Activation of coagulation in amniotic fluid during normal human pregnancy

Introduction

Amniotic fluid (AF) is an important medium for fetal development which exhibits high procoagulant activities; however, the role of these procoagulants during pregnancy has not been elucidated and might be associated with pregnancy complications. The current study aimed to evaluate factor X (FX) activation and its association with tissue factor (TF), tissue factor pathway inhibitor (TFPI) and coagulation activation markers in AF during normal human pregnancy.

Methods

Activation of FX and concentration of TF, free TFPI, D-dimer and prothrombin fragments (F1 + 2) were evaluated in AF samples obtained for chromosome analysis from 91 women with normal pregnancy: 65 samples were taken from patients at 16-20 weeks of gestation, 9 samples were drawn at 21-30 weeks and 17 samples−after 30 weeks of gestation.

Results

Activation of FX in AF significantly increased during normal pregnancy (from 65 ± 41 to 205 ± 80 equivalent RVV ng/mg total protein, P < 0.0001). TF and TFPI levels in AF also rose with gestational age. In contrast, the AF concentration of D-dimer and F1 + 2, markers of coagulation activation significantly decreased when expressed per mg total protein. Levels of free TFPI correlated with TF (r = 0.5, P < 0.001), and were 8-fold higher than those of TF during pregnancy.

Conclusion

High levels of TFPI might be associated with the inhibition of procoagulant activity in amniotic fluid during normal pregnancy, which may account for the rarity of clinical amniotic fluid embolism.     

Sural nerve grafting in robotic laparoscopic radical prostatectomy: interim report

BACKGROUND AND PURPOSE: Sural nerve grafting for patients undergoing prostatectomy has been previously reported using open and minimally invasive methods. We report our experience with sural nerve grafting during robot-assisted laparoscopic radical prostatectomy (RLRP). MATERIALS AND METHODS: Patients with preoperative potency and a minimum of 6 months follow-up were included in this prospective review. A total of 333 patients were identified between February 2003 and January 2006 who met these criteria including 22 of the 25 patients who underwent sural nerve grafting. Patients were divided into 5 groups to compare unilateral and bilateral sural nerve cohorts with non-nerve-sparing and unilateral and bilateral nerve-sparing groups. Patients were followed prospectively using health-related quality-of-life questionnaires. RESULTS: Twenty-two patients underwent sural nerve grafting that included three bilateral grafts. Mean follow-up was 14 months. There was no statistical difference in patients' ages, body mass index, preoperative prostate-specific antigen level, blood loss, complications, and positive margin rate. Operative time was statistically longer for both sural graft cohorts when compared with unilateral (without graft) and bilateral nerve sparing cohorts. No significant differences in subjective or objective sexual function, sexual bother, or urinary function were seen with 6 and 12 months follow-up, possibly related to smaller sural cohorts. Graft-related complications include leg pain in one patient. CONCLUSION: Sural nerve grafting during RLRP is technically feasible and safe and offers improved dexterity and visualization deep within the pelvis. However, a larger randomized cohort of patients will be required to validate any improved benefits afforded by the robot system.     

Embolization of renal-artery pseudoaneurysm after laparoscopic partial nephrectomy for angiomyolipoma: case report and literature review

BACKGROUND: Renal-artery pseudoaneurysm (RAP) is a well-described complication of trauma or percutaneous urologic procedures. Delayed bleeding from an RAP is rare after partial nephrectomy. CASE REPORT: We present a 49-year-old woman who, 24 days after undergoing a laparoscopic right partial nephrectomy for a mesophytic 2.5-cm tumor, developed gross hematuria. Prompt CT imaging, followed by therapeutic angio-embolization of a third-order segmental renal artery with coils, treated the pseudoaneurysm successfully. CONCLUSIONS: Renal-artery pseudoaneurysm is a rare, potentially life-threatening, condition that often is difficult to diagnose and requires a high index of clinical suspicion. Early use of selective angio-embolization minimizes morbidity and maximizes renal conservation. The etiology, diagnosis, and management are discussed.     

In-vitro gliding resistance of Lapra-Ty clip on polypropylene and glycolide sutures

BACKGROUND AND PURPOSE: The LapraTy clip (LTc) is a useful tool for supplementing knot-tying during reconstructive laparoscopic surgery. However, data regarding its safety and efficacy are scarce. We critically assessed the in-vitro performance of the LTc over different sizes of two suture materials commonly used during reconstructive procedures. MATERIALS AND METHODS: The gliding resistance (GR) of one or two LTcs was tested on various sizes of both Polysorb and Prolene sutures. The GR of each suture was then compared with its breaking strength. Forces were measured using a Vernier Force Sensor. RESULTS: The GR of one LTc was significantly lower than the breaking strength of all Polysorb and Prolene suture sizes with the exception of 7-0 Prolene, with which the suture broke before the LTc slipped off. When two LTcs were placed sequentially, the GR increased significantly compared with a single LTc and was equal to or greater than the breaking strength for Polysorb 3-0 to 5-0 and Prolene 3-0 to 6-0. The percentage of GR over breaking strength was inversely related to suture size and was significantly greater with Prolene than with the Polysorb suture of the same size. CONCLUSIONS: Our results provide a better understanding of the resistive force an LTc offers before slipping and therefore failing. The results observed with Prolene sutures are encouraging and must be further investigated in an animal study to confirm the safety of the LTc when used during reconstructive procedures.     

Insulin and leptin induce Glut4 plasma membrane translocation and glucose uptake in a human neuronal cell line by a phosphatidylinositol 3-kinase- dependent mechanism

The insulin-sensitive glucose transporter Glut4 is expressed in brain areas that regulate energy homeostasis and body adiposity. In contrast with peripheral tissues, however, the impact of insulin on Glut4 plasma membrane (PM) translocation in neurons is not known. In this study, we examined the role of two anorexic hormones (leptin and insulin) on Glut4 translocation in a human neuronal cell line that express endogenous insulin and leptin receptors. We show that insulin and leptin both induce Glut4 translocation to the PM of neuronal cells and activate glucose uptake. Wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase, totally abolished insulin- and leptin-dependent Glut4 translocation and stimulation of glucose uptake. Thus, Glut4 translocation is a phosphatidylinositol 3-kinase-dependent mechanism in neuronal cells. Next, we investigated the impact of chronic insulin and leptin treatments on Glut4 expression and translocation. Chronic exposure of neuronal cells to insulin or leptin down-regulates Glut4 proteins and mRNA levels and abolishes the acute stimulation of glucose uptake in response to acute insulin or leptin. In addition, chronic treatment with either insulin or leptin impaired Glut4 translocation. A cross-desensitization between insulin and leptin was apparent, where exposure to insulin affects leptin-dependent Glut4 translocation and vice versa. This cross-desensitization could be attributed to the increase in suppressor of cytokine signaling-3 expression, which was demonstrated in response to each hormone. These results provide evidence to suggest that Glut4 translocation to neuronal PM is regulated by both insulin and leptin signaling pathways. These pathways might contribute to an in vivo glucoregulatory reflex involving a neuronal network and to the anorectic effect of insulin and leptin.     

Isolated Cardiac Sarcoidosis: Establishing the Diagnosis With Electroanatomic Mapping-Guided Endomyocardial Biopsy

Diagnosing isolated cardiac sarcoidosis can be challenging, and requires a high index of suspicion. We report a case of a young woman who presented with sustained ventricular tachycardia, intermittent atrioventricular block and epsilon wave on electrocardiogram. Although the patient fulfilled Task Force criteria for arrhythmogenic right ventricular cardiomyopathy, sarcoidosis was suspected because of the presence of intermittent atrioventricular block. As illustrated in this report, the use of electroanatomic mapping-guided endomyocardial biopsy can be decisive in achieving the diagnosis and is a valuable approach in cases of suspected isolated cardiac sarcoidosis.     

Mechanism of ruminant placental lactogen action: molecular and in vivo studies

Ruminant placental lactogens (PLs) are structurally related to prolactins (PRLs) and growth hormones (GHs) and are secreted by placentae. Ruminant PLs are unusual in their capacity to bind and activate PRL and GH receptors (Rs) from other species. The present minireview summarizes several works showing that unlike in heterologous species (rat, rabbit, human), in homologous (ruminant) species, PLs act by activating PRLRs or by heterodimerizing GHRs and PRLRs, and suggests that this may be the main mechanism of PL action in vivo. Mutations impairing the ability of ovine (o)PL or bovine (b)PL to form complexes with PRLRs (but not with GHRs) do not cause loss of biological activity, because the transient existence of the homodimeric complex is still sufficient to initiate the signal transduction; however, mutants do lose their ability to activate homologous PRLRs. To explain this difference, we proposed a novel term-minimal time of homodimer persistence-which assumes that to initiate the signal transduction, a "minimal time" of homodimer existence is required for transphosphorylation of associated JAK2s. In interactions between ruminant PLs and homologous PRLRs, this minimal time is met through the interaction with homologous PRLRs, which has a shorter half-life than with heterologous PRLRs. Thus oPL or bPL are active in cells possessing both homologous and heterologous PRLRs. Mutations of PLs decrease the affinity, shortening the "time of homodimer persistence." In heterologous interactions, the minimal time is still sufficient to initiate the biological activity, whereas in homologous interactions, which in any case are weaker, further destabilization of the complex shortens its persistence below the minimal time, causing loss of biological activity.     

Uterus and ovaries in girls and young women with Turner syndrome evaluated by ultrasound and magnetic resonance imaging

Objective To determine uterine and ovarian size in Turner syndrome (TS) and to compare uterine and ovarian size evaluated by transabdominal ultrasound (US) and magnetic resonance imaging (MRI) in girls with TS and two groups of controls. Design A cross‐sectional study. Patients Forty‐one girls with TS (17·0 ± 3·3 years, range 11·2–24·9 years), 50 healthy age‐matched controls (16·9 ± 3·2 years, range 12·5–25·0 years) and 107 Tanner‐stage‐matched controls (15·0 ± 3·2 years, range 10·1–24·2). Measurements Uterine and ovarian volume by US and MRI. Results Ovaries were detected in 37% in TS by US and in 55% in TS by MRI (P = 0·1). Total ovarian volume was lower in TS compared to both groups of controls (TS vs C‐US: median 1·1 ml (range 0·1–29·3) vs 11·52 ml (1·9–77·9), P = 0·001, TS vs C‐MRI: 1·0 ml (0·1–34·2) vs 13·2 ml (2·4–30·1), P < 0·0005). Mean difference in total ovarian volume measured by MRI and US in patients with TS was 2·3 ± 3·8 ml (P = 0·01). Mean uterine volume by MRI was lower in TS compared to controls (29·5 ± 25·1 vs 54·3 ± 23·3 ml, P < 0·0005). Uterine volume by US was lower in TS at Tanner stage B5 compared to controls (TS vs C: 33·6 ± 18·2 vs 50·2 ± 18·0 ml, P = 0·007). Conclusions A larger ovarian volume was detected by MRI in TS compared to US. This finding is important with the advancements of performing ovarian biopsies for cryopreservation and later reimplantation. Mean uterine volumes by MRI and US in fully matured TS were lower compared to controls despite appropriate hormonal replacement therapy in TS.