Searching for the best model: ambiguity of inverse solutions and application to fetal magnetoencephalography

Fetal brain signals produce weak magnetic fields at the maternal abdominal surface. In the presence of much stronger interference these weak fetal fields are often nearly indistinguishable from noise. Our initial objective was to validate these weak fetal brain fields by demonstrating that they agree with the electromagnetic model of the fetal brain. The fetal brain model is often not known and we have attempted to fit the data to not only the brain source position, orientation and magnitude, but also to the brain model position. Simulation tests of this extended model search on fetal MEG recordings using dipole fit and beamformers revealed a region of ambiguity. The region of ambiguity consists of a family of models which are not distinguishable in the presence of noise, and which exhibit large and comparable SNR when beamformers are used. Unlike the uncertainty of a dipole fit with known model plus noise, this extended ambiguity region yields nearly identical forward solutions, and is only weakly dependent on noise. The ambiguity region is located in a plane defined by the source position, orientation, and the true model centre, and will have a diameter approximately 0.67 of the modelled fetal head diameter. Existence of the ambiguity region allows us to only state that the fetal brain fields do not contradict the electromagnetic model; we can associate them with a family of models belonging to the ambiguity region, but not with any specific model. In addition to providing a level of confidence in the fetal brain signals, the ambiguity region knowledge in combination with beamformers allows detection of undistorted temporal waveforms with improved signal-to-noise ratio, even though the source position cannot be uniquely determined.     

The CRF-1 receptor antagonist, CP-154,526, attenuates stress-induced increases in ethanol consumption by BALB/cJ mice

Background: Corticotropin‐releasing factor (CRF) signaling modulates neurobiological responses to stress and ethanol, and may modulate observed increases in ethanol consumption following exposure to stressful events. The current experiment was conducted to further characterize the role of CRF₁ receptor (CRF₁R) signaling in stress‐induced increases in ethanol consumption in BALB/cJ and C57BL/6N mice. Methods: Male BALB/cJ and C57BL/6N mice were given continuous access to 8% (v/v) ethanol and water for the duration of the experiment. When a baseline of ethanol consumption was established, animals were exposed to 5 minutes of forced swim stress on each of 5 consecutive days. Thirty minutes before each forced swim session, animals were given an intraperitoneal injection of a 10 mg/kg dose of CP‐154,526, a selective CRF₁R antagonist, or an equal volume of vehicle. The effect of forced swim stress exposure on consumption of a 1% (w/v) sucrose solution was also investigated in an ethanol‐naïve group of BALB/cJ mice. Results: Exposure to forced swim stress significantly increased ethanol consumption by the BALB/cJ, but not of the C57BL/6N, mice. Stress‐induced increases in ethanol consumption were delayed and became evident approximately 3 weeks after the first stressor. Additionally, forced swim stress did not cause increases of food or water intake and did not promote delayed increases of sucrose consumption. Importantly, BALB/cJ mice pretreated with the CRF₁R antagonist showed blunted stress‐induced increases in ethanol intake, and the CRF₁R antagonist did not influence the ethanol drinking of non‐stressed mice. Conclusions: The present results provide evidence that CRF₁R signaling modulates the delayed increase of ethanol consumption stemming from repeated exposure to a stressful event in BALB/cJ mice.     

Assessing persistent pain and its relation to affective distress, depressive symptoms, and pain catastrophizing in patients with chronic wounds: a pilot study

OBJECTIVE: The purpose of this study was to examine pain experience among patients with chronic wounds, assess the utility of pain assessment scales for chronic wound-related pain, and determine the relation of wound-related pain to wound stage, affective distress, depressive symptoms, and pain catastrophizing. DESIGN: In this cross-sectional study of patients with a mix of chronic wounds (n = 69) recruited for a study evaluating a telemedicine system for assessing chronic wounds, 19 men (12 with spinal cord injury) with wound-related pain were identified. Questionnaires included the Numerical Pain Rating Scale, McGill Pain Questionnaire, Brief Symptom Inventory, Center for Epidemiologic Studies Depression Scale, and the catastrophizing scale of the Coping Strategies Questionnaire. RESULTS: The McGill Pain Questionnaire was more sensitive to pain experience than a single rating of pain intensity. Wound stage was positively related to severity of pain. Pain catastrophizing was positively related to pain intensity and higher levels of affective distress and depressive symptoms. CONCLUSIONS: Pain associated with chronic wounds is a significant clinical challenge for both patients and health practitioners.     

Anti-i causing acute hemolysis following a negative immediate-spin crossmatch

A unique case of acute hemolysis following transfusion of red cells (RBCs) that were found compatible by immediate-spin (IS) crossmatch technique is reported. Screening tests for unexpected antibodies, using low-ionic-strength saline (LISS), 10 minutes' incubation at 37 degrees C, and anti-IgG, were nonreactive; however, 1 transfused unit was found crossmatch incompatible by indirect antiglobulin technique (IAT). An anti-i (titer 512 at 4 degrees C) that was not an autoantibody was identified in the patient's serum. Unlike the incriminated donor RBCs, most I+ RBCs did not react by LISS-IAT. Variable reactivity was seen with ficin-treated I+ RBCs, and there was marked hemolysis of iadult and icord RBCs. In marked contrast, dominant Lu(a-b-) RBCs, with reduced expression of i, did not react by any test method; nor did autologous I+, Lu(b+) RBCs. The in vivo clinical significance of this anti-i was confirmed by monocyte monolayer assay and RBC survival studies. The patient's i antigen may have been altered, by either chemotherapy or disease, and lacked part of the i antigen-mosaic. Her antibody was directed at epitopes of i that were absent from her RBCs. Those i epitopes missing from her RBCs are also absent on dominant Lu(a-b-) RBCs. This anti-i represents a unique cause of an acute hemolytic transfusion reaction. It also represents a case of acute immune-mediated hemolysis following transfusion of IS crossmatch-compatible blood when screening tests for unexpected antibodies are nonreactive. Because of the rarity of such cases (less than 1/200,000 RBC units transfused), modifications to pretransfusion testing protocols are not proposed.     

睾丸支持细胞对异基因T淋巴细胞的毒性作用

目的:分析睾丸支持细胞(塞尔托利氏细胞)对异基因T淋巴的细胞毒性作用。方法:实验于2006-01/07在解放军广州军区武汉总医院实验科完成。睾丸支持细胞取材于二三周龄SPF级Wistar雄性大鼠,由湖北省实验动物中心提供(许可证号:SCXK(鄂)-2003-005)。T淋巴细胞取材于体质量为200-250g的SPF级SD雄性大鼠脾脏,由湖北省实验动物中心提供(许可证号:SCXK(鄂)-2003-005)。将Wistar大鼠睾丸支持细胞与异基因SD大鼠T淋巴细胞共同培养。按睾丸支持细胞含量将实验分6组:对照组(0个睾丸支持细胞 DMEM/F12培养基100μL)、睾丸支持细胞1×103组(100μL)、睾丸支持细胞1×104组(100μL)、睾丸支持细胞1×105组(100μL)、睾丸支持细胞1×106组(100μL)及FasL单抗处理的睾丸支持细胞1×106组(经0.2μg抗FasL单克隆抗体封闭过的睾丸支持细胞1×106,100μL),每组均加1×105T淋巴细胞,6复孔培养48h,应用噻唑蓝比色法测定睾丸支持细胞对T淋巴细胞的毒性作用,用酶标仪于570nm处测各孔吸光度(A值),细胞毒性百分比(%)=(对照组A值-试验孔A值)/对照组A值×100%。结果:睾丸支持细胞1×103组、睾丸支持细胞1×104组、睾丸支持细胞1×105组及睾丸支持细胞1×106组对T淋巴细胞的细胞毒性百分比显著高于对照组、FasL单抗处理的睾丸支持细胞1×106组(8.75%,20.37%,65.07%,62.96%;0,3.85%,P<0.01);睾丸支持细胞1×103组-睾丸支持细胞1×105组随睾丸支持细胞数量增加,对T淋巴细胞的毒性作用也明显增加,当睾丸支持细胞数增加至1×105,杀伤作用的增加不再显著。FasL单抗处理的睾丸支持细胞1×106组与对照组相比差异无显著性意义(P>0.05)。结论:睾丸支持细胞对异基因T淋巴细胞有明显毒性作用,随着睾丸支持细胞增加,对异基因T淋巴细胞的抑制和杀伤作用也越大;但是当睾丸支持细胞达到一定数量后,其毒性作用不再增加;这种作用也可以被抗FasL单克隆抗体阻断。表明睾丸支持细胞FasL的表达是发挥免疫豁免作用的主要作用途径。     

Immunization recall: effectiveness and barriers to success in an urban teaching clinic.

OBJECTIVE: To examine effectiveness of immunization recall in an urban pediatric teaching clinic and to identify barriers to recall effectiveness. DESIGN: Randomized, controlled trial. Children aged 5 to 17 months who were not up to date (UTD) with recommended immunizations were identified and assigned to intervention (n = 294) or control groups (n = 309). The intervention consisted of a mailed postcard and up to 4 telephone calls. Two months after intervention, UTD status, visit, and probable missed opportunity rates were assessed. RESULTS: Of the intervention group, 30% could not be reached. In 12-month-old children in the intervention group compared with those in the control group, there was a trend toward higher UTD rates (51% vs 39%, P =.07) and a higher proportion of UTD children receiving immunizations as opposed to getting more complete documentation (25% vs 10%, P =.005). Similar differences between intervention and control children were not seen in the 7-month and 19-month age categories. More children in the intervention group had a health maintenance visit (17% vs 11%, P =.03). Of children in the intervention group who were seen when not UTD, 17 of 24 (71%) of those seen for an illness visit and 5 of 24 (21%) of those seen for health maintenance probably had missed opportunities to be immunized. CONCLUSIONS: Recall efforts were partially successful but were undermined by inability to reach the clinic population, poor documentation of immunizations, and missed opportunities.     

Characterization of a new myeloid leukemia cell line with normal cytogenetics (CG-SH)

A new myeloid leukemia cell line (CG-SH) with normal cytogenetics was established from a patient with acute myelogenous leukemia (AML) following myelodysplastic syndrome (MDS). The cells of CG-SH are immature blasts and have an immature myeloid phenotype (positive for myeloperoxidase, CD7, CD34, CD38, CD117, HLA-DR, negative for CD10, CD19, CD20, CD41, CD42). A partial expression of CD13, CD15, CD65 and a weak expression of CD33 and CD133 was noted. The cells are negative for EBER. By molecular analysis, a mutation of NRAS and heterozygous mutations of RUNX1 were detected. No mutations were detected in FLT3-ITD, MLL-PTD or NPM1. By real-time PCR, a series of 19 microRNAs was identified which are strongly expressed in CG-SH. In conclusion, a new cell line was established which will be useful for the study of AML with normal cytogenetics and mutations in NRAS and/or RUNX1.     

Alternative splicing and the progesterone receptor in breast cancer

Progesterone receptor status is a marker for hormone responsiveness and disease prognosis in breast cancer. Progesterone receptor negative tumours have generally been shown to have a poorer prognosis than progesterone receptor positive tumours. The observed loss of progesterone receptor could be through a range of mechanisms, including the generation of alternatively spliced progesterone receptor variants that are not detectable by current screening methods. Many progesterone receptor mRNA variants have been described with deletions of various whole, multiple or partial exons that encode differing protein functional domains. These variants may alter the progestin responsiveness of a tissue and contribute to the abnormal growth associated with breast cancer. Absence of specific functional domains from these spliced variants may also make them undetectable or indistinguishable from full length progesterone receptor by conventional antibodies. A comprehensive investigation into the expression profile and activity of progesterone receptor spliced variants in breast cancer is required to advance our understanding of tumour hormone receptor status. This, in turn, may aid the development of new biomarkers of disease prognosis and improve adjuvant treatment decisions.     

Cost of care using prophylactic negative pressure wound vacuum on closed laparotomy incisions

Objective

We wished to determine the reduction in the rate of wound complications that would render the use of prophylactic negative pressure wound vacuum therapy (NPWT) cost saving compared to routine incision care (RC) following laparotomy for gynecologic malignancy.

Methods

A decision tree was designed from a payer perspective to compare strategies for incision management following laparotomy for gynecologic malignancy: (1) RC; (2) prophylactic NPWT. Rates of wound complication, antibiotic use, re-hospitalization, re-operation, and home health use were obtained from a published cohort of 431 women who underwent laparotomy for endometrial cancer 2002–2007. Costs were estimated using Medicare reimbursements; cost of NPWT ($200) was obtained from hospital financial department. A 50% reduction in wound complications using NPWT was assigned initially and varied for sensitivity analysis.

Results

The mean BMI was 36. The wound complication rate was 31% (37% for BMI > 30, 41% for BMI > 40). The overall cost of incision care was $104 lower for NPWT than for RC. At the lowest cost of NPWT ($200), the risk of wound complication must be reduced by 33% (relative risk = 0.67) for NPWT to achieve cost savings in this cohort. Modeling obese and morbidly obese cohorts, the NPWT resulted in overall cost savings of $163 and $203, respectively, and the risk of wound complication must be reduced by 28% and 25%, respectively, for NPWT to achieve cost savings.

Conclusion

If the wound complication rate can be reduced by one-third, prophylactic NPWT is potentially cost saving in high-risk women undergoing laparotomy for gynecologic malignancy.