Covering soft tissue defects

In the past, the main emphasis in the treatment of complex limb injuries was placed upon the reconstruction of bony defects. Recently, however, reconstructive soft-tissue procedures have gained the attention they deserve. The salvage of a severely injured extremity depends rather on the feasibility of reconstructive surgical tissue procedures than on restoration of the bony defect. Sufficient vascularity is an essential condition for fracture healing and the prevention of post-traumatic complications like osteomyelitis and pseudarthrosis. If primary closure of a soft-tissue defect is not possible, preliminary covering has to be obtained with artificial skin replacement (vacuum sealing) until definitive covering with muscle or musculocutaneous flaps can be achieved. With the microvascular restorative techniques available today even complex soft-tissue problems can be solved. Nevertheless, an appropriate infrastructure and a trained and skilled surgeon are essential.     

Extremity soft tissue sarcoma with metastases to abdominopelvic surfaces

BACKGROUND: In a majority of patients with extremity soft tissue sarcoma, the lungs are the first site at which recurrent disease is detected. Other common sites of recurrence are the resection site, bone metastasis, and liver metastasis. Although abdomino pelvic sarcomatosis is common as a site of recurrence for visceral and retroperitoneal sarcoma, it has not been previously reported for extremity sarcoma. METHOD: We present three patients in whom extremity soft tissue sarcoma metastasized to the peritoneal surfaces, and in all three patients this was symptomatically the dominant site for recurrence. All of them underwent a palliative surgical cytoreduction and were then treated with intraperitoneal chemotherapy. RESULTS: In two of the three patients, isolated progression of peritoneal sarcomatosis has again occurred: one patient remains disease free at 14 months. CONCLUSIONS: Metastasis to peritoneal surfaces within the abdomen and pelvis must be considered a possible site for systemic dissemination of extremity soft tissue sarcomas. Effective treatments for sarcoma spread to peritoneal surfaces would benefit this small but symptomatic group of patients.     

Skeletal and soft tissue sarcomas. Treatment with adjuvant immunotherapy

Because there is evidence for an active immunologic response against sarcoma, a clinical trial of adjuvant immunotherapy using bacillus Calmette-Guérin (BCG) and tumor cell vaccine was begun. Eleven of 18 patients with localized soft tissue sarcoma who received immunotherapy are free of disease, compared to only 5 of 15 treated by operation alone who are free of disease. Furthermore, immunotherapy also prolonged the median disease-free interval from 7.3 months to 15 months in the patients who experienced recurrence of their disease.     

Clinical diagnosis of soft tissue tumors

At the secretory stage of tooth enamel formation the majority of the organic matrix is composed of amelogenin proteins that are believed to provide the scaffolding for the initial carbonated hydroxyapatite crystals to grow. The primary objective of this study was to investigate the interaction between amelogenins and growing apatite crystals. Two in vitro strategies were used: first, we examined the influence of amelogenins as compared to two other macromolecules, on the kinetics of seeded growth of apatite crystals; second, using transmission electron micrographs of the crystal powders, based on a particle size distribution study, we evaluated the effect of the macromolecules on the aggregation of growing apatite crystals. Two recombinant amelogenins (rM179, rM166), the synthetic leucine-rich amelogenin polypeptide (LRAP), poly(L-proline), and phosvitin were used. It was shown that the rM179 amelogenin had some inhibitory effect on the kinetics of calcium hydroxyapatite seeded growth. The inhibitory effect, however, was not as destructive as that of other macromolecules tested. The degree of inhibition of the macromolecules was in the order of phosvitin > LRAP > poly(L-proline) > rM179 > rM166. Analysis of particle size distribution of apatite crystal aggregates indicated that the full-length amelogenin protein (rM179) caused aggregation of the growing apatite crystals more effectively than other macromolecules. We propose that during the formation of hydroxyapatite crystal clusters, the growing apatite crystals adhere to each other through the molecular self-association of interacting amelogenin molecules. The biological implications of this adherence effect with respect to enamel biomineralization are discussed.     

Ion induced deformation of soft tissue

In this paper the effects of changing the ion concentration in and around a sample of soft tissue are investigated. The triphasic theory developed by Lai et al. (1990, Biomechanics of Diarthrodial Joints, Vol. 1, Berlin, Springer-Verlag) is reduced to two coupled partial differential equations involving fluid ion concentration and tissue solid deformation. These equations are given in general form for Cartesian, cylindrical and spherical geometries. After solving the two equations quantities such as fluid velocity, fluid pressure, chemical potentials and chemical expansion stress may be easily calculated. In the Cartesian geometry comparison is made with the experimental and theoretical work of Myers et al. (1984, ASME J. biomech. Engng, 106, 151-158). This dealt with changing the ion concentration of a salt shower on a strip of bovine articular cartilage. Results were obtained in both free swelling and isometric tension states, using an empirical formula to account for ion induced deformation. The present theory predicts lower ion concentrations inside the tissue than this earlier work. A spherical sample of tissue subjected to a change in salt bath ion concentration is also considered. Numerical results are obtained for both hypertonic and hypotonic bathing solutions. Of particular interest is the finding that tissue may contract internally before reaching a final swollen equilibrium state or swell internally before finally contracting. By considering the relative magnitude, and also variation throughout the time course of terms in the governing equations, an even simpler system is deduced. As well as being linear the concentration equation in the new system is uncoupled. Results obtained from the linear system compare well with those from the spherical section. Thus, biological swelling situations may be modelled by a simple system of equations with the possibility of approximate analytic solutions in certain cases.     

Chemotherapy of metastatic soft tissue sarcoma

The chemosensitivity of bone sarcomas contrasts sharply with the comparative initial chemoresistance of soft tissue sarcomas. The lack of new effective cytotoxic agents, delayed treatment due to a clinical presentation which is often innocuous and the absence of a consensus about the role of adjuvant chemotherapy after adequate surgery account for the slow progress achieved in the treatment of these tumours and for such an appalling prognosis. Chemotherapy is still purely palliative except for certain specific metastatic lesions, and median overall survival is more often than not below 12 months. However, the optimization of the therapeutic index of the most active antimitotic drugs, the ever-increasing acceptance of the concept of a dose-effect for the majority of these lesions, the particularly promising objective response rates with intensive drug combinations and a better understanding of the development process of certain lesions and histologic subtypes make it possible to envisage a rapid improvement in their still far too dismal prognosis.     

Therapy of soft tissue injuries--biological strategies

The traumatic soft tissue injury plays a central role in fracture healing. The knowledge of pathophysiological mechanisms has completely changed the management and therapy of injuries accompanied by soft tissue lesions. Treatment is aiming for prevention of the circle of hypoxia, microvascular perfusion disturbance, increased membrane permeability and potential infections. General therapeutic principles are decontamination, debridement, revascularisation and decompression. Modern methods of soft tissue treatment take these principles into consideration.     

Ibuprofen and skin and soft tissue superinfections in children with varicella

PURPOSE: To investigate the possible association between ibuprofen use and dermatologic superinfections among children with recent varicella infection. METHODS: A retrospective cohort study of children in Harvard Pilgrim Health Care, a health maintenance organization in New England, was conducted. Outcomes and exposures of interest were identified from automated medical and pharmacy records. Exposure was defined by dispensing of ibuprofen before varicella to avoid potential confounding by indication. RESULTS: Between July 1, 1990 and September 30, 1994, 89 superinfections developed among 7,013 cases of varicella. The 30-day risk of superinfection was 7.2/10(3) cases (95% CI = 5.8-8.8/10(3) cases). Four of 169 children dispensed ibuprofen within 180 days of varicella developed superinfection. Relative to children without prior use, children with ibuprofen dispensed in the month prior to varicella were 3.1 times more likely to be diagnosed with a superinfection (95% CI = 0.1-19.7; P-value: 0.31). Restriction of outcomes to superinfections treated with systemic antibiotics increased the odds ratio to 5.1 (95% CI = 0.1-32.5; P-value: 0.22). CONCLUSIONS: The results of this study are consistent with a broad range of effects including no association and suggest that further study is needed.     

Li-Fraumeni syndrome in pediatric patients with soft tissue sarcoma or osteosarcoma

Family history of cancer and features of the Li-Fraumeni syndrome (LFS) were investigated in 42 patients with soft tissue sarcoma or osteosarcoma in a pediatric hospital in Mexico City, and compared with 42 non-cancer children. Six subjects with cancer were found among 204 first-degree relatives of cancer patients while there were none among 183 first-degree relatives of non-cancer children. In three families, the proband had two affected relatives, and the type of neoplasia as well as the age of onset suggested the clinical diagnosis of LFS. Our results show that 7.1% of our pediatric patients with soft tissue sarcoma or osteosarcoma may belong to LFS families. The authors encourage pediatric and adult oncologists to pay more attention to the history of cancer in nuclear families for eventual hereditary cancer syndrome identification and cancer prevention.     

Bladder tumor. Presentation of 2 patients with soft tissue involvement

OBJECTIVE: To describe two uncommon cases of bladder tumor metastasizing to soft tissues. METHODS/RESULTS: Two patients with bladder tumor and cystic metastases in the abdominal wall are described. The cysts were easily palpable and were confirmed histologically. CONCLUSION: Soft tissues, like the abdominal wall, are unusual sites of metastasis of bladder tumor. The foregoing, however, should be considered in order to make an early diagnosis.     

Diagnosis and treatment of soft tissue tumors

Alterations in [Hb], which are mediated through changes in arterial oxygen content, and alterations in BV, which are mediated through changes in cardiac output (Q), have a significant effect on both VO2max and aerobic performance. If BV is held constant, a decrease in [Hb] (anaemia) causes a decrease in VO2max and aerobic performance, while an increase in [Hb] (blood doping) causes an increase in VO2max and aerobic performance. If [Hb] is held constant, an increase in BV can cause and increase in both VO2max and aerobic performance, while a decrease in BV can cause a decrease in VO2max and aerobic performance. In addition, an increase in BV can compensate for moderate reductions in [Hb] through increase in Q, allowing VO2max to remain unchanged or even increase. Also, a large portion of the difference in the enhanced cardiovascular function of endurance athletes is due to their high BV and the resultant enhancement of diastolic function. Hence, optimizing both [Hb] and BV is a very important consideration for endurance performance.     

Role of radiotherapy in soft tissue sarcoma

OBJECTIVE: To determine if the ammonia produced by Helicobacter pylori affects the phagocytic ability of human polymorphonuclear leucocytes as measured by the oxidative burst. METHODS: Interactions between opsonized urease-positive and -negative strains of H. pylori with polymorphonuclear leucocytes were studied in two series of experiments. In the first series of experiments, concentrations from 0 to 50 mM of NH4Cl were added to polymorphonuclear leucocytes. In the second series of experiments, bacteria were pre-incubated for 1 h with urea (0 to 50 mM) before addition of phagocytes. Luminol-dependent chemiluminescence was measured every 5 min over a 50-min period. The pH was verified in each treatment. RESULTS: Inhibition of chemiluminescence, increasing with concentration, was noted in all treatments when NH4Cl was added. When urea was added to urease-positive strains, chemiluminescence was significantly reduced when compared to the urease-negative strain and the zymosan control. This effect could not be attributed to a change in pH in the experiments using NH4Cl or urea at a concentration of 5 mM and 10 mM. CONCLUSION: Ammonia generated by H. pylori may contribute to the decreased activity of polymorphonuclear leucocytes in vivo.     

Oral soft tissue trauma: gingival degloving

The histologic and immunohistochemical features of a case of adult solitary cutaneous myofibroma are reported. The lesion consisted of interlacing bundles of spindle cells arranged around small vessels with hemangiopericytomatous appearance. Neoplastic cells were positive for vimentin and actin. Desmin, cytokeratins and Factor XIIIa were negative. Scattered Langerhans cells positive for S-100 protein and CD1a antigen, usually not reported within this type of neoplasm, were also present.