial frame. The mean follow-up time was 69.5 months (range 35–108 months). The mean external fixation time was 159.5 days (range 27–300 days). The mean external fixation index was 67.4 days/cm (12–610) in 26 limbs who underwent distraction osteogenesis. The mean length of distraction was 4.9 cm (range 0.2–14 cm). At final follow-up, all patients had returned to normal activities. Complications were in the form of knee arthrodesis in one patient, pin tract infection in six and residual shortening in eight patients. The use of EF and the principles of distraction osteogenesis, in the management of problems associated with benign bone tumours and related surgery yields successful results especially in young patients. With this approach, the risk for recurrence of shortening and deformity may be minimized with overcorrection or over-lengthening as dictated by preoperative planning.     

Treatment of intertrochanteric fractures in geriatric patients with a modified external fixator

Forty-two geriatric patients who had an intertrochanteric fracture were treated with a semicircular modification of the Ilizarov frame designed by Cattaneo and Catagni between January 1997 and September 2001. Twenty-five of the patients were female, 17 male. The average age of the patients was 77.5 years (range, 63-99). No intraoperative complication occurred. Deep pin-track infection was found in four patients and varus deformity was observed in two patients and shortening of less than 2 cm in 10 patients. Fixator removal was achieved in a mean time of 12 weeks (range, 10-18). No implant failure, refracture or stiffness of knee and hip joint movements was recorded. We concluded that the treatment of intertrochanteric fractures of the elderly patients with our modification provides significant advantages such as minimal operative and anaesthetic risks, no blood loss, early weight-bearing, short hospitalisation time and rapid union time.     

Profiling of β-Lactam Selectivity for Penicillin-Binding Proteins in Streptococcus pneumoniae D39

Selective fluorescent β-lactam chemical probes enable the visualization of the transpeptidase activity of penicillin-binding proteins (PBPs) at different stages of bacterial cell division. To facilitate the development of new fluorescent probes for PBP imaging, we evaluated 20 commercially available β-lactams for selective PBP inhibition in an unencapsulated derivative of the D39 strain of Streptococcus pneumoniae. Live cells were treated with β-lactam antibiotics at different concentrations and subsequently incubated with Bocillin FL (Boc-FL; fluorescent penicillin) to saturate uninhibited PBPs. Fluorophore-labeled PBPs were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and fluorescence scanning. Among 20 compounds tested, carbapenems (doripenem and meropenem) were coselective for PBP1a, PBP2x, and PBP3, while six of the nine penicillin compounds were coselective for PBP2x and PBP3. In contrast, the seven cephalosporin compounds tested display variability in their PBP-binding profiles. Three cephalosporin compounds (cefoxitin, cephalexin, and cefsulodin) and the monobactam aztreonam exhibited selectivity for PBP3, while only cefuroxime (a cephalosporin) was selective for PBP2x. Treatment of S. pneumoniae cultures with a sublethal concentration of cefuroxime that inhibited 60% of PBP2x activity and less than 20% of the activity of other PBPs resulted in formation of elongated cells. In contrast, treatment of S. pneumoniae cultures with concentrations of aztreonam and cefoxitin that inhibited up to 70% of PBP3 activity and less than 30% of other PBPs resulted in no discernible morphological changes. Additionally, correlation of the MIC and IC₅₀s for each PBP, with the exception of faropenem, amdinocillin (mecillinam), and 6-APA, suggests that pneumococcal growth inhibition is primarily due to the inhibition of PBP2x.     

Relationship between cord blood levels of IGF-I and ferritin in healthy term neonates

OBJECTIVE: We hypothesize that the balance of maternal and fetal insulin-like growth factor-I (IGF-I) concentrations contributes to the regulation of substrate distribution between mother and fetus, and may thus mediate the maintenance of blood ferritin concentration in the fetus. Therefore, the relationship between cord blood IGF-I to ferritin concentration was investigated. INFANTS AND METHODS: Twenty-six term neonates were recruited. Anthropometric measures were recorded and umbilical cord blood samples were collected at birth. We studied serum concentrations of IGF-I in relation to blood ferritin and anthropometric data in term neonates. To assess the importance of the correlation of ferritin with both IGF-I and all other parameters, multiple linear regression analysis was carried out, with ferritin as the dependent variable and IGF-I and anthropometric parameters as independent variables. RESULTS: The mean concentrations of cord blood IGF-I and ferritin levels were 45.2 +/- 36.8 ng/ml and 225.5 +/- 124.2 ng/ml, respectively, at birth. A positive correlation was observed between IGF-I and ferritin concentrations of term neonates (r = 0.53, p = 0.005). IGF-I emerged as a significant predictor of ferritin concentration (beta = 1.79, p = 0.005) contributing to 28% of its variability. CONCLUSIONS: We showed a relationship between cord blood IGF-I and ferritin levels in term neonates, suggesting that even within an unremarkable population, fetal ferritin level may be influenced by IGF-I. Moreover, we speculated that IGF-I might also be important in the regulation of placental transport of ferritin.     

Astrocyte-derived thrombospondin-2 is critical for the repair of the blood-brain barrier

Thrombospondin (TSP)-2-null mice have an altered brain foreign body response (FBR) characterized by increases in inflammation, extracellular matrix deposition, and leakage of the blood-brain barrier (BBB). In the present study, we investigated the role of TSP-2 in BBB repair during the brain FBR to mixed cellulose ester filters implanted in the cortex of wild-type (WT) and TSP-2-null mice for 2 days to 8 weeks. Histological and immunohistochemical analysis revealed enhanced and prolonged neuroinflammation in TSP-2-null mice up to 8 weeks after implantation. In addition, recovery of the BBB was compromised and was associated with increased gelatinolytic activity and low levels of collagen type IV in the basement membranes of TSP-2-null blood vessels. An analysis of protein extracts from implantation sites revealed elevated levels of matrix metalloproteinase (MMP)-2 and MMP-9 in TSP-2-null brains. TSP-2-null astrocytes secreted higher levels of both MMPs in vitro compared with their WT counterparts. Furthermore, TSP-2-null astrocytes were deficient in supporting the recovery of barrier function in WT endothelial cells. Finally, Western blot analysis of astrocytes and brain endothelial cells revealed TSP-2 expression only in the former. Taken together, our observations suggest that astrocyte-derived TSP-2 is critical for the maintenance of physiological MMP-2 and MMP-9 levels during the FBR and contributes to the repair of the BBB.     

Dysembryoplastic neuroepithelial tumors: proton MR spectroscopy,diffusion and perfusion characteristics

Introduction We describe the magnetic resonance (MR) imaging characteristics of dysembryoplastic neuroepithelial tumors (DNT) and discuss their differential diagnosis. Material and methods Proton MR spectroscopy (TE 30 and 136 ms), diffusion-weighted and perfusion images were retrospectively evaluated in 22 patients with pathologically proven DNT (17 male and 5 female, mean age 18.7 years) and 14 control subjects (10 male and 4 female, mean age 16.9 years). The results from the DNT patients and from the control subjects were compared using an independent sample t-test and the degree of correlation was tested by Pearson’s correlation. Results All DNTs were solitary and in a supratentorial cortical or subcortical location (ten temporal, eight frontal and four parietal). They had low-signal on T1-weighted images and high-signal on T2-weighted images without a prominent mass effect. Additionally a cystic appearance (six patients, 27.3%), cortical dysplasia (six patients, 27.3%) and contrast enhancement (four patients, 18.2%) were also noted. No significant differences were detected in NAA/Cho, NAA/Cr, NAA/Cho+Cr or Cho/Cr ratios between DNT and normal brain. DNTs had a significantly higher mI/Cr ratio and apparent diffusion coefficient (ADC) values and lower cerebral blood values than normal parenchyma (P < 0.001). ADC had the highest correlation with the diagnosis of DNT (r = 0.996) followed by relative cerebral blood volume (rCBV) (r = −0.883) and mI/Cr ratio (r = 0.663). Conclusion Proton MR spectroscopy, diffusion-weighted and perfusion imaging characteristics of DNTs provide additional information to their MR imaging findings. The MR spectrum showing a slight increase in mI/Cr ratio, and higher ADC and lower rCBV values than normal parenchyma help to differentiate DNTs from other cortical tumors, which had higher rCBV and lower ADC values than DNTs. This work was presented at the ASNR 45th Annual Meeting 2007.     

An alternative method for the treatment of nonunion of the tibia with bone loss

In this retrospective study we evaluated the method of acute shortening and distraction osteogenesis for the treatment of tibial nonunion with bone loss in 17 patients with a mean age of 36 years (10 to 58). The mean bone loss was 5.6 cm (3 to 10). In infected cases, we performed the treatment in two stages. The mean follow-up time was 43.5 months (24 to 96). The mean time in external fixation was 8.0 months (4 to 13) and the mean external fixator index was 1.4 months/cm (1.1 to 1.8). There was no recurrence of infection. The bone evaluation results were excellent in 16 patients and good in one, while functional results were excellent in 15 and good in two. The complication rate was 1.2 per patient. We conclude that acute shortening and distraction osteogenesis is a safe, reliable and successful method for the treatment of tibial nonunion with bone loss, with a shorter period of treatment and lower rate of complication.     

Long-term survival after regional chemotherapy for liver metastases from breast cancer. A case report

The prognosis of patients with liver metastases from breast cancer has to be regarded as rather unfavorable. A 45-year-old woman with cancer of the left breast and multiple simultaneous liver metastases was initially treated with cyclophosphamide, methotrexate, and 5-fluorouracil. After two treatment cycles a sonogram of the left breast revealed reduction of the tumor size and she underwent a modified radical mastectomy and hepatic artery catheterization. There was no change in the multiple lesions of the liver on abdominal ultrasonography. One week later a regional chemotherapy regimen was given through a hepatic arterial catheter with subcutaneous implanted reservoir. After completion of the seventh course of chemotherapy, ultrasonography revealed that the multiple liver metastases had regressed completely. To date (July 2001) there has been no relapse during the seven-year follow-up period. In conclusion, we suggest that intra-arterial regional chemotherapy may have an important role to play in the management of breast cancer patients with isolated liver metastases.     

Obstructive uropathy caused by testicular vein compression: multidetector-row computed tomography findings

Although the right testicular vein and ureter follow a close course at the level of the third lumbar vertebra, it is unusual for the right testicular vein to be a cause of ureteral obstruction. Previously, conventional computed tomography (CT) has been used for establishing this anatomic relation. A case of hydronephrosis in a man secondary to right testicular vein compression diagnosed with multidetector-row CT findings is described.