1,103 research outputs found

    Functional Magnetic Resonance Imaging Studies of the Primary Somatosensory Cortex in Relation to Complex Regional Pain Syndrome

    Get PDF
    Functional MRI was used to detect brain activations in the primary somatosensory cortex (SI) in response to a vibrotactile stimulus applied to the thumb (D1) and little finger (D5) of the right (R) and left (L) hands. Four studies were carried out with healthy subjects in order to determine the scanning and stimulation protocols that resulted in consistent and robust SI activity. It was found that a strong stimulus, compared to a weak stimulus, led to the SI activity being detected more frequently and at a more statistically significant level. Also, extending the scanning duration per digit further increased the T-scores. The SI activations for each digit showed multiple foci and were distributed throughout the SI area. However, a clustering occurred in separate centres for stimulation to RD1 and RD5 near the Brodmann area 1/Brodmann area 3 boundary. The Euclidean separations of the cortical digit representations for LD1-D5 and RD1-D5 were calculated on the basis of the `centre of mass' of the multiple activations. Observed separations ranged between 1.2 mm to 22.8 mm. A further vibrotactile fMRI study was carried out involving patients with complex regional pain syndrome (CRPS). It has been suggested an altered central processing mechanism is involved in the disease, possibly due to cortical reorganisation in the sensory/motor cortices. The most efficient experimental protocols from the healthy subject studies were used to determine if these cortical differences were present in four patients. Data were acquired over two scanning sessions, approximately four months apart. The study revealed multiple SI foci and overlapping between the digits in both the healthy and CRPS hands, similar to those observed in the first studies. Larger SI activations were detected in one patient, smaller SI activations were detected in another patient and two patients demonstrated cluster sizes in the normal range. The cluster sizes and the changes in size between the two scans suggest a correlation with the amount of pain experienced by the patients. A general lack of consistency in the results from all the studies may be attributed to the difficulty of reliably detecting SI activity at a field strength of 1.5 T.DAAR

    Alien Registration- Carr, Sarah M. (Houlton, Aroostook County)

    Get PDF
    https://digitalmaine.com/alien_docs/35894/thumbnail.jp

    SELENIUM FORM-INDUCED CHANGES IN THE EARLY LUTEAL PHASE CORPUS LUTEUM, THE BLOOD, AND THE ENDOMETRIUM DURING EARLY GESTATION IN BEEF COWS

    Get PDF
    Selenium (Se) deficient soils and thus forages are widespread throughout the United States, necessitating supplementation of this trace mineral in the diet of grass-fed cattle to negate detrimental effects of a deficiency on immune function, growth, and fertility. Conventionally, Se is supplemented to cattle in a vitamin-mineral mix as an inorganic form (ISe) although the organic forms (OSe) are available when cattle consumer forage, and OSe has been shown to increase the bioavailability of Se in cattle. Previous research has demonstrated supplementation with 1:1 mixture (MIX) of ISe and OSe compared to ISe alone increases systemic concentrations of progesterone (P4) in the early luteal phase of cows at a time in which the concentration of P4 can critically influence the endometrium and developing conceptus. Herein, a series of experiments were conducted to 1) determine the mechanism responsible for the MIX-induced increase in the early luteal phase concentration of systemic P4, 2) identify form of Se effects on systemic blood metabolites during early gestation, and 3) investigate interferon-induced changes in the caruncular (CAR) tissue of the endometrium as a response of different supplemental forms of Se (ISe vs. MIX) which may affect the ensuing process of implantation. The objectives of Experiment 1 were to confirm and expand upon the initial report of the MIX-induced increase in early luteal phase P4, determining systemic changes in P4 throughout gestation, and prolactin (PRL) throughout lactation. We observed a MIX-induced increase in systemic concentrations of P4 on day 7 of the estrous cycle, consistent with our initial report, with circulating P4 then remaining higher throughout gestation. In contrast, prolactin was lower in the MIX supplemented heifers at months 5 and 6 of lactation; supplemental form of Se can be used to manipulate early luteal phase and gestational concentrations of P4, and postpartum concentration of PRL. The objective of Experiment 2 was to investigate the mechanistic changes in the CL contributing to the increase in systemic P4 by analyzing changes in mRNA transcripts in the CL and the responses of steroidogenic luteal cells to select agonists in vitro. Initially, we observed human chorionic gonadotropin (hCG)-induced increases in P4 in culture media of luteal cells obtained from ISe-supplemented cows. Interestingly, qPCR revealed no significant differences in the steroidogenic transcripts in the CL, however the abundance of mRNA encoding 2 key transcripts regulating cholesterol uptake (Ldlr and Hsl) was increased in MIX-supplemented cows, collectively suggesting that the form of Se-induced effects on luteal production of P4 are the result of changes in cholesterol availability, rather than a direct effect on the expression of steroidogenic enzymes within the CL. Following Experiment 2, we investigated changes in systemic blood metabolites during early gestation in response to the form of Se. Therefore, the objective of Experiment 3 was to quantify relative changes in serum metabolic parameters at estrus, during the early luteal phase, and at maternal recognition of pregnancy (MRP). MIX-supplemented heifers compared to ISe had significantly lower concentration of total serum cholesterol and low/very low-density lipoproteins, as well as changes in serum glucose, aspartate aminotransferase (AST), and beta hydroxybutyrate (BHBA). The objective of Experiment 4 was to investigate transcriptomic changes in the CAR regions of the endometrium at MRP. Results revealed significant changes in interferon signaling and endometrial restructuring that would be expected just prior to implantation. Given the advanced conceptus development observed in MIX vs. ISe-supplemented heifers, coincident with the concurrent decrease in the level of expression of several known MRP-associated transcripts, it appears that the MIX supplement is shifting the timing of MRP, resulting in hastened conceptus development. Encompassing all results, manipulating the form of Se in the diet of grazing beef cattle significantly alters systemic levels of P4, blood metabolites, and transcriptomic changes in the CL and endometrium that can advance conceptus development during early gestation. MIX Se is a novel producer-friendly supplement that can ultimately improve whole animal physiology and fertility
    corecore