A phase II trial of the vitamin D analogue Seocalcitol (EB1089) in patients with inoperable pancreatic cancer

Inoperable cancer of the exocrine pancreas responds poorly to most conventional anti-cancer agents, and new agents are required to palliate this disease. Seocalcitol (EB1089), a vitamin D analogue, can inhibit growth, induce differentiation and induce apoptosis of cancer cell lines in vitro and can also inhibit growth of pancreatic cancer xenografts in vivo. Thirty-six patients with advanced pancreatic cancer received once daily oral treatment with seocalcitol with dose escalation every 2 weeks until hypercalcaemia occurred, following which patients continued with maintenance therapy. The most frequent toxicity was the anticipated dose-dependent hypercalcaemia, with most patients tolerating a dose of 10–15 μg per day in chronic administration. Fourteen patients completed at least 8 weeks of treatment and were evaluable for efficacy, whereas 22 patients were withdrawn prior to completing 8 weeks' treatment and in 20 of these patients withdrawal was due to clinical deterioration as a result of disease progression. No objective responses were observed, with five of 14 patients having stable disease in whom the duration of stable disease was 82–532 days (median=168 days). The time to treatment failure (n=36) ranged from 22 to 847 days, and with a median survival of approximately 100 days. Seocalcitol is well tolerated in pancreatic cancer but has no objective anti-tumour activity in advanced disease. Further studies are necessary to determine if this agent has any cytostatic activity in this malignancy in minimal disease states

Colostomia tipo hartmann em ratos: alterações morfológicas e dosagem de hidroxiprolina

A colostomia tem sido um procedimento cirúrgico freqüentemente empregado nas doenças colônicas, lesões traumáticas e neoplásicas. Este trabalho experimental, em ratos, visou estudar as progressivas mudanças morfológicas no cólon proximal e distal , após uma laparotomia e colostomia terminal, tipo Hartmann, que foram estudadas histologicamente e através da dosagem tecidual de hidroxiprolina. Utilizaram-se 40 ratos, machos, raça Wistar, com peso médio de 200 gramas, alocados em dois grupos (grupo I ou experimento e grupo II ou controle), subdivididos em quatro subgrupos: A,B,C e D com 10 animais em cada subgrupo. Os animais do grupo I (subgrupos A e B) foram submetidos à colostomia tipo Hartmann, no cólon distal, a 7,5cm do canal anal. Nos ratos do grupo II foi praticada apenas uma laparotomia mediana. Os animais dos subgrupo A e C foram sacrificados no 30º dia de P.O., enquanto que os animais dos subgrupos B e D o sacrifício foi no 60º dia de P.O. A análise histológica dos segmentos colônicos permitiu observar infiltrado inflamatório agudo e crônico na lâmina própria, achatamento pronunciado das criptas, diminuição do número de criptas e da celularidade epitelial, redução das células caliciformes e da mucossecreção, adelgaçamento da muscular da mucosa, mais intensos no coto colônico distal dos animais submetidos à colostomia terminal tipo Hartmann (subgrupos A e B). Os segmentos proximais apresentavam estas alterações, porém mais discretas. A dosagem de hidroxiprolina nos tecidos colônicos não revelou alterações estatisticamente significativas quanto ao conteúdo de colágeno ou do peso desidratado. Estes achados permitem demonstrar alterações morfológicas inflamatórias e hipotróficas mais pronunciadas no cólon distal de ratos submetidos à colostomia tipo Hartmann

Metabolic profiling of major vitamin D metabolites using Diels-Alder derivatization and ultra-performance liquid chromatography-tandem mass spectrometry

Biologically active forms of vitamin D are important analytical targets in both research and clinical practice. The current technology is such that each of the vitamin D metabolites is usually analyzed by individual assay. However, current LC-MS technologies allow the simultaneous metabolic profiling of entire biochemical pathways. The impediment to the metabolic profiling of vitamin D metabolites is the low level of 1α,25-dihydroxyvitamin D3 in human serum (15–60 pg/mL). Here, we demonstrate that liquid–liquid or solid-phase extraction of vitamin D metabolites in combination with Diels–Alder derivatization with the commercially available reagent 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) followed by ultra-performance liquid chromatography (UPLC)–electrospray/tandem mass spectrometry analysis provides rapid and simultaneous quantification of 1α,25-dihydroxyvitamin D3, 1α,25-dihydroxyvitamin D2, 24R,25-dihydroxyvitamin D3, 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2 in 0.5 mL human serum at a lower limit of quantification of 25 pg/mL. Precision ranged from 1.6–4.8 % and 5–16 % for 25-hydroxyvitamin D3 and 1α,25-dihydroxyvitamin D3, respectively, using solid-phase extraction

Vitamin D assays:past and present debates, difficulties, and developments

Clinical interest in Vitamin D and its purported roles not only in calcium and bone metabolism but in several other medical conditions (diabetes, cardiovascular disease, multiple sclerosis, cancer, psychiatric disorders, neuro-muscular disease) has led to a surge in laboratory requests for 25 hydroxy vitamin D and 1,25 dihydroxy vitamin D measurement. Circulating 25 hydroxy vitamin D concentration is routinely used as the best indicator of vitamin D status, but measurement of other metabolites, especially the physiologically active 1,25 dihyroxy vitamin D, are of clinical value. Over the last 40 years the development of assays for vitamin D and its metabolites from early competitive binding assays through to immunoassay and liquid chromatography aligned to mass spectrometry have demonstrated various analytical challenges, the advantages and disadvantages of each method are constantly changing with new technological developments. Immunoassay remains the predominant mode of measurement for 25-hydroxy vitamin D although problems with equimolar recovery of the D2 and D3 metabolites remain an issue. Standardisation of all assays has been improved but not resolved with the currently available reference materials as evidenced by the international vitamin D external quality assurance scheme, DEQAS. The choice of method for each laboratory remains a balance mainly between turn around time, convenience, cost and the specificity and accuracy of the information obtained. With increasing discussion and clinical interest surrounding other vitamin D metabolites the vitamin D assay debate is set to continue