The effect of the small and unstable autologous osteochondral graft on repairing the full-thickness large articular cartilage defect in a rabbit model.
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We have investigated the effect of the insufficient autologous osteochondral graft on healing of the large articular cartilage defect using a rabbit model. An osteochondral defect, 7 mm in diameter, was made on the patellar groove of the femoral condyle and repaired with two surgical procedures: Group I, the osteochondral fragment as half as the defect was grafted. The graft was unstable and the size of the graft was smaller than the defect. This is a model of the insufficient autologous osteochondral graft to the large articular cartilage defect; Group II, the defect was left empty. At 2, 4, 12, and 24 weeks after the surgery, the specimens were analyzed macroscopically and histologically. To evaluate the microscopic morphology, a histologic grading scale composed of 5 categories was used. In Group I, although the graft sank a little, a grafted cartilage survived and the reparative fibrous tissue filled the defect covering implanted cartilage. In contrast, in Group II, the defect was only partially covered by fibrocartilaginous tissue with a faintly staining matrix. Throughout the entire observed periods, the scores of the repaired cartilage in Group I are significantly higher than those in Group II. Even the half size of osteochondral graft has an effect to reduce the size of the cartilage defect such as the spacer and leads to better healing compared to the cartilage defect untreated. In case that it is hard to transplant an optimal osteochondral graft because of large cartilage lesion, even the small and unstable osteochondral plug should be transplanted. (+info)
Radial artery pseudoaneurysm successfully treated by compression bandage.
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In children, surgery for radial artery pseudoaneurysm (PA) may be followed by growth retardation of the hand because of inadequate blood flow. We believe this is the first report of a child with PA of the radial artery cured by compression bandage. Conservative management is a safe and valuable initial treatment option for uncomplicated radial PA. (+info)
Regeneration-specific expression pattern of three posterior Hox genes.
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Homeobox genes encode positional information during primary and secondary axis formation during development. For this reason, the Hox genes have attracted attention in regeneration research as well. At early stages of regeneration, Hox genes have been implicated in wound healing and the dedifferentiation process and at later stages in the patterning of the blastema. We studied the expression of three Abdominal B-type Hox genes in Xenopus: XHoxc10, XHoxa13, and XHoxd13 during normal limb development and during regeneration of limbs and tails. We compared their expression with nonregenerating and with wounded limbs and tails, respectively. We show that the temporal and spatial control of these three Hox genes in blastemas differs from normal development. All three are specific to regeneration, XHoxc10 is up-regulated at the right time and at the site where cells dedifferentiate and undifferentiated cells are recruited, whereas XHoxa13 is reexpressed slightly later in regeneration, when the blastemal cells proliferate and remains on during patterning of the blastema. XHoxd13 is not expressed until relatively late and appears to be involved only in patterning of the blastema. (+info)
Matrix metalloproteinase activity correlates with blastema formation in the regenerating MRL mouse ear hole model.
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The MRL mouse was proposed as a model of mammalian regeneration because it can close ear holes completely with the restoration of normal tissue. This regeneration process involves the formation of a blastema during healing, the re-appearance of cartilage and hair follicles, and healing without scarring. Such a process requires extensive tissue remodeling. To characterize differences in ear wounding responses between regenerating and nonregenerating mice, we examined and compared the extracellular matrix remodeling and the matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) response in the MRL and C57BL/6 mouse strains after injury. We found a correlation between the MRL's ability to break down the basement membrane, form a blastema, and close ear hole wounds and an inflammatory response with neutrophils and macrophages seen in the ear after injury. These cells were positive for MMP-2 and MMP-9 as well as TIMP-2 and TIMP-3. Clear differences between the MRL and B6 response to injury were seen that could explain the differences in healing and blastema formation in the MRL and lack of it in the B6 mice. This finding was further supported by enzyme activity as determined by gelatin zymography. (+info)
Regeneration of the ear after wounding in different mouse strains is dependent on the severity of wound trauma.
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The replacement and restoration of tissue mass after organ damage or injury in adult higher vertebrates is critical to the architecture and function of the organ. If replacement occurs with scar tissue, this often results in adverse effects on function and growth as well as an undesirable cosmetic appearance. However, certain mammals, such as the MRL/MpJ mouse, have shown a restricted capacity for regeneration, rather than scar tissue formation, after an excisional ear punch wound. To investigate the changes in tissue architecture leading to ear wound closure, initial ear wounding studies with a 2-mm clinical biopsy punch were performed on MRL/MpJ mice, by using C57BL/6 mice as a nonregenerative control strain. In contrast to previously reported studies on mouse ear regeneration, we observed that C57BL/6 mice in fact showed a limited regenerative capacity. One explanation for this difference could be attributed to the method of wounding used; both previous studies on mouse ear regeneration used a thumb punch, whereas our approach was to use a clinical biopsy punch. This approach led us to further investigate whether the severity of trauma applied influenced the rate of wound healing. We, therefore, compared the effects of the sharp clinical biopsy punch with that of a cruder thumb punch, and introduced a third strain of mouse, Balb/c, known to be a slow-healing strain. A new method to quantify ear punch hole closure was developed and a histologic investigation conducted up to 4 months after wounding. Image analysis data showed a reduction in original ear wound area of 85% in MRL/MpJ mice at 4 weeks and of 91.7% over 4 months by using a biopsy punch. In contrast, the crude thumb punch methodology resulted in an increase in wound area of up to 58% in Balb/c ears; thought to be due to increased necrosis of the wound site. All biopsy-punched wound areas plateaued in healing between days 28 and 112. Only 5 of 80 MRL/MpJ mouse ears showed no residual holes macroscopically after 28 days. Histologically, all strains of mice healed their ear wounds in a similar manner involving re-epithelialization, blastema-like formation, dermal extension, blood vessel formation, chondrogenesis, folliculogenesis, and skeletal muscle and fat differentiation. However, all regenerative features were more pronounced and accelerated in MRL/MpJ mice when compared with C57BL/6 and Balb/c biopsy-punched mouse ears. (+info)
Recently occurring adult tetanus in Korea: emphasis on immunization and awareness of tetanus.
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Since a nationwide childhood vaccination with tetanus toxoid, tetanus has become a rare disease in Korea. However, we recently experienced 17 cases of adult tetanus in a university hospital during a 21-month period. Seventy percent of the patients were female, and the mean age was 63 yr (range, 29-87). The majority (88.2%) of the patients did not get primary vaccinations for tetanus and decennial tetanus-diphtheria toxoid booster. Most patients (88.2%), who sustained acute injury, did not seek medical care for their wounds or did not receive the prophylaxis for tetanus. Tetanus was found most frequently among farmers. Tetanus was diagnosed initially only in 53% of patients. The case-fatality ratio was 23.5%. These cases show that recently occurring tetanus in Korea is a disease, affecting the elderly and the female who may have a lower immunity against tetanus, and the farmers who are likely to be exposed to Clostridium tetani. In addition, diagnosis of tetanus is often delayed in area where cases are seen infrequently. Therefore, improved education among patients and physicians, emphasis of anti-tetanus immunization and awareness of tetanus respectively, may be essential for the prevention of disease and the reduction of its mortality. (+info)
The cathelicidin anti-microbial peptide LL-37 is involved in re-epithelialization of human skin wounds and is lacking in chronic ulcer epithelium.
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The human cathelicidin anti-microbial protein, hCAP18 is a component of the innate immune system and has broad anti-microbial activity conferred by its C-terminal fragment LL-37. hCAP18 is constitutively produced in leukocytes and is induced in barrier organs upon inflammation and infection. We demonstrate here a novel role for this peptide in re-epithelialization of skin wounds. We show that high levels of hCAP18 are produced in skin in vivo upon wounding. The highest hCAP18 levels are attained at 48 h post-injury, declining to pre-injury levels upon wound closure. hCAP18 is detected in the inflammatory infiltrate and in the epithelium migrating over the wound bed. In chronic ulcers, however, hCAP18 levels are low and immunoreactivity for hCAP18/LL-37 is absent in ulcer edge epithelium. Using a noninflammatory ex vivo wound healing model, composed of organ-cultured human skin, we show that hCAP18 is strongly expressed in healing skin epithelium, and that treatment with antibodies raised and affinity purified against LL-37, inhibits re-epithelialization in a concentration-dependent manner. Immunoreactivity for the proliferation marker Ki67 is absent in the epithelium of such inhibited wounds, suggesting that LL-37 may play a part in epithelial cell proliferation. Thus, we suggest that, in addition to being an anti-microbial peptide, LL-37 also plays a part in wound closure and that its reduction in chronic wounds impairs re-epithelialization and may contribute to their failure to heal. (+info)
Penetrating cardiac wounds: A comparison of different therapeutic methods.
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The management of penetrating wounds of the heart has been controversial. During the last 10 years we have used 3 different therapeutic approaches for the treatment of these wounds and the obtained results comprise this report. From 1964 to 1974 we treated 102 patients, four of whom expired immediately after their arrival to the clinic. The remaining 98 patients were divided into five groups according to their clinical presentation and treatment. Group I, 17 patients (14 with stab and 3 with bullet wound) seen with cardiac tamponade from 1964 to 1967 were treated first with pericardiocentesis and then were operated upon if pericardiocentesis yielded no results or if cardiac tamponade recurred. Fourteen patients recovered and three died, with an overall mortality of 17.5% Group II, 34 patients (23 with stab and 11 with bullet wound) were seen with cardiac tamponade from 1968 to 1971. The patients with stab wound were managed the same as group I patients and those with bullet wound were operated upon immediately. Twenty-nine recovered and 5 died, with an overall mortality of 14.7%. Group III, 20 patients (12 with stab and 8 with bullet wound) were seen with cardiac tamponade from 1972 to 1974. All of them were operated upon immediately and pericardiocentesis was used in this group only to provide time for a safe operation. Nineteen recovered and one died, with an overall mortality of 5%. Group IV, 20 patients (5 with stab and 15 with bullet wound) with massive bleeding, were operated upon immediately. Ten (4 out of the 5 with stab and 6 out of the 15 with bullet wound) recovered, with a mortality rate of 50%. Group V, seven patients were seen throughout the study period without bleeding or cardiac tamponade. Some of them were operated upon electively and others are being followed and all have done well. This study suggests (1) that patients with penetrating wound of the heart and cardiac tamponade or bleeding will derive better results if they are operated upon as soon as possible and if pericardiocentesis is used to provide time for a safe operation and (2) that those with other manifestations should be evaluated and if their lesion is significant, they should be operated upon electively. (+info)