Foveal Cone Structure in Patients With Blue Cone Monochromacy

Purpose: Blue cone monochromacy (BCM) is a rare inherited cone disorder in which both long- (L-) and middle- (M-) wavelength sensitive cone classes are either impaired or nonfunctional. Assessing genotype-phenotype relationships in BCM can improve our understanding of retinal development in the absence of functional L- and M-cones. Here we examined foveal cone structure in patients with genetically-confirmed BCM, using adaptive optics scanning light ophthalmoscopy (AOSLO). / Methods: Twenty-three male patients (aged 6-75 years) with genetically-confirmed BCM were recruited for high-resolution imaging. Eight patients had a deletion of the locus control region (LCR), and 15 had a missense mutation-Cys203Arg-affecting the first two genes in the opsin gene array. Foveal cone structure was assessed using confocal and non-confocal split-detection AOSLO across a 300 × 300 µm area, centered on the location of peak cell density. / Results: Only one of eight patients with LCR deletions and 10 of 15 patients with Cys203Arg mutations had analyzable images. Mean total cone density for Cys203Arg patients was 16,664 ± 11,513 cones/mm2 (n = 10), which is, on average, around 40% of normal. Waveguiding cone density was 2073 ± 963 cones/mm2 (n = 9), which was consistent with published histological estimates of S-cone density in the normal eye. The one patient with an LCR deletion had a total cone density of 10,246 cones/mm2 and waveguiding density of 1535 cones/mm2. / Conclusions: Our results show that BCM patients with LCR deletions and Cys203Arg mutations have a population of non-waveguiding photoreceptors, although the spectral identity and level of function remain unknown

Assessment of murine collagen-induced arthritis by longitudinal non-invasive duplexed molecular optical imaging

In the present study we evaluated the use of four commercially available fluorescent probes to monitor disease activity in murine CIA and its suppression during glucocorticoid therapy.  Arthritis was induced in male DBA/1 mice by immunization with type II collagen in Complete Freund's Adjuvant, followed by a boost of collagen in PBS. Four fluorescent probes from PerkinElmer in combination [ProSense 750 fluorescent activatable sensor technology (FAST) with Neutrophil Elastase 680 FAST and MMPSense 750 FAST with CatK 680 FAST] were used to monitor disease development from day 5 through to day 40 post-immunization. Fluorescence generated in vivo by the probes was correlated with clinical and histological score and paw measurements.  The fluorescence intensity emitted by each probe was shown to correlate with the conventional measurements of disease. The highest degree of correlation was observed with ProSense 750 FAST in combination with Neutrophil Elastase 680 FAST; these probes were then used to successfully assess CIA suppression during dexamethasone treatment.  We have demonstrated that longitudinal non-invasive duplexed optical fluorescence imaging provides a simple assessment of arthritic disease activity within the joints of mice following the induction of CIA and may represent a powerful tool to monitor the efficacy of drug treatments in preclinical studies

Using a runway paradigm to assess the relative strength of rats' motivations for enrichment objects

Laboratory animals should be provided with enrichment objects in their cages; however, it is first necessary to test whether the proposed enrichment objects provide benefits that increase the animals’ welfare. The two main paradigms currently used to assess proposed enrichment objects are the choice test, which is limited to determining relative frequency of choice, and consumer demand studies, which can indicate the strength of a preference but are complex to design. Here, we propose a third methodology: a runway paradigm, which can be used to assess the strength of an animal’s motivation for enrichment objects, is simpler to use than consumer demand studies, and is faster to complete than typical choice tests. Time spent with objects in a standard choice test was used to rank several enrichment objects in order to compare with the ranking found in our runway paradigm. The rats ran significantly more times, ran faster, and interacted longer with objects with which they had previously spent the most time. It was concluded that this simple methodology is suitable for measuring rats’ motivation to reach enrichment objects. This can be used to assess the preference for different types of enrichment objects or to measure reward system processes

Hyperpolarized13c mri of tumor metabolism demonstrates early metabolic response to neoadjuvant chemotherapy in breast cancer

Purpose: To compare hyperpolarized carbon 13 (13C) MRI with dynamic contrast material–enhanced (DCE) MRI in the detection of early treatment response in breast cancer. Materials and Methods: In this institutional review board–approved prospective study, a woman with triple-negative breast cancer (age, 49 years) underwent13C MRI after injection of hyperpolarized [1–carbon 13 {13C}]-pyruvate and DCE MRI at 3 T at baseline and after one cycle of neoadjuvant therapy. The13C-labeled lactate-to-pyruvate ratio derived from hyperpolarized13C MRI and the pharmacokinetic parameters transfer constant (Ktrans) and washout parameter (kep ) derived from DCE MRI were compared before and after treatment. Results: Exchange of the13C label between injected hyperpolarized [1-13C]-pyruvate and the endogenous lactate pool was observed, catalyzed by the enzyme lactate dehydrogenase. After one cycle of neoadjuvant chemotherapy, a 34% reduction in the13C-labeled lactate-to-pyruvate ratio resulted in correct identification of the patient as a responder to therapy, which was subsequently confirmed via a complete pathologic response. However, DCE MRI showed an increase in mean Ktrans (132%) and mean kep (31%), which could be incorrectly interpreted as a poor response to treatment. Conclusion: Hyperpolarized13C MRI enabled successful identification of breast cancer response after one cycle of neoadjuvant chemotherapy and may improve response prediction when used in conjunction with multiparametric proton MRI

Hyperpolarized 13C-MRI of Tumor Metabolism Demonstrates Early Metabolic Response to Neoadjuvant Chemotherapy in Breast Cancer

Purpose: To compare hyperpolarized carbon-13 (13C)-MRI with dynamic contrast-enhanced MRI (DCE-MRI) for detecting early treatment response in breast cancer. Materials and Methods: In this institutional review board-approved prospective study, one woman with triple-negative breast cancer (age 49) underwent 13C-MRI following injection of hyperpolarized [1-13C]pyruvate and DCE-MRI at 3 T at baseline and after a single cycle of neoadjuvant therapy. The 13C-lactate/13C-pyruvate ratio derived from hyperpolarized 13C-MRI and the pharmacokinetic parameters Ktrans and kep derived from DCE-MRI were compared, before and after treatment. Results: Exchange of the 13C-label between injected hyperpolarized [1-13C]pyruvate and the endogenous lactate pool was demonstrated, catalyzed by the enzyme lactate dehydrogenase. After one cycle of neoadjuvant chemotherapy, a 34% reduction in the 13C-lactate/13C-pyruvate ratio was shown to correctly identify the patient as a responder to therapy, which was subsequently confirmed by a complete pathologic response. However, DCE-MRI showed an increase in the pharmacokinetic parameters Ktrans (132%) and kep (31%), which could be incorrectly interpreted as a poor response to treatment. Conclusion: Hyperpolarized 13C-MRI successfully identified response in breast cancer after a single cycle of neoadjuvant chemotherapy and may improve response prediction when used in conjunction with multiparametric proton MRI.This work was supported by a Wellcome Trust Strategic Award, Cancer Research UK (CRUK; Grants C8742/A18097, C19212/ A16628, C19212/A911376, and C197/A16465), the Austrian Science Fund (Grant J4025-B26), the CRUK Cambridge Centre, the CRUK & Engineering and Physical Sciences Research Council Cancer Imaging Centre in Cambridge and Manchester, the Mark Foundation for Cancer Research and Cancer Research UK Cambridge Centre (Grant C9685/A25177), CRUK National Cancer Imaging Translational Accelerator Award, Addenbrooke’s Charitable Trust, the National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Experimental Cancer Medicine Centre, and Cambridge University Hospitals National Health Service Foundation Trust

Bad faith in All’s Well That Ends Well

All’s Well That Ends Well is a complicated and disturbing play that has a comic ending, but which seems anything but a comedy with a forced marriage based on bed-trickery between the reluctant Bertram and the feisty and witty Helena. Unsurprisingly, audiences have tended to side with Helena and the play has been classified as a “problem comedy” ever since William Lawrence identified this particular group of Shakespeare plays nearly a century ago. I want to argue in this essay that the play might better be classified as an “equivocation” play alongside Macbeth, Othello, and Troilus and Cressida and that the anxieties about fidelity, honesty and truthfulness in marriage need to be read in terms of the fear of religious tolerance/intolerance which dominated religious politics in the early years of James’s reign before the passing of the Oath of Allegiance (1606). The play is notable for its interest in chop logic, which the clown in particular displays throughout the play, a counterpoint to the arguments of Bertram and Helena who want very different things, but who are bound together as future husband and wife. Although the language of treason and treachery is used throughout, the play is less interested in answering the question of how far one can trust a stranger within than the issue of how far one can accommodate the needs of others. This article is published as part of a collection to commemorate the 400th anniversary of William Shakespeare’s death

Characterization of Retinal Structure in ATF6-Associated Achromatopsia

Purpose: Mutations in six genes have been associated with achromatopsia (ACHM): CNGA3, CNGB3, PDE6H, PDE6C, GNAT2, and ATF6. ATF6 is the most recent gene to be identified, though thorough phenotyping of this genetic subtype is lacking. Here, we sought to test the hypothesis that ATF6-associated ACHM is a structurally distinct form of congenital ACHM. Methods: Seven genetically confirmed subjects from five nonconsanguineous families were recruited. Foveal hypoplasia and the integrity of the ellipsoid zone (EZ) band (a.k.a., IS/OS) were graded from optical coherence tomography (OCT) images. Images of the photoreceptor mosaic were acquired using confocal and nonconfocal split-detection adaptive optics scanning light ophthalmoscopy (AOSLO). Parafoveal cone and rod density values were calculated and compared to published normative data as well as data from two subjects harboring CNGA3 or CNGB3 mutations who were recruited for comparative purposes. Additionally, nonconfocal dark-field AOSLO images of the retinal pigment epithelium were obtained, with quantitative analysis performed in one subject with ATF6-ACHM. Results: Foveal hypoplasia was observed in all subjects with ATF6 mutations. Absence of the EZ band within the foveal region (grade 3) or appearance of a hyporeflective zone (grade 4) was seen in all subjects with ATF6 using OCT. There was no evidence of remnant foveal cone structure using confocal AOSLO, although sporadic cone-like structures were seen in nonconfocal split-detection AOSLO. There was a lack of cone structure in the parafovea, in direct contrast to previous reports. Conclusions: Our data demonstrate a near absence of cone structure in subjects harboring ATF6 mutations. This implicates ATF6 as having a major role in cone development and suggests that at least a subset of subjects with ATF6-ACHM have markedly fewer cellular targets for cone-directed gene therapies than do subjects with CNGA3- or CNGB3-ACHM

Imaging breast cancer using hyperpolarized carbon-13 MRI.

Our purpose is to investigate the feasibility of imaging tumor metabolism in breast cancer patients using 13C magnetic resonance spectroscopic imaging (MRSI) of hyperpolarized 13C label exchange between injected [1-13C]pyruvate and the endogenous tumor lactate pool. Treatment-naïve breast cancer patients were recruited: four triple-negative grade 3 cancers; two invasive ductal carcinomas that were estrogen and progesterone receptor-positive (ER/PR+) and HER2/neu-negative (HER2-), one grade 2 and one grade 3; and one grade 2 ER/PR+ HER2- invasive lobular carcinoma (ILC). Dynamic 13C MRSI was performed following injection of hyperpolarized [1-13C]pyruvate. Expression of lactate dehydrogenase A (LDHA), which catalyzes 13C label exchange between pyruvate and lactate, hypoxia-inducible factor-1 (HIF1α), and the monocarboxylate transporters MCT1 and MCT4 were quantified using immunohistochemistry and RNA sequencing. We have demonstrated the feasibility and safety of hyperpolarized 13C MRI in early breast cancer. Both intertumoral and intratumoral heterogeneity of the hyperpolarized pyruvate and lactate signals were observed. The lactate-to-pyruvate signal ratio (LAC/PYR) ranged from 0.021 to 0.473 across the tumor subtypes (mean ± SD: 0.145 ± 0.164), and a lactate signal was observed in all of the grade 3 tumors. The LAC/PYR was significantly correlated with tumor volume (R = 0.903, P = 0.005) and MCT 1 (R = 0.85, P = 0.032) and HIF1α expression (R = 0.83, P = 0.043). Imaging of hyperpolarized [1-13C]pyruvate metabolism in breast cancer is feasible and demonstrated significant intertumoral and intratumoral metabolic heterogeneity, where lactate labeling correlated with MCT1 expression and hypoxia