Increased 18F-FDG Uptake in Lhermitte-Duclos Disease With Cowden Syndrome Revealed by PET-MRI

International audienceA 62-year-old woman, with the history of breast and colorectal cancer, presented intermittent diplopia. A cerebellar lesion was revealed by F-FDG PET-MRI without post-gadolinium enhancement, but with increased perfusion and strong F-FDG uptake. The diagnosis of Cowden syndrome with PTEN gene mutation, linked to higher risk of neoplasia and occurrence of hamartomatous lesions characteristic of the Lhermitte-Duclos disease (LDD), was confirmed by genetic investigation

Can Nuclear Imaging Techniques Predict Patient Outcome and Guide Medical Management in Hereditary Transthyretin Cardiac Amyloidosis?

International audiencePurpose of Review Nuclear imaging recently gained a key role in the diagnosis and prognostic assessment of transthyretin (TTR)-related cardiac amyloidosis. This review aims at summarizing the state-of-the art regarding the implementation of nuclear imaging in the management of hereditary mutated TTR-cardiac amyloidosis (mTTR-CA). Recent Findings Although cardiac uptake of bone tracers is acknowledged as a specific marker of TTR amyloid cardiac burden, recent studies validated the implementation of bone scan in the flow chart for non-invasive diagnosis and follow-up of CA in multicenter trials. Simultaneously, cardiac denervation evidenced by MIBG scintigraphy proved to be a strong and independent prognostic marker of poor outcome in mTTR-CA. Summary By its unique ability to assess both amyloid burden and cardiac denervation, nuclear imaging may prove useful as part of multimodality imaging tools to trigger treatment initiation and monitoring in patients with mTTR-CA

Dorsomedial Hypothalamic Lesions Block Syrian Hamster Testicular Regression in Short Day Lengths Without Diminishing Increased Testosterone Negative-Feedback Sensitivity1

The dorsomedial nucleus (DMN) of the hypothalamus, the only site within the mediobasal hypothalamus of Syrian hamsters that both binds melatonin and has abundant concentrations of androgen receptors, has been proposed as a target tissue for induction of seasonal changes in brain sensitivity to steroid negative feedback. We tested whether DMN ablation, which does not interfere with pineal gland secretion of melatonin in short day lengths, prevents testicular regression by altering sensitivity to steroid negative feedback. Hamsters with DMN lesions, unlike control hamsters, failed to undergo testicular regression after transfer from a long (14 h light/day) to a short day length (8 h light/day); however, increased negative-feedback inhibition of follicle-stimulating hormone by testosterone was not compromised by ablation of the DMN, indicating that this tissue is not an essential mediator of seasonal changes in feedback sensitivity. We propose a redundant neural network comprised of multiple structures, each of which contributes to neuroendocrine mechanisms, that determines the effect of short days on gonadal function

Dorsomedial Hypothalamic Lesions Block Syrian Hamster Testicular Regression in Short Day Lengths Without Diminishing Increased Testosterone Negative-Feedback Sensitivity1

The dorsomedial nucleus (DMN) of the hypothalamus, the only site within the mediobasal hypothalamus of Syrian hamsters that both binds melatonin and has abundant concentrations of androgen receptors, has been proposed as a target tissue for induction of seasonal changes in brain sensitivity to steroid negative feedback. We tested whether DMN ablation, which does not interfere with pineal gland secretion of melatonin in short day lengths, prevents testicular regression by altering sensitivity to steroid negative feedback. Hamsters with DMN lesions, unlike control hamsters, failed to undergo testicular regression after transfer from a long (14 h light/day) to a short day length (8 h light/day); however, increased negative-feedback inhibition of follicle-stimulating hormone by testosterone was not compromised by ablation of the DMN, indicating that this tissue is not an essential mediator of seasonal changes in feedback sensitivity. We propose a redundant neural network comprised of multiple structures, each of which contributes to neuroendocrine mechanisms, that determines the effect of short days on gonadal function

Exposure duration to mutated TTR is a key parameter determining diphosphonates cardiac uptake in FAP

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Dose Reduction in Brain [18F]FDG PET/MRI: Give It Half a Chance

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