Stabilized dried blood spot collection

During the collection phase of the dried blood spot method, practitioners need to ensure that there is no smearing of the blood sample on the filter paper or else readings from it will be invalid. This can be difficult to accomplish in the field if there is relative motion between the site of blood discharge on the finger and the filter paper. In this article, a gyroscope stabilization method is introduced and demonstrated to provide consistent and improved dried blood spot collection within a circular guide region notwithstanding the presence of rocking.     

Blimp-1-Dependent IL-10 Production by Tr1 Cells Regulates TNF-Mediated Tissue Pathology

Tumor necrosis factor (TNF) is critical for controlling many intracellular infections, but can also contribute to inflammation. It can promote the destruction of important cell populations and trigger dramatic tissue remodeling following establishment of chronic disease. Therefore, a better understanding of TNF regulation is needed to allow pathogen control without causing or exacerbating disease. IL-10 is an important regulatory cytokine with broad activities, including the suppression of inflammation. IL-10 is produced by different immune cells; however, its regulation and function appears to be cell-specific and context-dependent. Recently, IL-10 produced by Th1 (Tr1) cells was shown to protect host tissues from inflammation induced following infection. Here, we identify a novel pathway of TNF regulation by IL-10 from Tr1 cells during parasitic infection. We report elevated Blimp-1 mRNA levels in CD4⁺ T cells from visceral leishmaniasis (VL) patients, and demonstrate IL-12 was essential for Blimp-1 expression and Tr1 cell development in experimental VL. Critically, we show Blimp-1-dependent IL-10 production by Tr1 cells prevents tissue damage caused by IFNγ-dependent TNF production. Therefore, we identify Blimp-1-dependent IL-10 produced by Tr1 cells as a key regulator of TNF-mediated pathology and identify Tr1 cells as potential therapeutic tools to control inflammation.     

Radiation dose of digital radiography (DR) versus micro-dose x-ray (EOS) on patients with adolescent idiopathic scoliosis: 2016 SOSORT- IRSSD “John Sevastic Award” Winner in Imaging Research

Background

Patients with adolescent idiopathic scoliosis (AIS) frequently receive x-ray imaging at diagnosis and subsequent follow monitoring. The ionizing radiation exposure has accumulated through their development stage and the effect of radiation to this young vulnerable group of patients is uncertain. To achieve the ALARA (as low as reasonably achievable) concept of radiation dose in medical imaging, a slot-scanning x-ray technique by the EOS system has been adopted and the radiation dose using micro-dose protocol was compared with the standard digital radiography on patients with AIS.

Methods

Ninety-nine participants with AIS underwent micro-dose EOS and 33 underwent standard digital radiography (DR) for imaging of the whole spine. Entrance-skin dose was measured using thermoluminescent dosimeters (TLD) at three regions (i.e. dorsal sites at the level of sternal notch, nipple line, symphysis pubis). Effective dose and organ dose were calculated by simulation using PCXMC 2.0. Data from two x-ray systems were compared using independent-samples t-test and significance level at 0.05. All TLD measurements were conducted on PA projection only. Image quality was also assessed by two raters using Cobb angle measurement and a set of imaging parameters for optimization purposes.

Results

Entrance-skin dose from micro-dose EOS system was 5.9–27.0 times lower at various regions compared with standard DR. The calculated effective dose was 2.6?±?0.5 (μSv) and 67.5?±?23.3 (μSv) from micro-dose and standard DR, respectively. The reduction in the micro-dose was approximately 26 times. Organ doses at thyroid, lung and gonad regions were significantly lower in micro-dose (p?<?0.001). Data were further compared within the different gender groups. Females received significantly higher (p?<?0.001) organ dose at ovaries compared to the testes in males. Patients with AIS received approximately 16–34 times lesser organ dose from micro-dose x-ray as compared with the standard DR. There was no significant difference in overall rating of imaging quality between EOS and DR. Micro-dose protocol provided enough quality to perform consistent measurement on Cobb angle.

Conclusions

Entrance-skin dose, effective dose and organ dose were significantly reduced in micro-dose x-ray. The effective dose of a single micro-dose x-ray (2.6 μSv) was less than a day of background radiation. As AIS patients require periodic x-ray follow up for surveillance of curve progression, clinical use of micro-dose x-ray system is beneficial for these young patients to reduce the intake of ionizing radiation.

     

Conditional gene inactivation by combining tetracycline-mediated transcriptional repression and auxin-inducible degron-mediated degradation

Characterizing the functions of essential cell cycle control genes requires tight and rapid inducible gene inactivation. Drawbacks of current conditional depletion approaches include slow responses and incomplete depletion. We demonstrated that by integrating the tetracycline-controlled promoter system and the auxin-inducible degron (AID) system together, AID-tagged proteins can be downregulated more efficiently than the individual technology alone. When used in conjunction with CRISPR-Cas9-mediated disruption of the endogenous locus, this system facilitates the analysis of essential genes by allowing rapid and tight conditional depletion, as we have demonstrated using several cell cycle-regulatory genes including cyclin A, CDK2, and TRIP13. The vectors constructed in this study allow expression of AID-fusion proteins under the control of tetracycline-controlled promoters and should be useful in studies requiring rapid and tight suppression of gene expression in mammalian cells.