超声心动图对心律失常胎儿预后的预测价值

胎儿心律失常是一种较常见的胎儿疾病。超声心动图能在产前对胎儿心律失常进行分类和诊断已早有报道,为探讨超声心动图对提示胎儿心律失常预后的预测价值,我们对134例行超声心动图检查发现心律失常的胎儿进行了随访(死胎经尸检证实),将结果报道如下。     

Alpha-melanocyte stimulating hormone protects against H2O2-induced inhibition of wound restitution in IEC-6 cells via a Syk kinase- and NF-kappabeta-dependent mechanism

Epithelial injury and repair are central consequences of ischemia and reperfusion of the gut. Intestinal mucosal wounds are repaired in part by epithelial restitution. However, the signaling mechanisms regulating restitution remain poorly understood, and few therapies to enhance restitution have been described. Previously we demonstrated that alpha-melanocyte-stimulating hormone (alpha-MSH) protected against postischemic gut injury in the rat. In this report, we tested the effects and mechanisms of alpha-MSH on wound restitution of rat small intestine (IEC-6) cells subjected to H2O2 stress with or without scrape wounding. H2O2 treatment resulted in tyrosine phosphorylation of Syk kinase and its downstream target IkappaBalpha, with subsequent NF-kappaB activation. Alpha-MSH and the Syk kinase inhibitor piceatannol blocked these processes. In scrape-wounded cells, H2O2 inhibited wound restitution, and this was partially restored by cotreatment with alpha-MSH or piceatannol. In contrast, overexpression of NF-kappaB p65 or Syk kinase, but not a dominant-negative mutant of Syk kinase, aggravated H2O2 inhibition of wound restitution, and inhibitors of c-Src tyrosine kinase or phosphatidylinositol-3 kinase were without effect. The results indicate an important role for Syk tyrosine kinase and the NF-kappaB pathway in the response to oxidant stress and the impairment of epithelial restitution in IEC-6 cells. The data also disclose that the beneficial effects of alpha-MSH on gut ischemia/reperfusion injury may relate to its acceleration of epithelial restitution.     

Decreases in ventricular volume correlate with decreases in ventricular pressure in idiopathic normal pressure hydrocephalus patients who experienced clinical improvement after implantation with adjustable valve shunts

OBJECTIVE: This retrospective study examined whether changes in ventricular volume correspond with changes in adjustable valve pressure settings in a cohort of patients who received shunts to treat idiopathic normal pressure hydrocephalus. We also examined whether these pressure-volume curves and other patient variables would co-occur with a positive clinical response to shunting. METHODS: We selected 51 patients diagnosed with idiopathic normal pressure hydrocephalus who had undergone implantation of a Codman Hakim programmable valve (Medos S.A., Le Locle, Switzerland). Clinical data were gathered from the patients' records and clinical notes by an investigator blinded to patients' ventricular volumes. Ventricular volume was measured using 3D Slicer, an image analysis and interactive visualization software package developed and maintained at the Surgical Planning Laboratory at Brigham and Women's Hospital. RESULTS: Eighty-six percent of patients with gait disturbance at presentation showed improvement of this symptom, 70% experienced improvement in incontinence, and 69% experienced improvement in dementia. For the group showing 100% clinical improvement, the correlation coefficient of average changes in valve pressure over time (delta P/delta T) and average changes in ventricular volume over time (delta V/delta T) were high at 0.843 (P < 0.05). For the group experiencing no or only partial improvement, the correlation coefficient was 0.257 (P = 0.32), indicating no correlation between average delta V/delta T and average delta P/delta T for each patient. CONCLUSION: This was a carefully analyzed modeling study of idiopathic normal pressure hydrocephalus treatment made possible only by adjustable valve technology. With careful volumetric analysis, we found that changes in ventricular volume correlated with adjustments in valve pressure settings for those patients who improved clinically after shunting. This suggests that positive clinical responders retained parenchymal elasticity, emphasizing the importance of dynamic changes in this cohort.     

Exact image reconstruction on PI-lines from minimum data in helical cone-beam CT

The development of accurate and efficient algorithms for image reconstruction from helical cone-beam projections remains a subject of active research. In the last few years, a number of quasi-exact and exact algorithms have been developed. Among them, the Katsevich algorithms are of filtered backprojection type and thus possess computational advantages over other existing exact algorithms. In this work, we propose an alternative approach to reconstructing exactly an image from helical cone-beam projections. Based on this approach, we develop an algorithm that requires less data than do the existing quasi-exact and exact algorithms, including the Katsevich algorithms. Our proposed algorithm is also of filtered backprojection type with one-dimensional filtering performed along a PI-line in image space. Therefore, it is (at least) computationally as efficient as the Katsevich algorithms. We have performed a preliminary numerical study to demonstrate and validate the proposed algorithm using computer-simulation data. The implication of the proposed approach and algorithm appears to be significant in that they can naturally address the long object problem as well as the super-short scan problem and, most importantly, in that they provide the opportunity to reconstruct images within any selected region of interest from minimum data, allowing the use of detector with a reduced size, the selection of a minimum number of rotation angles and thus the reduction of radiation dose delivered to the imaged subject.     

Overexpression of adenovirus E3-11.6K protein induces cell killing by both caspase-dependent and caspase-independent mechanisms

Recent studies have shown enhanced antitumor efficacy with adenoviruses that either lack E1B-19K or overexpress E3-11.6K (also known as adenoviral death protein). E1B-19K is a well-characterized anti-apoptotic protein, and viruses with E1B-19K deletions show increased cytopathicity. However, the mechanism of cell killing by E3-11.6K, which plays an important role in killing infected cells and virion release, is not well characterized. To understand the mechanism of cell killing following E3-11.6K overexpression, we constructed a recombinant adenovirus, Ad-ME, by introducing viral major late promoter upstream of the E3-11.6K sequence. Similar to the E1B-19K-deleted virus, E1B/19K-, Ad-ME induced cell death to a greater extent than the wild-type virus. Cell shrinkage, membrane blebbing, activation of caspases 3 and 9, cleavage of poly(ADP-ribose)polymerase (PARP), DNA degradation, and ratio of ADP to ATP in Ad-ME-infected cells indicated that apoptosis contributes to cell death following E3-11.6K overexpression. However, the levels of activation of caspases 3 and 9 were lower in cells infected with Ad-ME compared to those infected with E1B/19K-. Furthermore, cell killing by Ad-ME was not effectively inhibited by Z-VAD-FMK, a general caspase inhibitor. Taken together, our results suggest both caspase-dependent and caspase-independent mechanisms of cell killing due to overexpression of E3-11.6K.     

Spontaneous Basilar Membrane Oscillation and Otoacoustic Emission at 15 kHz in a Guinea Pig

A spontaneous otoacoustic emission (SOAE) measured in the ear canal of a guinea pig was found to have a counterpart in spontaneous mechanical vibration of the basilar membrane (BM). A spontaneous 15-kHz BM velocity signal was measured from the 18-kHz tonotopic location and had a level close to that evoked by a 14-kHz, 15-dB SPL tone given to the ear. Lower-frequency pure-tone acoustic excitation was found to reduce the spontaneous BM oscillation (SBMO) while higher-frequency sound could entrain the SBMO. Octave-band noise centered near the emission frequency showed an increased narrow-band response in that frequency range. Applied pulses of current enhanced or suppressed the oscillation, depending on polarity of the current. The compound action potential (CAP) audiogram demonstrated a frequency-specific loss at 8 and 12 kHz in this animal. We conclude that a relatively high-frequency spontaneous oscillation of 15 kHz originated near the 15-kHz tonotopic place and appeared at the measured BM location as a mechanical oscillation. The oscillation gave rise to a SOAE in the ear canal. Electric current can modulate level and frequency of the otoacoustic emission in a pattern similar to that for the observed mechanical oscillation of the BM.     

Anti-SARS virus antibody responses against human SARS-associated coronavirus and animal SARS-associated coronavirus-like virus

Severe acute respiratory syndrome (SARS) is an infectious disease first recognized in November 2002 in Guangdong province, China. It was spread to many countries all over the world within a few months. 1.2 By April 2003,     

Attenuation of GVHD for allo-bone marrow transplantation recipient by fasL-fas pathway in an H-2 haplotype disparate mouse combination

Fas (CD95 ) ,atypeⅠtransmembraneproteinoftumornecrosisfactor (TNF)andtumorgrowthfactor (TGF )receptorfamily ,isexpressedonavari etyofhumanorgansandsometumorcellsbesidesac tivatedmatureTcellsandlymphocytestransducedbyhumanTlymphocytevirus (HTLV ) ,humanim…     

Should patients with a pre-operative prostatespecific antigen greater than 15ng/ml be offered radical prostatectomy?

Background Patients with prostate cancer with a pre-operative prostate-specific antigen (PSA) τ;15ng/ml who undergo radical retropubic prostatectomy (RRP) generally do not have a good outcome, yet may have organ-confined cancer and should be offered the option of surgery. Aim To assess the outcome of patients who underwent RRP with a pre-operative PSA ≥ 15ng/ml. Methods Thirty-four patients, mean pre-operative PSA: 25.46ng/ml (15.03–76.6) and mean Gleason score: 6.4 (5–9) were assessed. Results Two groups were identified. Group I: 41% (14/34) have no biochemical recurrence to mean follow up of 58 months (30–106). Mean PSA: 18.8ng/ml (15.03–25.84). Mean Gleason score: 6.1 (5–7). Clinical stage: T1c in 80%. No patient had seminal vesicle or lymph node involvement. Group II: 59% (20/34) have biochemical recurrence or died (3) from their disease to mean follow up of 66 months (36–98). Mean PSA: 28.9ng/ml (15.28–76.6). Mean Gleason score: 6.7 (5–9). Clinical stage: T1c in 25%. Eleven patients had seminal vesicle (8) involvement or positive lymph nodes (3) or both (2). Conclusion RRP seems feasible in patients whose pre-operative PSA is between 15 and 25ng/ml with stage T1c, Gleason score ≤ 7 and negative lymph node frozen section.