Portal venous hemodynamics in chronic liver disease: effects of posture change and exercise

Changes of portal hemodynamics with the progression of chronic liver disease and changes caused by body posture and physical exercise were investigated using an ultrasonic pulsed Doppler flowmeter in healthy adults and in patients with chronic persistent hepatitis, chronic active hepatitis, and cirrhosis. Portal venous velocity was significantly reduced in patients with chronic active hepatitis, cirrhosis without a large splenorenal shunt, and cirrhosis with a large splenorenal shunt, compared with normal subjects and patients with chronic persistent hepatitis. Portal venous flow, by contrast, was significantly reduced only in patients with cirrhosis and a large splenorenal shunt compared with normal subjects and with the other three groups; there was no significant difference in portal venous flow among the latter four groups. Both portal venous velocity and flow showed a tendency toward further reduction in patients with cirrhosis who had hepatofugal flow of part of the superior mesenteric venous blood into the splenic vein and a large splenorenal shunt. Both exercise and posture change from supine to sitting significantly reduced portal venous velocity and portal venous flow in normal subjects, as well as in the patients with chronic liver disease.     

Reduction in camera-specific variability in [<Superscript>123</Superscript>I]FP-CIT SPECT outcome measures by image reconstruction optimized for multisite settings: impact on age-dependence of the specific binding ratio in the ENC-DAT database of healthy controls

Purpose

Quantitative estimates of dopamine transporter availability, determined with [¹²³I]FP-CIT SPECT, depend on the SPECT equipment, including both hardware and (reconstruction) software, which limits their use in multicentre research and clinical routine. This study tested a dedicated reconstruction algorithm for its ability to reduce camera-specific intersubject variability in [¹²³I]FP-CIT SPECT. The secondary aim was to evaluate binding in whole brain (excluding striatum) as a reference for quantitative analysis.

Methods

Of 73 healthy subjects from the European Normal Control Database of [¹²³I]FP-CIT recruited at six centres, 70 aged between 20 and 82 years were included. SPECT images were reconstructed using the QSPECT software package which provides fully automated detection of the outer contour of the head, camera-specific correction for scatter and septal penetration by transmission-dependent convolution subtraction, iterative OSEM reconstruction including attenuation correction, and camera-specific “to kBq/ml” calibration. LINK and HERMES reconstruction were used for head-to-head comparison. The specific striatal [¹²³I]FP-CIT binding ratio (SBR) was computed using the Southampton method with binding in the whole brain, occipital cortex or cerebellum as the reference. The correlation between SBR and age was used as the primary quality measure.

Results

The fraction of SBR variability explained by age was highest (1) with QSPECT, independently of the reference region, and (2) with whole brain as the reference, independently of the reconstruction algorithm.

Conclusion

QSPECT reconstruction appears to be useful for reduction of camera-specific intersubject variability of [¹²³I]FP-CIT SPECT in multisite and single-site multicamera settings. Whole brain excluding striatal binding as the reference provides more stable quantitative estimates than occipital or cerebellar binding.

     

Determination of Depth-Dependent Intradermal Immunogenicity of Adjuvanted Inactivated Polio Vaccine Delivered by Microinjections via Hollow Microneedles

Purpose

The aim of this study was to investigate the depth-dependent intradermal immunogenicity of inactivated polio vaccine (IPV) delivered by depth-controlled microinjections via hollow microneedles (HMN) and to investigate antibody response enhancing effects of IPV immunization adjuvanted with CpG oligodeoxynucleotide 1826 (CpG) or cholera toxin (CT).

Methods

A novel applicator for HMN was designed to permit depth- and volume-controlled microinjections. The applicator was used to immunize rats intradermally with monovalent IPV serotype 1 (IPV1) at injection depths ranging from 50 to 550 μm, or at 400 μm for CpG and CT adjuvanted immunization, which were compared to intramuscular immunization.

Results

The applicator allowed accurate microinjections into rat skin at predetermined injection depths (50–900 μm), -volumes (1–100 μL) and -rates (up to 60 μL/min) with minimal volume loss (±1–2%). HMN-mediated intradermal immunization resulted in similar IgG and virus-neutralizing antibody titers as conventional intramuscular immunization. No differences in IgG titers were observed as function of injection depth, however IgG titers were significantly increased in the CpG and CT adjuvanted groups (7-fold).

Conclusion

Intradermal immunogenicity of IPV1 was not affected by injection depth. CpG and CT were potent adjuvants for both intradermal and intramuscular immunization, allowing effective vaccination upon a minimally-invasive single intradermal microinjection by HMN.

     

Comparison of anthropometric measurements of adiposity in relation to cancer risk: a systematic review of prospective studies

Purpose

In epidemiology, the relationship between increased adiposity and cancer risk has long been recognized. However, whether the association is the same for measures of abdominal or whole body adiposity is unclear. The aim of this systematic review is to compare cancer risk, associated with body mass index (BMI), an indicator of whole body adiposity, with indicators of abdominal adiposity in studies in which these indicators have been directly measured.

Methods

We conducted a systematic search from 1974 (EMBASE) and 1988 (PubMed) to September 2015 with keywords related to adiposity and cancer. Included studies were limited to cohort studies reporting directly measured anthropometry and performing mutually adjusted analyses.

Results

Thirteen articles were identified, with two reporting on breast cancer, three on colorectal cancer, three on endometrial cancer, two on gastro-oesophageal cancer, two on renal cancer, one on ovarian cancer, one on bladder cancer, one on liver and biliary tract cancer and one on leukaemia. Evidence suggests that abdominal adiposity is a stronger predictor than whole body adiposity for gastro-oesophageal, leukaemia and liver and biliary tract cancer in men and women and for renal cancer in women. Abdominal adiposity was a stronger predictor for bladder and colorectal cancer in women, while only BMI was a predictor in men. In contrast, BMI appears to be a stronger predictor for ovarian cancer. For breast and endometrial cancer, both measures were predictors for cancer risk in postmenopausal women.

Conclusions

Only few studies used mutually adjusted and measured anthropometric indicators when studying adiposity–cancer associations. Further research investigating cancer risk and adiposity should include more accurate non-invasive indicators of body fat deposition and focus on the understudied cancer types, namely leukaemia, ovarian, bladder and liver and biliary tract cancer.

     

Quantification of deep medullary veins at 7 T brain MRI

Objectives

Deep medullary veins support the venous drainage of the brain and may display abnormalities in the context of different cerebrovascular diseases. We present and evaluate a method to automatically detect and quantify deep medullary veins at 7 T.

Methods

Five participants were scanned twice, to assess the robustness and reproducibility of manual and automated vein detection. Additionally, the method was evaluated on 24 participants to demonstrate its application. Deep medullary veins were assessed within an automatically created region-of-interest around the lateral ventricles, defined such that all veins must intersect it. A combination of vesselness, tubular tracking, and hysteresis thresholding located individual veins, which were quantified by counting and computing (3-D) density maps.

Results

Visual assessment was time-consuming (2 h/scan), with an intra-/inter-observer agreement on absolute vein count of ICC?=?0.76 and 0.60, respectively. The automated vein detection showed excellent inter-scan reproducibility before (ICC?=?0.79) and after (ICC?=?0.88) visually censoring false positives. It had a positive predictive value of 71.6 %.

Conclusion

Imaging at 7 T allows visualization and quantification of deep medullary veins. The presented method offers fast and reliable automated assessment of deep medullary veins.

Key Points

? Deep medullary veins support the venous drainage of the brain ? Abnormalities of these veins may indicate cerebrovascular disease and quantification is needed ? Automated methods can achieve this and support human observers ? The presented method provides robust and reproducible detection of veins ? Intuitive quantification is provided via count and venous density maps