320-detector CT coronary angiography with prospective and retrospective electrocardiogram gating in a single heartbeat: comparison of image quality and radiation dose

OBJECTIVES

To compare the image quality, radiation dose and diagnostic accuracy of 320-detector CT coronary angiography with prospective and retrospective electrocardiogram (ECG) gating in a single heartbeat.

METHODS

Two independent reviewers separately scored image quality of coronary artery segment for 480 cardiac CT studies in a prospective group and a retrospective group (240 patients with a heart rate <65 beats per minute in each group). The two groups matched well for clinical characteristics and CT parameters. There was good agreement for image quality scores of coronary artery segment between the independent reviewers (κ=0.73). Of the 7023 coronary artery segments, the image quality scores of the prospective group and retrospective group were not significantly different (p>0.05). The mean radiation dose was 10.0 ± 3.5 mSv (range 6.2-21.6 mSv) for prospective ECG gating at 65-85% of R-R interval (the interval between the R-wave of one heartbeat to the R-wave of the next). The mean radiation dose for retrospective ECG-triggered modulated scans was 23.2 ± 3.4 mSv (range 17-27.4 mSv). The mean radiation dose was 57% lower for prospective gating than for retrospective gating (p<0.01).

RESULTS

Compared with coronary angiography, the results for prospective vs retrospective ECG gating were 92% vs 90% for sensitivity (p=0.23), 89% vs 91% for specificity (p=0.19), 90% vs 93% for positive predictive value (p=0.25) and 92% vs 95% for negative predictive value (p=0.21) for lesions with ≥50% stenosis, respectively.

CONCLUSION

320-detector CT coronary angiography performed with prospective ECG gating has similar subjective image quality scores, but a 57% lower radiation dose than retrospective ECG gating in a single heartbeat.

Remote Internet access to advanced analytical facilities: a new approach with Web-based services

Over the past decade, the increasing availability of the World Wide Web has held out the possibility that the efficiency of scientific measurements could be enhanced in cases where experiments were being conducted at distant facilities. Examples of early successes have included X-ray diffraction (XRD) experimental measurements of protein crystal structures at synchrotrons and access to scanning electron microscopy (SEM) and NMR facilities by users from institutions that do not possess such advanced capabilities. Experimental control, visual contact, and receipt of results has used some form of X forwarding and/or VNC (virtual network computing) software that transfers the screen image of a server at the experimental site to that of the users' home site. A more recent development is a web services platform called Science Studio that provides teams of scientists with secure links to experiments at one or more advanced research facilities. The software provides a widely distributed team with a set of controls and screens to operate, observe, and record essential parts of the experiment. As well, Science Studio provides high speed network access to computing resources to process the large data sets that are often involved in complex experiments. The simple web browser and the rapid transfer of experimental data to a processing site allow efficient use of the facility and assist decision making during the acquisition of the experimental results. The software provides users with a comprehensive overview and record of all parts of the experimental process. A prototype network is described involving X-ray beamlines at two different synchrotrons and an SEM facility. An online parallel processing facility has been developed that analyzes the data in near-real time using stream processing. Science Studio and can be expanded to include many other analytical applications, providing teams of users with rapid access to processed results along with the means for detailed discussion of their significance.

Cancer stem cell marker ALDH1 expression is associated with lymph node metastasis and poor survival in esophageal squamous cell carcinoma: a study from high incidence area of northern China

Tumor recurrence and metastasis is the leading cause of death in esophageal squamous cell carcinoma (ESCC). Cancer stem cell (CSC) may be responsible for tumor growth and maintenance of aggressive behavior. Aldehyde dehydrogenase 1 (ALDH1) has been proposed as one of the possible candidates for a CSC marker. The expression of ALDH1 may be correlated with the clinicopathologic factor and clinical outcome of patients with ESCC. The purpose of this study was to investigate the expression of ALDH1 protein in human ESCC tissues, and evaluated the clinical implication of ALDH1 expression for these patients. All 79 patients who underwent esophagectomy for ESCC between January 2005 and June 2006 were enrolled in this study. The expression of ALDH1 in ESCC and adjacent noncancerous tissues was analyzed by immunohistochemistry. ALDH1 was mainly expressed in ESCC cell nucleus. For the 79 ESCC patients, increased nuclear accumulation of ALDH1 was found in 12 (15.2%) specimens. ALDH1 expression was correlated with poor histological differentiation (P= 0.003), lymph node metastasis (P= 0.011), and late pathologic TNM classification (pTNM) staging (P= 0.003). Patients in ALDH1 positive group had a significantly poor 5-year overall survival than those in the negative group (8.3% vs. 52.2%, P= 0.025). We have demonstrated for the first time that the CSC marker, ALDH1, is expressed in human ESCC. The expression of ALDH1 protein in nucleus of the ESCC is significantly associated with lymph node metastasis and poor survival. Our results highly indicate the involvement of ALDH1 in the aggressive behavior of ESCC.

Radiological and clinical findings of 25 patients with invasive pulmonary aspergillosis: retrospective analysis of 2150 liver transplantation cases

OBJECTIVE

The purpose of this study was to evaluate the radiological and clinical findings of invasive pulmonary aspergillosis (IPA) after liver transplantation.

METHODS

This study included 25 consecutive liver transplant recipients with histologically confirmed IPA after liver transplantation. Radiological examinations performed for diagnosis were available in all patients. Clinical findings and changes in clinical response and radiological findings after treatment were also evaluated.

RESULTS

3 main radiological findings were identified: nodules, 64% (16/25); masses, 36% (9/25); and consolidations in a patchy pattern, 20% (5/25). A tree-in-bud pattern was found in 12% (3/25) of patients. In 8 (32%) of 25 patients, we found a combination of 2 or more of these signs: 5 (20%) patients presented with concurrent nodules accompanied by patchy consolidations and/or tree-in-bud, and 3 (12%) patients showed masses accompanied by large consolidations. A halo sign was observed in 20 (80%) of 25 patients. Hypodense sign and cavitary lesions were encountered in 17 (68%) of 25 patients. Follow-up radiological findings after treatment showed improvement in 18 patients, no change in 4 patients and progression in 3 patients. There were three aspergillosis-associated deaths during the follow-up period. The onset time of IPA was a median of 31 days after transplantation. The most common symptom at diagnosis was fever (n=15). None of the 25 patients had leukopaenia at the time of the diagnosis of IPA.

CONCLUSIONS

The most common radiological findings of IPA after liver transplantation are multiple nodules with or without halo sign, masses and consolidations, which usually appear about 1 month after transplantation.

Microbial profiles in saliva from children with and without caries in mixed dentition

OBJECTIVE

The purpose of this study was to determine the bacterial profiles in saliva of the isolated children for studying caries etiology.

MATERIALS AND METHODS

  Samples were collected from isolated children from 6 to 8years old including 20 caries-free (dmfs=0) (healthy) and 30 caries-active individuals (dmfs>8) (patients). 16S rRNA genes were amplified by PCR from bacterial DNA of saliva sample and labeled via incorporation of Cy3-dCTP in second nested PCR. After hybridization of labeled amplicons on HOMIM, the microarray slides were scanned and original data acquired from professional software.

RESULTS

Collectively, 94 bacterial species or clusters representing six bacterial phyla and 30 genera were detected. A higher bacterial diversity was observed in patients than in healthy samples. Statistical analyses revealed eight species or clusters were detected more frequently in diseased patients than in healthy samples, while six different species were detected more frequently in healthy as compared to diseased patients.

CONCLUSION

The diversity of microbe within saliva derived from isolated population increased in caries-active status, and there are some bacteria in salivary flora can be as candidate biomarkers for caries prognosis in mixed dentition. The imbalances in the resident microflora may be the ultimate mechanism of dental caries.

Hemodynamic and morphological vasculature response to a burn monitored using a combined dual-wavelength laser speckle and optical microangiography imaging system

A multi-functional imaging system capable of determining relative changes in blood flow, hemoglobin concentration, and morphological features of the blood vasculature is demonstrated. The system combines two non-invasive imaging techniques, a dual-wavelength laser speckle contrast imaging (2-LSI) and an optical microangiography (OMAG) system. 2-LSI is used to monitor the changes in the dynamic blood flow and the changes in the concentration of oxygenated (HbO), deoxygenated (Hb) and total hemoglobin (HbT). The OMAG system is used to acquire high resolution images of the functional blood vessel network. The vessel area density (VAD) is used to quantify the blood vessel network morphology, specifically the capillary recruitment. The proposed multi-functional system is employed to assess the blood perfusion status from a mouse pinna before and immediately after a burn injury. To our knowledge, this is the first non-invasive, non-contact and multifunctional imaging modality that can simultaneously measure variations of several blood perfusion parameters.

Value of three-dimensional power Doppler to predict clinical and histological response to neoadjuvant chemotherapy in locally advanced cervical carcinoma

OBJECTIVE

Platinum-based neoadjuvant chemotherapy followed by radical hysterectomy is an alternative therapeutic strategy for locally advanced cervical carcinoma but variables used to predict chemotherapy response are not well defined. We investigated the potential of three-dimensional (3D) power Doppler in predicting response to neoadjuvant chemotherapy.

METHODS

We enrolled 61 eligible patients with locally advanced cervical carcinoma who underwent neoadjuvant chemotherapy followed by surgery or radiation. Before the initial chemotherapy, we measured 3D power Doppler vascular indices, including vascularization index (VI), flow index (FI) and vascularization flow index (VFI), of the whole cervical carcinoma. We also measured two-dimensional (2D) hemodynamic parameters, such as resistance index and pulsatility index, at three random spots inside the tumor. The associations of all parameters with clinical and histological responses to chemotherapy were evaluated through univariable and multiple logistic regression analysis.

RESULTS

The clinical and histological response rates to chemotherapy were 70.5% and 70.7%, respectively. Univariable logistic regression analysis showed that VI, FI and VFI were significantly higher in clinical responders than in non-responders (P < 0.05), and that FI was significantly higher in histological responders (P = 0.012). Multiple logistic regression analysis showed that FI was the only significant factor associated with both clinical and histological responses. The best FI cut-off values were 35.3 and 37.3 for clinical response and histological response, respectively (with sensitivity 86.0% and 73.2%, and specificity 72.2% and 64.7%). Interestingly, none of the 2D hemodynamic parameters was significantly correlated with either response.

CONCLUSION

FI is a potential marker for predicting both clinical and histological responses to chemotherapy in patients with locally advanced cervical carcinoma.

Biomarker responses in fish exposed to sediments from northern Taihu Lake

Our study investigated multiple biomarker responses of goldfish exposed to sediments collected from northern Taihu Lake. The activities of acetylcholinesterase, 7-ethoxyresorufin-O-deethylase, glutathione-S-transferase and superoxide dismutase did not differ significantly from controls following exposure to sediment from the center of the lake. However, sediment collected from the northern bays did significantly alter enzymatic activities. An integrated biomarker response (IBR) was calculated and used to evaluate the impact of pollutants from different stations. The results indicated that Mashan in Meiliang Bay and Xiaogongshan in Gong Bay were the most stressful places for fish. Sediment polychlorinated biphenyl and polybrominated diphenyl ether concentrations were associated with IBR variation.

Conserved haplotype blocks within the sheep MHC and low SNP heterozygosity in the Class IIa subregion

This report describes single-nucleotide polymorphisms (SNPs) in the sheep major histocompatibility complex (MHC) class II and class III regions and provides insights into the internal structure of this important genomic complex. MHC haplotypes were deduced from sheep family trios based on genotypes from 20 novel SNPs representative of the class II region and 10 previously described SNPs spanning the class III region. All 30 SNPs exhibited Hardy-Weinberg proportions in the sheep population studied. Recombination within an extended sire haplotype was observed within the class II region for 4 of 20 sheep chromosomes, thereby supporting the presence of separated IIa and IIb subregions similar to those present in cattle. SNP heterozygosity varied across the class II and III regions. One segment of the class IIa subregion manifested very low heterozygosity for several SNPs spanning approximately 120 Kbp. This feature corresponds to a subregion within the human MHC class II region previously described as a 'SNP desert' because of its paucity of SNPs. Linkage disequilibrium (LD) was reduced at the junction separating the putative class IIb and IIa subregions and also between the class IIa and the class III subregions. The latter observation is consistent with either an unmapped physical separation at this location or more likely a boundary characterized by more frequent recombination between two conserved subregions, each manifesting high within-block LD. These results identify internal blocks of loci in the sheep MHC, within which recombination is relatively rare.

A novel gene with a vWD domain and three Kazal-type domains: molecular cloning and expression in the ovary of the oriental river prawn, Macrobrachium nipponense

A novel gene encoding avon Willebrand factor D (vWD) domain and three Kazal-type domains was firstly indentified from the ovary of the oriental river prawn Macrobrachium nipponense and this gene was named as MnvWD-Kazal. Bioinformatics analyses showed that this gene encodes a protein of 857 amino acids with a predicted molecular mass of 92.7 kDa. Real-time quantitative PCR (RT-QPCR) analyses revealed that the level of MnvWD-Kazal mRNA expression varied in the developing ovary and substantially differed between other tissues. In the ovary, the level of MnvWD-Kazal expression gradually increased from the perinucleolus (PN) stage to the yolk granule (YG) stage, and then abruptly decreased at the sexual maturation (MA) stage. The maximum expression occurred in the YG stage and the minimum was at the paracmasis (PM) stage. The expression level of MnvWD-Kazal in the intestine was much higher than that in other tissues. The differential expressions of MnvWD-Kazal at different stages of the ovary suggest that this novel gene may play a critical role in the oocyte maturation of M. nipponense.

Supercontinuum light source enables in vivo optical microangiography of capillary vessels within tissue beds

This Letter reports on the use of a supercontinuum light source to achieve ultrahigh resolution and ultrahigh sensitive optical microangiography (OMAG) imaging of microcirculations within tissue beds in vivo. After passing through a specially designed optical filter with a passband of 120 nm centered on 800 nm, the light source is coupled into an optic-fiber-based OMAG system that provides a measured axial resolution of ∼3 μm over a ranging distance of 2 mm. Within this ranging distance, the system gives an averaged signal-to-noise ratio of 87 dB and a sensitivity roll-off of 7 dB at an A-scan rate of 70 kHz. We demonstrate the capability of the system to visualize a detailed microvascular perfusion map, including the single red blood cells within the capillaries, by imaging a mouse ear flap in vivo.

Ultrahigh sensitive optical microangiography reveals depth-resolved microcirculation and its longitudinal response to prolonged ischemic event within skeletal muscles in mice

The primary pathophysiology of peripheral arterial disease is associated with impaired perfusion to the muscle tissue in the lower extremities. The lack of effective pharmacologic treatments that stimulate vessel collateralization emphasizes the need for an imaging method that can be used to dynamically visualize depth-resolved microcirculation within muscle tissues. Optical microangiography (OMAG) is a recently developed label-free imaging method capable of producing three-dimensional images of dynamic blood perfusion within microcirculatory tissue beds at an imaging depth of up to ∼2 mm, with an unprecedented imaging sensitivity of blood flow at ∼4 μm∕s. In this paper, we demonstrate the utility of OMAG in imaging the detailed blood flow distributions, at a capillary-level resolution, within skeletal muscles of mice. By use of the mouse model of hind-limb ischemia, we show that OMAG can assess the time-dependent changes in muscle perfusion and perfusion restoration along tissue depth. These findings indicate that OMAG can represent a sensitive, consistent technique to effectively study pharmacologic therapies aimed at promoting the growth and development of collateral vessels.

Glargine promotes proliferation of breast adenocarcinoma cell line MCF-7 via AKT activation

Glargine is widely used as a long-acting insulin analogue in the treatment of diabetes mellitus. However, this insulin analogue has been recently suspected to be associated with an increased risk of cancer. The aim of this study was to investigate the influence of glargine on proliferation of breast adenocarcinoma cell line (MCF-7) and its possible mechanism. Effects of glargine and regular human insulin on the cell proliferation were tested in ER-positive MCF-7 cells by MTT assay. Apoptosis in MCF-7 cells was measured by flow cytometry. The protein levels of p-AKT, Bcl-2, and Bax were also determined by Western blotting and immunohistochemistry, respectively. The result showed that glargine (100, 200 nmol/l) stimulated proliferation of ER-positive MCF-7 cells compared with regular human insulin. At the same time, glargine decreased the percentage of early apoptosis in MCF-7 cells. Otherwise, glargine (100 nmol/l) stimulated the p-AKT in a time-dependent manner in MCF-7 cells. Furthermore, we found that glargine downregulated the level of Bax protein and upregulated that of Bcl-2 (p <0.05). These data show that glargine promote the proliferation of breast adenocarcinoma cells in vitro, probably by preventing apoptosis.

Nitric oxide in enteric nervous system mediated the inhibitory effect of vasopressin on the contraction of circular muscle strips from colon in male rats

BACKGROUND

Arginine vasopressin (AVP) is widely used in the treatment of critical diseases with hypotension, but the reports about its effect on gastrointestinal motility are controversial. The purpose of this study was to characterize the role of AVP in the regulation of colonic motility and the underlying mechanism.

METHODS

The contraction of the circular muscle strips (CM) of colon in male rats was monitored by a polygraph. The expressions of cytoplasmic inducible nitric oxide synthase (iNOS), I-κB, and the nuclear P65 in proximal colon were measured by Western blot. The V(1) receptors (V(1) Rs) and iNOS were localized by immunohistochemistry. The content of nitric oxide (NO) in the colon was measured by Griess reagent at the absorbance of 560 nm.

KEY RESULTS

Arginine vasopressin (10(-10) -10(-6) mol L(-1)) caused a concentration-dependent inhibition on CM contraction. Pretreatment with one of the following chemicals, including V-1880 (10(-7) mol L(-1)), TTX (10(-5) mol L(-1)), L-NAME (10(-4) mol L(-1)), NPLA (10(-7) mol L(-1)), SMT (10(-3) mol L(-1)), and PDTC (10(-3) mol L(-1)), attenuated the inhibitory effect of AVP on CM contraction. Arginine vasopressin increased the expression of iNOS and the content of NO in proximal colon. These effects were attenuated by pretreatment with PDTC (10(-3) mol L(-1)). Following AVP administration, the amount of cytoplasmic I-κB decreased, but that of nuclear P65 increased. Double immunofluorescence labeling revealed that V(1) Rs and iNOS were co-localized on the cells of myenteric plexus in proximal colon.

CONCLUSIONS & INFERENCES

Arginine vasopressin inhibited the contraction of CM in proximal colon. This effect was mediated by NO produced from NF-κB-iNOS pathway and neuronal NOS activation in myenteric plexus.

In vivo volumetric imaging of microcirculation within human skin under psoriatic conditions using optical microangiography

BACKGROUND AND OBJECTIVE

There is a growing body of evidence suggesting that vascular abnormalities may play crucial role in several dermatologic diseases, such as psoriasis, port wine stain, and skin cancer. To improve our understanding of vascular involvement in these skin conditions, there is a need for a non-invasive imaging modality capable of assessing 3D microcirculations within skin tissue beds in vivo. This study aims to demonstrate whether ultra-high sensitive optical microangiography (UHS-OMAG) is feasible to visualize skin microcirculations in 3D and to quantify microvascular vessel density under normal and psoriatic conditions in vivo.

STUDY DESIGN/MATERIAL AND METHODS

An UHS-OMAG system operating at 1,310 nm wavelength was used for in vivo imaging of microcirculation in human skin. The system has a spatial resolution of ∼10 µm × 20 µm (axial × lateral), running at 280 fps to acquire 3D imaging dataset to represent morphology and capillary level microvascular blood perfusion within the scanned skin tissue volume. The sensitivity of the system to the blood flow is as low as ∼4 µm/second. With this system, we performed the imaging experiments on the skin of a volunteer with stable plaque-type psoriasis. The microcirculation and structural information of normal and diseased skins were compared both qualitatively and quantitatively.

RESULTS

The UHS-OMAG is capable of differentiating the microcirculation within the normal skins from that in the psoriatic skins. The 3D optical images show that the blood vessel elongation and the dense network in the psoriatic lesion skin, the appearance of which is not observed within the normal skin. Based on the results obtained from one subject, the statistical analyses show that higher blood vessel density presented within the psoriasis lesion skin than that of the normal skin.

CONCLUSIONS

UHS-OMAG can be a valuable tool for imaging skin microcirculations non-invasively with high-speed and high-sensitivity, and therefore may have a useful role in future clinical diagnosis and treatment of dermatologic diseases such as psoriasis in human subjects.