The impact of cataract on the quantitative,non‐invasive assessment of retinal blood Flow

Purpose: The aim of the study was to determine the impact of cataract on the quantitative, non‐invasive assessment of retinal blood flow assessed by bidirectional laser Doppler flowmetry and simultaneous vessel densitometry. Methodology: Ten patients scheduled for extracapsular cataract extraction using phacoemulsification and intraocular lens implantation between the ages of 61 and 84 (mean age 73 years, SD ± 8) were prospectively recruited. Two visits were required to complete the study; one visit prior to extracapsular cataract extraction and one at least 6 weeks after the surgery to allow for sufficient postoperative recovery. The severity of cataract was documented using the Lens Opacity Classification System (LOCS, III) at the first visit. Retinal arteriolar hemodynamics were measured at both visits using the high‐intensity setting of the Canon Laser Blood Flowmeter. Results: All eyes showed no clinical signs of postoperative intraocular inflammation. The quantitative assessment of retinal arteriolar diameter and blood flow were reduced following extracapsular cataract extraction (Wilcoxon signed‐rank test, p = 0.022 and p = 0.028, respectively); however, centreline blood velocity was not significantly changed (Wilcoxon signed‐rank test, p = 0.074). Intraocular pressure was unchanged pre‐ and postcataract extraction. Conclusions: Retinal vessel densitometry assessment in the presence of cataract results in the erroneous elevation of the diameter measurement and thereby the calculation of blood flow. The bidirectional Doppler assessment of blood velocity appears to be more robust to light scatter induced by cataract. Care needs to be exercised in the interpretation of studies of retinal vessel diameter or blood flow that utilize similar densitometry techniques.     

Retinal fractals and acute lacunar stroke

This study aimed to determine whether retinal fractal dimension, a quantitative measure of microvascular branching complexity and density, is associated with lacunar stroke. A total of 392 patients presenting with acute ischemic stroke had retinal fractal dimension measured from digital photographs, and lacunar infarct ascertained from brain imaging. After adjusting for age, gender, and vascular risk factors, higher retinal fractal dimension (highest vs lowest quartile and per standard deviation increase) was independently and positively associated with lacunar stroke (odds ratio [OR], 4.27; 95% confidence interval [CI], 1.49–12.17 and OR, 1.85; 95% CI, 1.20–2.84, respectively). Increased retinal microvascular complexity and density is associated with lacunar stroke. ANN NEUROL 2010;68:107–111     

Rhizomelic Chondrodysplasia Punctata and cardiac pathology

Tijdschrift voor Kindergeneeskunde -     

Peripheral quantitative computer tomographic,histomorphometric, and removal torque analyses of two different non‐coated implants in a rabbit model

Objective: The objectives of this study were (1) to investigate the bone–tissue response to zirconia and titanium implants at the implant‐to‐bone interface and at the periosteal level and (2) to quantitatively measure the mineral density of the peri‐implant bone using peripheral quantitative computer tomography (pQCT). Material and methods: Ten 3.5 mm × 6.6 mm screw‐shaped threaded implants fabricated from titanium and zirconia were inserted into the mid‐tibial diaphysis of five male New Zealand white rabbits. Calcein green was administered at 4 weeks post‐implantation. The animals were sacrificed after 6 weeks and implants were retrieved and analyzed in terms of bone‐to‐implant contact (BIC), bone area (BA), mineralized surface (MS) percentage, inter‐thread calcein labels, removal torque (RT) values, as well as pQCT measurements. Findings: No statistically significant differences were detected between the zirconia and titanium implants in terms of BIC, RT, and pQCT. However, statistically significant higher BA and MS levels were found in the titanium group, while the higher amount of calcein labels occupying the threads were found in the zirconium group. Significant differences were also found in the quantity and the composition of bone at the bone–implant interfacial area vs. the region 1.5 mm away from the bone–implant interface, irrespective of the implant type. Conclusion: Zirconia implants demonstrated a lower bone remodeling activity in the periosteal region. The bone at the bone–implant interface shows a significantly lower cortical bone density, a higher trabecular density, and trabecular mineral content. Finally, zirconia and titanium implants showed similar bone–implant responses in terms of BIC and RT. To cite this article:
Shin D, Blanchard SB, Ito M, Chu T‐MG. Peripheral quantitative computer tomographic, histomorphometric, and removal torque analyses of two different non‐coated implants in a rabbit model.
Clin. Oral Impl. Res. 22 , 2011; 242–250.
doi: 10.1111/j.1600‐0501.2010.01980.x     

Clinical implications of minimal residual disease monitoring by quantitative polymerase chain reaction in acute myeloid leukemia patients bearing nucleophosmin (NPM1) mutations.

To explore the validity and prognostic significance of minimal residual disease detection by quantitative polymerase chain reaction (qPCR) in patients of acute myeloid leukemia (AML) bearing Nucleophosmin (NPM1) mutations, we quantified mutants in 194 bone marrow samples from 38 patients with a median follow-up time of 20.6 months. Following induction chemotherapy, a median of 2.78 log decline in mutant copy number was observed. Relapse was always accompanied by significant increase of mutant numbers (P<0.001). After achieving complete remission (CR), the mutant copy number was significantly higher in patients with subsequent relapse than in those remaining in continuous CR (P<0.001). Presence of detectable mutants after treatment predicted relapse if no further chemotherapy was administered. Furthermore, the patients with any rise of mutant signals during serial follow-up had 3.2-fold increase of relapse risk compared to those with persistently low or undetectable signals (P<0.001). Patients who could achieve mutant reduction to <0.1% of internal control had significantly longer overall survival (OS) (P=0.004) and relapse-free survival (RFS) (P<0.001). Failure to achieve 2 logs of reduction after consolidation predicted shorter OS (P=0.01) and RFS (P=0.001). In conclusion, qPCR monitoring may have prognostic impact in AML patients with NPM1 mutations.     

Radiosynthesis of [18F]PBR111, a selective radioligand for imaging the translocator protein (18 kDa) with PET

PBR111 (2‐(6‐chloro‐2‐(4‐(3‐fluoropropoxy)phenyl)imidazo[1,2‐a]pyridin‐3‐yl)‐N,N‐diethylacetamide) is a novel, reported, high‐affinity and selective ligand for the translocator protein (18 kDa). PBR111 has been labelled with fluorine‐18 (half‐life: 109.8 min) using our Zymate‐XP robotic system. The process involves (A) a simple one‐step tosyloxy‐for‐fluorine nucleophilic aliphatic substitution (performed at 165°C for 5 min in DMSO using K[¹⁸F]F‐Kryptofix^®222 and 6.8–7.6 µmol of the corresponding tosylate as precursor for labelling) followed by (B) C‐18 PrepSep cartridge pre‐purification and (C) semi‐preparative HPLC purification on a Waters Symmetry^® C‐18. Up to 4.8 GBq (130 mCi) of [¹⁸F]PBR111 could be obtained with specific radioactivities ranging from 74 to 148 GBq/µmol (2–4 Ci/µmol) in 75–80 min (HPLC purification and SepPak^®‐based formulation included), starting from a 37.0 GBq (1.0 Ci) [¹⁸F]fluoride batch. Overall non‐decay‐corrected isolated yields were 8–13% (13–21% decay‐corrected). Copyright © 2008 John Wiley & Sons, Ltd.     

Cyclin D3 Is Essential for Intestinal Epithelial Cell Proliferation

Intestinal epithelium is a complex organ that undergoes continuous proliferation. D-type cyclins bind cyclin-dependent kinases (Cdk4 and Cdk6) and are expressed during the transition from G0 into the S phase. Previously, we reported that cyclins D1 and D3 are induced by growth factors in two rat intestinal epithelial cell lines, IEC-6 and RIE-1. However, transforming growth factor beta induces G1 arrest in both intestinal cell lines without inhibiting cyclin D3, suggesting that cyclin D3 may not have essential functions in the gut. In the present study, we determined whether cyclin D3 is required for the transition from G0 into the S phase in intestinal epithelial cells. Microinjection of anti-cyclin D3 antiserum inhibited quiescent IEC-6 and RIE-1 cells from entering the S phase, while cells microinjected with a nonspecific mouse immunoglobin G continued to progress into the S phase. We also examined the expression of cyclin D3 in rat jejunal mucosa after fasting and refeeding. Cyclin D3 levels were not altered by fasting and refeeding; however, Cdk4 expression was suppressed by fasting and returned to control levels after refeeding. Our results suggest that cyclin D3 is essential for intestinal epithelial cell proliferation, although its expression is not regulated by dietary restriction.