The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
Lisa Baumann Kreuziger - One of the best experts on this subject based on the ideXlab platform.
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lack of efficacy of Pyridoxine vitamin b6 treatment in acquired idiopathic sideroblastic anaemia including refractory anaemia with ring sideroblasts
European Journal of Haematology, 2011Co-Authors: Lisa Baumann Kreuziger, Alexandra P Wolanskyj, Curtis A Hanson, David P SteensmaAbstract:Pyridoxine, or vitamin B6, is commonly used to treat acquired idiopathic sideroblastic anaemia (AISA, including refractory anaemia with ring sideroblasts), but the efficacy of this therapy in an unselected AISA population (i.e. patients without confirmed ALAS2 or other Pyridoxine-responsive germline mutations) has not been established. We reviewed clinical data from 231 patients with AISA and found that 42% of 203 evaluable patients had been treated with Pyridoxine. Only 6.8% of Pyridoxine-treated patients experienced a haemoglobin improvement (‡1.5 g ⁄dL) meeting 2006 International Working Group for Myelodysplastic Syndromes standardised response criteria. As some patients received combination therapy with erythropoietin or other agents, improvement could be attributed to Pyridoxine monotherapy in only one patient (1.4%). Smaller, less meaningful increments in haemoglobin levels of 0.5 g ⁄dL were observed in 13.5% of patients. Response to therapy did not correlate with International Prognostic Scoring System (IPSS) risk group or multilineage vs unilineage dysplasia. New symptomatic peripheral neuropathy was noted in 2.3% of patients treated with Pyridoxine. In this large series of unselected patients with sideroblastic anaemia, Pyridoxine therapy was ineffective and was associated with a risk of adverse effects. Pyridoxine therapy should be reserved for patients with known or suspected Pyridoxine-responsive mutations.
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lack of efficacy of Pyridoxine vitamin b6 treatment in acquired idiopathic sideroblastic anemia including refractory anemia with ring sideroblasts
Blood, 2010Co-Authors: Lisa Baumann Kreuziger, Alexandra P Wolanskyj, David P SteensmaAbstract:Abstract 2919 Background: Sideroblastic anemias can be either hereditary due to congenital mutations in factors critical for iron processing or heme biosynthesis, or acquired; acquired sideroblastic anemias may be induced by alcohol or medications, but are usually idiopathic. Pyridoxine, a form of vitamin B6, plays a critical role in heme synthesis as a cofactor for δ-aminolevulinic acid synthetase (ALAS). Some subtypes of congenital sideroblastic anemia, such as those associated with mutations in the ALAS2 gene encoding the erythrocyte-expressed isoform of ALAS, may respond to Pyridoxine therapy at doses ranging from 5–500 mg/day. Anecdotal reports of improvement with Pyridoxine therapy in cases of acquired idiopathic sideroblastic anemia (AISA) have led to widespread clinical use of this agent in patients with refractory anemia with ring(ed) sideroblasts (RARS) and refractory cytopenia with multilineage dysplasia associated with ring sideroblasts (RCMD-RS). However, there are no systematic studies of the effectiveness of Pyridoxine in AISA. Methods: We reviewed clinical and laboratory data from 231 adult patients with marrow aspirate-proven AISA (i.e., RARS or RCMD-RS, based on 2001 WHO criteria) evaluated at our institution between 1994 and 2007. Responses to Pyridoxine were assessed using 2006 International Working Group (IWG) standardized criteria for MDS (erythroid response with hemoglobin increase by 91.5 mg/dl). The relationship between response to Pyridoxine and disease subtype or International Prognostic Scoring System (IPSS) stratification was assessed using χ2 test, using a p-value limit of Results: 86 of the 231 patients (42%) were treated with Pyridoxine for an average of 19 months (range 1–114 months) at a mean dose of 167 mg/day (range 50–600 mg/day). Sufficient follow-up data to allow response evaluation were available from 74 (86%) of the 86 patients who received Pyridoxine. Only 5/86 patients (6.8%) receiving Pyridoxine met IWG response criteria for hematological improvement, but 3 of these 5 patients also received erythropoetin and 1 also received prednisone concomitantly with Pyridoxine therapy. Therefore, only 1/86 (1.4%) patient9s improvement in hemoglobin could be attributed to Pyridoxine monotherapy. ALAS2 genotype data were not available from these 5 patients. The dose of Pyridoxine was not associated with response to therapy (187.5 mg daily in responders vs. 157 mg daily in non-responders (p=0.60). Patients with RCMD-RS were more likely to be treated with vitamin B6 compared to patients with RARS (p= Conclusions: Pyridoxine is commonly prescribed to patients with AISA in clinical practice, and this agent is often continued for a long period of time despite lack of evidence of objective response. Pyridoxine is an ineffective therapy in AISA that induces symptomatic peripheral neuropathy in some patients. Therefore, Pyridoxine therapy should be limited to patients with known or suspected congenital mutations that confer Pyridoxine responsiveness, and therapeutic trials should be brief to avoid adverse effects. Disclosures: No relevant conflicts of interest to declare.
Gideon Koren - One of the best experts on this subject based on the ideXlab platform.
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comparing Pyridoxine and doxylamine succinate Pyridoxine hcl for nausea and vomiting of pregnancy a matched controlled cohort study
The Journal of Clinical Pharmacology, 2015Co-Authors: Eliza Pope, Caroline Maltepe, Gideon KorenAbstract:Nausea and vomiting of pregnancy (NVP) is a common gestational condition. This is the first study to compare the use of vitamin B6 (Pyridoxine) versus Diclectin (doxylamine succinate-Pyridoxine HCl) for NVP symptoms. Participants were pregnant women with NVP who used either Pyridoxine or doxylamine succinate-Pyridoxine HCl for ≥4 days prior to calling the Motherisk NVP Helpline. Women receiving Pyridoxine only (n = 80) were matched to a woman taking doxylamine succinate-Pyridoxine HCl only (n = 80), accounting for potential confounders and baseline level of NVP, measured by the Pregnancy Unique Quantification of Emesis (PUQE) score. Change in NVP severity after a week of therapy with either Pyridoxine or doxylamine succinate-Pyridoxine HCl was quantified using the PUQE-24 scale, which describes NVP symptoms 24 hours prior to their call. Doxylamine succinate-Pyridoxine HCl use found a significant reduction in PUQE score, compared with Pyridoxine (+0.5 versus -0.2, P < .05; negative denotes worsening). This association was especially prominent in women with more severe symptoms, where doxylamine succinate-Pyridoxine HCl use saw a mean improvement of 2.6 versus 0.4 with Pyridoxine (P < .05). As well, doxylamine succinate-Pyridoxine HCl use was associated with fewer women experiencing moderate to severe scores after a week of treatment, compared with the Pyridoxine group (7 versus 17, P < .05), despite similar baseline PUQE scores.
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Comparing Pyridoxine and doxylamine succinate‐Pyridoxine HCl for nausea and vomiting of pregnancy: A matched, controlled cohort study
Journal of clinical pharmacology, 2015Co-Authors: Eliza Pope, Caroline Maltepe, Gideon KorenAbstract:Nausea and vomiting of pregnancy (NVP) is a common gestational condition. This is the first study to compare the use of vitamin B6 (Pyridoxine) versus Diclectin (doxylamine succinate-Pyridoxine HCl) for NVP symptoms. Participants were pregnant women with NVP who used either Pyridoxine or doxylamine succinate-Pyridoxine HCl for ≥4 days prior to calling the Motherisk NVP Helpline. Women receiving Pyridoxine only (n = 80) were matched to a woman taking doxylamine succinate-Pyridoxine HCl only (n = 80), accounting for potential confounders and baseline level of NVP, measured by the Pregnancy Unique Quantification of Emesis (PUQE) score. Change in NVP severity after a week of therapy with either Pyridoxine or doxylamine succinate-Pyridoxine HCl was quantified using the PUQE-24 scale, which describes NVP symptoms 24 hours prior to their call. Doxylamine succinate-Pyridoxine HCl use found a significant reduction in PUQE score, compared with Pyridoxine (+0.5 versus -0.2, P < .05; negative denotes worsening). This association was especially prominent in women with more severe symptoms, where doxylamine succinate-Pyridoxine HCl use saw a mean improvement of 2.6 versus 0.4 with Pyridoxine (P < .05). As well, doxylamine succinate-Pyridoxine HCl use was associated with fewer women experiencing moderate to severe scores after a week of treatment, compared with the Pyridoxine group (7 versus 17, P < .05), despite similar baseline PUQE scores.
David P Steensma - One of the best experts on this subject based on the ideXlab platform.
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lack of efficacy of Pyridoxine vitamin b6 treatment in acquired idiopathic sideroblastic anaemia including refractory anaemia with ring sideroblasts
European Journal of Haematology, 2011Co-Authors: Lisa Baumann Kreuziger, Alexandra P Wolanskyj, Curtis A Hanson, David P SteensmaAbstract:Pyridoxine, or vitamin B6, is commonly used to treat acquired idiopathic sideroblastic anaemia (AISA, including refractory anaemia with ring sideroblasts), but the efficacy of this therapy in an unselected AISA population (i.e. patients without confirmed ALAS2 or other Pyridoxine-responsive germline mutations) has not been established. We reviewed clinical data from 231 patients with AISA and found that 42% of 203 evaluable patients had been treated with Pyridoxine. Only 6.8% of Pyridoxine-treated patients experienced a haemoglobin improvement (‡1.5 g ⁄dL) meeting 2006 International Working Group for Myelodysplastic Syndromes standardised response criteria. As some patients received combination therapy with erythropoietin or other agents, improvement could be attributed to Pyridoxine monotherapy in only one patient (1.4%). Smaller, less meaningful increments in haemoglobin levels of 0.5 g ⁄dL were observed in 13.5% of patients. Response to therapy did not correlate with International Prognostic Scoring System (IPSS) risk group or multilineage vs unilineage dysplasia. New symptomatic peripheral neuropathy was noted in 2.3% of patients treated with Pyridoxine. In this large series of unselected patients with sideroblastic anaemia, Pyridoxine therapy was ineffective and was associated with a risk of adverse effects. Pyridoxine therapy should be reserved for patients with known or suspected Pyridoxine-responsive mutations.
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lack of efficacy of Pyridoxine vitamin b6 treatment in acquired idiopathic sideroblastic anemia including refractory anemia with ring sideroblasts
Blood, 2010Co-Authors: Lisa Baumann Kreuziger, Alexandra P Wolanskyj, David P SteensmaAbstract:Abstract 2919 Background: Sideroblastic anemias can be either hereditary due to congenital mutations in factors critical for iron processing or heme biosynthesis, or acquired; acquired sideroblastic anemias may be induced by alcohol or medications, but are usually idiopathic. Pyridoxine, a form of vitamin B6, plays a critical role in heme synthesis as a cofactor for δ-aminolevulinic acid synthetase (ALAS). Some subtypes of congenital sideroblastic anemia, such as those associated with mutations in the ALAS2 gene encoding the erythrocyte-expressed isoform of ALAS, may respond to Pyridoxine therapy at doses ranging from 5–500 mg/day. Anecdotal reports of improvement with Pyridoxine therapy in cases of acquired idiopathic sideroblastic anemia (AISA) have led to widespread clinical use of this agent in patients with refractory anemia with ring(ed) sideroblasts (RARS) and refractory cytopenia with multilineage dysplasia associated with ring sideroblasts (RCMD-RS). However, there are no systematic studies of the effectiveness of Pyridoxine in AISA. Methods: We reviewed clinical and laboratory data from 231 adult patients with marrow aspirate-proven AISA (i.e., RARS or RCMD-RS, based on 2001 WHO criteria) evaluated at our institution between 1994 and 2007. Responses to Pyridoxine were assessed using 2006 International Working Group (IWG) standardized criteria for MDS (erythroid response with hemoglobin increase by 91.5 mg/dl). The relationship between response to Pyridoxine and disease subtype or International Prognostic Scoring System (IPSS) stratification was assessed using χ2 test, using a p-value limit of Results: 86 of the 231 patients (42%) were treated with Pyridoxine for an average of 19 months (range 1–114 months) at a mean dose of 167 mg/day (range 50–600 mg/day). Sufficient follow-up data to allow response evaluation were available from 74 (86%) of the 86 patients who received Pyridoxine. Only 5/86 patients (6.8%) receiving Pyridoxine met IWG response criteria for hematological improvement, but 3 of these 5 patients also received erythropoetin and 1 also received prednisone concomitantly with Pyridoxine therapy. Therefore, only 1/86 (1.4%) patient9s improvement in hemoglobin could be attributed to Pyridoxine monotherapy. ALAS2 genotype data were not available from these 5 patients. The dose of Pyridoxine was not associated with response to therapy (187.5 mg daily in responders vs. 157 mg daily in non-responders (p=0.60). Patients with RCMD-RS were more likely to be treated with vitamin B6 compared to patients with RARS (p= Conclusions: Pyridoxine is commonly prescribed to patients with AISA in clinical practice, and this agent is often continued for a long period of time despite lack of evidence of objective response. Pyridoxine is an ineffective therapy in AISA that induces symptomatic peripheral neuropathy in some patients. Therefore, Pyridoxine therapy should be limited to patients with known or suspected congenital mutations that confer Pyridoxine responsiveness, and therapeutic trials should be brief to avoid adverse effects. Disclosures: No relevant conflicts of interest to declare.
Kei Uchida - One of the best experts on this subject based on the ideXlab platform.
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formation of beta galactosides of Pyridoxine using sporobolomyces singularis
Methods in Enzymology, 1997Co-Authors: Yukio Suzuki, Kei UchidaAbstract:Publisher Summary Two β -galactosylPyridoxines and a β -galactobiosylPyridoxine are formed in high yield in a culture filtrate of Sporobolomyces singularis ( S. singularis ), when grown in a medium containing lactose and Pyridoxine. All of the compounds are isolated as needle crystals and identified as 5'- O -( β -D-galactopyranosyl)Pyridoxine, 4'- O -( β -D-galactopyranosyl)Pyridoxine, and 4'- O -[ β -D-galactopyranosyl-(1→4)- O - β -D-galactopyranosyl] Pyridoxine, respectively. Also, the yeast, when grown on a culture medium containing cellobiose and Pyridoxine, produces a remarkable amount of 5'- O -( β -D-glucopyranosyl)Pyridoxine and 4'- O -( β -D-glucopyranosyl)Pyridoxine in a culture broth. S. singularis, when grown on a culture medium containing cellobiose and Pyridoxine, forms 5'- O -( β -D-glucopyranosyl) Pyridoxine and 4'- O -( β -D-glucopyranosyl)Pyridoxine in the culture broth. These compounds are identified by comparison with the characteristics of 5'- O -( β -D-glucopyranosyl)Pyridoxine and 4'- O -( β -D-glucopyranosyl) Pyridoxine synthesized from cellobiose and Pyridoxine by wheat bran β -glucosidase. The maximum yield of 4'- O -( β -D-glucopyranosyl)Pyridoxine from lactose and Pyridoxine by intact cells is observed at pH 4.0, while the yield of 5'- O -( β -D-glucopyranosyl) Pyridoxine is observed at pH 5.5. Lactose, o -nitrophenyl β -D-galactopyranoside, cellobiose, salicin, phenyl β -D-glucopyranoside, and p -nitrophenyl β -D-glucopyranoside effect the formation of glycosylPyridoxine, but galactose, glucose, glucose 1-phosphate, melibiose, raffinose, maltose, and sucrose are quite ineffective.
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formation of β galactosyl compounds of Pyridoxine in growing culture of sporobolomyces singularis
Biochimica et Biophysica Acta, 1992Co-Authors: Yukio Suzuki, Kei UchidaAbstract:Abstract Several Pyridoxine compounds were found to be formed in a high yield in a growing culture of Sporobolomyces singularis containing lactose and Pyridoxine. Three compounds, I, II and III, were isolated from cultured broth by Dowex 50W-X8 colum chromatography, paper chromatography, lyophilization, and then obtained as needle crystals (m.p. (decomp.): I, 204–206°C; II, 192–194°C; III, 222–223°C. [α]D16: I, −27.7° (c = 3.82, H2O); II, −1.6° (c = 2.52, H2O); III, + 8.3° (c = 3.98, H2O)). Compounds I, II, and III were identified as 5′-O-(β- d -galactopyranosyl)-Pyridoxine , 4′-O-(β- d -galactopyranosyl)-Pyridoxine , and 4′-O-(β- d -galactopyranosyl -(1 → 4)-β- d -galactopyranosyl)-Pyridoxine , respectively, on the basis of the various experimental results, viz., ultraviolet, infra-red, 1H-NMR, and 13C-NMR spectra, products by hydrolysis with acid and with α- and β-galactosidases, migration on paper electrophoresis, and Gibbs reaction in the presence and absence of boric acid. Also, the yeast produced a remarkable amount of β-glucosyl compounds of Pyridoxine in cultured broth, when grown on cellobiose and Pyridoxine.
Eliza Pope - One of the best experts on this subject based on the ideXlab platform.
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comparing Pyridoxine and doxylamine succinate Pyridoxine hcl for nausea and vomiting of pregnancy a matched controlled cohort study
The Journal of Clinical Pharmacology, 2015Co-Authors: Eliza Pope, Caroline Maltepe, Gideon KorenAbstract:Nausea and vomiting of pregnancy (NVP) is a common gestational condition. This is the first study to compare the use of vitamin B6 (Pyridoxine) versus Diclectin (doxylamine succinate-Pyridoxine HCl) for NVP symptoms. Participants were pregnant women with NVP who used either Pyridoxine or doxylamine succinate-Pyridoxine HCl for ≥4 days prior to calling the Motherisk NVP Helpline. Women receiving Pyridoxine only (n = 80) were matched to a woman taking doxylamine succinate-Pyridoxine HCl only (n = 80), accounting for potential confounders and baseline level of NVP, measured by the Pregnancy Unique Quantification of Emesis (PUQE) score. Change in NVP severity after a week of therapy with either Pyridoxine or doxylamine succinate-Pyridoxine HCl was quantified using the PUQE-24 scale, which describes NVP symptoms 24 hours prior to their call. Doxylamine succinate-Pyridoxine HCl use found a significant reduction in PUQE score, compared with Pyridoxine (+0.5 versus -0.2, P < .05; negative denotes worsening). This association was especially prominent in women with more severe symptoms, where doxylamine succinate-Pyridoxine HCl use saw a mean improvement of 2.6 versus 0.4 with Pyridoxine (P < .05). As well, doxylamine succinate-Pyridoxine HCl use was associated with fewer women experiencing moderate to severe scores after a week of treatment, compared with the Pyridoxine group (7 versus 17, P < .05), despite similar baseline PUQE scores.
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Comparing Pyridoxine and doxylamine succinate‐Pyridoxine HCl for nausea and vomiting of pregnancy: A matched, controlled cohort study
Journal of clinical pharmacology, 2015Co-Authors: Eliza Pope, Caroline Maltepe, Gideon KorenAbstract:Nausea and vomiting of pregnancy (NVP) is a common gestational condition. This is the first study to compare the use of vitamin B6 (Pyridoxine) versus Diclectin (doxylamine succinate-Pyridoxine HCl) for NVP symptoms. Participants were pregnant women with NVP who used either Pyridoxine or doxylamine succinate-Pyridoxine HCl for ≥4 days prior to calling the Motherisk NVP Helpline. Women receiving Pyridoxine only (n = 80) were matched to a woman taking doxylamine succinate-Pyridoxine HCl only (n = 80), accounting for potential confounders and baseline level of NVP, measured by the Pregnancy Unique Quantification of Emesis (PUQE) score. Change in NVP severity after a week of therapy with either Pyridoxine or doxylamine succinate-Pyridoxine HCl was quantified using the PUQE-24 scale, which describes NVP symptoms 24 hours prior to their call. Doxylamine succinate-Pyridoxine HCl use found a significant reduction in PUQE score, compared with Pyridoxine (+0.5 versus -0.2, P < .05; negative denotes worsening). This association was especially prominent in women with more severe symptoms, where doxylamine succinate-Pyridoxine HCl use saw a mean improvement of 2.6 versus 0.4 with Pyridoxine (P < .05). As well, doxylamine succinate-Pyridoxine HCl use was associated with fewer women experiencing moderate to severe scores after a week of treatment, compared with the Pyridoxine group (7 versus 17, P < .05), despite similar baseline PUQE scores.
