Testicular Rupture: A Tough Nut to Crack.

Blunt scrotal injury represents a diagnostic dilemma for emergency physicians (EP). Consequently, point-of-care ultrasound (POCUS) has emerged as a tool for early investigation of the acute scrotum in the emergency department. We describe a case where an EP used scrotal POCUS to immediately visualize the loss of testicular contour and underlying heterogeneous parenchyma to rapidly make the diagnosis of testicular rupture in a young male presenting with scrotal trauma. The use of POCUS in this case expedited therapy, likely improving the patient's outcome. To our knowledge, this is the first detailed description of testicular rupture diagnosed with POCUS by an EP.

A critical role for CCR2/MCP-1 interactions in the development of idiopathic pneumonia syndrome after allogeneic bone marrow transplantation.

Idiopathic pneumonia syndrome (IPS) is a major complication after allogeneic bone marrow transplantation (allo-BMT) and involves the infiltration of donor leukocytes and the secretion of inflammatory cytokines. We hypothesized that leukocyte recruitment during IPS is dependent in part upon interactions between chemokine receptor 2 (CCR2) and its primary ligand monocyte chemoattractant protein-1 (MCP-1). To test this hypothesis, IPS was induced in a lethally irradiated parent --> F1 mouse BMT model. Compared with syngeneic controls, pulmonary expression of MCP-1 and CCR2 mRNA was significantly increased after allo-BMT. Transplantation of CCR2-deficient (CCR2-/-) donor cells resulted in a significant reduction in IPS severity compared with transplantation of wild-type (CCR2+/+) cells and in reduced bronchoalveolar lavage (BAL) fluid cellularity and BAL fluid levels of tumor necrosis factor-alpha (TNF-alpha) and soluble p55 TNF receptor (sTNFRI). In addition, neutralization of MCP-1 resulted in significantly decreased lung injury compared with control-treated allogeneic recipients. Experimental data correlated with preliminary clinical findings; patients with IPS have elevated levels of MCP-1 in the BAL fluid at the time of diagnosis. Collectively, these data demonstrate that CCR2/MCP-1 interactions significantly contribute to the development of experimental IPS and suggest that interventions blocking these receptor-ligand interactions may represent novel strategies to prevent or treat this lethal complication after allo-BMT.

Role of CXCR3-induced donor T-cell migration in acute GVHD.

OBJECTIVE: The chemokine receptor CXCR3 has an important role in the migration of effector T cells. To investigate the role of CXCR3 on donor cells in acute graft vs host disease (GVHD) we used a well-defined experimental bone marrow transplantation (BMT) model where acute GVHD is mediated by donor CD8(+) T cells against minor histocompatibility antigens. METHODS; Lethally irradiated C3H.SW recipients were transplanted from either wild-type B6 or CXCR3(-/-) B6 donors. Donor T-cell expansion was analyzed in the spleen and small intestine of recipients by FACS. Donor T-cell function was analyzed by cytokine secretion. The severity of acute GVHD was assessed by histopathological analysis of intestine and liver, GVHD clinical scores, and survival after BMT. RESULTS: Significantly higher numbers of donor CD8(+) CXCR3(-/-) T cells were found in the spleen on days +7 and +14 compared to donor wild-type T cells. By contrast, the number of CD8(+) T cells in the small bowel of BMT recipients from CXCR3(-/-) donors was sevenfold lower than from wild-type donors. Systemic concentrations of INF-gamma and TNF-alpha were equivalent between groups. Animals that received CXCR3(-/-) donor T cells demonstrated diminished GI tract and liver damage and showed improved survival after BMT compared to recipients of wild-type donor cells (43% vs 0%, p<0.001). CONCLUSION: The migration of donor CD8(+) T cells to GVHD target organs such as the intestine depends on the expression of CXCR3 and contributes significantly to GVHD damage and overall mortality.

Early changes in gene expression profiles of hepatic GVHD uncovered by oligonucleotide microarrays.

The liver, skin, and gastrointestinal tract are major target organs of acute graft-versus-host disease (GVHD), the major complication of allogeneic bone marrow transplantation (BMT). In order to gain a better understanding of acute GVHD in the liver, we compared the gene expression profiles of livers after experimental allogeneic and syngeneic BMT using oligonucleotide microarray. At 35 days after allogeneic BMT when hepatic GVHD was histologically evident, genes related to cellular effectors and acute-phase proteins were up-regulated, whereas genes largely related to metabolism and endocrine function were down-regulated. At day 7 after BMT before the development of histologic changes in the liver, interferon gamma (IFN-gamma)-inducible genes, major histocompatibility (MHC) class II molecules, and genes related to leukocyte trafficking had been up-regulated. Immunohistochemistry demonstrated that expression of IFN-gamma protein itself was increased in the spleen but not in hepatic tissue. These results suggest that the increased expression of genes associated with the attraction and activation of donor T cells induced by IFN-gamma early after BMT is important in the initiation of hepatic GVHD in this model and provide new potential molecular targets for early detection and intervention of acute GVHD.

Pretreatment of donors with interleukin-18 attenuates acute graft-versus-host disease via STAT6 and preserves graft-versus-leukemia effects.

Interleukin-18 (IL-18) is a unique cytokine that modulates both T(H)1/T(H)2 responses, but its ability to modulate diseases through induction of T(H)2 cytokines is unclear. It has been shown to play an important role in allogeneic bone marrow transplantation (BMT). Because immune responses of allogeneic BM donors may affect acute graft-versus-host disease (GVHD), we investigated the effect of pretreating BM transplant donors with IL-18 on the severity of acute GVHD using a well-characterized experimental BMT model (BALB/c-->B6). Pretreatment of allogeneic BM transplant donors with IL-18 significantly improved survival (80% vs 0%; P <.001), and reduced clinical, biochemical, and pathologic indices of acute GVHD in BM transplant recipients. IL-18 pretreatment was associated with reduced interferon gamma (IFN-gamma) and greater IL-4 secretion by donor T cells after BMT. Acute GVHD mortality was reduced when IL-18 was administered to donors deficient in IFN-gamma and signal transducer and activator of transcription 4 (STAT4) but not STAT6 signaling molecules, suggesting a critical role for STAT6 signaling in IL-18's protective effect. IL-18 treatment did not alter donor CD8(+) cytotoxic T-lymphocyte (CTL) activity and preserved graft-versus-leukemia (GVL) effects after allogeneic BMT (70% vs 10%; P <.01). Together these data illustrate that pretreatment of donors with IL-18 prior to allogeneic BMT attenuates acute GVHD in a STAT6-dependent mechanism while preserving GVL effects.

Role of toll-like receptors in changes in gene expression and NF-kappa B activation in mouse hepatocytes stimulated with lipopolysaccharide.

The liver is an important site of host-microbe interaction. Although hepatocytes have been reported to be responsive to lipopolysaccharide (LPS), the global gene expression changes by LPS and mechanism(s) by which LPS stimulates cultured hepatocytes remain uncertain. Cultures of primary mouse hepatocytes were incubated with LPS to assess its effects on the global gene expression, hepatic transcription factors, and mitogen-activated protein (MAP) kinase activation. DNA microarray analysis indicated that LPS modulates the selective expression of more than 80 genes and expressed sequence tags. We have shown previously that hepatocytes express CD14, which is required both for uptake and responsiveness to LPS. In other cells, responsiveness to microbial products requires expression of Toll-like receptors (TLR) and their associated accessory molecules. Hepatocytes expressed TLR1 through TLR9 as well as MyD88 and MD-2 transcripts, as shown by reverse transcriptase PCR analysis, indicating that hepatocytes express all known microbe recognition molecules. The MAP kinase extracellular signal-regulated kinase 1/2 was phosphorylated in response to LPS in mouse hepatocytes, and the levels of phosphorylation were lower in hepatocytes from TLR4-null mice. NF-kappa B activation was reduced in TLR4-mutant or -null hepatocytes compared to control hepatocytes, and this defect was partially restored by adenoviral transduction of mouse TLR4. Thus, hepatocytes respond to nanogram concentrations of LPS through a TLR4 response pathway.