Serology and ultrasound for diagnosis of choledocholithiasis

Introduction

Magnetic resonance cholangiopancreatography (MRCP) is not a routine investigation to exclude choledocholithiasis unless there is clinical or biochemical suspicion of common bile duct (CBD) stones. This study attempted to determine which radiological or serological parameters best predicted CBD stones.

Methods

All patients undergoing MRCP from 2005 to 2011 were selected. Patients with pancreatitis were excluded. Liver function tests (LFTs) at admission and prior to MRCP were recorded, as was abdominal ultrasonography and MRCP results. Parameters measured routinely on LFTs included alkaline phosphatase (ALP), alanine transaminase (ALT) and bilirubin. Receiver operating characteristic curve area analysis (area under the curve [AUC]) and chi-squared analysis were undertaken.

Results

Overall, 195 patients were identified, 71 of whom had CBD stones on MRCP. Raised ALP levels on admission demonstrated a correlation with CBD stones (AUC: 0.619, odds ratio [OR]: 3.16, p=0.06). At ultrasonography, a dilated CBD (OR: 3.76, p<0.001) and intrahepatic duct dilation (OR: 5.56, p<0.001) were highly significant predictors. However, only 37% of patients had a dilated CBD on ultrasonography. Ongoing elevation of LFT parameters, particularly ALP (AUC: 0.707, OR: 4.64, p<0.001) and ALT (AUC: 0.646, OR: 5.40, p<0.001), displayed a significant correlation with CBD stones.

Conclusions

Ongoing (even if minor) elevations of liver function test parameters should prompt the need to exclude CBD stones even in the presence of a normal CBD diameter on ultrasonography.     

Thrombin causes subsecond changes in protein phosphorylation of platelets

We have developed a general quenched-flow approach to study platelet function as early as 0.3 seconds after stimulation. Phosphorylation of 20- and 40-kd proteins has been analyzed during the first five seconds of platelet response to thrombin from 0.1 to 5.0 U/mL and compared with the progress of aggregation and serotonin secretion. The onset time for aggregation and phosphorylation of both proteins was less than one second, although with lowest (less than 0.5 U/mL) thrombin levels, a lag of up to 0.6 seconds occurred before 40K phosphorylation increased. The thrombin sensitivity of aggregation and 20K phosphorylation was approximately twice that of 40K phosphorylation, with Ka values of 0.51 and 0.53 v 1.10 U/mL, respectively. External calcium was necessary for maximal 20K phosphorylation, since EDTA inhibited this by 30%. The 40K phosphorylation was not affected by EDTA. Platelet activation by thrombin thus induced biochemical changes well before one second. The quenched-flow approach may help to reveal relationships between phospholipase activation, calcium fluxes, and protein phosphorylation during these early periods of platelet function.     

Diagnostic role of an immunoassay-detected polymorphism of factor IX for potential carriers of hemophilia B

In hemophilia B, assays based on a monoclonal antifactor IX specific for the Thr-148 variant of an exonic polymorphism have diagnosed carriers in selected families by either establishing linkage or by indicating the presence or absence of a given normal factor IX. The sensitivity of the immunoassays for detecting heterozygous women was explored by comparing results from immunoassays with solid-phase polyclonal v the monoclonal antifactor IXs. Factor IX with the normal Ala-148 variant gave a flat dilution curve, qualitatively distinct from factor IX with the Thr-148 variant in the monoclonal assay. The two were indistinguishable in the polyclonal assay. Mixtures of equal amounts of the two types gave an intermediate result, about half as reactive in the monoclonal as compared with the polyclonal assay system. Whereas mixtures with 10% Ala-148 and 90% Thr-148 factor IXs could not readily be distinguished from Thr-148 factor IX plasma, as little as 1% of the Thr-148 protein was detected in Ala-148 factor IX plasma. The frequency of the Ala-148 variant varied in individuals with different ethnic backgrounds; it was found in 29% of white, 12% of black, and none of Asian blood donors' factor IX genes in Seattle. Only 4% of samples from South African black men were nonreactive (ie, Ala- 148). The Thr/Ala-148 dimorphism is in strong linkage disequilibrium with Taql restriction fragment length polymorphisms (RFLPs). Three recombinations were noted in normal white genes and one in a normal black factor IX gene (less than 2% of those examined). In 34 white families with at least one woman being a possible carrier, genetically, the immunoassay results were informative in 18. RFLP analyses were informative in eight of the 15 families tested. In five families each, assignment of carrier status was made to a woman by only DNA or only immunoassay results, whereas the other approach was noninformative. The immunoassays provide a rapid, inexpensive screening test and complement DNA analysis in white women who are potential carriers of hemophilia B.     

Reliability and validity of the German short version of the Activities specific Balance Confidence (ABC-D6) scale in older adults

The Activities specific Balance Confidence (ABC) is a questionnaire which was developed to assess falls-associated self-efficacy. The aim of this study was to evaluate reliability and validity of the German abbreviated 6-item version of the ABC scores in community-dwelling older people. The study sample included 384 subjects (age 71.1 ± 9.7). In order to determine the psychometric properties, reliability and validity were assessed through administration of the German adaptation of the ABC-D16 to participants twice, 10 days apart, and comparison of the ABC-D16 and the ABC-D6 with functional measures of balance and mobility (one-leg stance; 10 m walk; TUG; Fullerton Advanced Balance Scale (FAB)), physical activity (Physical Activity Scale for the Elderly (PASE)), physical fitness (30 s arm curl, 30 s chair stand, 6 min walk), cognition (Trail-Making-Test (TMT)), falls status, and quality of life (SF36). Factor analyses suggested a 1-factor solution for the ABC-D6 scale (explained variance 79.8%). Internal consistency (.95) and test-retest reliability (.98) for the ABC-D6 scores were excellent. Scores on the ABC-D6 were significantly lower than on the ABC-D16, but ABC-D16 and ABC-D6 scores were highly correlated (.94). There was an increasing difference in the ABC-scores between men and women with increasing age. Fallers reported lower balance confidence than non-fallers. The ABC-D6 score significantly correlated with functional measures of balance and mobility, physical activity, physical fitness, cognition, and quality of life (−.698 < r < .720). It was found that the ABC-D6 is a reliable and valid instrument to asses falls-associated self-efficacy and may be used in future research projects and clinical trials.     

Persistence of depression in African American and Caucasian women at midlife: findings from the Study of Women Across the Nation (SWAN)

This study prospectively examined the course of depression in African American and Caucasian midlife women over an 11-year period. Racial differences in lifetime history of depression, severity of depressive symptoms and rates of depressive disorders at baseline, and persistence or recurrence of depression over an 11 year period were examined. Predictors of persistence/recurrence of depression were also examined. The sample was comprised of 423 midlife women enrolled in the Study of Women Across the Nation (SWAN) Mental Health Study (MHS). All participants completed baseline and annual assessments, which included self-reported measures of health, functioning, and psychosocial factors, and clinician administered assessments of psychiatric disorders. Logistic regression analyses were used to examine predictors of depression persistence/recurrence. Findings indicated that African American and Caucasian women did not differ significantly in rates of lifetime and baseline depressive disorders, or severity of depressive symptoms. Annual assessments revealed no significant differences between the groups in rates of persistent/recurrent depression. While African American and Caucasian women do not differ in recurrence of depression at midlife, factors associated with depression differed by race.     

Pin-on-Disc Modelling with Mesh Deformation Using Discrete Element Method

The pin-on-disc test is a standard sliding wear test used to analyse sliding properties, including wear contour and wear volume. In this study, long-term laboratory test performance is compared with a short-term numerical model. A discrete element method (DEM) approach combined with an Archard wear model and a deformable geometry technique is used. The effect of mesh size on wear results is evaluated, and a scaling factor is defined to relate the number of revolutions between the experiment and the numerical model. The simulation results indicate that the mesh size of the disc has a significant effect on the wear contour. The wear depth and wear width follow a normal distribution after experiencing a run-in phase, while the wear volume has a quadratic relation with the number of revolutions. For the studied material combination, the calibration of the wear coefficient shows that the wear volume of the pin-on-disc test accurately matches the simulation results for a minimum of eight revolutions with a wear coefficient lower than 2 × 10⁻¹¹ Pa⁻¹.     

抗血管生成因子Angiostatin与Endostatin作用下肿瘤血管生成的二维数值模拟

目的数值模拟抗血管生成因子Angiostatin和Endostatin对肿瘤血管生成的影响。方法建立肿瘤内外血管生成的二维离散数学模型。模型耦合两种抗血管生成因子Angiostatin和Endostatin的抑制效应,数值模拟在促血管生成因子诱导下肿瘤微血管网生成,讨论血管生成抑制因子的影响。结果抗血管生成因子Angiostatin对肿瘤内外血管网络生成的速度和成熟度有抑制作用。抗血管生成因子Angiostatin和Endostatin耦合作用时,在肿瘤血管生成的早期有明显的抑制效应;在肿瘤血管生成的中后期,它们可以降低肿瘤血管化程度。结论本文模型能够较好的模拟抗血管生成因子Angiostatin和Endostatin对内皮细胞迁移和增殖的抑制作用。     

Gadoxetic acid enhanced MRI for differentiation of FNH and HCA: a single centre experience

Objectives

Evaluation of enhancement characteristics of histopathologically confirmed focal nodular hyperplasias (FNHs) and hepatocellular adenomas (HCAs) with gadoxetic acid-enhanced MRI.

Methods

Sixty-eight patients with 115 histopathologically proven lesions (FNHs, n?=?44; HCAs, n?=?71) examined with gadoxetic acid-enhanced MRI were retrospectively enrolled (standard of reference: surgical resection, n?=?53 patients (lesions: FNHs, n?=?37; HCAs, n?=?53); biopsy, n?=?15 (lesions: FNHs, n?=?7; HCAs, n?=?18)). Two radiologists evaluated all MR images regarding morphological features as well as the vascular and hepatocyte-specific enhancement in consensus.

Results

For the hepatobiliary phase, relative enhancement of the lesions and lesion to liver enhancement were significantly lower for HCAs (mean, 48.7 (±48.4) % and 49.4 (±33.9) %) compared to FNHs (159.3 (±92.5) %; and 151.7 (±79) %; accuracy of 89 % and 90 %, respectively; P?<?0.001). Visual strong uptake of FNHs vs. hypointensity of HCAs in the hepatobiliary phase resulted in an accuracy of 92 %. This parameter was superior to all other morphological and dynamic vascular criteria alone and in combination (accuracy, 54–85 %).

Conclusions

For differentiation of FNHs and HCAs by means of MRI, gadoxetic acid uptake in the hepatobiliary phase was found to be superior to all other criteria alone and in combination.

Key Points

? EOB-MRI is well suited to differentiate FNHs and hepatocellular adenomas. ? For this purpose hepatobiliary phase is superior to unenhanced and dynamic imaging. ? Hepatobiliary phase (peripheral) hyper- or isointensity is typical for FNH. ? Hepatobiliary phase hypointensity is typical for hepatocellular adenomas. ? EOB-MRI helps to avoid misinterpretations of benign hepatocellular lesions.     

Early postpartum hemorrhage after induction of labor

M.M., a 25‐year‐old Hispanic primigravida at 41 weeks and 6 days gestation, presented to the labor and delivery unit for postdates induction of labor, accompanied by the father of the baby. She reported normal fetal movement and denied any loss of fluid or vaginal bleeding. Her prenatal course was uncomplicated. The fetal heart rate was reassuring. Occasional contractions were recorded by the tocometer, but not felt by M.M. A pelvic exam found her cervix to be 1 cm dilated, 80% effaced, soft and posterior, with the vertex at ?2 station with membranes intact. Based on a Bishop score of 7, the decision was made to proceed with induction of labor with intravenous oxytocin per hospital protocol of 1 mU every 15 minutes to a maximum of 5 contractions in 10 minutes lasting no more than 60 to 90 seconds or a maximum dose of 20 mU/min. Three hours after oxytocin was initiated, M.M.'s cervical exam was 2 cm dilated, 80% effaced, with the vertex at ?2 station. The fetal heart rate baseline was 135 beats per minute with moderate variability and no decelerations. Six hours after admission, M.M. requested pain relief. Her cervical exam was 4 cm dilated, 90% effaced, with the vertex at ?1 station. The oxytocin was infusing at 16 mU/min and the fetal heart rate was reassuring. Pain management options were discussed with the client and, after being counseled on the risks and benefits, she opted for epidural anesthesia. Eight hours after admission, M.M.'s uterine contractions became difficult to detect with the external tocometer. At examination, her cervix was found to be 7 cm dilated, 100% effaced, with the vertex at 0 station. The oxytocin was infusing at 20 mU/min. The midwife counseled the client on the need to monitor uterine contractions when receiving oxytocin and the decision was made to rupture M.M's bag of waters and place an intrauterine pressure catheter. M.M.'s membranes were ruptured and it was noted that she had a moderate amount of clear amniotic fluid. The intrauterine pressure catheter was placed without complications and recorded adequate uterine contractions of 230 MvU. Eleven hours after admission, M.M. reported rectal pressure and a desire to push. Her cervix was examined and found to be fully dilated with the vertex at +2 station, and again the fetal heart rate was reassuring. Pushing efforts were commenced. One and a half hours later—12 and half hours after the initiation of induction—M.M. gave birth to a vigorous baby girl weighing 3000 g, with Apgar scores of 9 and 9 at 1 and 5 minutes, respectively. The oxytocin infusion was discontinued immediately after delivery. Twenty‐five minutes later, the placenta was expelled spontaneously and appeared intact. An infusion of 20 units of oxytocin in 1000 cc of lactated ringers was given intravenously at 125 ml/hr. Fundal massage was started immediately after delivery of the placenta, because the uterine fundus was found to be boggy, and vaginal bleeding continued to increase. Bimanual uterine compression was added to control the hypotonic uterine bleeding. The urinary bladder was catheterized, producing 100 ml of urine. Ten units of oxytocin were administered intramuscularly in the thigh, again with poor response. Methylergonovine maleate 0.2 mg was then given intramuscularly. The obstetrician on call was notified of the client's uncontrolled immediate postpartum hemorrhage related to atony. Four minutes after Methergine administration, the fundus was firm and bleeding minimal. Twelve hours after delivery, M.M.'s hemoglobin (Hgb) and hematocrit (Hct) were noted to have decreased 23% from her levels at admission. Her Hgb was 7.8 g/dL, and she had an Hct of 23.9%. Her vital signs remained stable throughout, urine output satisfactory, and the client was able to tolerate walking without assistance.     

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