The cerebellum modulates thirst.

The cerebellum, a phylogenetically ancient brain region, has long been considered strictly a motor control structure. Recent studies have implicated the cerebellum in cognition, sensation, emotion and autonomic function, making it an important target for further investigation. Here, we show that cerebellar Purkinje neurons in mice are activated by the hormone asprosin, leading to enhanced thirst, and that optogenetic or chemogenetic activation of Purkinje neurons induces rapid manifestation of water drinking.

Bone turnover change after randomized switch from tenofovir disoproxil to tenofovir alafenamide fumarate in men with HIV.

Objective: Bone loss in people with HIV (PWH) is poorly understood. Switching tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF) has yielded bone mineral density (BMD) increases. PETRAM (NCT#:03405012) investigated whether BMD and bone turnover changes correlate.

Utility of a simplified [F] sodium fluoride PET imaging method to quantify bone metabolic flux for a wide range of clinical applications.

We review the rationale, methodology, and clinical utility of quantitative [F] sodium fluoride ([F]NaF) positron emission tomography-computed tomography (PET-CT) imaging to measure bone metabolic flux (K, also known as bone plasma clearance), a measurement indicative of the local rate of bone formation at the chosen region of interest. We review the bone remodelling cycle and explain what aspects of bone remodelling are addressed by [F]NaF PET-CT. We explain how the technique works, what measurements are involved, and what makes [F]NaF PET-CT a useful tool for the study of bone remodelling.

The additive effect of vitamin K supplementation and bisphosphonate on fracture risk in post-menopausal osteoporosis: a randomised placebo controlled trial.

Unlabelled: This study assessed whether vitamin K, given with oral bisphosphonate, calcium and/or vitamin D has an additive effect on fracture risk in post-menopausal women with osteoporosis. No difference in bone density or bone turnover was observed although vitamin K supplementation led to a modest effect on parameters of hip geometry.

Purpose: Some clinical studies have suggested that vitamin K prevents bone loss and may improve fracture risk.

Input function and modeling for determining bone metabolic flux using [ F] sodium fluoride PET imaging: A step-by-step guide.

Studies of skeletal metabolism using measurements of bone metabolic flux (K ) obtained with [ F] sodium fluoride ([ F]NaF) positron emission tomography (PET) scans have been used in clinical research for the last 30 years. The technique has proven useful as an imaging biomarker in trials of novel drug treatments for osteoporosis and investigating other metabolic bone diseases, including chronic kidney disease mineral and bone disorder. It has also been shown to be valuable in metastatic bone disease in breast cancer patients and may have potential in other cancer types, such as prostate cancer, to assess early bone fracture risk.

A Short Dynamic Scan Method of Measuring Bone Metabolic Flux Using [F]NaF PET.

[F]NaF PET measurements of bone metabolic flux (K) are conventionally obtained with 60-min dynamic scans analysed using the Hawkins model. However, long scan times make this method expensive and uncomfortable for subjects. Therefore, we evaluated and compared measurements of K with shorter scan times analysed with fixed values of the Hawkins model rate constants.

Comparison of ordered-subset expectation maximization and filtered back projection reconstruction based on quantitative outcome from dynamic [18F]NaF PET images.

[18F]NaF PET imaging is a useful tool for measuring regional bone metabolism. However, due to tracer in urine, [18F]NaF PET images of the hip reconstructed using filtered back projection (FBP) frequently show streaking artifacts in slices through the bladder leading to noisy time-activity curves unsuitable for quantification. This study compares differences between quantitative outcomes at the hip derived from images reconstructed using the FBP and ordered-subset expectation maximization (OSEM) methods.

Serum vitamin K (phylloquinone) is associated with fracture risk and hip strength in post-menopausal osteoporosis: A cross-sectional study.

Purpose: Vitamin K may play a potential role in bone metabolism, although further evidence is needed. The mechanisms behind its skeletal effects and optimum intake for maintaining bone health remain poorly defined. To elucidate these two issues, we investigated the association between circulating vitamin K (phylloquinone) concentrations with fracture risk, bone mineral density (BMD), hip geometry and plasma dephospho-uncarboxylated-Matrix Gla Protein (dp-ucMGP), an extra-hepatic vitamin K dependent protein (VKDP), in post-menopausal osteoporosis (PMO).

The influence of CT and dual-energy X-ray absorptiometry (DXA) bone density on quantitative [F] sodium fluoride PET.

Background: [F] sodium fluoride PET/CT provides quantitative measures of bone metabolic activity expressed by the parameters standardised uptake value (SUV) and bone plasma clearance ( ) that correlate with measurements of bone formation rate obtained by bone biopsy with double tetracycline labelling. Both SUV and relate to the tracer uptake in each millilitre of tissue. In general, the bone region of interest (ROI) includes both mineralised bone {generally with a high concentration of [F]NaF} and bone marrow (with a much lower concentration), suggesting that correcting SUV and for volumetric bone mineral density (vBMD) and measuring them with respect to the tracer uptake in each gram of bone mineral might improve the correlation with the findings of bone biopsy.

Site specific measurements of bone formation using [F] sodium fluoride PET/CT.

Dynamic positron emission tomography (PET) imaging with fluorine-18 labelled sodium fluoride ([F]NaF) allows the quantitative assessment of regional bone formation by measuring the plasma clearance of fluoride to bone at any site in the skeleton. Today, hybrid PET and computed tomography (CT) dual-modality systems (PET/CT) are widely available, and [F]NaF PET/CT offers a convenient non-invasive method of studying bone formation at the important osteoporotic fracture sites at the hip and spine, as well as sites of pure cortical or trabecular bone. The technique complements conventional measurements of bone turnover using biochemical markers or bone biopsy as a tool to investigate new therapies for osteoporosis, and has a potential role as an early biomarker of treatment efficacy in clinical trials.

Relevance of Bisphosphonate Therapy in Osteoporosis and Cancer--No Cause for Alarm in Dentistry.

This report provides important background information on osteoporosis (OP) and bone complications of cancer for the dental team, and discusses why bisphosphonate (BP) therapy is vital for patients with the two conditions. It also addresses several questions, including in particular: 'Is withholding BP therapy the best way to prevent osteonecrosis of the jaw (ONJ) occurrence?' Also,'Of the two, which is more important: ONJ or OP fracture prevention?' CPD/Clinical Relevance: BP therapy offers OP patients the promise of a fracture-free life and the prevention of fracture-related pain, disability, loss of qualify of life (QOL) and the shortening of life. Without BP therapy, the lifetime risk of fracture occurrence in OP patients is as high as 1 in 2 women and 1 in 5 men; whilst using it, the relative risk of ONJ occurrence is as low as between 1 in 10, 000 and 1 in 100, 000.

Sea snake harvest in the gulf of Thailand.

Conservation of sea snakes is virtually nonexistent in Asia, and its role in human-snake interactions in terms of catch, trade, and snakebites as an occupational hazard is mostly unexplored. We collected data on sea snake landings from the Gulf of Thailand, a hotspot for sea snake harvest by squid fishers operating out of the ports of Song Doc and Khanh Hoi, Ca Mau Province, Vietnam. The data were collected during documentation of the steps of the trading process and through interviewers with participants in the trade.

Imaging of site specific bone turnover in osteoporosis using positron emission tomography.

The functional imaging technique of dynamic fluorine-18 labeled sodium fluoride positron emission tomography ((18)F-NaF PET) allows the quantitative assessment of regional bone formation by measuring the plasma clearance of fluoride to bone at any site in the skeleton. (18)F-NaF PET provides a novel and noninvasive method of studying site-specific bone formation at the hip and spine, as well as areas of pure cortical or trabecular bone. The technique complements conventional measurements of bone turnover using biochemical markers and bone biopsy as a tool to investigate new treatments for osteoporosis, and holds promise of a future role as an early biomarker of treatment efficacy in clinical trials.

Correcting (18)F-fluoride PET static scan measurements of skeletal plasma clearance for tracer efflux from bone.

Objective: The aim of the study was to examine whether (18)F-fluoride PET ((18)F-PET) static scan measurements of bone plasma clearance (Ki) can be corrected for tracer efflux from bone from the time of injection.

Materials And Methods: The efflux of tracer from bone mineral to plasma was described by a first-order rate constant kloss. A modified Patlak analysis was applied to 60-min dynamic (18)F-PET scans of the spine and hip acquired during trials on the bone anabolic agent teriparatide to find the best-fit values of kloss at the lumbar spine, total hip and femoral shaft.

(18)F-fluoride positron emission tomography measurements of regional bone formation in hemodialysis patients with suspected adynamic bone disease.

(18)F-fluoride positron emission tomography ((18)F-PET) allows the assessment of regional bone formation and could have a role in the diagnosis of adynamic bone disease (ABD) in patients with chronic kidney disease (CKD). The purpose of this study was to examine bone formation at multiple sites of the skeleton in hemodialysis patients (CKD5D) and assess the correlation with bone biopsy. Seven CKD5D patients with suspected ABD and 12 osteoporotic postmenopausal women underwent an (18)F-PET scan, and bone plasma clearance, K i, was measured at ten skeletal regions of interest (ROI).

¹⁸F-fluoride PET as a noninvasive imaging biomarker for determining treatment efficacy of bone active agents at the hip: a prospective, randomized, controlled clinical study.

The functional imaging technique of ¹⁸F-fluoride positron emission tomography (¹⁸F-PET) allows the noninvasive quantitative assessment of regional bone formation at any skeletal site, including the spine and hip. The aim of this study was to determine if ¹⁸F-PET can be used as an early biomarker of treatment efficacy at the hip. Twenty-seven treatment-naive postmenopausal women with osteopenia were randomized to receive teriparatide and calcium and vitamin D (TPT group, n = 13) or calcium and vitamin D only (control group, n = 14).

Semiautomatic region-of-interest validation at the femur in (18)F-fluoride PET/CT.

Unlabelled: The assessment of regional skeletal metabolism using (18)F-fluoride PET ((18)F-PET) requires segmentation of the tissue region of interest (ROI). The aim of this study was to validate a novel approach to define multiple ROIs at the proximal femur similar to those used in dual x-ray absorptiometry. Regions were first drawn on low-dose CT images acquired as a routine part of the PET/CT study and transferred to the (18)F-PET images for the quantitative analysis of bone turnover.

Quantitative PET Imaging Using (18)F Sodium Fluoride in the Assessment of Metabolic Bone Diseases and the Monitoring of Their Response to Therapy.

Studies of bone remodeling using bone biopsy and biochemical markers of bone turnover measured in serum and urine are important for investigating how new treatments for osteoporosis affect bone metabolism. Positron emission tomography with (18)F sodium fluoride ((18)F NaF PET) for studying bone metabolism complements these conventional methods. Unlike biochemical markers, which measure the integrated response to treatment across the whole skeleton, (18)F NaF PET can distinguish changes occurring at sites of clinically important osteoporotic fractures.

A semipopulation input function for quantifying static and dynamic 18F-fluoride PET scans.

Purpose: We describe a semipopulation input function for evaluating bone plasma clearance from static and dynamic (18)F-fluoride PET scans.

Methods: The semipopulation input function was derived by fitting an exponential curve to venous plasma measurements obtained 30-60 min after injection and adding a population residual curve representing the bolus peak scaled for injected activity and adjusted for time of peak counts. The residual curve was found from nine postmenopausal women who had continuous arterial blood samples and venous samples taken every 10 min.

Comparison of six quantitative methods for the measurement of bone turnover at the hip and lumbar spine using 18F-fluoride PET-CT.

Aim: The aim of this study was to evaluate the relationship between different quantification methods used for the measurement of bone plasma clearance (K(i)) using F-PET at the hip and lumbar spine.

Methods: Twelve healthy postmenopausal women aged 52-71 years were recruited. Each participant underwent 60-min dynamic F-PET scans at the lumbar spine and hip on two separate occasions with an injected activity of 90 and 180 MBq, respectively.

Estimation of regional bone metabolism from whole-body 18F-fluoride PET static images.

Purpose: We evaluate a new quantitative method of acquiring and analysing (18)F positron emission tomography (PET) studies that enables regional bone plasma clearance (K ( i )) to be estimated from static scans acquired at multiple sites in the skeleton following a single injection of tracer.

Methods: Dynamic lumbar spine (18)F PET data from two clinical trials were used to simulate a series of static scans acquired 30-60 min after injection. Venous blood samples were taken at 30, 40, 50 and 60 min and K ( i ) evaluated by Patlak analysis and the static scan method.