Detection of gynecological cancer; use of fluorescence microscopy to show nucleic acids in malignant growth

Vitamin D resistant rickets is not a rare disorder. Increased awareness of this metabolic disorder during the examination of children with bowed legs, even infants receiving normal supplements of vitamin D, may lead to diagnosis oftener. Ten previously unrecorded cases of this disorder are included within this report. Three of the patients had associated congenital anomalies which also required treatment. Treatment of the vitamin D resistant rickets consists of the oral administration of large doses of vitamin D. Careful observation of patients during vitamin D therapy to prevent overdosage and resultant hypercalcemia is of utmost importance. Surgical correction of the bony deformities is rarely necessary. The cause of vitamin D resistant rickets is thought to be a defect of renal tubular mechanisms.     

The history of resistant rickets: A model for understanding the growth of biomedical knowledge

Two essential periods may be identified in the early stages of the history of vitamin D-resistant rickets. The first was the period during which a very well known deficiency disease, rickets, acquired a scientific status: this required the development of unifying principles to confer upon the newly developing science of pathology a doctrine without which it would have been condemned to remain a collection of unrelated facts with very little practical application. One first such unifying principle was provided by the notion of hygiene; while the blanket explanations provided by this notion alone were much too general to enable rickets to achieve scientific status, it did point out the need to look for specific external causes for the disease and to examine the life-style and dietary habits of the patients. The second phase of the conceptualization of the disease was the assumption of a specific cause — that is, using concepts developed in the area of infectious diseases. This was made possible by fundamental similarities between deficiency and infectious diseases, in spite of their apparent differences. Both types of illness have some of the characteristics of what Georges Canguilhem calls the ontological representation of disease⁷⁷ as opposed to dysharmonic representations, which primarily concern the endocrine diseases. It is precisely this shift from one to the other manner of perceiving ill health that enabled the identification of the vitamin D-resistant rickets. Conceptualization of the notion of vitamin D resistancy required that the conditions causing the disease be looked for within the organism rather than outside it; this was thus the first time that endocrine concepts were applied to studying the physiology of vitamin D.The history of resistant rickets therefore represents an interesting model for understanding the growth of biomedical knowledge. It allows the development of a number of more general ideas on the question of the relationship between biology and medicine and on the thorny problem of specificity in medical thinking. As far as this topic is concerned it can be seen that there was an ongoing exchange between medical and biological thinking during the initial period up until 1937, and that one could deny any such specificity in medical thinking during this same period. Albright, for example, used human diseases as spontaneously produced models for experimental biology. It was also more feasible for an experimental biologist to administer toxic doses than for a clinician to do so.     

Vitamin-D-deficient rickets in Manitoba, 1972-84.

Vitamin-D-deficient rickets still exists in children in Manitoba and adjacent areas. Between 1972 and 1984, 48 cases were documented at Winnipeg Children''s Hospital. The patients ranged in age from 1 to 49 months; 40 were Canadian natives (38 Indians and 2 Inuit), most of whom lived in the Island Lake area of northern Manitoba. Of the 48, 16 had clinical signs of rickets, 12 had tetany due to hypocalcemia and 38 had radiologic evidence of rickets. Hypocalcemia was found in 27, and hypophosphatemia in 19; hyperaminoaciduria was found in 7 of 20. All 48 had elevated serum alkaline phosphatase levels. In addition to rickets, 16 patients aged 12 months or more had evidence of malnutrition. Climate and lifestyle in northern areas of the Canadian midwest result in little or no biosynthesis of vitamin D by solar radiation; therefore, adequate dietary vitamin D intake is essential to prevent deficiency. The diets of pregnant women and infants in these areas are deficient in vitamin D. The authors recommend vitamin D supplements for all pregnant women and infants in areas of risk to eradicate this preventable disease.     

A girl with a novel splice site mutation in VDR supports the role of a ligand-independent VDR function on hair cycling

Mutations in vitamin D receptor (VDR) cause hereditary vitamin D resistant rickets (HVDRR). We reported a Thai girl with HVDRR, presenting with an early onset of rickets and partial alopecia. She was a product of a consanguineous couple. Mutation analysis showed that she was homozygous for a novel splice site mutation of the VDR gene, 462 + 1 G --> C, resulting in incorporation of the whole 254 bp of the intron 4 into its mRNA. The mutated protein is expected to contain no ligand-binding domain. The fact that she did not develop total alopecia despite of no VDR ligand-binding domain supports that VDR function on hair cycling is ligand independent.     

Rickets and Osteomalacia in the Glasgow Pakistani Community, 1961-71

The prevalence of vitamin D deficiency was reassessed in April and May 1971, 10 years after the discovery of widespread late rickets and osteomalacia in the Glasgow Pakistani community. Evidence of vitamin D deficiency was found in 28 out of 115 adults and children examined (24%). Children at the age of puberty were most severely affected by rickets, whereas most infants and younger children in the survey were protected by vitamin D supplements. Mild biochemical osteomalacia was common in Pakistani women.A total of 21 Pakistani and Indian children with rickets were admitted to Glasgow hospitals during 1968-70. These comprised 10 children with infantile rickets and 11 with late rickets. Four of the latter group required osteotomy for severe rachitic deformity.Late rickets and osteomalacia in Pakistani and Indian immigrants are not primarily due to nutritional deficiency of vitamin D, though the high phytate content of their diet may be of aetiological importance. A combination of environmental, social, and endogenous factors, the relative importance of which is not at present clear, may also be involved. Advice on the prophylaxis of vitamin D deficiency should be given to all Pakistani and Indian communities in the United Kingdom.     

A novel mutation in helix 12 of the vitamin D receptor impairs coactivator interaction and causes hereditary 1,25-dihydroxyvitamin D-resistant rickets without alopecia

Hereditary vitamin D-resistant rickets (HVDRR) is a genetic disorder most often caused by mutations in the vitamin D receptor (VDR). The patient in this study exhibited the typical clinical features of HVDRR with early onset rickets, hypocalcemia, secondary hyperparathyroidism, and elevated serum concentrations of alkaline phosphatase and 1,25-dihydroxyvitamin D [1,25-(OH)(2)D(3)]. The patient did not have alopecia. Assays of the VDR showed a normal high affinity low capacity binding site for [(3)H]1,25-(OH)(2)D(3) in extracts from the patient's fibroblasts. However, the cells were resistant to 1,25-dihydroxyvitamin D action as demonstrated by the failure of the patient's cultured fibroblasts to induce the 24-hydroxylase gene when treated with either high doses of 1,25-(OH)(2)D(3) or vitamin D analogs. A novel point mutation was identified in helix H12 in the ligand-binding domain of the VDR that changed a highly conserved glutamic acid at amino acid 420 to lysine (E420K). The patient was homozygous for the mutation. The E420K mutant receptor recreated by site-directed mutagenesis exhibited many normal properties including ligand binding, heterodimerization with the retinoid X receptor, and binding to vitamin D response elements. However, the mutant VDR was unable to elicit 1,25-(OH)(2)D(3)-dependent transactivation. Subsequent studies demonstrated that the mutant VDR had a marked impairment in binding steroid receptor coactivator 1 (SRC-1) and DRIP205, a subunit of the vitamin D receptor-interacting protein (DRIP) coactivator complex. Taken together, our data indicate that the mutation in helix H12 alters the coactivator binding site preventing coactivator binding and transactivation. In conclusion, we have identified the first case of a naturally occurring mutation in the VDR (E420K) that disrupts coactivator binding to the VDR and causes HVDRR.     

In vivo function of VDR in gene expression-VDR knock-out mice

Vitamin D exerts many biological actions through nuclear vitamin D receptor (VDR)-mediated gene expression. The transactivation function of VDR is activated by binding 1,25-dihydroxyvitamin D₃[1,25(OH)₂D₃], an active form of vitamin D. Conversion from 25(OH)D₃ is finely regulated in kidney by 25(OH)D₃ 1-hydroxylase[25(OH)D 1-hydroxylase], keeping serum levels of 1,25(OH)₂D₃ constant. Deficiency of vitamin D and mutations in the genes like VDR (type II genetic rickets) are known to cause rickets like lowered serum calcium, alopecia and impaired bone formation. However, the molecular basis of vitamin D–VDR system in the vitamin D action in intact animals remained to be established. In addition, the 1-hydroxylase gene from any species had not yet been cloned, irrespective of its biological significance and putative link to the type I genetic rickets. We generated VDR-deficient mice (VDR KO mice). VDR KO mice grew up normally until weaning, but after weaning they developed abnormality like the type II rickets patients. These results demonstrated indispensability of vitamin D–VDR system in mineral and bone metabolism only in post-weaning life. Using a newly developed cloning system, we cloned the cDNA encoding a novel P450 enzyme, mouse and human 1-hydroxylase. The study in VDR KO mice demonstrated the function of liganded VDR in the negative feed-back regulation of 1,25(OH)₂D₃ production. Finally, from the analysis of type I rickets patients, we found missense genetic mutations in 1-hydroxylase, leading to the conclusion that this gene is responsible for the type I rickets.     

A unique insertion/duplication in the VDR gene that truncates the VDR causing hereditary 1,25-dihydroxyvitamin D-resistant rickets without alopecia

Hereditary vitamin D resistant rickets (HVDRR) is caused by mutations in the vitamin D receptor (VDR). Here we describe a patient with HVDRR who also exhibited some hypotrichosis of the scalp but otherwise had normal hair and skin. A 102 bp insertion/duplication was found in the VDR gene that introduced a premature stop (Y401X). The patient's fibroblasts expressed the truncated VDR, but were resistant to 1,25(OH)2D3. The truncated VDR weakly bound [3H]-1,25(OH)2D3 but was able to heterodimerize with RXR, bind to DNA and interact with the corepressor hairless (HR). However, the truncated VDR failed to bind coactivators and was transactivation defective. Since the patient did not have alopecia or papular lesions of the skin generally found in patients with premature stop mutations this suggests that this distally truncated VDR can still regulate the hair cycle and epidermal differentiation possibly through its interactions with RXR and HR to suppress gene transactivation.     

A unique mutation in the vitamin D receptor gene in three Japanese patients with vitamin D-dependent rickets type II: utility of single-strand conformation polymorphism analysis for heterozygous carrier detection.

Vitamin D-dependent rickets type II is a hereditary disease resulting from a defective vitamin D receptor. In three Japanese patients with vitamin D-dependent rickets type II whose fibroblasts displayed normal cytosol binding and impaired nuclear uptake of 1,25-dihydroxyvitamin D3, western, Southern, and northern analyses failed to disclose any abnormalities in vitamin D3 receptor protein and its gene. Exons 2 and 3 of the vitamin D receptor cDNA, which encode the DNA-binding domain consisting of two zinc fingers, were amplified by PCR and sequenced to identify the specific mutations in the vitamin D receptor gene. In the three patients and one normal control a T-to-C transition was found in the putative initiation codon, while this transition was not observed in another normal control. This finding suggested that an original initiation codon was located at positions 10-12 in the human vitamin D receptor cDNA sequence reported previously. In contrast, a unique G-to-A transition at position 140 in exon 3, resulting in substitution of arginine by glutamine at residue 47, was revealed only in these three patients. The arginine at 47 is located between two zinc fingers and is conserved within all steroid hormone receptors. Therefore, it is highly conceivable that this amino acid substitution is responsible for the defect of the vitamin D receptor in the patients. Single-strand conformation polymorphism analysis of amplified DNA confirmed that all patients were homozygous and that parents from one family were heterozygous carriers for this mutation.     

Growth rate in children with vitamin-D-dependent rickets in relation to 1-alpha-hydroxyvitamin D3 dosage.

Growth rate of five children with vitamin D-dependent rickets was analyzed during the long-term treatment with an active analog of vitamin D3. Considerable increase in growth rate together with the improvement of biochemical values and radiological pattern took place during the initial phase of administration of 1-hydroxyvitamin D3. During the maintenance treatment of long duration with 1-hydroxyvitamin D3 both the acceleration of growth and catch-up growth persisted. However, in 4 among 5 children studied an inhibition of growth was observed during different periods of time. Only in one boy was this connected with the conclusion of the process of physiological growth. In three remaining children a slow-down in growth rate appeared during the pre-pubertal period or was the effect of lowering the dose of 1-hydroxyvitamin D3 as an countermeasure to hypercalciuria. In such cases inhibition of growth was caused by the administration of too small a dose of 1-hydroxyvitamin D3 in relation to the requirement. In all cases the appearance of biochemical features of rickets aggravation, such as low blood serum phosphate concentration and elevated alkaline phosphatase activity, preceded the observable inhibition of growth. The results obtained allow us to conclude that the inhibition of growth observed during the long-term treatment of rickets with 1-hydroxyvitamin D3 may be regarded as the first signal of inadequate dosage of 1-hydroxy vitamin D3.     

Policy for prevention of Asian rickets in Britain: a preliminary assessment of the Glasgow rickets campaign.

Evidence of continuing hospital admissions of patients with Asian rickets and osteomalacia led to a further attempt to provide more effective preventive measures for the Glasgow Asian community. Dose-response studies showed that the equivalent of 10 microgram of vitamin D daily would provide effective prophylaxis, and a general practice survey showed that self-administered vitamin D supplements would reduce the prevalence and severity of Asian rickets. A multidisciplinary working group devised a preventive campaign based on the free issue of vitamin D supplements on demand to children who required them. Supported by a health education programme for community health personnel and the Asian community, the first 16 months of the campaign produced an eight-fold rise in the issue of supplements to older Asian children and a 33% increase in their issue to infants of all ethnic groups. Because more children are receiving vitamin D supplementation the campaign seems likely to reduce the prevalence of Asian rickets in Glasgow.     

Prevention of rickets in Asian children: assessment of the Glasgow campaign.

In March 1979 the Greater Glasgow Health Board launched a campaign to reduce the high prevalence of rickets in Asian children in the city. A precampaign survey had shown that voluntary low dose vitamin D supplementation would reduce the prevalence of rickets in Asian children. 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. There was a considerable reduction in the total prevalence of rickets in this survey compared with the precampaign survey. Hospital discharges of Asian children with rickets declined rapidly after the start of the campaign.     

Intestinal calcium-binding protein in animals fed normal and rachitogenic diets: I. Rat studies.

Measurements were made of duodenal calcium-binding protein (CaBP) on rats during development of rickets and, subsequently, following vitamin-D2 treatment. Results showed a poor inverse correlation between duodenal CaBP and rickets. In rats fed a phosphate-deficient rachitogenic diet, duodenal CaBP concentration finally fell below detectable limits, but CaBP was still readily measurable 2 weeks after rickets was clearly established. Following a massive dose of vitamin D2 (50 000 I.U.) to rachitic animals, CaBP was formed. However, a small dose of vitamin D2 (500 I.U. daily for 4 days) was insufficient to demonstrate CaBP synthesis than vitamin-D treatment alone. The rachitogenic diet supplemented with phosphate, which caused osteoporosis but not rickets, inhibited CaBP synthesis. The results suggest that nutritional deficiencies from the rachitogenic diet, in addition to vitamin-D deficiency, inhibited CaBP synthesis.     

骨密度检测对婴幼儿佝偻病早期诊断的临床意义

目的:探讨骨密度检测在佝偻病早期诊断中的应用价值。方法:收集衡水市哈励逊国际和平医院门诊诊治的600例婴幼儿,以血清维生素D327.5 nmol/L为判定标准分为非佝偻病组和佝偻病组,比较两组婴幼儿维生素D3、骨碱性磷酸酶和骨密度,绘制维生素D3、骨碱性磷酸酶、骨密度诊断结果的ROC曲线图,对骨密度检测结果进行评价。结果:佝偻病组婴幼儿维生素D3和骨密度Z值明显低于非佝偻病组,骨碱性磷酸酶显著高于非佝偻病组(P0.05)。维生素D3诊断佝偻病的ROC曲线下面积为0.951,灵敏度为0.973,特异度为0.840;骨碱性磷酸酶诊断佝偻病的ROC曲线下面积为0.866,灵敏度为0.824,特异度为0.747;骨密度Z值诊断佝偻病的ROC曲线下面积为0.923,灵敏度为0.826,特异度为0.875,骨密度指标诊断佝偻病的曲线下面积和维生素D3比较无统计学意义(P0.05),但骨密度指标诊断佝偻病的曲线下面积大于骨碱性磷酸酶(P0.05)。结论:超声骨密度检测在婴幼儿佝偻病早期诊断中具有一定价值,其诊断敏感性、特异性、准确率与维生素D3诊断基本相当,且骨密度检测存在无创、可重复性高等优点。     

Biologically active metabolite of vitamin D3 from bone, liver, and blood serum

Radioactive metabolites present in bone, blood, liver, and feces of rats given (3)H vitamin D(3) have been isolated. Of these the aqueous soluble metabolite(s) from tissue and all those isolated from feces did not cure rickets in rats, while all the others were at least partially active in this regard. 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. As much as 50-80% of the radioactivity in bone was found in this metabolite after a 500 IU oral dose of (3)H vitamin D(3). With 10 IU doses of 1,2-(3)H vitamin D(3), most of the radioactivity of the organs examined was found in this metabolite fraction. This metabolite appears to be more polar than vitamin D and is not an esterified form of the vitamin nor a complex of the vitamin with tissue lipids. Its possible role as the metabolically active form of the vitamin is discussed.     

Vitamin-D-dependent rickets type 2

Vitamin-D-dependent rickets type 2 results from autosomal recessive mutations of the vitamin D receptor gene. With congenital total body alopecia and onset of rickets during the second half of the first year of life, patients display rapidly progressing rachitic bone changes, hypocalcemia and secondary hyperparathyroidism. This article describes extensive personal experience with about one third of the world's reported cases, their clinical course, the physiological consequences, diagnostic steps, molecular findings and therapeutic approach, as they developed over the course of the last 25 years.     

Co-existence of X-linked hypophosphatemic rickets (XLH) and primary hyperparathyroidism: case report and review of the literature

X-linked hypophosphatemic rickets (XLH) is a dominant disorder characterized by hypophosphatemia due to impaired renal tubular reabsorption of inorganic phosphate. Cardinal manifestations include defective calcification of cartilage and bone, growth retardation and resistance to phosphorus and vitamin D therapy. Although secondary hyperparathyroidism (HPT) is a common complication of treatment, autonomous HPT is rare, especially in the absence of previous phosphate therapy. We report a case of an adult untreated male XLH patient with primary HPT and give a brief review of the literature regarding the prevalence and pathophysiology of this complication.     

The vitamin D story: a collaborative effort of basic science and clinical medicine

The discovery in 1919-1924 of vitamin D and its production in skin and foods by UV irradiation led to the elimination of rickets as a major medical problem. The identification and chemical preparation of vitamin D in the next decade provided large quantities of vitamin D to the physician for the treatment of a variety of metabolic bone diseases. Early in the 1960s, little was known about the function of vitamin D in causing mineralization of the skeleton, and hence in preventing the disease rickets in children and osteomalacia in adults. With the application of modern tools of biochemistry came the discovery that vitamin D must first be modified by 25-hydroxylation in the liver followed by 1 alpha-hydroxylation in the kidney to produce the vitamin D hormone 1 alpha,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. This process is strongly feedback-regulated and is one of the major endocrine systems regulating plasma calcium and phosphorus concentrations. Furthermore, it is a major endocrine system regulating bone mass and state. With the chemical synthesis of 1,25-(OH)2D3 and many of its analogs has come the possibility of treating a number of metabolic bone diseases not previously managed adequately, such as vitamin D-resistant rickets, hypoparathyroidism, renal osteodystrophy, and osteoporosis. By using 1,25-(OH)2D3, considerable work has been carried out to understand how this hormone facilitates calcium transport across the intestinal membrane. Modern work is described on the molecular mechanism of action of the vitamin D hormone in eliciting the cellular responses that result in mineral homeostasis. The possible use of the vitamin D analogs to bring about differentiation of myelocytic-type leukemias and in the treatment of psoriasis has been an important new development. This paper will thus be a blend of basic science of the vitamin D system and the application of that information to the treatment of disease.     

VD缺乏相关疾病及其合理补充的临床意义

：众所周知,人体内维生素D水平与少年佝偻病和老年骨质疏松直接相关。最近大量流行病学证据还表明,维生素D（VD）缺乏是多种自身免疫性疾病,癌症,心血管疾病,抑郁症,老年痴呆症,感染性疾病,肌肉骨骼功能下降等的危险因素之一。另外,胰岛素抵抗,高血压和高胆固醇血症也与维生素D缺乏有关。因此,合理补充维生素D可以降低多种疾病风险,并对心血管疾病的风险有益。本文系根据已有的研究结论,阐述维生素D水平与多种临床疾病之间的关联,并对人体血清VD浓度合理监测及合理补充的临床意义做一综述。