(1) The research on rickets (1922-1932), culminating in the discovery of the antirachitic effect of sterol irradiated with ultraviolet light.
(2) In order to clarify the effect of products of photochemical conversion of sterols on cholesterol biosynthesis, rat skin samples were incubated with 2-(14)C-acetate in the presence of the antirachitic agent Dk and 7beta-hydroxycholesterol.
(3) Vitamin D sulphate, the water soluble conjugate of vitamin D, was present in higher concentrations than that reported for vitamin D in lipid fraction; however, the antirachitic activity of vitamin D sulphate is yet to be studies.
(4) A comparison of the HPLC method to the AOAC biological and chemical procedures shows that the HPLC method most closely approximates the antirachitic activity of a cholecalciferol sample.
(5) This idea also shows the lag time in response of rats to 1alpha-hydroxycholecalciferol has more potent antirachitic activity than vitamin D and does not lose its activity with chronic oral administration.
(6) The results are not conclusive on the inhibition or lack of inhibition of the antirachitic activity of 5,6-cis-vitamin D3 by the presence of 5,6-trans-vitamin D3 in the feed.
(7) This vitamin derivative is active in stimulating intestinal calcium transport and bone calcium mobilization in the rat and exhibits antirachitic activity.
(8) The vitamin D3 metabolites 1 alpha,24R,25- and 1 alpha,25S,26-trihydroxy vitamin D3 and their combinations with 1 alpha,25-dihydroxy vitamin D3 were tested for antirachitic activity in rats, chicken and Japanese quails.
(9) On the basis of the results obtained it is concluded that the relative potency of the trans isomer is, at the most, 5% and that the antirachitic activity of the trans isomer is not markedly enhanced (an increase to a relative potency of 16%, at the most) if the cis isomer is also included in the diet.
(10) Its antirachitic activity equals that of 1,25-dihydroxyvitamin D3 in the rat.
(11) However this increase was suppressed by administration of actinomycin D, and then this result suggests that the antirachitic effect of T3 is mediated by somehow de novo protein synthesis.
(12) It was demonstrated that 1alpha-OH D3 showed antirachitic action, when the physiological reaction to vitamin D3 was inhibited by dietary strontium.
(13) A significant difference between vitamins D2 and D3 exists in their antirachitic activity in poultry.
(14) In theory, supplementation with 2000 IU (50 micrograms) vitamin D should have increased the calculated antirachitic activity of the milk in winter to the levels of unsupplemented mothers in September; however, responses varied widely among individuals.
(15) Sulfoconjugated vitamin D has been claimed to have an important antirachitic activity and to be present at higher amounts than free vitamin D in maternal milk.
(16) After all, T3 acting as an antirachitic agent, the most likely possibility is that T3 provides favorable conditions for mineralization of bone by improving Pi transport in various types of cells, even under rachitogenic condition, at least of hypophosphatemic type, and correction of phosphate metabolism may be the most essential prerequisite for cure of this type of rickets.
(17) Two biological assays were conducted in which the antirachitic activity in chicks of 5,6-trans-vitamin D3 added to feed is compared with that of 5,6-cis-vitamin D3.
(18) A correlation between the activation of sterol synthesis and the concentration of the antirachitic agent was found.
(19) The irradiated biomass of the strains accumulated ergosta-5,7-dien-3 beta-ol and also cholesta-5,7,24-trien-3 beta-ol and cholesta-5,7,22,24-tetraen-3 beta-ol is characterized by high antirachitic activity.
(20) Simulteneously an increase is detected in the metabolic fund of cholesterol synthesis precursors, including 7-dehydrocholesterol, which is necessary to form antirachitic compounds in the organism.
Rickets
Definition:
(n. pl.) A disease which affects children, and which is characterized by a bulky head, crooked spine and limbs, depressed ribs, enlarged and spongy articular epiphyses, tumid abdomen, and short stature, together with clear and often premature mental faculties. The essential cause of the disease appears to be the nondeposition of earthy salts in the osteoid tissues. Children afflicted with this malady stand and walk unsteadily. Called also rachitis.
Example Sentences:
(1) A survey carried out two and three years after the launch of the official campaign also showed a reduction in the prevalence of rickets in children taking low dose supplements equivalent to about 2.5 micrograms (100 IU) vitamin D daily.
(2) Phenobarbital did not retard growth nor impede the response to vitamin D therapy of concomitant rickets.
(3) Where UV radiation is restricted, individual propensity to rickets within a given Asian community is mainly determined by dietary factors.
(4) In a large commercial goat farm rickets-like symptoms were diagnosed in goat kids.
(5) One of the metabolites proved to be as active as the parent vitamin in curing rickets and was found in large amounts in liver, blood, and bone.
(6) The influence of extra phosphorus (P) and calcium (Ca) on the incidence of rickets was studied in 40 infants with a birthweight below 1.5 kg.
(7) The healing of rickets, the stimulation of intestinal Ca and P transport, the effect on bone mineral, and the induction of renal calcifications have been examined.
(8) It has been confirmed that the foetal parathyroid glands are important in development and that thyroparathyroidectomy (TXPTX) of the ovine foetus with thyroxine (T4) replacement leads to hypocalcaemia, retarded skeletal development, depressed calcification and rickets, relative to thyroidectomy plus T4 replacement.
(9) A boy with Lowe syndrome who manifested renal Fanconi syndrome by severe hypophosphatemic rickets, failure to thrive, and metabolic acidosis failed to improve with conventional bolus therapy of phosphate and bicarbonate.
(10) Some of the factors predisposing to rickets were assessed in the rachitic children and in age-matched controls.
(11) Vitamin D deficiency contributes to bone demineralization and rickets.
(12) Lymphocyte cell lines were established from five patients with vitamin D-dependent rickets, type II (VDDR-II).
(13) Clinical signs of rickets are still absent at this time, while an increased activity of the serum alkaline phosphatase signals the beginning of the illness.
(14) The majority of this thickening was due to an increase in the zone of proliferation, identical to that which occurs in calcium-deficiency rickets.
(15) A 22-month-old girl with cystinotic rickets was given 1 microgram 1,25-dihydroxycholecalciferol (1,25-DHCC) daily in addition to standard treatment.
(16) The patients were divided into 5 groups, 1) Osteomalacia and rickets 42 cases, showing typical changes of bone in X-ray films.
(17) In addition, the improved growth and healing of rickets further attest to the efficacy of the new treatment.
(18) In contrast, it appears that doses of either drug that are curative in D deficiency rickets are only partly active in PDR.
(19) During the latter half of an infant's first year, adequate mineral and vitamin D intakes may be important not only for the prevention of rickets but also for the attainment of optimal adult peak bone mass.
(20) Renal tubular dysfunctions with secondary rickets may be lacking altogether, even in chronic patients.