Metabolic activity of Staphylococcus epidermidis is high during initial and low during late experimental foreign-body infection.
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Foreign-body infection (FBI) is notoriously resistant to eradication by antibiotic treatment. It is hypothesized that reduced bacterial metabolic activity contributes to this resistance. We examined the metabolic activity of Staphylococcus epidermidis in 204 samples recovered during in vitro foreign-body colonization and in 424 samples recovered during in vivo FBI in a rat model. Metabolic activity was measured by determining the amount of 16S rRNA per genome by quantitative PCR. The initial foreign-body-associated growth proved to be a metabolically active process, both in vitro and in vivo. The initial 16S rRNA content was similar to that observed during in vitro exponential-growth phase. However, during late in vivo FBI, a 114-fold (P << 0.0001) decrease in the 16S rRNA content was observed, indicating that there was markedly decreased metabolic activity. This decreased metabolic activity during late FBI can explain at least in part why such infections are so difficult to eradicate with conventional antibiotic treatment. (+info)
Subcutaneous injection of mercury: "warding off evil".
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Deliberate injection of mercury, especially subcutaneous injection, is rare but is seen in psychiatric patients, individuals who attempt suicide, those who are accidentally injected, and boxers who wish to build muscle bulk. Metallic mercury plays a major role in ethnic folk medicine. Neurologic and renal complications can result from high systemic levels of mercury, and subcutaneous injection usually results in sterile abscesses. Urgent surgical evacuation and close monitoring for neurologic and renal functions as well as chelation (if toxicity is indicated) are key aspects of treatment. Education of the adverse effects and dangers of mercury is important, especially in pregnant women and children. As increased immigration changes demographic patterns, proper disposal of mercury and preventing its sale and use should become urgent societal priorities. Psychiatric consultation should be obtained whenever appropriate. (+info)
An in-vivo model to interrogate the transition from acute to chronic inflammation.
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This study describes the modulation of the rodent foreign body giant cell (FBGC) response to subcutaneously implanted, biodegradable poly(lactide-co-glycolide)/calcium phosphate (PLGA/CaP) composites by application of a thin surface coat of calcium phosphate. Macroporous PLGA/CaP composite scaffolds, with interconnecting macroporosity, were half coated with a 3mm thick layer of CaP by immersion in simulated body fluid. Half-coated scaffolds were implanted subcutaneously in the dorsum of male Wistar rats for 1, 4 and 8 weeks. Specimens were embedded in paraffin and tissue sections evaluated by light microscopy with particular reference to the FBGC response. Histomorphometry revealed that FBGCs were in contact with 6% (+/- 3.5%) of the uncoated half, at 1 week, but no FBGCs were seen on the coated half. By 4 weeks, FBGCs were seen on both the uncoated and coated halves of the scaffolds with 87% (+/-10%) and 36% (+/-4%) FBGC/polymer contact respectively. By 8 weeks these FBGC contact percentages had risen to 97% (+/-0.45%) in the case of the uncoated halves of scaffolds, but decreased to 22% (+/-4%) in the case of the CaP-coated halves. Thus the CaP coating abrogated the FBGC response to the underlying polymer. Such a model may prove useful in providing an experimental system whereby both the mechanisms of biocompatibility and the transition from acute to chronic inflammation could be interrogated. (+info)
Tissue adhesives for a sutureless fadenoperation: an experimental study in a rabbit model.
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PURPOSE: To use tissue adhesives for a sutureless Fadenoperation to eliminate perioperative risks related to the sutures. METHODS: In an in vivo procedure, 120 superior recti muscles in New Zealand White rabbits were subjected to the posterior fixation procedure, at a distance of 6 mm from the insertion point of the muscle. They were divided into four groups of 30 muscles, according to the material used to perform a myopexy: group 1 (control): nonabsorbable 5-0 polyester sutures; group 2: n-butyl-2-cyanoacrylate adhesive; group 3: fibrin glue; group 4: gelatin-resorcin-formaldehyde-glutaraldehyde (GRFG) adhesive. The animals were examined at 1, 7, 14, and 21 days after surgery. Afterward, they were killed, and their eyes were enucleated to measure the distance between the myopexy and the anatomic insertion point and to assure the strength of the bond with a dynamometer. Finally, a histologic examination was performed. RESULTS: Almost all eyes were clear after the third week, although group 4 presented the most intense inflammatory reaction. In histologic examination, groups 1 and 2 showed a chronic inflammatory reaction of the foreign-body type, with similar intensity. Fibrin glue induced minimal inflammation, but GRFG adhesive produced a pronounced reaction. Concerning the distance of the myopexy, groups 1 and 2 presented measures close to the expected distance of 6 mm, whereas groups 3 and 4 showed a greater variability. All groups performed well in the strength test, with no statistically significant differences among them. CONCLUSIONS: n-Butyl-2-cyanoacrylate adhesive performed best in the sutureless Fadenoperation, characterized by precision in the expected distance of myopexy, sufficient resistance to separation, and acceptable inflammatory reaction. (+info)
Analysis of a retrieved delta III total shoulder prosthesis.
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A reversed Delta III total shoulder prosthesis was retrieved post-mortem, eight months after implantation. A significant notch was evident at the inferior pole of the scapular neck which extended beyond the inferior fixation screw. This bone loss was associated with a corresponding, erosive defect of the polyethylene cup. Histological examination revealed a chronic foreign-body reaction in the joint capsule. There were, however, no histological signs of loosening of the glenoid base plate and the stability of the prosthetic articulation was only slightly reduced by the eroded rim of the cup. (+info)
Mast cells and the inflammatory response to different implanted biomaterials.
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The biocompatibility of dental materials is a topic of increasing importance for dentists. We investigated the effects of alloys for ceramic crowns and removable prostheses on the skin and lymphoid organs of rats. We used three groups of Sprague Dawley rats: group I as the control, with groups II and III implanted with different biomaterials into subcutaneous pockets. After sacrifice, the rat skin around the implant and the lymph nodes was studied. The tissues of implanted rats were morphologically different from the control animals as they showed a number of mast cells that increased 7 days after the implant with both alloys. These cells decreased 14 days after the implant with alloy for ceramic crowns whereas they were still high 28 days after the implant with alloy for removable prostheses. The findings suggest that both alloys induced different and time-dependent inflammatory reactions. Our findings have importance in the future rational design of biocompatible implantable and blood-contact biomaterials. (+info)
Clinical analysis of disc battery ingestion in children.
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BACKGROUND: The purpose of this study was to evaluate the characteristics, management, and outcomes of disc battery ingestion in children. METHODS: We reviewed the medical records of children aged between 1 and 15 years old admitted to Chang Gung Children's Hospital due to disc battery ingestion from September 1997 through July 2003). The diagnosis of disc battery ingestion was based upon history, clinical symptoms, and results of imaging studies. The clinical data reviewed included sex, age, clinical manifestation, hospital course, imaging findings, and endoscopic results. RESULTS: We found 12 cases (8 males and 4 females) of disc battery ingestion with a mean age of 1.8 +/- 3.43 years (range, 9 months to 5 years). Two patients had symptoms of vomiting, nausea, and abdominal pain. Two cases with no history of disc battery ingestion and were accidentally found by X ray studies. Four cases had their batteries impacted in the esophagus and eight cases had their batteries impacted in stomach. In those patients with esophageal impaction, one died suddenly, and the batteries were removed successfully by endoscope in the other three. Among those patients with batteries in the stomach, two patients underwent endoscope removal and the other 6 patients experienced smooth courses and the batteries spontaneously passed through the gastrointestinal tract within 5 days. The diameter of the ingested disc batteries ranged from 12 mm to 23 mm. The duration of hospitalization varied from 1 day to 61 days. Four patients had obvious damage of gastrointestinal mucosa including three esophageal mucosal erosion lesions, and one gastric mucosa erosion lesions with hemorrhage. Two patients experienced complications: one died suddenly due to tension in the pneumothorax and penumoperitoneum and the other had tracheoesophageal fistula. CONCLUSIONS: Most cases of disc battery ingestion run uneventful courses. However, the ingestion of some disc batteries may be fatal or complicated with life-threatening events. If the battery impacts in the esophagus, emergency endoscopic management is necessary. Once in the stomach, the battery will usually pass through the gastrointestinal tract without long-term complications. (+info)
Five year study of tissue reaction to synthetic sutures.
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Sutures were implanted in the abdominal wall muscles of rabbits and specimens recovered at intervals from six month to five years. Tissue reaction around Nylon and Dacron was minimal. The reaction of Teflon coated Dacron was increased because of shedding of the Teflon. The polypropylene sutures showed fragmentation in 4% of the sutures examined and the perisutural formation of bone, cartilage or both in 2.6%. (+info)