[Treatment of open abdomen combined with entero-atmospheric fistula: A retrospective study].

Objective: The purpose of this study was to analyze the course and outcome of patients with combined entero-atmospheric fistulas in open abdomen treatment. Methods: In this retrospective observational study, we collected data on 214 patients with open abdomen complicated by entero-atmospheric fistulas admitted to Research Institute of General Surgery, Jinling Hospital, Affiliated Hospital of Medical School from January 2012 to January 2021. We collected their basic characteristics, aetiology, treatment plan, and prognosis, including the durations of hospitalization and open treatment, time to resumption of enteral nutrition, duration and prognosis of definitive surgery, and overall prognosis. Results: Of the 214 patients with open abdomen complicated with entero-enteral fistulas, 23 (10.7%) died (11 of multiple organ failure caused by abdominal infection, five of abdominal cavity bleeding, four of pulmonary infection, one of airway bleeding, one of necrotizing fasciitis, and one of traumatic brain injury). The remaining 191 underwent definitive surgery at our hospital. The patients who underwent definitive surgery were predominantly male (156 patients, 81.7%); their age was (46.5±2.5) years. Trauma and gastrointestinal tumors (120 cases, 62.8%) predominated among the primary causes. The reasons for abdominal opening were, in order, severe abdominal infection (137 cases, 71.7%, damage control surgery (29 cases, 15.2%), and abdominal hypertension (25 cases, 13.1%). Temporary abdominal closure measures were used to classify the participants into a skin-only suture group (104 cases) and a skin-implant group (87 cases). Compared with the skin-implant group, in the skin-suture-only group the proportion of male patients was lower (74.7% [65/87] vs. 87.5% [91/104], χ2=5.176, P=0.023), the mean age was older ([48.3±2.0] years vs. [45.0±1.9] years, t=-11.671, P<0.001), there were fewer patients with trauma (32.2% [28 /87] vs. 58.7% [61/104), χ2=13.337, P<0.001), intensive care stays were shorter ([8.9±1.0] days vs. [12.7±1.6] days, t=19.281, P<0.001), total length of stay was shorter ([29.3±2.0] days vs. [31.9±2.0] days, t=9.021,P<0.001), there was a higher percentage of colonic fistulas (18.4% [16/87] vs. 8.7% [9/104], χ2=3.948, P=0.047), but fewer multiple fistulas (11.5% [10/87] vs. 34.6% [36/104], χ2=14.440, P<0.001). As to fistula management, a higher percentage of fistula sealing methods using 3D-printed intestinal stents were implemented in the skin-only suture group (60.9% [53/87] versus 43.3% [45/104], χ2=5.907, P=0.015). Compared with the implant group, the skin-only suture group had a shorter mean time to performing provisional closure ( [9.5±0.8] days vs. [16.0±0.6] days, t=66.023, P<0.001), shorter intervals to definitive surgery ( [165.0±10.7] days vs. [198.9±8.3] days, t=26.644, P<0.001), and less use of biopatches (56.3% [49/87) vs. 71.2% [74/104], χ2=4.545, P=0.033). Conclusions: Open abdomen complicated with entero-enteral fistulas is more common in male, and is often caused by trauma and gastrointestinal tumor. Severe intra-abdominal infection is the major cause of open abdomen, and most fistulae involves the small intestine. Collection and retraction of intestinal fluid and 3D-printed entero-enteral fistula stent sealing followed by implantation and skin-only suturing is an effective means of managing entero-enteral fistulas complicating open abdominal cavity. Earlier closure of the abdominal cavity with skin-only sutures can shorten the time to definitive surgery and reduce the rate of utilization of biopatches.

Dendritic cells: a new player in osteoimmunology.

Recent studies have suggested that the dys-regulated progressive immune responses in some inflammatory conditions can lead to significantly increased osteoclasts (OC) frequency and activity associated with active bone destruction; termed inflammation-induced bone loss. Among the inflammatory infiltrates, monocytes/macrophages (Mo/MQ), T and B cells, have been well studied and documented as central players in osteoimmunological interactions (osteoimmunology: is an interdisciplinary field linking the immune and skeletal systems). We and others investigated the role(s) of dendritic cells (DC) during inflammation-induced osteoclastogenesis and bone loss. In addition to their innate effector functions, DC are potent professional antigen-presenting cells (APC) involved in triggering and orchestrating adaptive immunity, thereby implicated as potential osteo-immune players. Herein, bone remodeling and DC's biology including their development and functions are reviewed along with the contribution of DC at the crossroad of the osteo-immune interface during the process of inflammation-induced osteoclastogenesis. Furthermore, we provide a summary of recent progress, and discuss a proposed alternative mechanism underlying inflammation-induced bone loss. Understanding the cellular and molecular mechanisms regulating DC's roles in inflammation-induced osteoclastogenesis and bone loss might benefit future treatment approaches, especially if targeting DC can be translated into therapeutic strategies to ameliorate both tissue inflammation and bone destruction during disease progression associated with inflammatory bone diseases.

Protective and destructive immunity in the periodontium: Part 1--innate and humoral immunity and the periodontium.

Based on the results of recent research in the field, the present paper will discuss the protective and destructive aspects of the innate vs. adaptive (humoral and cell-mediated) immunity associated with the bacterial virulent factors or antigenic determinants during periodontal pathogenesis. Attention will be focused on: (i) the Toll-like receptors (TLR), the innate immune repertoire for recognizing the unique molecular patterns of microbial components that trigger innate and adaptive immunity for effective host defenses, in some general non-oral vs. periodontal microbial infections; (ii) T-cell-mediated immunity, Th-cytokines, and osteoclastogenesis in periodontal disease progression; and (iii) some molecular techniques developed and used to identify critical microbial virulence factors or antigens associated with host immunity (using Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis as the model species). Therefore, further understanding of the molecular interactions and mechanisms associated with the host's innate and adaptive immune responses will facilitate the development of new and innovative therapeutics for future periodontal treatments.

Protective and destructive immunity in the periodontium: Part 2--T-cell-mediated immunity in the periodontium.

Based on the results of recent research in the field and Part 1 of this article (in this issue), the present paper will discuss the protective and destructive aspects of the T-cell-mediated adaptive immunity associated with the bacterial virulent factors or antigenic determinants during periodontal pathogenesis. Attention will be focused on: (i) osteoimmunology and periodontal disease; (ii) some molecular techniques developed and applied to identify critical microbial virulence factors or antigens associated with host immunity (with Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis as the model species); and (iii) summarizing the identified virulence factors/antigens associated with periodontal immunity. Thus, further understanding of the molecular mechanisms of the host's T-cell-mediated immune responses and the critical microbial antigens related to disease pathogenesis will facilitate the development of novel therapeutics or protocols for future periodontal treatments.

Functional human T-cell immunity and osteoprotegerin ligand control alveolar bone destruction in periodontal infection.

Periodontitis, a prime cause of tooth loss in humans, is implicated in the increased risk of systemic diseases such as heart failure, stroke, and bacterial pneumonia. The mechanisms by which periodontitis and antibacterial immunity lead to alveolar bone and tooth loss are poorly understood. To study the human immune response to specific periodontal infections, we transplanted human peripheral blood lymphocytes (HuPBLs) from periodontitis patients into NOD/SCID mice. Oral challenge of HuPBL-NOD/SCID mice with Actinobacillus actinomycetemcomitans, a well-known Gram-negative anaerobic microorganism that causes human periodontitis, activates human CD4(+) T cells in the periodontium and triggers local alveolar bone destruction. Human CD4(+) T cells, but not CD8(+) T cells or B cells, are identified as essential mediators of alveolar bone destruction. Stimulation of CD4(+) T cells by A. actinomycetemcomitans induces production of osteoprotegerin ligand (OPG-L), a key modulator of osteoclastogenesis and osteoclast activation. In vivo inhibition of OPG-L function with the decoy receptor OPG diminishes alveolar bone destruction and reduces the number of periodontal osteoclasts after microbial challenge. These data imply that the molecular explanation for alveolar bone destruction observed in periodontal infections is mediated by microorganism-triggered induction of OPG-L expression on CD4(+) T cells and the consequent activation of osteoclasts. Inhibition of OPG-L may thus have therapeutic value to prevent alveolar bone and/or tooth loss in human periodontitis.

The function of TGF-beta-mediated innocent bystander suppression associated with physiological self-tolerance in vivo.

Innocent bystander suppression has been demonstrated in experimental models of transplantation tolerance and oral tolerance. This phenomenon is associated with expression of cytokines such as TGF-beta or/and type II cytokines (e.g., IL-4, IL-10). However, the mechanism responsible for bystander suppression is poorly understood, as is its role in antigen-specific self-tolerance. Here, we describe a series of investigations using an antigen coimmunization strategy to examine the outcome of bystander suppression in vivo in a well-characterized physiological model, using beef insulin transgenic (BI-Tg) mice, for self-tolerance. Our results demonstrate that: (1) T-cell-mediated peripheral hyporesponsiveness, or CD4(+) regulatory type II Th cell-mediated adoptive transfer of peripheral hyporesponsiveness (defined by an ELISA antibody assay), is antigen-specific at induction but effector-nonspecific (bystander suppression) when the self-antigen (BI) and a control antigen (chicken ovalbumin) are coadministered in BI-Tg mice; (2) bystander suppression is manifest as a local and transient, rather than a systemic and long-term, phenomenon; (3) bystander suppression is both time and antigen dose dependent; and (4) anti-TGF-beta Mab abolishes the effect of bystander suppression in vivo. We suggest that TGF-beta-mediated innocent bystander suppression associated with physiological self-tolerance thus produces no major biological consequence for general immune responsiveness. It may prevent the activation of auto(or cross)-reactive lymphocytes.

Multiple levels of regulation for self-tolerance in beef insulin transgenic mice.

To characterize the mechanism(s) of tolerance toward soluble self-antigens (Ags), beef insulin (BI) transgenic (Tg) mice were generated in which the transgene was expressed in pancreatic beta-cells. Our previous data showed that: (i) Ag-specific tolerance can be induced and/or maintained in peripheral T cells in thymectomized BI-Tg mice and (ii) CD4+ Th2 regulatory T cells are involved in maintaining peripheral tolerance (by anti-BI antibody response). In this paper, we have further characterized the relationship of low levels of BI expression (10(-10)-10(-11) M) in Th1/Th2 activation. In addition, we have explored intrathymic events associated with tolerance to self-Ags not expressed in the thymus and/or to circulating self-Ags. Limiting dilution analysis showed that there was a significantly higher frequency of BI-specific Th2 cells in Tg mice with a corresponding higher frequency of Th1 cells in non-Tg mice. While there was no transgene expression in the thymus (by RT-PCR), independent studies showed that BI can be processed and presented in the Tg thymus, which correlated with the Ag-specific hyporesponsiveness of mature thymocyes detected in vitro. High-dose rIL-2 (150 U/ml) was able to restore in vitro peripheral T cell response of Tg mice to levels comparable to those of the non-Tg control. Collectively, our data suggest that: (i) there is a differential activation of BI-specific Th1/Th2 cells in vivo in the presence of low Ag concentration; (ii) the thymus may play a role in self-tolerance to Ags whose expression in adults is restricted to the periphery; and (iii) multiple levels of regulation such as thymic selection, peripheral anergy, and active suppression may be involved in tolerance to BI in BI-Tg mice.

An immunological renal disease in transgenic mice that overexpress Fli-1, a member of the ets family of transcription factor genes.

The proto-oncogene Fli-1 is a member of the ets family of transcription factor genes. Its high expression in the thymus and spleen and the presence of DNA binding sites for Fli-1 in a number of lymphoid cell-specific gene suggest that Fli-1 is involved in the regulation of lymphopoiesis. Activation of the Fli-1 gene by either chromosomal translocation or viral insertion leads to Ewing's sarcoma in humans and erythroleukemia in mice, respectively. Thus, Fli-1 is normally involved in pathways involved in the regulation of cell growth and differentiation. We have generated H-2Kk-Fli-1 transgenic mice that overexpress Fli-1 in various mouse tissues, with the highest levels of Fli-1 protein in the thymus and spleen. These Fli-1 transgenic mice developed a high incidence of a progressive immunological renal disease and ultimately died of renal failure caused by tubulointerstitial nephritis and immune-complex glomerulonephritis. The incidences of renal disease correlated with the levels of Fli-1 protein in lymphoid tissues of transgenic lines. The hypergammaglobulinemia, splenomegaly, B-cell hyperplasia, accumulation of abnormal CD3+ B220+ T lymphoid cells and CD5+ B220+ B cells in peripheral lymphoid tissues, and detection of various autoantibodies in the sera of diseased Fli-1 transgenic mice suggested the involvement of an immune dysfunction in the pathogenesis of the renal disease. In addition, splenic B cells from transgenic mice exhibited increased proliferation and prolonged survival in vitro in response to mitogens. Taken together, these data suggest that overexpression or ectopic expression of Fli-1 perturbs normal lymphoid cell function and programmed cell death. Thus, H-2Kk-Fli-1 transgenic mice may serve as a murine model for autoimmune disease in humans, such as systemic lupus erythematosus.

Evidence for Th2 cell-mediated suppression of antibody responses in transgenic, beef insulin-tolerant mice.

Clonal deletion, anergy and suppression have all been considered mechanisms of immunological tolerance. Although adoptive transfer of immunosuppression has been shown to occur in the periphery, particularly for transplantation tolerance, it has proven difficult to characterize this phenomenon further, due to the lack of suppressor T cell clones. To characterize tolerance towards a physiological soluble antigen, we constructed beef insulin (BI) transgenic (Tg) BALB/c (H-2d) mice, in which the BI transgene is expressed in pancreatic beta cells. These Tg mice were tolerant to BI immunization at the level of both humoral and cell-mediated immune responses. Adoptive transfer of splenocytes from Tg mice into normal syngeneic BALB/c mice demonstrated that the reduction in antibody production is regulated by transferred T cells. The cytokine profile of T cell clones obtained after selection in vitro demonstrated dominant Th1 clones from normal non-Tg mice and dominant Th2 clones from Tg mice. Some Th2 clones (CD4+) from Tg mice produced significant suppression of antibody production after adoptive transfer into normal syngeneic BALB/c mice. These data confirm the existence of Th2 regulatory T cells in vivo in a model of peripheral tolerance to a physiological soluble antigen as a potential mechanism for self tolerance.

Characterization of the insulin A-chain major immunogenic determinant presented by MHC class II I-Ad molecules.

Data are presented which demonstrate the minimal insulin peptide required to activate a large group of insulin-specific T hybrids following presentation by either live or fixed APC, is the N-terminal insulin-A(1-13) peptide. Functional activation and competition assays using both live and fixed APC with 19 synthesized variants of the N-terminal bovine insulin A-chain molecule permitted classification of peptide residues into MHC agretope and T cell epitope regions. Our findings indicate insulin A-chain peptide occupies the Ag binding groove of class II MHC in an extended conformation as a result of intracellular reduction of A-loop disulfide bonds. Insulin A-chain Cys7 and Cys11 residues represent two independent T cell epitopes N- and C-terminal to the A-loop region. Data are presented that demonstrate the unique residues associated with several insulin isoform molecules contribute to the peptide agretope region. Our findings may suggest peptide agretopes may subtly modify the peptide/MHC conformation presented to TCR.

Gingival crevicular fluid gelatinase and its relationship to periodontal disease in human subjects.

Collagenolytic enzymes released by neutrophils are associated with the destruction of periodontium in periodontal diseases. Measurement of these enzymes in gingival crevicular fluid (GCF) could be used to test for periodontal diseases and thereby simplify diagnosis. To test this hypothesis, gelatinase (MMP-9) was analyzed in GCF samples with a simple assay system. GCF was collected by a mouthrinse method from 10 patients with gingivitis (G); 10 well-treated and maintained periodontitis patients (TP) without detectable loss of attachment; and 9 patients with recurrent loss of periodontal attachment (greater than 2 mm) and/or abscess formation (RP). Clinical measurements including tooth mobility (MOB) and gingival attachment level (GAL) were made monthly for a maximum of 10 months. Active and latent forms of gelatinase were measured by a functional assay using gelatin substrate-gel enzymography and the activities were quantified by laser densitometry. Reproducibility analysis demonstrated that the assay (inter-gel, inter-assay, inter-scan) and diurnal variations were small compared to biological variation. The presence of active gelatinase was detected in 97.8% of TP samples, 86.4% of RP samples, but in only 11.4% of G samples. In addition, the mean active gelatinase activity was found to be significantly higher (p less than 0.001) in the RP (71,006 U) than the TP (43,814 U) groups, both of which were higher (p less than 0.001) than the G group (2824 U). During periods of attachment loss, samples from the RP group exhibited a 2-fold increase of mean active gelatinase activity (129,414 U).(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistochemical localization of Leu-M1 carbohydrate antigen in human oral squamous cell carcinoma.

Twenty-six biopsy specimens of oral squamous cell carcinomas were examined by the avidin biotin peroxidase complex (ABC) method for the presence of an epithelial cell membrane bound lacto-N-fucopentaose III, known also as Leu-M1 or Lex antigen. In normal oral epithelium, Leu-M1 antigen was expressed on keratinizing epithelia in the stratum spinosum. In well-differentiated carcinomas the antigen was found on the cell membrane of nucleate cells in infiltrating epithelial islands. Such pattern in moderately well and in poorly differentiated carcinomas was minimally expressed and was associated with flattened squamous cells or otherwise recorded negative. Leu-M1 antigen immunoreactivity in normal oral epithelia and in carcinomas was comparable to that of blood group H-2 chain that were examined. It was concluded that the intensity of the reaction parallels the magnitude of differentiation of epithelia. Leu-M1 antigen can serve as a marker of differentiation in oral squamous epithelium.