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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A systematic review of vitamin D for prevention of acute lower respiratory infection among children

Wu, Tianshu, 吴添舒 January 2013 (has links)
Objective: Acute lower respiratory infection (ALRI) is the leading cause of mortality in pediatric group all around the world. Vitamin D has been demonstrated to play a possible role in the prevention of ALRI in children because of its physiological importance in the immune system. This systematic review aims to explore the protective role of vitamin D on ALRIs among children and its preventive effectiveness by synthesizing RCTs. And the other objective is to determine dosage of vitamin D with the best effect by investigating the association of different level of vitamin D supplementation with risk of ALRIs. Methods: Studies were searched through three databases PubMed, ISI Web of Knowledge and Cochran Central Register of Controlled Trials and Cochran Library databases among publication from April2003 to April 2013 with a combination of key terms. Inclusion and exclusion criteria were used to select studies. And then CONSORT guideline and JADAD scale were used to assess quality of these studies. Data on outcome measurements including health outcomes (e.g. incidence of pneumonia and influenza A, duration of recovery of pneumonia and bronchiolitis, the risk of relapse of pneumonia, the number of parent-reported ARIs); and surrogate outcomes (e.g. measuring scores of ATAQ test) were extracted and tabulated. The association with vitamin D level of risk of ALRIs were explored as well. Results: Eight RCTs were found to be relevant and adopted in this systematic review of the 796 identified articles in English or Chinese. The findings were mixed, but most studies suggested vitamin D supplementation reduced risk or illness duration of ALRIs significantly among children with different levels of vitamin D deficiency. Four studies suggested statistically significant risk reduction on incidence of repeat pneumonia (by29%, 95%CI 6% to 46%), parent-reported ARIs (by 48%, 95%CI 11% to 69), influenza A (by 42%, 95%CI 1% to 66%), and asthma exacerbation triggered by ALRIs (P= 0.029), while one study showed an insignificant outcome. For recovery events and hospitalization of ALRIs, three studies suggested statistically significant reduction on recovery time from pneumonia (P= 0.008), severe asthma (P= 0.004) and bronchiolitis (P< 0.05), and two studies suggested significant decrease on duration of hospitalization for bronchiolitis (P< 0.05) and pneumonia (P= 0.005). The increasing changes in serum 25(OH)D were consistent with the significant difference of ALRIs events between intervention and control groups. Conclusion: Overall, the evidence is insufficient to conclude that vitamin D supplementation is beneficial to all kinds of children in preventing or assistant treating ALRIs. More number of high quality, large scale and unbiased RCTs should be conducted to confirm the effectiveness of vitamin D among children in Hong Kong and different areas in mainland China. / published_or_final_version / Public Health / Master / Master of Public Health
2

Combination of vitamins K₂ & D₃ supplementation enhances bone anabolism in type 2 diabetes-associated osteoporosis / CUHK electronic theses & dissertations collection

January 2014 (has links)
Despite numerous studies have demonstrated an association of type 2 diabetes mellitus (T2DM) and osteoporosis, the underlying mechanism connecting these two conditions remains elusive. Clinically, combined calcium and vitamin D supplement is the commonest osteoporosis therapy; however, recent studies have suggested an increase in cardiovascular risks associated with calcium plus vitamin D supplementation. Therefore, an alternative strategy in treating osteoporosis patients with T2DM is urgently needed. In this study, we hypothesized that combined administration of menaquinone-4 (vitamin K₂, biologically active form of vitamin K) and 1α,25-dihydroxyvitamin D₃ (vitamin D₃, biologically active form of vitamin D) as a novel therapy in treating osteoporosis of T2DM patients. Anabolic effect of vitamin K₂ and vitamin D₃, alone or in combination, was assessed on primary osteoblasts harvested from the iliac crests of C57BL/KsJ lean (db⁺/m⁺) and obese/diabetic (db⁺/db⁺, leptin receptor-deficient) mice. Furthermore, the underlying cellular mechanism was also investigated. Serum undercarboxylated osteocalcin (an indication of vitamin K₂ level) level was higher whereas vitamin D₃ level was lower in db⁺/db⁺ mice, and sections of the iliac crests of db⁺/db⁺ mice illustrated extensive porous structures filled with enlarged adipocytes compared with db⁺/m⁺ mice. Lower levels of bone anabolic markers and bone formation transcription factors (osteocalcin, Runx2, Dlx5, ATF4, type I collagen, OSX, alkaline phosphatase (ALP) activity, p-Smad1/5/8 and p-ERK1/2) were observed in the osteoblasts of db⁺/db⁺ mice. Acute vitamin D₃ (10 nM) application elicited a more sustained and greater magnitude of increase of [Ca²⁺]ᵢ in osteoblasts of db⁺/m⁺ mice when compared with db⁺/db⁺ mice. A significantly higher level of calcium deposits in osteoblasts was observed in db⁺/m⁺ mice when compared to db⁺/db⁺ mice. Co-administration of vitamin K₂ (10 nM) and vitamin D₃ (10 nM) caused an enhancement of calcium deposits in osteoblasts in both strains of mice. Vitamins K₂ and D₃ co-administration time-dependently (7, 14 and 21 days) increased the levels of bone anabolic markers and transcription factors for bone formation, with a greater magnitude of increase observed in osteoblasts of db⁺/db⁺ mice. Suppressed expression of calcium-sensing receptor (CaSR), F-actin, V-ATPase, vitamin D receptor (VDR) and pregnane X receptor (PXR) observed in osteoblasts of db⁺/db⁺ mice were partially reversed by combined vitamins treatment. Moreover, combined vitamins K₂ plus D₃ treatment significantly enhanced migration and the appearance of surface microvilli and ruffles of osteoblasts of db⁺/db⁺ mice. Effects of combined vitamins K₂ plus D₃ treatment observed in osteoblasts of db⁺/db⁺ and db⁺/m⁺ mice were eradicated by warfarin (20 µM, a vitamin K epoxide reductase inhibitor). Thus, our results illustrate that vitamins K₂ plus D₃ supplementation is a novel therapeutic strategy in treating osteoporosis of T2DM patients. / 儘管大量研究已證明第二類型糖尿病和骨質疏鬆症的關聯,連接這兩個病症的基本機制仍然是難以捉摸的。在臨床上,鈣和維生素D的綜合補充劑是最常見的骨質疏鬆症治療,然而最近的研究卻表明服用鈣和維生素D的綜合補充劑會增加患者的心血管風險,因此急切需要尋找可以給予同時患有骨質疏鬆症和第二類型糖尿病患者的替代治療。在本研究中,我們假設甲萘醌-4(維生素K₂,維生素K生物活性形式)和1α,25 - 二羥基維生素D₃(維生素D₃,維生素D的生物活性形式)可以嘗試在同時患有骨質疏鬆症和第二類型糖尿病患者身上作為一種革新的療法。本研究從C57BL/KsJ瘦削/非糖尿病 (db⁺/m⁺) 的小鼠和肥胖/帶有第二類型糖尿病基因 (db⁺/db⁺) 兼有瘦素受體缺陷的小鼠的髂嵴原始成骨細胞上對維生素K₂和維生素D₃單獨或組合使用的合成代謝作用進行了評估。此外,我們也對該成骨細胞的底層機制進行了一系列的研究。 / 在肥胖/帶有第二類型糖尿病基因的小鼠血清內低羧骨鈣素水平(維生素K₂水平的指標)較高而維生素D水平較低,另外,它們的髂嵴的部分與瘦削/非糖尿病的小鼠相比,呈現出比較廣泛的多孔結構並填滿了擴大的脂肪細胞。從肥胖/帶有第二類型糖尿病基因的小鼠的成骨細胞中,可以觀察到它們的骨合成代謝的標誌物和骨骼形成的轉錄因子 (骨鈣蛋白,Runx2,Dlx5,ATF4,第一類型骨膠原,OSX,鹼性磷酸酶 (ALP) 活性,p-Smad1/5/8和p-ERK1/2) 的水平比較低。急性維生素D₃ (10 nM) 的應用在瘦削/非糖尿病小鼠的成骨細胞比起在肥胖/帶有第二類型糖尿病基因的小鼠的成骨細胞引起更持續和更大幅度的細胞內鈣變化增加。在瘦削/非糖尿病小鼠的成骨細胞中比起在肥胖/帶有第二類型糖尿病基因的小鼠的成骨細胞有顯著較高的鈣沉積形成。維生素K₂ (10 nM) 和維生素D₃ (10 nM) 的綜合藥在兩種小鼠的成骨細胞中可以有效地增強鈣沉積的形成。維生素K₂和維生素D₃的綜合藥對增加骨合成代謝的標誌物和骨形成轉錄因子的水平有時間依賴性 (7,14和21日),療程越長至21日,在肥胖/帶有第二類型糖尿病基因小鼠的成骨細胞中有更大的幅度的增加。合併維生素治療能部分有效地逆轉在肥胖/帶有第二類型糖尿病基因小鼠的成骨細胞中被抑制表達的鈣敏感受體 (CASR),F-肌動蛋白,V-ATP酶,維生素D受體 (VDR) 和孕烷X受體 (PXR)。此外,結合維生素K₂加維生素D₃治療顯著增強了肥胖/帶有第二類型糖尿病基因小鼠的成骨細胞的細胞遷移和增加了成骨細胞表面外觀的微絨毛和褶皺。在瘦削/非糖尿病小鼠的成骨細胞及肥胖/帶有第二類型糖尿病基因的小鼠的成骨細胞上結合維生素K₂加維生素D₃的治療效果被華法林 (20 μM,維生素K環氧化物還原酶抑製劑) 根除。因此,我們的結果証明了維生素K₂加維生素D₃補充劑的結合使用可有效地作為治療第二類型糖尿病患者並患有骨質疏鬆症的一種新的治療策略。 / Poon, Chui Wa Christina. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2014.n5203 / Includes bibliographical references (leaves 135-151). / Abstracts also in Chinese. / Title from PDF title page (viewed on 26, October, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.
3

Postnatal vitamin D supplementation normalizes neonatal bone mass following maternal dietary vitamin D deficiency in the guinea pig

Finch, Sarah L. January 2007 (has links)
Since vitamin D deficiency is common at birth, the objective of this study was to test if postnatal vitamin D supplementation would normalize bone mineralization. Forty guinea pigs were randomized to receive a diet with or without vitamin D3 during pregnancy. Newborn pups were randomized to receive 10 IU of vitamin D3 or a placebo daily until d28. Measurements at birth and d28 included whole body and regional bone mass, osteocalcin and deoxypyridinoline, plus biomechanical testing of excised tibias and femurs. Offspring from deficient sows had lower body weight, whole body and tibia bone mineral content (BMC) and lower osteocalcin and biomechanical integrity. By d28 this group had lower whole body bone density and femur BMC, unless supplemented. Interactions with gender showed males continued to have low 25(OH)D despite supplementation. Therefore, neonates born to sows with dietary vitamin D deficiency require supplemental vitamin D to support normal bone mineral accretion.
4

Vitamin D- induced down regulation of RAD51 in head and neck squamous cell carcinoma (HNSCC), In Vitro and In Vivo

Hautea, Rhea P. 01 January 2011 (has links)
The active form of Vitamin D (VD3) has been shown to induce pro-apoptotic and anti-proliferative effects in several mammalian cancer cell types. The molecular mechanisms of tumor suppression, however, are not clearly understood. Previous research has shown that head and neck squamous cell carcinoma (HNSCC) responds to VD3. This thesis used both in vivo and in vitro models to examine the effect of VD3 in HNSCC. Former work in the Albala laboratory showed that hamsters that received systemic VD3 and topical treatment of 7,12-dimethylbenz(a)anthracene (DMBA) to the buccal pouch showed no or delayed carcinogenesis over the 14-week study compared to DMBA-only treated hamsters. This research further investigated the effect of VD3 in this hamster model. Using immunohistochemical (IHC) and western blot analysis, we demonstrate that systemic application of VD3to hamsters downregulates Rad51 expression in the buccal pouch and hinders the onset of tumor formation. Rad51 is a protein that plays a critical role in cell proliferation and homologous recombinational DNA repair. In the in vitro model, we show that Rad51 expression decreased in response to 100nM VD3 in HNSCC cell lines. The dose and time-dependence of VD3 on these cells was also examined. Western blot analysis and comet assay investigations confirmed that the SCC25 cell line is most sensitive to 100nM VD3 than to other doses tested, and that VD3 impairs the DNA-damage response. SiRNA and co-immunoprecipitation studies examined the potential of Chk 1 and p38 MAPK as upstream regulators of Rad51. Rad51 protein expression was found to be associated with early carcinogenesis from HNSCC cancer patients using IHC studies of human carcinomas from the oral cavity. This study focused on further identifying the role of Rad51 in response to VD3 in HNSCC.
5

Postnatal vitamin D supplementation normalizes neonatal bone mass following maternal dietary vitamin D deficiency in the guinea pig

Finch, Sarah L. January 2007 (has links)
No description available.
6

Studies on the role of vitamin D in asthma patients from a South Florida pulmonary practice

Unknown Date (has links)
Vitamin D insufficiency/deficiency is widespread in asthma, and epidemiological studies point to an association between low serum 25-hydroxyvitamin D level and poor asthma control and increased severity. In humans. Vitamin D is principally derived from sunlight induced cutaneous conversion of 7-dehydrocholesterol to vitamin D and oral supplementation. We sought to determine if established and chronic-persistent adult asthma patients from a South-Florida pulmonary patient population, with abundant sunshine availability and oral vitamin D supplementation exhibit vitamin D insufficiency/deficiency. A trend to vitamin D insufficiency was observed in approximately 65% of both adult asthma patients and apparently healthy (non-asthmatic) volunteers. . The transcription factors required for Th9 conversion, PU.1 and IRF-4, were down-regulated by vitamin D. The generation of Th9 cells was inhibited equally by vitamin D and dexamethasone when used alone, but the effect was additive when both steroids were used in combination. Our studies using non-specifically stimulated cells were extended by analyzing the effect of vitamin D on allergen specific stimulation. The response of CD4+ T cells obtained from the blood of house dust mite positive asthmatics was studied. House dust mite allergen elicited a classical Th2 phenotype response (IL-4, IL-5, IL-9, and IL-13 cytokine profile) and vitamin D effectively inhibited those key Th2 cytokines. We conclude that vitamin D appears to be of significant clinical benefit in our cohort of patients, i.e., established chronic adult human asthma, by down-regulating key immune cells including Th9, Th17, and Th2 involved in this disorder. / by Amjad Munim. / Thesis (Ph.D.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
7

Vitamin D, neuromuscular control and falling episodes in Australian postmenopausal women

Austin, Nicole January 2009 (has links)
Falls in the older population have devastating consequences on the psychological and physiological health of the individual. Due to the complexity of interacting factors associated with ageing, pathology and falling episodes, determination of a primary cause or set of causes has been difficult to establish. Deficits in components of neuromuscular control have been widely studied with the coordinated interaction of sensory and motor system components being presented as a fundamental factor in the reduction of falling episodes. A causal relationship between deficits in vitamin D status and falling episodes has also been suggested. Furthermore, a relationship between poor vitamin D status, falling episodes and poor neuromuscular performance has been reported. The aims of the current study were designed to advance understanding in three aspects of the problem of falls prevention. Firstly an examination of the reliability of testing procedures commonly used in assessment of falls risk was undertaken. The Physiological Profile Assessment (PPA) testing procedure was selected as a commonly used tool and the reliability of its various components (sensory, motor and balance) was undertaken as an independent assessment of this approach to assessing falls propensity. Secondly, a case control study of fallers and non fallers was undertaken in which the neuromuscular tests evaluated in the reliability study were used to assess differences in neuromuscular control. The influence of vitamin D status on these measures was also considered. Thirdly, a 12-month randomised controlled trial of vitamin D/calcium supplementation or placebo/calcium was undertaken to identify the effect on falls outcome and individual measures of neuromuscular control.
8

Uticaj statusa vitamina D na metaboličku aktivnost kosti i koštanu masu kod bolesnika sa alkoholnom cirozom jetre / Effects of vitamin D status on bone metabolism and bone mass in patients with alcoholic liver cirrhosis

Savić Željka 27 October 2014 (has links)
<p>Uvod: Hepatička osteodistrofija je termin koji obuhvata metaboličke bolesti kosti udružene sa hroničnim bolestima jetre. U alkoholnoj cirozi (AC) jetre postoji visoka zastupljenost deficijencije vitamina D proporcionalna stepenu disfunkcije jetre, ali njena uloga u patogenezi hepatičke osteodistrofije nije dovoljno obja&scaron;njena. Nivo 25(OH)D odražava status vitamina D. Kod AC jetre izmenjena je metabolička aktivnost kosti i suprimirano je formiranje kosti &scaron;to dovodi do smanjenja ko&scaron;tane mase. U centru interesovanja je postizanje optimalnog statusa vitamina D. Stavovi o suplementaciji vitaminom D kod AC jetre nisu jasno definisani. Cilj rada: Utvrditi nivo vitamina D, ispitati metaboličku aktivnost kosti i mineralnu gustinu kosti kod bolesnika sa AC jetre. Utvrditi efekte suplementacije sa 1000 IU vitamina D3 na dan tokom godinu dana u odnosu na metaboličku aktivnost kosti i mineralnu gustinu kosti kod ispitivanih bolesnika. Bolesnici i metode: Istraživanje je sprovedeno na Klinici za gastroenterologiju i hepatologiju Kliničkog centra Vojvodine u Novom Sadu kao prospektivna intervencijska studija sa primenom suplementacije sa 1000 IU vitamina D3 na dan kod bolesnika sa AC jetre. Grupu bolesnika koja je uključena u istraživanje (1) činilo je 70 bolesnika mu&scaron;kog pola sa dijagnozom AC jetre. Bolesnici su imali četiri pregleda (P), odnosno tačke studije: P1-uključivanje bolesnika i započinjanje suplementacije vitaminom D; P2, P3 i P4 posle tri, &scaron;est i dvanaest meseci suplementacije vitaminom D, redom. Prilikom svakog pregleda rađene su analize funkcije jetre, metabolizma kosti i statusa vitamina D. Na početku (P1) i na kraju istraživanja (P4) vr&scaron;eno je merenje mineralne gustine kosti (BMD) DXA metodom. Gubitak bolesnika od P1 do P4 bio je dvadeset, na različitim tačkama studije. Prvi deo istraživanja odnosi se na Grupu bolesnika koja je uključena u istraživanje (1) i zavr&scaron;ila prvi pregled (P1). Pedeset bolesnika je zavr&scaron;ilo kompletno istraživanje po predviđenom protokolu i oni se zbog realizacije svih pregleda i ponovljenih merenja posmatraju kao: Grupa bolesnika koja je zavr&scaron;ila istraživanje (2). Rezultati: (1): Kod bolesnika sa AC jetre utvrđena je deficijencija vitamina D, snižen nivo osteokalcina, normalni nivoi CrossLapsa, PTH, ukupnog i jonizovanog kalcijuma, fosfora i magnezijuma. Osteopeniju je imalo 42,65% a osteoporozu 14,71% ispitanika. Kod svih ispitanika najniži BMD izmeren je na vratu femura. (2): Suplementacija vitaminom D dovela je do značajnog porasta 25(OH)D. U odnosu na osteokalcin konstatovana je pozitivna razlika vrednosti P1/P4, iako je nivo ostao ispod donje granice normale. Kod nivoa CrossLapsa i PTH razlika P1/P4 je negativna, ali su nivoi u sva četiri merenja u okviru referentnih vrednosti. Na lumbalnoj kičmi do&scaron;lo je do pobolj&scaron;anja BMD za 0.87%, a pogor&scaron;anja su na vratu femura -1.87 % i kuku -1.65%. Konstatovano je i pobolj&scaron;anje funkcije jetre. Zaključci: Kod bolesnika sa AC jetre pobolj&scaron;anje statusa vitamina D dovodi do povećanja formiranja kosti i pobolj&scaron;anja ko&scaron;tane mase na lumbalnoj kičmi. Neophodno je određivanje statusa vitamina D kod svih bolesnika sa AC jetre i uvođenje suplementacije vitaminom D kod bolesnika koji imaju nivo 25(OH)D &lt; 80 nmol/l, uz tromesečne kontrole efekta. Kod postavljanja dijagnoze AC jetre potrebno je inicijalno određivanje BMD. Kod suplementacije vitaminom D nakon inicijalnog DXA pregleda sledeći se preporučuje nakon jedne do dve godine.</p> / <p>Introduction: The term Hepatic osteodystrophy defines a group of metabolic bone diseases associated with underlying chronic liver disease. Alcoholic liver cirrhosis (ALC) is characterized by high incidence of vitamin D deficiency that is proportional to the level of liver failure; however, its role in the pathogenesis of hepatic osteodystrophy has not yet been fully elucidated. The level of 25(OH)D best reflects the vitamin D status. ALC is characterized by changed bone metabolic activity and suppressed bone formation, resulting in the decrease in bone mass. The key topic of interest is the achievement of optimal vitamin D status. The attitude of health professionals towards vitamin D supplementation in alcoholic liver cirrhosis has not yet been clearly defined. The aim of the research: Determining of vitamin D levels, investigating the metabolic activity of the bone and bone mass in patients with alcoholic liver cirrhosis (ALC); Determining the effects of vitamin D3 supplementation at the dose 1000 IU/day during a one-year period in relation to metabolic activity of the bone and bone mineral density (BMD) in the investigated patient population. Patients and methods: The research was conducted at the Clinic for Gastroenterology and Hepatology of the Clinical Centre of Vojvodina in Novi Sad. The research was designed as a prospective interventional study implicating vitamin D3 supplementation at the dose 1000 IU/day to patients with ALC. The investigated patient population (1) encompassed 70 male patients diagnosed with ALC. The patients underwent four examinations (P), that is, research phases: P1 &ndash; inclusion of the patient into the study and introduction of vitamin D supplementation; P2, P3 and P4 after 3, 6 and 12 months of vitamin D supplementation treatment, respectively. Each examination included the analysis of liver function, bone metabolism and vitamin D status. At the beginning (P1) and at the end (P4) of the investigation period, bone mineral density (BMD) was measured by means of dual-energy x-ray absorptiometry (DXA) method. Twenty patients dropped out from the research at different stages throughout the investigation period (P1 to P4). The first part of the investigation pertains to the Group of patients who were included into the study (1) and completed the first examination (P1). Fifty patients have completed the entire research according to the foreseen protocol encompassing all examinations and repeated measurements. These patients are considered a Group of patients who completed the research (2) Results: (1): In ALC patients, vitamin D deficiency and decreased osteocalcin levels were established, as well as normal levels of CrossLaps, PTH, total and ionized calcium, phosphorus and magnesium. Osteopenia and osteoporosis were established in 42.65% and 14.71% of patients, respectively. The lowest BMD was measured in the femoral neck in all patients. (2): Vitamin D supplementation resulted in significant increase in 25(OH)D. Analysis of osteocalcin level revealed positive P1/P4 difference, even though the level remained below the lower normal limit. The levels of CrossLaps and PTH revealed negative P1/P4 difference; however, the levels determined at all four measurements were within the reference values. An improvement of BMD for 0.87% was established in lumbar spine, whereas a decrease was noticed in femoral neck (1.87%) and hip (1.65%). Furthermore, an improvement of liver function was established. Conclusions: Improvement of vitamin D status in ALC patients results in an increase of bone formation and improvement of body mass in lumbar spine. Determining the vitamin D status in all patients with ALC is of outmost importance, as well as the vitamin D supplementation of patients with levels of 25(OH)D &lt; 80 nmol/l along with the monitoring of treatment outcome at three-month intervals. Establishment of the diagnosis of alcoholic liver cirrhosis should encompass initial measurement of BMD. In case of vitamin D supplementation treatment, the initial DXA examination should be repeated after the period of one to two years.</p>

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