To summarize the diagnosis and management of a highly sensitized renal transplant recipient who developed Legionella pneumophila infection during the perioperative period. A 48-year-old male recipient presented early after transplantation with both acute allograft rejection and pulmonary infection. The acute rejection episode was successfully reversed with appropriate treatment, whereas the pulmonary infection continued to progress. Initial microbiological tests were negative, and empirical antimicrobial therapy was ineffective. Legionella pneumophila was subsequently detected by metagenomic next-generation sequencing of bronchoalveolar lavage fluid obtained via bronchoscopy. Following combined therapy with moxifloxacin and tigecycline, along with withdrawal of immunosuppressive agents, the pulmonary lesions completely resolved.

To summarize the diagnosis and management of a highly sensitized renal transplant recipient who developed Legionella pneumophila infection during the perioperative period. A 48-year-old male recipient presented early after transplantation with both acute allograft rejection and pulmonary infection. The acute rejection episode was successfully reversed with appropriate treatment, whereas the pulmonary infection continued to progress. Initial microbiological tests were negative, and empirical antimicrobial therapy was ineffective. Legionella pneumophila was subsequently detected by metagenomic next-generation sequencing of bronchoalveolar lavage fluid obtained via bronchoscopy. Following combined therapy with moxifloxacin and tigecycline, along with withdrawal of immunosuppressive agents, the pulmonary lesions completely resolved.

Objective: To investigate the effects of denatured collagen type Ⅰ on differentiation of human fibroblasts into myofibroblasts. Methods: A small amount of normal skin donated by burn patients undergoing scar surgery was collected. Human fibroblasts were obtained by method of explant culture and then sub-cultured. The fourth passage of cells were used in the following experiments. (1) Fibroblasts were divided into normal collagen group and denatured collagen group according to the random number table, with 10 wells in each group. Fibroblasts in normal collagen group were cultured on normal collagen type Ⅰ coated coverslips. Fibroblasts in denatured collagen group were cultured on denatured type Ⅰ collagen coated coverslips. Expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemical method, and the percentage of PCNA positive cells was calculated. (2) Another batch of fibroblasts were grouped and treated as in (1), with 12 wells in each group. Proliferation activity of cells was determined with methyl-thiazolyl-tetrazolium colorimetry method. (3) Another batch of fibroblasts were grouped and treated as in (1), and the microfilament morphology of cells was observed by rhodamine-phalloidin staining. (4) Another batch of fibroblasts were grouped and treated as in (1). Expression of α smooth muscle actin (α-SMA) of cells was detected by immunohistochemical method, and expression of OB-cadherin of cells was detected by immunofluorescence method. (5) Another batch of fibroblasts were divided into normal collagen, denatured collagen, and common coverslips groups according to the random number table, with 6 wells in each group. Fibroblasts in normal collagen and denatured collagen groups were treated as in (1), while fibroblasts in common coverslips group were cultured on coverslips without collagen coating. Expressions of α-SMA and OB-cadherin of cells were determined with Western blotting. (6) Another batch of fibroblasts were grouped and treated as in (5), and then the mRNA expressions of collagen type Ⅰ, collagen type Ⅲ, and α-SMA of cells were determined with real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were processed with t test, one way analysis of variance, and least-significant difference test. Results: (1) The percentage of PCNA positive cells in denatured collagen group was (83±9)%, significantly higher than (29±9)% in normal collagen group (t=13.53, P<0.01). (2) The proliferation activity of fibroblasts in denatured collagen group was 0.32±0.06, significantly higher than 0.25±0.05 in normal collagen group (t=3.06, P<0.01). (3) The microfilament of fibroblasts in normal collagen group was arranged vertically and in parallel way, paralleling the long axis of cells. The microfilament of fibroblasts in denatured collagen group was denser and thicker. (4) Most fibroblasts in normal collagen group showed long shuttle-like shape typically. Morphology of fibroblasts in denatured collagen group changed, and cells were obviously spreading. Expressions of α-SMA and OB-cadherin of fibroblasts in denatured collagen group were stronger than those in normal collagen group. (5) Expressions of α-SMA of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 1.69±0.41, 0.89±0.27, and 1.46±0.42. Expression of α-SMA of fibroblasts in denatured collagen group was significantly higher than that in normal collagen group (P<0.01). Expressions of OB-cadherin of fibroblasts in denatured collagen, normal collagen, and common coverslips groups were respectively 5.17±0.28, 2.21±0.10, and 4.01±0.56. Expression of OB-cadherin of fibroblasts in denatured group was significantly higher than that in normal collagen group (P<0.01). (6) There was no significant difference in mRNA expression of collagen type Ⅰ of fibroblasts in denatured collagen, normal collagen, and common coverslips groups (F=2.71, P>0.05). The mRNA expressions of collagen type Ⅲ and α-SMA of fibroblasts in normal collagen group were significantly lower than those in denatured collagen group (P<0.01). Conclusions Denatured collagen type Ⅰ may influence the activity of fibroblasts, thus inducing fibroblasts differentiating into myofibroblasts.

OBJECTIVETo observe the fibrosis of skin after damage to the fat dome structure in skin of pig.

METHODSTotally 4 pieces of skin grafts of intermediate thickness in the size of 5 cm × 5 cm were obtained from both sides beside the spine of back in each of the 4 female red Duroc pigs with pedicle on one side with Humby knife performed by burn specialists, who were rich in clinical experience. These skin grafts were assigned as thin dermis group (TD). Pedicled tissue grafts in the size of 5 cm × 5 cm with the thickness of 1.5 mm were obtained within the wounds resulted from former incision with the same method mentioned above, and these tissue grafts were set as fat dome group (FD). The above-mentioned two groups of skin grafts were sutured back in situ immediately after completion of the former procedures. On post surgery day (PSD) 7, 14, and 21, 5 wounds were respectively selected according to the random number table for gross observation of the surgical areas. Tissue samples were obtained from corresponding surgical area deep to the deep fascia after gross observation at above-mentioned time points. Some of the tissue samples were used for observation of distribution of collagen fibers in the regions of operation of both groups of skin grafts with HE staining, and the breadth of fibrosis was measured; some of the tissue samples were used for observation of distribution of type I or III collagen fibers in the regions of incision of both two groups of skin grafts with Sirius red staining. Data were processed with two independent sample t test.

RESULTSA little scab on the edge of wounds was observed on PSD 7; all the wounds were healed on PSD 14; a few hairs were observed growing in the surgical area on PSD 21. HE staining showed that traces of incision were observed in the superficial layer of dermis and at the junction between dermis and fat dome at each time point; profuse hyperplasia of collagen fibers with parallel and orderly arrangement were observed in the region of incision of skin grafts in groups TD and FD at each time point. The breadth of fibrosis of the region of incision of skin grafts was respectively (251 ± 31), (240 ± 3 7), and (342 ± 69) µm in group TD, (239 ± 36), (286 ± 61), and (332 ± 28) µm in group FD on PSD 7, 14, 21, without significantly statistical difference (with t values respectively 0.750, -1.971, and 0.375, P values above 0.05). Sirius red staining showed that large amount of type III collagen fibers and small amount of type I collagen fibers arranging parallelly were present in the region of incision of skin grafts in groups TD and FD at each time point.

CONCLUSIONSUnder the circumstances of relatively intact restoration of dermal tissue, no excessive fibrosis was observed after simple incisional injury of fat dome in skin of pig.

Animals ; Burns ; surgery ; Dermis ; surgery ; transplantation ; Female ; Fibrosis ; complications ; Graft Survival ; Male ; Skin ; Skin Transplantation ; methods ; Skin, Artificial ; Swine ; Wound Healing

Objective To detect the histological characteristics of collagen nodules from hypertrophic scars (HS) and investigate the origin of collagen nodules.Methods The scar tissues were collected from patients with plastic operation.Morphological characteristics of collagen nodules were observed by light microscopy of HE-stained sections; expressions of type Ⅰ /Ⅲ collagens were observed by polarized light microscopy of sirius red-stained sections; expression and distribution of myofibroblasts (MFb)-specific protein (α-smooth muscle actin,α-SMA) were observed by immunostaining in order to observe level of local tissue tension.Results Collagen nodules varied in shape,not only sphereshaped,and in size.Moreover,abundant fibroblasts (Fb) with large and light-stained nuclei were seen in the nodules compared to non-nodule area,indicating that the cells located in the modules were active.Some collagen nodules were composed largely of collagen type Ⅲ (green),but some mainly contained collagen type Ⅰ (red or yellow),indicating the difference in the time of nodule formation.α-SMA was expressed mainly in the deep dermis equivalent to the level of reticular layer of the new scar tissues (2 months after injury) ; α-SMA was expressed mainly in the nodules of the old scar tissues (2-10 years after injury),but almost not in non-nodule areas except for a strongly positive staining in the vessels.Moreover,α-SMA presented a heterogeneous distribution in the collagen nodules,with stronger expression in the epidermal end than in the subcutaneous tissue end and stronger expression in the superficial dermis than that in the deeper part.It was suggested that there existed massive amount of MFb and high tension in the nodules arid that the tension distribution was not uniform in or between the nodules.Conclusions Collagen nodules are of varying shape and size and collagen types are associated with the time of nodule formation.Moreover,Formation of the collagen nodules may be closely related to the distribution and evolution of the local tissue tension.

Objective To explore the repair method for refractory diabetic wound. Methods A total of 206 patients with refractory diabetic foot ulcers were treated with proper surgical treatments.Results Of all, 106 patients were treated by skin flap (51.5 % ), with one stage wound healing rate of 85.8%; 122 patients were repaired with split-thickness skin graft ( 59.2% ), with survival rate of the graft for 79.5%. Simple toe amputation was made in 34 patients (46 toes). The high level amputation was performed in 56 patients (27.2%). Of all, 132 patients were followed up for 6-18 months, which showed that ulcer recurred in 12 patients (9.1%). Conclusion Timely and effective treatment as well as flap and skin graft repair could reduce high level amputation rate of diabetic foot ulcer and promote the quality of life.