Vascular homografts for vessel substitution in skeletal and soft tissue sarcomas of the limbs.

Large vessel involvement by skeletal and soft tissue sarcomas of the extremities does not change the modern limb sparing surgery for those neoplasms. An arterial and, if the vein is open, a venous bypass should always be offered to any patient young or old, with high or low grade sarcoma, because preserving the limb permits quicker rehabilitation, which is particularly useful in the case of a short life expectancy. In 650 cases of skeletal sarcomas, 10 arterial (1.5%) and four venous bypasses were done, all with autologous veins but one in PTFE; we had no problems except a silent arterial occlusion. Of 1000 patients with soft tissue sarcomas, 32 (3%) had vessel involvement permitting limb sparing surgery. The arterial bypass, which is the limb-saving operation, was performed 16 times with a PTFE with one early occlusion and four cases of prosthesis infection, with two amputations despite redo operation with an autologous vein. The more recent 16 cases were, therefore, always done with biological vessel substitution--autologous vein or tissue bank vessel--with only one infection that healed without operation and one case of homograft rupture followed by amputation. Since 1999 in all 13 resected cases with an open vein, we did the arterial and the venous bypass (twice PTFE, six autologous vein, and five bank vessel) with the aim of avoiding postoperative venous hypertension, but only four of the venous bypasses remained open. Venous bypasses are a harmless, but still experimental, procedure.

Proteases and interleukin-6 gene analysis in 92 giant cell tumors of bone.

BACKGROUND: Giant cell tumor of bone (GCT) is a benign tumor with a significant tendency to recur locally and rarely to produce pulmonary metastases. It is characterized by the presence of multinucleated osteoclast-like giant cells together with mononuclear spindle-shaped cells. Few prognostic markers have been reported to predict the clinical outcome of GCT patients, so is very important to find the factor that can be implicated in its potential aggressiveness. PATIENTS AND METHODS: Different groups of GCT patients were selected for this study, including patients without evidence of disease and patients who recurred locally or with lung metastasis. The total of 92 tumor samples also included the specimens of the local recurrences and the lung metastases. By using immunohistochemistry and real-time quantitative polymerase chain reaction techniques, the genetic and proteic analyses were performed on the urokinase-type plasminogen activator (u-PA), its receptor (u-PAR) and its inhibitor (PAI-1), which have been described to be frequently implicated in the process of degradation of the extracellular matrix during the metastatic process. Interleukin-6 (IL-6), a cytokine released by GCT cells, which stimulates resorption of bone, was also analyzed. RESULTS: IL-6, u-PA, u-PAR and PAI 1 genes were found amplified, respectively, in 7%, 5%, 8% and 12% of total cases (92). In particular, the percentages of amplified genes were higher in the GCT cells that gave rise to metastases (12 cases) and in the samples of lung metastases (nine cases) compared with the disease-free group of patients (60 cases). CONCLUSIONS: These results suggest a possible association of these factors with a higher biological aggressiveness of GCT. Morever, it appears that increased expression of the IL-6, u-PA, u-PAR and PAI1 proteins might not depend on mutation of the corresponding genes.

Vertebral hemi-resection for bone tumor with wide invasion of the vertebral canal: modified surgical method.

The authors describe a variation in the method of vertebral hemi-resection used for the treatment of neoplasms that present a wide invasion of the vertebral canal. This is followed by a review of the literature on the subject.

Knee resection arthrodesis with allograft: a long-term follow-up study.

A consecutive series of 57 patients treated by knee resection arthrodesis for malignant or aggressive tumor around the knee was reviewed. Infection was present only after repeated surgery for other complications, delayed union or non-union occurred in 50% of the cases that could be evaluated, but were still easy to manage. Fracture incidence was higher than expected (32.6%) even occurring after 10 years; this was difficult to deal with and it often led to failure. The best possible method of fixation is still being debated, but locked nail and allograft cementation is often advised. Several satisfactory functional results were however achieved when surgery was performed in young patients; final results can be less satisfactory when there is leg length discrepancy and poor acceptance on the part of the patient. In recent years this type of surgery has been limited to younger male patients (10 to 14 years of age) in whom extra-articular knee resection was required or when most of the quadriceps muscle must be removed.

Fractionation and characterization of a conjugate between a polymeric drug-carrier and the antitumor drug camptothecin.

A conjugate between the antitumor drug camptothecin and the polymeric drug-carrier poly[N-(2-hydroxypropyl)methacrylamide] was synthesized and fractionated. The conjugate samples, both fractionated and unfractionated, were characterized with a multi-detector SEC system using three on-line detectors: a multi-angle light scattering photometer, a viscometer, and a refractometer. The used mobile phase (DMF + 0.01 M LiBr + 0.05 M CH(3)COOH) derives from previous experience with similar conjugates. Narrow molar mass distribution fractions of the conjugate obtained by means of a semipreparative LC system were used to derive the coefficients of the Mark-Houwink-Sakurada relationship and to check the universal calibration of the SEC system. This study has demonstrated that the conjugate elutes according to the hydrodynamic volume. Thus, a conventional SEC method that uses only an on-line refractometer detector, commercially available narrow standards, and the universal calibration is adequate for the characterization of the molar mass distribution. Also the size and the conformation of the conjugate were studied by means of the gyration radius-molar mass power law.

Polymer-bound camptothecin: initial biodistribution and antitumour activity studies.

Camptothecin (CPT) is a potent, antitumour drug acting mainly through inhibition of topoisomerase I during the S-phase of the cell cycle. Despite its impressive antitumour activity, clinical development was halted for unpredictable toxic events. Two soluble N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers were synthesised to contain CPT (5 wt.% and 10 wt.%). CPT was covalently linked at its alpha-hydroxyl group to the polymers through a Gly-Phe-Leu-Gly- spacer. In-vitro, CPT-conjugates were fairly resistant to hydrolysis in plasma as in buffer at neutral pH (0.2-0. 4% free CPT/h), while elastase and cysteine-proteases were able to release the active drug. Plasma levels in mice after intravenous administration of CPT-conjugates confirmed the modest hydrolysis in plasma. Plasma levels were approximately 5-fold lower than those observed at the highest tolerated dose of CPT administered in classical vehicles. Biodistribution in HT29 human colon carcinoma bearing mice was carried out after i.v. injection of [3H]CPT-conjugate and free [3H]CPT. Radioactivity uptake in tumour was evident only after [3H]CPT-conjugate treatment. Repeated intravenous administration of CPT-conjugates to HT29-bearing mice gave more than 90% tumour inhibition, some complete tumour regressions and no toxic deaths. The improved pharmacological profile on HT29 human colon carcinoma xenografts of the first poly(HPMA)-CPT conjugates might be ascribed to their prolonged intra-tumour retention and sustained release of the active drug.

[Mammography and prevention of breast carcinoma. Epidemiological considerations concerning female population of a Rome district]. / Mammografia e prevenzione del carcinoma della mammella. Considerazioni epidemiologiche sulla popolazione femminile di un quartiere di Roma.

At the present time breast cancer represents the primary reason of death caused by cancer amongst the female population of the western countries. Since the actuation of primary prevention programmes results impossible, the aim that must be considered primary is to attain a diagnosis of such tumour as precociously as possible. This research proposes to value the inclination of the female population of a District in Rome, of different classes of age, to have a mammography test in a state of spontaneous screening, in view of a next institution of a structured program of secondary prevention in the area of reference. The results have been examined with relation to the age limits considered as optimum for a correct application of this diagnostic methodology, in line with technical and epidemiological considerations.

Mechanism of suramin-induced deoligomerization of tumor necrosis factor alpha.

Deoligomerization of human tumor necrosis factor alpha (TNF), spiked with 125I-labeled form, was studied quantitatively using size-exclusion chromatography and off-line monitoring with a gamma-counter. A detailed investigation of the oligomeric state of TNF was carried out as a function of its own concentration (0.3-7500 nM referred to the subunit, M(r) 17,000) in the absence or in the presence of various amounts (10, 100, 1000 microM) of suramin, an inhibitor of TNF biological activity in vitro, which promotes TNF deoligomerization. The dependence of trimeric form content on total TNF concentration was modeled with a sequential dissociation process (trimer-->dimer-->monomer) assuming an identical dissociation constant for each step, Kd1 = 0.2 nM. This model was used as the simplest for data fitting although, generally, no chromatographic resolution of dimeric species could be obtained. Best fitting of all data could be achieved with a model including a conformational change of TNF trimer into a state more prone to deoligomerization (Kd2 = 400 nM), which was favored by suramin binding. A kinetic study of TNF dissociation by the same method produced values for the deoligomerization rate of trimer: on the average, koff approximately 4 x 10(-5) S-1 (t1/2 approximately 5 h) between 4 and 20 degrees C with little dependence on suramin concentration; at 37 degrees C, a sizable increase is observed in the presence of 1 mM suramin (koff = 2.3 x 10(-4) S-1, t1/2 = 0.8 h). Data of suramin inhibition on TNF receptor binding, as obtained after incubation times much shorter than the above half-life of trimer, indicate that suramin binding to TNF trimer is the early mechanism of receptor binding inhibition.

Correlation between growth inhibition and intranuclear doxorubicin and 4'-deoxy-4'-iododoxorubicin quantitated in living K562 cells by microspectrofluorometry.

Intranuclear drug concentration in cells treated with doxorubicin (DXR) or with 4'-deoxy-4'-iododoxorubicin (IDX) was measured by means of a quantitative microspectrofluorometric technique recently developed by us. Resolution of free and bound drug contributions in fluorescence emission spectra, as collected from a microvolume of single living cell nuclei, provided concentration data with about 10% indetermination. Uptake of DXR and IDX into the nucleus of K562 cells and DXR-resistant K562/DXR cells could then be studied with a sensitive, nondestructive technique. Growth inhibitory concentrations of K562 and K562/DXR cells, when measured with respect to drug content in the medium, differed by a factor of 25 in the case of DXR and by a factor of three in the case of IDX. By contrast, intranuclear drug concentrations measured at corresponding growth inhibitory concentrations are found to be nearly constant, i.e., independent of cellular-resistant phenotype and of anthracycline structure. This result supports an identical mechanism of action for the two drugs, most probably targeted to the nucleus, and ascribes to intracellular transport the different potency of the two drugs in the two cell lines.

Quantitative study of doxorubicin in living cell nuclei by microspectrofluorometry.

Doxorubicin-DNA association has been studied by quantitative microspectrofluorometry. Fluorescence emission spectra from a microvolume of single living cell nuclei treated with doxorubicin have been analyzed in terms of difference in spectral shape and fluorescence yield between free and DNA-bound drug. Contribution of each spectral component to the total signal was calculated by least-squares linear regression. With this method of analysis, total drug concentration has been determined with an error of less than 10%. Moreover, the uptake into the nucleus has been studied in a non destructive way, avoiding use of 14C-labelled drug. Kinetic studies of drug accumulation into the nuclei were conducted on sensitive and resistant cells.