Soft tissue reconstruction following total knee arthroplasty: treatment possibilities and retrospective analysis of plastic surgery therapy treatment possibilities

AIM: We performed a retrospective analysis of patients with soft tissue defects following total knee arthroplasty and therapy. Furthermore, we described the possibilities of covering soft tissue defects following knee arthroplasty. METHOD: In 5 patients, soft tissue defects following knee arthroplasty were covered with medial M. gastrocneminus flaps. Localisation and size of the defect, microbiology, risk factors, and interval between arthroplasty and the occurrence of the soft tissue defect were retrospectively analysed. RESULTS: On average, defects occurred 9 weeks after prosthesis implantation. In all cases, the soft tissue defect developed in the area of the incision. In 3 cases, wound infection was diagnosed. Four patients exhibited factors associated with wound-healing failure. No prosthesis was lost. CONCLUSION: The gastrocneminus muscle flap provides good quality coverage with small donor site defect, permits early mobilisation, and allows for fast rehabilitation. The risk of flap loss is minimal. Early and adequate defect coverage can reduce both prosthesis loss and amputation rates.     

Insurance status and race represent independent predictors of undergoing laparoscopic surgery for appendicitis: secondary data analysis of 145,546 patients

BACKGROUND: Studies have shown that racial and socioeconomic differences lead to inequality in access to health care. It is unknown whether insurance status and race affect the choice of surgical treatment for patients presenting with appendicitis. STUDY DESIGN: Patients with primary ICD-9 procedure codes for laparoscopic and open appendectomy were selected from the 1998, 1999, and 2000 Nationwide (US) Inpatient Samples. The primary predictor variables were insurance status (private, Medicare, Medicaid, other) and race (Caucasian, African American, Hispanic, other). Multiple logistic regression models were used to assess whether insurance status and race are associated with the choice of surgical procedure for patients presenting with appendicitis. RESULTS: Discharge abstracts of 145,546 patients were used for our analyses. There were 32,407 patients (22.3%) who underwent laparoscopic appendectomy and 113,139 patients (77.7%) who had open appendectomy. Although 24.2% of privately insured patients underwent laparoscopic appendectomy, only 16.9% of Medicare patients, 17.4% of Medicaid patients, and 19.6% of patients in the "other" insurance category were treated using the laparoscopic procedure (p < 0.001). Caucasian patients underwent laparoscopic surgery in 24.8%, African Americans in 18.6%, Hispanics in 19.6%, and other ethnicities in 18.8% of patients (p < 0.001). Compared with the Medicaid subset, and after adjusting for potential confounders such as age, gender, race, patient comorbidity, median ZIP code income, hospital location and teaching status, and presence of abscess or perforation, privately insured patients (odds ratio [OR] = 1.26, 95% [CI [1.20, 1.33], p < 0.001) and Medicare patients (OR = 1.17, 95% CI [1.05, 1.30], p = 0.004) were significantly more likely to undergo laparoscopic surgery. Caucasian patients (OR = 1.42, 95% CI [1.33, 1.51], p < 0.001) and Hispanics (OR = 1.12, 95% CI [1.04, 1.20], p = 0.002) were significantly more likely to have laparoscopic appendectomy, compared with African Americans, even after adjusting for the previously mentioned confounders and insurance status. CONCLUSIONS: Even after adjusting for potential confounders, insurance status and race are marked independent predictors of having laparoscopic surgery in patients treated for appendicitis in this sample.     

Development of multinuclear giant cells during the degradation of Bioglass particles in rabbits

Bioglass particles of the compositions 45s5, 52s, and 55s were implanted in the distal femoral epiphysis of rabbits. Animals were sacrificed at 7, 28, and 84 days postoperatively and specimens investigated using electron microscopy and electron dispersive X-ray analysis. The intention was to correlate the finding of different types of multinuclear giant cells (MNGC) in the center of the implantation bed with earlier hypothesized accumulated particle eluates and changed particle compositions. The distribution of Si, Na, Ca, P, O, S, and Cl throughout the implantation bed was analyzed. Bioglass particles degraded either in Si-rich remnants or in CaP-shells. MNGC of foreign body giant cell type in high numbers as well as of osteoclast-like type at later time intervals in small numbers were found on the surface of Si-rich as well as on Ca- and P-rich particle remnants. Osteoclast-like cells were detected on the particles after transformation in CaP-shells. It is concluded that the formation of different types of MNGC is determined by the composition of the substrate, that is, osteoclast-like cells develop exclusively on resorbable substrates. The absolute number of MNGC depended on the time after implantation and the solubility of the implant. Bone bonding, however, only occurred on Ca- and P-rich surfaces.     

Drug interaction with T-cell receptors: T-cell receptor density determines degree of cross-reactivity

BACKGROUND: Immune-mediated adverse reactions to drugs are often due to T-cell reactivity, and cross-reactivity is an important problem in pharmacotherapy. OBJECTIVE: We investigated whether chemical inert drugs can stimulate T cells through their T-cell receptor (TCR) and analyzed the cross-reactivities to related compounds. METHODS: We transfected human TCRs isolated from two drug-reactive T-cell clones (TCCs) by PCR into a TCR-negative mouse T-cell hybridoma. The TCCs were isolated from a patient with drug hypersensitivity to the antibacterial sulfonamide sulfamethoxazole (SMX). RESULTS: The transfectants reacted to SMX only in the presence of antigen-presenting cells (APCs). Glutaraldehyde-fixed APCs, however, were sufficient to elicit T-cell stimulation, indicating a processing-independent direct interaction of the drug with the TCR and MHC molecule. The transfected hybridomas secreted IL-2 in a drug dose-dependent manner, whereas the degree of reactivity was dependent on the level of TCR expression. One transfectant reacted not only to SMX but also to related sulfonamide compounds. Interestingly, high TCR expression increased cross-reactivity to other structurally related compounds. In addition, SMX-specific TCR cross-reacted only with sulfonamides bearing a sulfanilamide core structure but not with sulfonamides such as celecoxib, furosemide, or glibenclamide. CONCLUSIONS: These results demonstrate that the T-cell reactivity to drugs is solely determined by the TCR. Moreover, these results show that cross-reactivity of structurally similar compounds correlates with the density of the TCR. Stably transfected T-cell hybridomas may represent a powerful screening tool for cross-reactivity of newly generated sulfonamide-containing compounds such as celecoxib.     

Identification of enterohepatic Helicobacter species in patients suffering from inflammatory bowel disease

Using a group-specific PCR assay, we investigated the presence of enterohepatic Helicobacter species in gut specimens from patients with inflammatory bowel disease. Enterohepatic Helicobacter species were detected in 12% (3 of 25) of the patients with Crohn's disease, in 17% (3 of 18) of the ulcerative colitis samples, and in 4% (1 of 23) of the controls.     

Plasminogen activities and concentrations in patients with sporadic Creutzfeldt-Jakob disease

Human plasminogen has been shown to interact with the abnormal disease-specific prion protein. Till now, no data are available for patients with Creutzfeldt-Jakob disease (CJD). Therefore, we compared plasminogen concentrations and plasminogen activities in patients with sporadic CJD and controls with other dementia, which were collected in the framework of the German CJD Surveillance study. Patients with CJD had significantly higher plasminogen concentrations than patients with other forms of dementia and plasminogen specific activities were lower in CJD patients. The reasons for these abnormalities are not clear at the moment. The results may reflect a disease-specific prion protein and plasminogen interaction in patients with CJD. Other possible explanations are plasminogen polymorphisms and genotypes with distinct plasminogen activity levels in CJD than in controls, which should be a subject for further studies.     

Segments of puumala hantavirus nucleocapsid protein inserted into chimeric polyomavirus-derived virus-like particles induce a strong immune response in mice

Insertion of a short-sized epitope at four different sites of yeast-expressed hamster polyomavirus major capsid protein VP1 has been found to result in the formation of chimeric virus-like particles. Here, we demonstrate that the insertion of 45 or 120 amino acid-long segments from the N-terminus of Puumala hantavirus nucleocapsid protein into sites 1 (amino acids 80-89) and 4 (amino acids 288-295) of VP1 allowed the highly efficient formation of virus-like particles. In contrast, expression level and assembly capacity of fusions to sites 2 (amino acids 222-225) and 3 (amino acids 243-247) were drastically reduced. Immunization of BALB/c mice with chimeric virus-like particles induced a high-titered antibody response against the hantavirus nucleocapsid protein, even in the absence of any adjuvant. The strongest response was observed in mice immunized with virus-like particles harboring 120 amino acids of hantavirus nucleocapsid protein. According to the immunoglobulin subclass distribution of nucleocapsid protein-specific antibodies a mixed Th1/Th2 response was detected. The VP1 carrier itself also induced a mixed Th1/Th2 response, which was found to be reduced in mice immunized with virus-like particles harboring 120 amino acid-long inserts. In conclusion, hamster polyomavirus VP1 represents a promising carrier moiety for future vaccine development.     

In vivo imaging of leukocyte trafficking in blood vessels and tissues

Selective recruitment of blood-borne leukocytes to tissues and their proper positioning within them is crucial for the many integrated functions of the immune system. Intravital microscopy (IVM) techniques have been employed for more than a century to study these events at the single-cell level in living animals. Conventional video-based IVM allows the visualization of extremely rapid adhesion events at the interface between blood and tissue. Multiphoton IVM is a relatively new tool for imaging the slower dynamics of cell migration and cell-cell interactions in the extravascular space in three dimensions. Fueled by the burgeoning development of sophisticated fluorescent markers and increasingly powerful imaging tools, we are currently witnessing the emergence of a new field in immuno-imaging, in which leukocyte function and cell-cell communication is explored in a truly physiological context.