Dachshund Homolog 1: Unveiling Its Potential Role in Megakaryopoiesis and Bacillus anthracis Lethal Toxin-Induced Thrombocytopenia.

Lethal toxin (LT) is the critical virulence factor of Bacillus anthracis, the causative agent of anthrax. One common symptom observed in patients with anthrax is thrombocytopenia, which has also been observed in mice injected with LT. Our previous study demonstrated that LT induces thrombocytopenia by suppressing megakaryopoiesis, but the precise molecular mechanisms behind this phenomenon remain unknown. In this study, we utilized 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced megakaryocytic differentiation in human erythroleukemia (HEL) cells to identify genes involved in LT-induced megakaryocytic suppression. Through cDNA microarray analysis, we identified Dachshund homolog 1 (DACH1) as a gene that was upregulated upon TPA treatment but downregulated in the presence of TPA and LT, purified from the culture supernatants of B. anthracis. To investigate the function of DACH1 in megakaryocytic differentiation, we employed short hairpin RNA technology to knock down DACH1 expression in HEL cells and assessed its effect on differentiation. Our data revealed that the knockdown of DACH1 expression suppressed megakaryocytic differentiation, particularly in polyploidization. We demonstrated that one mechanism by which B. anthracis LT induces suppression of polyploidization in HEL cells is through the cleavage of MEK1/2. This cleavage results in the downregulation of the ERK signaling pathway, thereby suppressing DACH1 gene expression and inhibiting polyploidization. Additionally, we found that known megakaryopoiesis-related genes, such as FOSB, ZFP36L1, RUNX1, FLI1, AHR, and GFI1B genes may be positively regulated by DACH1. Furthermore, we observed an upregulation of DACH1 during in vitro differentiation of CD34-megakaryocytes and downregulation of DACH1 in patients with thrombocytopenia. In summary, our findings shed light on one of the molecular mechanisms behind LT-induced thrombocytopenia and unveil a previously unknown role for DACH1 in megakaryopoiesis.

Distinguishing between interstitial and angular pregnancies: Is there a role for saline infusion sonohysterography?

OBJECTIVE: Interstitial pregnancy occurs in the intramural segment of the Fallopian tubes, while angular pregnancy is one that is located in one of the lateral angles of the uterine cavity. The differential diagnosis and treatment of these conditions are important. We have used saline infusion sonohysterography (SIS) to help in differential diagnosis. CASE REPORT: A 36-year-old female with a case of suspected left interstitial ectopic pregnancy was admitted. Her diagnostic laparoscopy showed no tubal ectopic pregnancy, and D&C demonstrated no villi. She underwent SIS which showed a sac in the interstitial part but close to the tubal ostium. The second case involves a 21-year-old female who was 9-weeks pregnant. Ultrasonography could not differentiate between interstitial and angular pregnancy. SIS clearly demonstrated angular pregnancy with a missed abortion, and therapeutic D&C was done smoothly. CONCLUSION: From reviewing past literature, SIS does not appear to have any proven adverse effect on the pregnancy although it is not widely accepted. This article highlights the benefits of using SIS to aid in the differential diagnosis between the two conditions, especially in unusual cases like ours.

Suppressive effect of dengue virus envelope protein domain III on megakaryopoiesis.

Dengue virus (DENV) infection can cause severe, life-threatening events, and no specific treatments of DENV infection are currently approved. Although thrombocytopenia is frequently observed in dengue patients, its pathogenesis is still not fully understood. Previous studies have suggested that DENV-induced thrombocytopenia occurs through viral-replication-mediated megakaryopoiesis inhibition in the bone marrow; however, the exact mechanism for megakaryopoiesis suppression remains elusive. In this study, a reductionist approach was applied, in which C57B/6J mice were inoculated with recombinant DENV-envelope protein domain III (DENV-EIII) instead of the full viral particle. Our results demonstrated that DENV-EIII-suppressed megakaryopoiesis is similar to those observed with DENV infection. Furthermore, in agreement with our in vivo analyses, DENV-EIII sufficiently suppressed the megakaryopoiesis of progenitor cells from murine bone marrow and human cord blood in vitro. Additional analyses suggested that autophagy impairment and apoptosis are involved in DENV-EIII-mediated suppression of megakaryopoiesis. These data suggest that, even without viral replication, the binding of DENV-EIII to the cell surface is sufficient to suppress megakaryopoiesis.

Cornual wedge resection for interstitial pregnancy and postoperative outcome.

INTRODUCTION: Traditionally, interstitial pregnancies were treated with cornual resection or hysterectomy via laparotomy. However, increasingly, interstitial pregnancies are treated with laparoscopic cornuotomy, ie, removal of ectopic pregnancy tissue with preservation of uterine architecture. Although this technique may increase the incidence of persistent and recurrent interstitial pregnancy, it can potentially maintain patient fertility and decrease their risk for future uterine rupture. In a case series of patients with interstitial pregnancies treated with cornual wedge resection, we examined fertility outcomes, rates of subsequent uterine rupture, and rates of persistent or recurrent interstitial pregnancy. MATERIALS AND METHODS: We conducted a retrospective medical record review of cases (n = 29) of cornual wedge resection for interstitial pregnancy, performed between 1992 and 2013 at one hospital. RESULTS: Of the 29 cases, two later presented with uterine rupture; one, who also had a prior wedge resection, was found with scar dehiscence during a subsequent caesarean section. The incidence of subsequent uterine rupture and dehiscence was 30%. There were no cases of persistent ectopic pregnancy or recurrent interstitial pregnancy. Most (71.4%) patients who were trying to conceive achieved subsequent pregnancy. DISCUSSION: There is debate regarding the recommended surgical technique to treat interstitial pregnancies; cornual resection and cornuotomy are both important considerations. Choice of the technique employed continues to require careful consideration.

Amniotic Fluid Embolism with Isolated Coagulopathy: A Report of Two Cases.

Amniotic Fluid Embolism (AFE) is a catastrophic complication of pregnancy with high mortality rate. The most common clinical presentation is an abrupt onset of cardiopulmonary collapse. Here, we present an uncommon variant involving isolated disseminated intravascular coagulation that developed without antecedent cardiopulmonary disturbances. Both patients developed symptoms soon after delivery. Blood test was sent at 14 minutes postpartum for the second patient due to suspected amniotic fluid embolism. Fetal components were observed in the uterine veins of the lower uterine segments in both cases. Amniotic fluid embolism with disseminated intravascular coagulopathy typically progresses faster than disseminated intravascular coagulopathy associated with other causes and symptoms. It usually develops within two hours of delivery. Prompt recognition and treatment of this entity is crucial to survival.

Erythropoiesis suppression is associated with anthrax lethal toxin-mediated pathogenic progression.

Anthrax is a disease caused by the bacterium Bacillus anthracis, which results in high mortality in animals and humans. Although some of the mechanisms are already known such as asphyxia, extensive knowledge of molecular pathogenesis of this disease is deficient and remains to be further investigated. Lethal toxin (LT) is a major virulence factor of B. anthracis and a specific inhibitor/protease of mitogen-activated protein kinase kinases (MAPKKs). Anthrax LT causes lethality and induces certain anthrax-like symptoms, such as anemia and hypoxia, in experimental mice. Mitogen-activated protein kinases (MAPKs) are the downstream pathways of MAPKKs, and are important for erythropoiesis. This prompted us to hypothesize that anemia and hypoxia may in part be exacerbated by erythropoietic dysfunction. As revealed by colony-forming cell assays in this study, LT challenges significantly reduced mouse erythroid progenitor cells. In addition, in a proteolytic activity-dependent manner, LT suppressed cell survival and differentiation of cord blood CD34(+)-derived erythroblasts in vitro. Suppression of cell numbers and the percentage of erythroblasts in the bone marrow were detected in LT-challenged C57BL/6J mice. In contrast, erythropoiesis was provoked through treatments of erythropoietin, significantly ameliorating the anemia and reducing the mortality of LT-treated mice. These data suggested that suppressed erythropoiesis is part of the pathophysiology of LT-mediated intoxication. Because specific treatments to overcome LT-mediated pathogenesis are still lacking, these efforts may help the development of effective treatments against anthrax.

Suppressive effects of anthrax lethal toxin on megakaryopoiesis.

Anthrax lethal toxin (LT) is a major virulence factor of Bacillus anthracis. LT challenge suppresses platelet counts and platelet function in mice, however, the mechanism responsible for thrombocytopenia remains unclear. LT inhibits cellular mitogen-activated protein kinases (MAPKs), which are vital pathways responsible for cell survival, differentiation, and maturation. One of the MAPKs, the MEK1/2-extracellular signal-regulated kinase pathway, is particularly important in megakaryopoiesis. This study evaluates the hypothesis that LT may suppress the progenitor cells of platelets, thereby inducing thrombocytopenic responses. Using cord blood-derived CD34(+) cells and mouse bone marrow mononuclear cells to perform in vitro differentiation, this work shows that LT suppresses megakaryopoiesis by reducing the survival of megakaryocytes. Thrombopoietin treatments can reduce thrombocytopenia, megakaryocytic suppression, and the quick onset of lethality in LT-challenged mice. These results suggest that megakaryocytic suppression is one of the mechanisms by which LT induces thrombocytopenia. These findings may provide new insights for developing feasible approaches against anthrax.

Gynecological surgery caused vesicovaginal fistula managed by Latzko operation.

OBJECTIVE: In developed countries, vesicovaginal fistula (VVF) is a rare complication after gynecological surgery. In this report, the Latzko procedure was used to repair VVF to evaluate its safety and efficacy. MATERIALS AND METHODS: Between 1991 and 2009, cases in which VVF developed after various gynecological surgeries and repaired using the Latzko procedure were included. The cause of VVF and outcome after Latzko procedure were reported. The previous published reports regarding Latzko procedure were also listed and compared. The median follow-up period was 8 years. RESULTS: Six cases of VVF were documented in this period. All fistulas were simple type with a fistular size of less than 2cm. In three of six cases, fistulas developed after a hysterectomy for carcinoma in situ of cervix. Of those remaining, one case developed after staging an operation for endometrial adenocarcinoma, while the other two cases occurred after hysterectomy for myoma. Five cases were repaired successfully. One case had postoperative complications such as fever and urinary tract infection. Intraoperative blood loss and hospital stay were minimal. There was no recurrence of VVF postoperatively among successful cases during the follow-up period. CONCLUSION: Adequate exposure of the fistular site is a key point to a successful repair. The Latzko method is a minimal access procedure for VVF repair. This technique may be considered a first-line treatment of VV fistula.

Internal pudendal artery injury during prolapse surgery using nonanchored mesh.

Herein is presented the case of a patient with stage 2 uterine prolapse treated surgically using nonanchored mesh. Complications were internal pudendal artery injury and a massive presacral hematoma that formed after surgery. Transcatheter arterial embolization was performed immediately, and the bleeding stopped. The patient subsequently experienced difficulty micturating and defecating because of presacral hematoma compression. Self-micturation and defecation capabilities were regained gradually at approximately 1 week after surgery. The hematoma resolved completely by 71 days postoperatively. Comprehensive knowledge of pelvic anatomy is important when performing surgery to treat prolapse using mesh kits. Removing the mesh and prophylactic antibiotic therapy is a means of conservatively managing a pelvic hematoma caused by prolapse surgery.

Repair of uterine rupture in twin gestation after laparoscopic cornual resection.

Spontaneous uterine rupture in the course of pregnancy is a rare event that usually occurs in a scarred uterus. The event occurs mostly during the intrapartum period and is potentially catastrophic for both mother and fetus. We report a case of 2-cm cornual rupture in a pregnant woman at 13 weeks twin gestation with previous history of cornual pregnancy successfully managed via laparoscopy. Sudden onset of abdominal pain and vaginal bleeding was noted first. Physical examination revealed stable vital signs, lower abdominal tenderness, and mild rebounding pain. Pelvic ultrasonography revealed twin pregnancy at 13 weeks with extrauterine saccular structure 6 cm in diameter located on the left fundus and contiguous with an intrauterine oligohydramnics twin. Exploratory laparotomy was promptly performed, and a small rupture about 2 cm in diameter was observed on the upper portion of the left fundus, the site of a previous laparoscopic cornual resection scar. A protruding amniotic sac of about 6 cm diameter and containing some part of the umbilical cord was seen. The uterine rupture site was repaired directly after aspiration of amniotic fluid from the protruding sac. After surgery, the patient received antibiotics, 17-OH-progesterone for potential rupture of membranes and prematurity. Tocolysis with Ritodrine for irregular uterine contractions was given at 22 weeks gestation. Steroids were given at 24 weeks gestation. The pregnancy ended with a successful delivery by cesarean section because of uncontrollable uterine contractions at 30 5/7 weeks gestation. In conclusion, although termination of pregnancy would normally be recommended when uterine rupture occurs, a different approach to management may now be accepted.