Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038002 (splenomegaly)
 9,873 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Subcutaneous injection of nonspecific irritants such as magnesium silicate (talc) provokes granulomatous inflammation in the rat. Part of the acute phase response (APR) in these animals is the loss of trabecular bone at sites distant from the site of inflammation. To assess the possible involvement of vitamin D in the bone loss, we studied the development of the acute phase response in vitamin D-deprived rats. The serum APR provoked by subcutaneous inflammation in rachitic rats consisted of hypozincemia, hypercupremia, increased alkaline phosphatase activity and adrenocorticotropic hormone (ACTH) concentration, and was similar to that in control animals except for the absence of hypoferremia. Control rats with talc-induced subcutaneous inflammation also had splenomegaly and decreased total and mononuclear peripheral blood cell counts, while subcutaneous inflammation did not induce spleen changes in rachitic rats. Subcutaneous inflammation induced the loss of trabecular bone and decreased the osteoblastic cell count in tibial metaphyses in control animals. Rachitic rats had abundant osteoid on trabecular surfaces, and the number of osteoblasts and osteoclasts was comparable to that of the controls. Subcutaneous inflammation did not affect any of the bone parameters in rachitic rats. These results indicate that vitamin D plays an important role in the generation of the acute phase response during inflammation, particularly in the induction of spleen and bone cell changes. The discrepancy of the blood on one hand and bone and spleen indices of the APR on the other, indicate that they may be divergent pathways in the generation of the inflammatory response, some of which may be dependent on vitamin D.
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PMID:Role of 1,25-dihydroxyvitamin D3 in the generation of the acute-phase response in rats with talc-induced granulomatosis. 835 76

Thrombocytopenia and splenomegaly improved in one of the four patients receiving 1 alpha-hydroxyvitamin D3 (1 alpha(OH)D3) for treatment of primary myelofibrosis (PMF). We compared the clinical results with the in vitro effects of vitamin D3 metabolites on the growth and collagen synthesis of bone marrow fibroblasts. The effects of vitamin D3 metabolites on control human bone marrow fibroblasts were first studied in vitro. On the growth, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and 24,25-dihydroxyvitamin D3 (24,25(OH)2D3) inhibited the platelet derived growth factor (PDGF) or human serum-induced proliferation at the concentrations of more than 10(-10) M, while in the presence of transforming growth factor-beta (TGF-beta) the inhibitory effects were mild or non-inhibitory. Both vitamin D3 metabolites inhibited procollagen synthesis at a concentration of more than 10(-8) M. The effect of 1,25(OH)2D3 on the PMF patients was examined. In two of the four patients, the human serum-induced growth inhibitory effect was observed at the concentration of 10(-8) M, in one patient no inhibition was observed and in one patient inhibition was observed at 10(-10) M, as was observed in the control donors. During the treatment with 1 alpha(OH)D3 the serum level of 1,25(OH)2D3 was 1-2 x 10(-10) M. These findings suggest that a minority of PMF patients have marrow fibroblasts with growth sensitivity to a pharmacological level of vitamin D3 and could be treated with 1 alpha(OH)D3 with some clinical improvements.
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PMID:1 alpha-Hydroxyvitamin D3 in the treatment of primary myelofibrosis: in vitro effect of vitamin D3 metabolites on the bone marrow fibroblasts. 838 71

1,25-dihydroxyvitamin D3, the active metabolite of vitamin D, partially inhibits antigen and mitogen-driven lymphocyte stimulation. We studied the effect of granulomatous inflammation on the sensitivity of lymphocytes to 1,25-dihydroxyvitamin D3 in vitro, measuring the inhibitory effect of 1,25-dihydroxyvitamin D3 on mitogenesis of splenocytes of mice with chronic inflammation induced by subcutaneous injection of talc. Systemic manifestations of the local inflammation included loss in body weight, splenomegaly, enhanced DNA synthesis by freshly isolated splenocytes and enhanced prostaglandin secretion by activated splenocytes. Splenocytes from animals with local inflammation were more susceptible to inhibition by 1,25-dihydroxyvitamin D3, but not by prostaglandin E2. This increased sensitivity to 1,25-dihydroxyvitamin D3 was abolished by blocking prostaglandin synthesis in splenocyte cultures with indomethacin and was restored by adding prostaglandin E2. This effect cannot be attributed to enhanced prostaglandin synthesis in the presence of 1,25-dihydroxyvitamin D3, but is probably due to a qualitative change in the response of splenocytes from inflamed animals to the combined action of 1,25-dihydroxyvitamin D3 and prostaglandin E2.
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PMID:Foreign body granulomatous inflammation increases the sensitivity of splenocytes to immunomodulation by 1,25-dihydroxyvitamin D3. 850 38

Myelofibrosis is an uncommon condition that causes anaemia, failure to thrive and massive splenomegaly. This case report describes migrant Sudanese twins who developed myelofibrosis secondary to severe rickets from a combination of poor diet, inadequate sun exposure, and a breastfeeding mother who wore hijab and was also vitamin D deficient.
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PMID:Twin troubles--rickets causing myelofibrosis. 1763 91

The vitamin D hormone 1,25-dihydroxyvitamin D(3) [1,25(OH)(2) D(3) ], the biologically active form of vitamin D, is not only essential for mineral metabolism but may have important functions beyond calcium homoeostasis. By gene targeting, we have recently generated mice expressing a functionally inactive mutant vitamin D receptor (VDR). After a change in environmental conditions from specific pathogen free (SPF) conditions to a modified barrier system, a high percentage of aged mutant, but not wild-type, mice developed a haematological disorder characterized by splenomegaly, granulocytosis, thrombocytosis and dysplastic changes with displacement of erythropoiesis in bone marrow during the following months. All cases were associated with very high serum levels of the acute phase reaction protein serum amyloid A (SAA). Serological testing of affected mice revealed antibodies against murine hepatitis virus (MHV). However, electron microscopy of spleen and bone marrow cells did not reveal virus particles, and clinical signs of infectious diseases were absent. We hypothesize that a non-functioning VDR is associated with a latent defect in the regulation of myeloid cell differentiation and proliferation. Under the conditions of environmental stress, this latent defect may predispose to a deregulation of myelopoiesis in the form of a leukaemoid reaction accompanied by dysplastic changes. Thus, 1,25(OH)(2) D(3) may be an important inhibitory factor in the onset and progression of myeloproliferative and myelodysplastic diseases.
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PMID:A non-functioning vitamin D receptor predisposes to leukaemoid reactions in mice. 2030 Dec 29

Vitamin D insufficiency is a global health issue. Although classically associated with rickets, low vitamin D levels have also been linked to aberrant immune function and associated health problems such as inflammatory bowel disease (IBD). To test the hypothesis that impaired vitamin D status predisposes to IBD, 8-wk-old C57BL/6 mice were raised from weaning on vitamin D-deficient or vitamin D-sufficient diets and then treated with dextran sodium sulphate (DSS) to induce colitis. Vitamin D-deficient mice showed decreased serum levels of precursor 25-hydroxyvitamin D(3) (2.5 +/- 0.1 vs. 24.4 +/- 1.8 ng/ml) and active 1,25-dihydroxyvitamin D(3) (28.8 +/- 3.1 vs. 45.6 +/- 4.2 pg/ml), greater DSS-induced weight loss (9 vs. 5%), increased colitis (4.71 +/- 0.85 vs. 1.57 +/- 0.18), and splenomegaly relative to mice on vitamin D-sufficient chow. DNA array analysis of colon tissue (n = 4 mice) identified 27 genes consistently (P < 0.05) up-regulated or down-regulated more than 2-fold in vitamin D-deficient vs. vitamin D-sufficient mice, in the absence of DSS-induced colitis. This included angiogenin-4, an antimicrobial protein involved in host containment of enteric bacteria. Immunohistochemistry confirmed that colonic angiogenin-4 protein was significantly decreased in vitamin D-deficient mice even in the absence of colitis. Moreover, the same animals showed elevated levels (50-fold) of bacteria in colonic tissue. These data show for the first time that simple vitamin D deficiency predisposes mice to colitis via dysregulated colonic antimicrobial activity and impaired homeostasis of enteric bacteria. This may be a pivotal mechanism linking vitamin D status with IBD in humans.
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PMID:Vitamin D deficiency in mice impairs colonic antibacterial activity and predisposes to colitis. 2039 25

A 67-year-old trout fisherman presented with a six-week history of polyuria, polydipsia, dyspnoea on exertion and the development of subcutaneous extensor surface skin nodules. He was hypercalcaemic with acute renal impairment. Parathyroid hormone was suppressed and vitamin D levels were within normal limits. The patient had a past history of hypothyroidism, but thyroid replacement was adequate. Hypoadrenalism, myeloma and metastatic malignancy were excluded. Biopsy of a subcutaneous nodule revealed dermally based non-caseating granulomata, consistent with sarcoidosis. Serum angiotensin-converting enzyme was elevated, and computerized tomography scanning of the chest and abdomen revealed widespread lymphadenopathy with multiple lung nodules and splenomegaly. Prednisolone therapy produced rapid resolution of his skin lesions and normalization of his bone and renal biochemistry. The mechanism of hypercalcaemia in sarcoidosis is poorly understood but is thought to involve parathyroid hormone-independent 1-hydroxylation of 25-hydroxyvitamin D within sarcoid lesions. This process may be exacerbated by exposure to UV light and it is of interest that this patient developed symptoms after a period of intense trout fishing in the good weather of April and May 2007.
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PMID:A trout fisherman with hypercalcaemia and skin lesions. 2187 32