Pancreatic perfusion modulation following glucose stimulation assessed by noninvasive arterial spin labeling (ASL) MRI.

BACKGROUND: More than 100 million adults in the US suffer from prediabetes or type-2 diabetes. Noninvasive imaging of pancreas endocrine function might provide a surrogate marker of ß-cell functional integrity loss linked to this disease. PURPOSE: To noninvasively assess pancreatic blood-flow modulation following a glucose challenge using arterial spin labeling (ASL) MRI. STUDY TYPE: Prospective. SUBJECTS: Fourteen adults (30 ± 7 years old, 3M/11F, body mass index [BMI] = 24 ± 3 kg.m-2 ). FIELD STRENGTH/SEQUENCE: 3T MRI / background-suppressed pseudocontinuous PCASL preparation with single-shot fast-spin-echo (FSE) readout before and after an oral glucose challenge using either fruit juice (n = 7) or over-the-counter glucose gel (n = 7). ASSESSMENT: Subjects were fasting prior to initiation of oral stimulation, then dynamic perfusion measurements were performed every 2 minutes for 30 minutes. We quantified absolute blood flow at each timepoint. STATISTICAL TESTS: Repeated-measures analysis of variance (ANOVA) followed by paired t-tests to assess for a significant effect of glucose challenge on measured perfusion. RESULTS: Measured basal blood flow was 187 ± 53 mL/100g/min. A significant blood flow increase of +38 ± 26% was observed 10 minutes poststimulation (P < 0.05) and continuing until the end of the experiment. The gel stimulation provided the most consistent results, with an early rise followed by an additional later increase consistent with the known pancreatic insulin response to elevated blood glucose. Across-subject variations in blood flow increase were partially attributable to basal flow, with a negative correlation of r = -0.84 between basal and maximal relative flow increase in the gel group. DATA CONCLUSION: ASL can be used to measure pancreatic flow in response to a glucose challenge, which could be linked to insulin release and secretion. This paradigm might be useful to characterize disorders of glucose regulation. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2020;51:854-860.

An observational study reveals that neonatal vitamin D is primarily determined by maternal contributions: implications of a new assay on the roles of vitamin D forms.

BACKGROUND: Vitamin D concentrations during pregnancy are measured to diagnose states of insufficiency or deficiency. The aim of this study is to apply accurate assays of vitamin D forms [single- hydroxylated [25(OH)D2, 25(OH)D3], double-hydroxylated [1α,25(OH)2D2, 1a25(OH)2D3], epimers [3-epi-25(OH)D2, 3-epi-25(OH)D3] in mothers (serum) and neonates (umbilical cord) to i) explore maternal and neonatal vitamin D biodynamics and ii) to identify maternal predictors of neonatal vitamin D concentrations. METHODS: All vitamin D forms were quantified in 60 mother- neonate paired samples by a novel liquid chromatography -mass spectrometry (LC-MS/MS) assay. Maternal characteristics [age, ultraviolet B exposure, dietary vitamin D intake, calcium, phosphorus and parathyroid hormone] were recorded. Hierarchical linear regression was used to predict neonatal 25(OH)D concentrations. RESULTS: Mothers had similar concentrations of 25(OH)D2 and 25(OH)D3 forms compared to neonates (17.9 ± 13.2 vs. 15.9 ± 13.6 ng/mL, p=0.289) with a ratio of 1:3. The epimer concentrations, which contribute approximately 25% to the total vitamin D levels, were similar in mothers and neonates (4.8 ± 7.8 vs. 4.5 ± 4.7 ng/mL, p=0.556). No correlation was observed in mothers between the levels of the circulating form (25OHD3) and its active form. Neonatal 25(OH)D2 was best predicted by maternal characteristics, whereas 25(OH)D3 was strongly associated to maternal vitamin D forms (R²=0.253 vs. 0.076 and R2=0.109 vs. 0.478, respectively). Maternal characteristics explained 12.2% of the neonatal 25(OH)D, maternal 25(OH)D concentrations explained 32.1%, while epimers contributed an additional 11.9%. CONCLUSIONS: By applying a novel highly specific vitamin D assay, the present study is the first to quantify 3-epi-25(OH)D concentrations in mother-newborn pairs. This accurate assay highlights a considerable proportion of vitamin D exists as epimers and a lack of correlation between the circulating and active forms. These results highlight the need for accurate measurements to appraise vitamin D status. Maternal characteristics and circulating forms of vitamin D, along with their epimers explain 56% of neonate vitamin D concentrations. The roles of active and epimer forms in the maternal-neonatal vitamin D relationship warrant further investigation.

Decoding the Behavior of a Queenless Colony Using Sound Signals.

Honeybees are reported to be the most vital pollinators of agricultural and horticultural crops. However, their widespread decline has raised great attention to the need to monitor their activity in order to identify the causes and implement countermeasures. The recording and analysis of signals used by honeybees for their communication in their hive can be a very helpful tool to the beekeepers for the remote control of the hives. Thus, in the present study, we used a set of sound recording data taken inside the hives to automatically detect the sounds of the bees over a certain period, to distinguish between queenright and queenless states, and to find the gradual changes in the queenless state. Unlike what was commonly believed, noticeable changes in the sound signals of all experimental colonies were observed just one hour after the queens' removal from the hive, while the sound signals were intensified over a period of 5 h, after which the transmitted signal stabilized to the equivalent of a queenless state. The colonies seemed to return to their normal sounds 9-10 days after the reintroduction of the queens in the hives. Our study concluded that timely intervention of the queen's absence combined with the immediate intervention of the beekeeper may be a determining factor in mitigating the adverse effects that occur from the queen's loss.

Erectile dysfunction in patients with hyper- and hypothyroidism: how common and should we treat?

CONTEXT: Erectile dysfunction (ED) is associated with numerous diseases and aging. OBJECTIVE: The objective of the study was to investigate the impact of hyper- and hypothyroidism on male sexual health by using the Sexual Health Inventory for Males (SHIM). DESIGN: Seventy-one men, 27 hyper- and 44 hypothyroid and a similar number of controls were included in the study. A validated SHIM 5-item questionnaire was administered to all participants. Patients were asked to respond before and a year after initiation of treatment for thyroid dysfunction. A score between 25 and 22 is considered normal, between 21 and 11 diagnostic of mild to moderately severe ED, and 10 or less diagnostic of severe ED. RESULTS: Fifty-six men with thyroid dysfunction (78.9%; 19 hyperthyroid and 37 hypothyroid) had a SHIM score of 21 or less, compared with 24 controls (33.8%) (P < 0.0001). Twenty-one patients with ED (37.5%) had SHIM scores 10 or less, indicative of severe ED, compared with six controls (25%) (P < 0.01). ED was more prevalent in patients with hyperthyroidism and hypothyroidism, compared with controls (P < 0.001 and P < 0.0001, respectively). Positive correlation was found between SHIM scores and serum free T(4) (r = 0.413, P = 0.005) and negative for TSH (r = -0.669, P < 0.001). After treatment a significant increase of SHIM scores was noted in both hyperthyroid (P < 0.0001) and hypothyroid (P < 0.0001) patients. CONCLUSIONS: ED is extremely common in males with dysthyroidism. Treatment of the latter restores erectile function. Screening for thyroid dysfunction in men presenting with ED is recommended, whereas specific treatment for ED should be postponed in such patients for at least 6 months after achieving euthyroidism because the latter might be responsible for ED.

Increased osteoclastogenesis in patients with vertebral fractures following discontinuation of denosumab treatment.

OBJECTIVE: To test the hypothesis that rebound of bone remodeling is responsible for clinical vertebral fractures reported in a few patients with osteoporosis after cessation of denosumab treatment. DESIGN: In this case-control study we compared clinical and biochemical characteristics of postmenopausal women with clinical vertebral fractures 8-16 months after the last injection of denosumab (Dmab/Fx+, n = 5) with those of treatment-naïve women with such fractures (Fx+, n = 5). In addition, 5 women who discontinued denosumab treatment but did not sustain vertebral fractures 18-20 months after the last injection were studied (Dmab/Fx-, n = 5). METHODS: We measured serum microRNAs, gene expression of mRNAs of factors regulating formation and activity of osteoclasts and biochemical markers of bone and mineral metabolism. In Dmab/Fx+ and Fx+ women, blood was taken 4-8 weeks after the fracture. RESULTS: Compared to Fx+ women, Dmab/Fx+ women had higher serum P1NP and CTx levels, and significantly lower serum miR-503 and miR-222-2 that downregulate osteoclastogenesis and osteoclast activity, and higher RANK (13-fold) and CTSK (2.6-fold) mRNA. The respective values of Dmab/Fx- women were in the same direction as those of Dmab/Fx+ women but of a lesser magnitude. CONCLUSIONS: Bone fragility in women with clinical vertebral fractures after stopping denosumab therapy is pathophysiologically different from that of treatment-naïve women with osteoporosis and clinical vertebral fractures and it is associated with upregulation of markers of osteoclast formation and activity. The small number of women with this rare event studied is a limitation.

Fuzzy logic-based risk of fall estimation using smartwatch data as a means to form an assistive feedback mechanism in everyday living activities.

This Letter aims to create a fuzzy logic-based assistive prevention tool for falls, based on accessible sensory technology, such as smartwatch, resulting in monitoring of the risk factors of falls caused by orthostatic hypotension (OH); a drop in systolic blood pressure (DSBP) >20 mmHg due to postural changes. Epidemiological studies have shown that OH is a high risk factor for falls and has a strong impact in quality of life (QoL) of the elderly's, especially for some cases such as Parkinsonians. Based on smartwatch data, it is explored here how statistical features of heart rate variability (HRV) can lead to DSBP prediction and estimation of the risk of fall. In this vein, a pilot study was conducted in collaboration with five Greek Parkinson's Foundation patients and ten healthy volunteers. Taking into consideration, the estimated DSBP and additional statistics of the user's medical/behavioural history, a fuzzy logic inference system was developed, to estimate the instantaneous risk of fall. The latter is fed back to the user with a mechanism chosen by him/her (i.e. vibration and/or sound), to prevent a possible fall, and also sent to the attentive carers and/or healthcare professionals for a home-based monitoring beyond the clinic. The proposed approach paves the way for effective exploitation of the contribution of smartwatch data, such as HRV, in the sustain of QoL in everyday living activities.

Rising serum 25-hydroxy-vitamin D levels after weight loss in obese women correlate with improvement in insulin resistance.

OBJECTIVE: The objective of the study was to examine changes of 25-hydroxy-vitamin D (25OHD) and PTH blood levels 4 and 20 wk after low-calorie diet-induced weight loss. METHODS: Forty-four obese women [aged 40.6 +/- 11.4 yr, body mass index (BMI) 36.7 +/- 4.9 kg/m(2)] and 25 controls (BMI 22.9 +/- 1.5 kg/m(2)) were examined. Anthropometric and cardiometabolic parameters and 25OHD and PTH levels were determined at baseline and 4 and 20 wk after a low-calorie diet. RESULTS: At baseline, 25OHD levels were lower in obese compared with control subjects (17 +/- 6.0 vs. 23.8 +/- 8.7 ng/ml, P < 0.001), whereas no differences were found in PTH levels. In all women, a negative correlation was found between 25OHD levels and body weight (BW) (r -0.32, P < 0.001), BMI (r -0.37, P < 0.001), waist circumference (r -0.26, P < 0.05), and percent fat mass (r -0.38, P = 0.001) as determined by bioelectrical impedance analysis. The 4-wk low-calorie diet (n = 37) reduced BW and led to significant improvements in the homeostasis model assessment (HOMA) index and lipid levels. The 20-wk low-calorie diet (n = 26) resulted in reduction of BW and BMI by 10%, HOMA index (4.7 +/- 3.8 vs. 3.10 +/- 1.7, P < 0.01), and lipids levels (except high density lipoprotein cholesterol) and increase in 25OHD (15.4 +/- 6.0 vs. 18.3 +/- 5.1 ng/ml, P < 0.05), compared with baseline. PTH levels were unchanged. The increase of 25OHD levels was associated with the reduction of insulin levels and HOMA index (r -0.43, P < 0.05). CONCLUSIONS: Blood 25OHD levels were low in obese women and correlated inversely with severity measures of obesity. Weight loss of 10% after low-calorie diet increased 25OHD levels, and this increase was mainly associated with improvement of insulin resistance.

Hypothyroidism has an adverse effect on human spermatogenesis: a prospective, controlled study.

BACKGROUND: Abnormalities of spermatogenesis are associated with numerous diseases and aging. The objective of this study was to investigate the impact of hypothyroidism on human spermatogenesis and different sperm function tests. METHODS: Twenty-five hypothyroid men and 15 normal individuals were investigated. Semen analysis, fructose and acid phosphatase measurements, teratozoospermia index (TZI), and acridine orange test were determined before and 6-9 months after the initiation of treatment with levothyroxine. RESULTS: Morphology is the only sperm parameter that differs significantly between hypothyroid patients and controls (p < 0.0001). After treatment, morphology improved significantly (p < 0.001). Motility was also decreased before treatment in comparison with controls, and improved after treatment. However, the difference was not significant. TZI correlated with free thyroxine. CONCLUSIONS: Hypothyroidism has an adverse effect on human spermatogenesis. Morphology is the only sperm parameter that is significantly affected. Motility may also be affected, but further studies regarding this are needed. Screening for thyroid dysfunction in males who present with a defect in spermatogenesis is strongly recommended, and if hypothyroidism is noted, the response to thyroid hormone should be evaluated before initiating other treatments.