Mouse embryo-derived NIH3T3 fibroblasts adopt an osteoblast-like phenotype when treated with 1alpha,25-dihydroxyvitamin D(3) and dexamethasone in vitro

This study examines the capability of NIH3T3 fibroblasts to express osteoblastic markers following stimulation with a number of hormones and growth factors in vitro. Of the agents tested, 1alpha,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) dose-dependently induced alkaline phosphatase (ALP) activity in NIH3T3 cells, and this effect was enhanced by the addition of dexamethasone (Dex), which when administered alone caused no detectable ALP expression. The combined use of 1,25(OH)(2)D(3) and Dex also stimulated the synthesis of osteocalcin, and osteopontin. Furthermore, cells treated with the both hormones, in the presence of beta-glycerophosphate and l-ascorbic acid, formed mineralized plaques, indicating an osteoblast (OB) phenotype. By contrast, the differentiation induced by 1,25(OH)(2)D(3) or 1,25(OH)(2)D(3) plus Dex was significantly antagonized by transforming growth factor-beta1 and all trans-retinoic acid. These data indicate that NIH3T3 cells have the potential to adopt an OB-like phenotype and may prove to be a convenient model for studying the early events of osteogenic differentiation and the specific interactions of 1,25(OH)(2)D(3) with glucocorticoids in controlling this process in vitro.

Vitamin D and scalp psoriasis

Calcipotriene has been shown to be safe and effective for the treatment of psoriasis. For scalp psoriasis, the safety advantage of this nonsteroid agent is as important as its efficacy. Even though monotherapy with calcipotriene solution may not always be efficacious for severe scalp psoriasis, many patients are managed effectively with a sequential therapy regimen consisting of 3 phases. In phase 1 (clearing), patients apply clobetasol solution or gel in the morning and calcipotriene solution in the evening daily for 2 weeks. After the scalp psoriasis improves, clobetasol is reduced to weekends and calcipotriene solution is applied on weekdays (phase 2, transitional). Phase 3 is maintenance on calcipotriene solution alone to prevent recurrence. For patients with recalcitrant scalp psoriasis-where only a clobetasol-strength, superpotent topical corticosteroid is effective-a flip-flop therapy regimen has been proposed that allows for the safe, prolonged use of clobetasol solution by limiting its treatment to twice a day for 2-week periods with the use of calcipotriene solution twice a day for a minimum of 2 weeks during the corticosteroid-free in-between periods.

Topical calcipotriol plus oral fumaric acid is more effective and faster acting than oral fumaric acid monotherapy in the treatment of severe chronic plaque psoriasis vulgaris

BACKGROUND

Calcipotriol is an established topical therapy for psoriasis vulgaris.

OBJECTIVE

This study aimed to investigate whether the addition of calcipotriol to fumaric acid ester (FAE) monotherapy had an additive efficacy and an FAE-sparing effect in patients with severe plaque psoriasis.

METHODS

This multicentre, randomised, double-blind, vehicle-controlled study included 143 patients for up to 13 weeks treatment. Group A received FAE tablets (Fumaderm) with an increasing daily dosage from 105 to 1,075 mg + ointment vehicle. Group B received FAE tablets + calcipotriol ointment (50 microg/g). Ointments were applied twice daily. Clinical response was assessed using percentage changes in the Psoriasis Area and Severity Index (PASI), from baseline to treatment end.

RESULTS

The mean percentage change in the PASI was -76.1% in group B and -51.9% in group A, the difference between treatments was -24.2% (95% CI from -34.2 to -14.2%; p < 0.001). Group B responded more rapidly to treatment. Investigators' and patients' overall efficacy assessments were significantly more favourable for group B (p < or = 0.001). Group B was prescribed less FAE than group A. This difference was greatest at the last visit (mean daily dose 529 and 685 mg, respectively; p = 0.006). Overall adverse events in the two groups were similar.

CONCLUSION

This study shows that the combination of calcipotriol and FAEs is significantly more effective and faster acting than FAE monotherapy in the treatment of severe plaque psoriasis. The combination has a slight FEA-sparing effect and therefore a superior benefit/risk ratio.

Different effects of 22-oxacalcitriol and calcitriol on the course of experimental chronic renal failure

Calcitriol, 1,25(OH)(2)D(3), has been reported to have a beneficial effect on bone histology in patients with predialysis chronic renal failure; however, such treatment involves a risk of hypercalcemia. To investigate the effects of 1,25(OH)(2)D(3) and 22-oxacalcitriol (OCT) on the progression of histologic deterioration, we administered intraperitoneal 1,25(OH)(2)D(3) or OCT, three times a week, to rats with adriamycin-induced progressive renal failure, from the 10th week after the induction of ADR-induced nephropathy. The rats were divided into the following groups: (1) high-dose 1,25(OH)(2)D(3), 0.2 microg/kg (group D(3)-0.2); (2) low-dose 1,25(OH)(2)D(3), 0.04 microg/kg (group D(3)-0.04); (3) high-dose OCT, 0.2 microg/kg (group OCT-0.2); (4) low-dose OCT, 0.04 microg/kg (group OCT-0.04); and (5) ADR-induced nephropathy (group ADR). The death rate at week 20 in group D(3)-0.2 was 50%, significantly higher than the death rates in the other groups, except for group D(3)-0.04 (P <.05). The serum creatinine and blood urea nitrogen levels were the highest in group D(3)-0.2, although the difference was not significant. In contrast, in groups OCT-0.2 and OCT-0.04, tubular changes and interstitial volume were smaller than in groups D(3)-0.2 and D(3)-0.04 (P <.05). Although calcium deposits increased in group D(3)-0.2, the difference was not significant. Glomerular expression of transforming growth factor-beta1 (TGF-beta1) expression was less in groups OCT-0.2 and OCT-0.04 than in groups D(3)-0.2 and D(3)-0.04 (P <.05). Glomerular fibronectin expression was less in group OCT-0.2 than in groups D(3)-0.2 and ADR (P <.05). Tubulointerstitial expression of TGF-beta1 was greater in group D(3)-0.2 than in group ADR and greater in group D(3)-0.04 than in group OCT-0.04 (P <.05). We conclude that a high dose of 1,25(OH)(2)D(3) accelerated the progressive renal deterioration of ADR-induced nephropathy, and, as a result, OCT was able to attenuate renal histologic lesions.

[A case with secondary hyperparathyroidism suggesting the direct suppressive effect of maxacalcitol on osteoblasts]

The direct effect of vitamin D on osteoblasts in secondary hyperparathyroidism(2 degrees HPT) is not necessarily obvious. We found an unusual hemodialyzed patient without any response to oral calcitriol pulse therapy(4 micrograms x 2/week), and who was administered maxacalcitol at a dose of up to 15 micrograms x 3/week for 28 months. Plasma intact parathyroid hormone(PTH) was not suppressed from the initial level of 1,773 pg/ml to 2,100 pg/ml. However, on the contrary, alkaline phosphatase(ALP) was successively suppressed from 2 weeks from the initial level of 1,261 IU/l to 276 IU/l. This result suggests a direct suppressive effect of maxacalcitol on osteoblasts in 2 degrees HPT.

Renoprotection following treatment of secondary hyperparathyroidism with percutaneous ethanol injection in pre-dialysis patients

What could be done for patients with chronic renal failure are marginally beneficial. Among 58 pre-dialysis patients, we found 24 of chronic glomerulonephritis (CGN) with serum creatinine >5 mg/dl and intact parathyroid hormone (i-PTH) >200 pg/ml. In this study, we determined if the residual renal function could be preserved when hyperparathyroidism was corrected by either low-dose calcitriol treatment or ethanol injection. The 58 CGN patients were divided into three groups. The first group, which comprised 11 cases with i-PTH >200 pg/ml and had parathyroid mass, were treated by ultrasonography-guided percutaneous ethanol injection therapy (PEIT). The second study group composed of 13 cases with i-PTH >200 pg/ml without parathyroid mass were treated by calcitriol 1 microg every other day. The third group made up of 34 cases with i-PTH <200 pg/ml, who did not receive calcitriol or ethanol therapy. All patients were followed up within 2 years or until dialysis. The average rate of decline in renal function (slope of reciprocal serum creatinine vs. time) was 0.0025 +/- 0.0026 dl/mg month in group 1, 0.0054 +/- 0.0024 in group 2, and 0.0067 +/- 0.0025 in group 3 (p = 0.018 in group 1 vs. group 2, p < 0.001 in group 1 vs. group 3). The declines of i-PTH, phosphorus, and alkaline phosphatase, and the increase of calcium were all significantly different between group 1 and group 3. Two cases of group 1, 6 cases of group 2, and 20 cases of group 3 entered into dialysis during this study. In conclusion, selective PEIT guided by color Doppler flow mapping is an effective therapy for treating hyperparathyroidism and protecting the residual renal function.

Limited benefit of topical calcipotriol in lichen planus treatment: a preliminary study

BACKGROUND

Lichen planus (LP) is a papulosquamous dermatosis in which immunologic mechanisms play an important role in its pathogenesis. Topical calcipotriol, which mainly stimulates differentiation and inhibits proliferation of keratinocytes, also has immunosuppressive and anti-inflammatory functions.

AIM

To investigate the therapeutical effects of topical calcipotriol in LP.

METHODS

A total of 18 histopathologically proved LP patients were advised to apply calcipotriol ointment twice daily to all affected skin areas except genitalia. Clinical evaluation of all patients was performed monthly and response to treatment was assessed on clinical grounds (erythematous and/or violaceous color, thickness and scale of the lesions) as partial, complete or no response. If there was no response at the end of the second month, topical calcipotriol was stopped. If there was partial clinical improvement at the end of the second month, the treatment was continued for one additional month.

RESULTS

In all, 16 patients completed the study. Of the study population, 56.25% (9/16) responded to topical calcipotriol treatment which was used for a maximum of 3 months. Complete clearing of the lesions with post-inflammatory hyperpigmentation and partial improvement were obtained in 31.25% (5/16) and 25% (4/16) of the patients, respectively. No improvement was observed in 43.75% (7/16) of the patients.

CONCLUSION

Topical calcipotriol can be used in the treatment of LP as a therapeutic option, although it is not the first-choice drug.

Vitamin D receptor: a potential target for intervention

Epidemiologic data suggest that low exposure to vitamin D or 1alpha,25-dihydroxycholecalciferol (calcitriol) increases the risk of prostate cancer. Calcitriol, a central factor in bone and mineral metabolism, is also a potent antiproliferative agent in a wide variety of malignant cell types. We have demonstrated that calcitriol has significant antitumor activity in vitro and in vivo in prostate and squamous cell carcinoma model systems. Calcitriol, in these models, induces a significant G0/G1 arrest and modulates p21(Waf1/Cip1) and p27(Kip1), the cyclin-dependent kinase inhibitors. Calcitriol induces poly (adenosine diphosphate-ribose) polymerase cleavage, increases bax/bcl-2 ratio, reduces levels of phosphorylated mitogen-activated protein kinases (P-MAPKs; also known as extracellular signal-related kinase [ERK] 1/2) and phosphorylated Akt, induces caspase-dependent mitogen-activated protein kinase kinase (MEK) cleavage and upregulation of MEK kinase-1, all potential markers of the apoptotic pathway. We also have demonstrated that dexamethasone (dex) potentiates the antitumor effect of calcitriol through effects on the vitamin D receptor and decreases calcitriol-induced hypercalcemia. We initiated phase 1 and phase 2 trials of calcitriol, either alone or in combination with carboplatin, paclitaxel, or dex. Data from these studies indicate that high-dose calcitriol is feasible on an intermittent schedule, the maximum tolerated dose (MTD) is unclear, and dex or paclitaxel appear to ameliorate hypercalcemia. Studies continue to define the MTD of calcitriol on this intermittent schedule, either alone or with other agents, and to evaluate the mechanisms of calcitriol effects in prostate cancer models.

Modulation of renal Ca2+ transport protein genes by dietary Ca2+ and 1,25-dihydroxyvitamin D3 in 25-hydroxyvitamin D3-1alpha-hydroxylase knockout mice

Pseudovitamin D-deficiency rickets (PDDR) is an autosomal disease characterized by hyperparathyroidism, rickets, and undetectable levels of 1,25-dihydroxyvitaminD3 (1,25(OH)2D3). Mice in which the 25-hydroxyvitamin D3-1alpha-hydroxylase (1alpha-OHase) gene was inactivated presented the same clinical phenotype as patients with PDDR and were used to study renal expression of the epithelial Ca2+ channel (ECaC1), the calbindins, Na+/Ca2+ exchanger (NCX1), and Ca2+-ATPase (PMCA1b). Serum Ca2+ (1.20+/-0.05 mM) and mRNA/protein expression of ECaC1 (41+/-3%), calbindin-D28K (31+/-2%), calbindin-D9K (58+/-7%), NCX1 (10+/-2%), PMCA1b (96+/-4%) were decreased in 1alpha-OHase-/- mice compared with 1alpha-OHase+/- littermates. Feeding these mice a Ca2+-enriched diet normalized serum Ca2+ levels and expression of Ca2+ proteins except for calbindin-D9K expression. 1,25(OH)2D3 repletion resulted in increased expression of Ca2+ transport proteins and normalization of serum Ca2+ levels. Localization of Ca2+ transport proteins was clearly polarized in which ECaC1 was localized along the apical membrane, calbindin-D28K in the cytoplasm, and calbindin-D9K along the apical and basolateral membranes, resulting in a comprehensive mechanism facilitating renal transcellular Ca2+ transport. This study demonstrated that high dietary Ca2+ intake is an important regulator of the renal Ca2+ transport proteins in 1,25(OH)2D3-deficient status and thus contributes to the normalization of blood Ca2+ levels.

Safety and efficacy of combined high-dose treatment with calcipotriol ointment and solution in patients with psoriasis

BACKGROUND

In the vast majority of psoriatic patients, psoriatic lesions are localised on the body as well as on the scalp. Therefore, safety data on the combined use of calcipotriol in lotion and calcipotriol in ointment are needed.

OBJECTIVE

This study investigated the effect of high-dose treatment with a combination of calcipotriol ointment and scalp solution on calcium metabolism, indices of bone turnover and PASI in patients with extensive psoriasis.

METHODS

Following a 2-week wash-out period, 88 patients were randomised to 4 weeks of treatment with either calcipotriol ointment/scalp solution (80-100 g/week and 30-50 ml/week, respectively; n = 41) or with a dithranol/tar regimen (n = 47). Patients were seen at weeks 1, 2 and 4 during treatment and 1 week following cessation of treatment.

RESULTS

No significant differences at the end of treatment were found between the 2 groups with respect to 24-hour urinary excretion of calcium (expressed as calcium/creatinine ratio), phosphate or pyridinoline, serum concentrations of calcium (albumin corrected), creatinine, phosphate, parathyroid hormone, 25-hydroxyvitamin D(3), 1,25-dihydroxyvitamin D(3), osteocalcin, alkaline phosphatase (total and bone-specific iso-enzymes) or 1-collagen telopeptide. At the end of treatment, the psoriasis area and severity index had decreased by 57.4% in the calcipotriol group and by 36.1% in the dithranol/tar group (p = 0.004). Investigators' and patients' assessments of overall efficacy also favoured treatment with calcipotriol (p < 0.001).

CONCLUSION

The combined use of calcipotriol ointment/scalp solution did not affect the indices of calcium metabolism or bone turnover and was significantly more effective than dithranol/tar in reducing disease severity and extent in patients with extensive psoriasis.

Prevention of bone loss in ovariectomized rats by combined treatment with risedronate and 1alpha,25-dihydroxyvitamin D3

Bisphosphonates inhibit bone loss through inhibition of osteoclast-mediated bone resorption. At low doses, vitamin D metabolites can prevent bone loss in models of osteopenia in rats by an antiresorptive effect, while at high doses they also stimulate osteoblast activity and show an anabolic effect. Therefore, combined therapy with bisphosphonates and vitamin D analogs might be expected to be more effective than either treatment alone. It was the aim of this study to compare the efficacy of risedronate and of the naturally occurring vitamin D hormone 1alpha,25-dihydroxyvitamin D3 (calcitriol), alone and in combination, for the prevention of ovariectomy-induced bone loss in rats. One hundred ten female 4-month-old Sprague-Dawley rats were used for this experiment. Ninety rats were bilaterally ovariectomized (OVX), 10 rats were sham-operated (SHAM), and 10 rats were killed at the time of surgery as a baseline control. Groups of rats (10 rats/group) received vehicle or daily doses of 0.1 mg or 0.5 mg of risedronate or 0.05 microg or 0.1 microg of calcitriol/kg body weight, alone and in combination. Both compounds were administered orally via gavage, commencing on the day after surgery. Although estrogen deficiency-induced bone loss was prevented by individual prophylactic administration of risedronate or calcitriol, OVX rats treated with a combination of risedronate and calcitriol had higher bone mineral density (BMD), cancellous bone area (B.Ar), and bone strength in long bones and vertebrae compared with rats receiving risedronate alone. Furthermore, calcitriol enhanced the suppressive effects of risedronate on osteoclast number and partially counteracted the suppressive effects of risedronate on bone formation and histomorphometric indices of osteoblast team performance. Risedronate did not reduce the anabolic effect of calcitriol, and at the high dose it normalized hypercalcemia in calcitriol-treated OVX rats. Therefore, this study in OVX rats suggests that combined therapy with bisphosphonates and vitamin D analogs may offer advantages over the treatment with bisphosphonates or vitamin D analogs alone.

Adaptive dose finding for phase I clinical trials of drugs used for chemotherapy of cancer

Phase I clinical trials of cancer chemotherapy drugs are intended to determine the maximum tolerable dose (MTD). Thestandard method employed is a rule-based dose-escalation scheme in which escalation depends on the number of patients at a dose level that have dose-limiting toxicity (DLT). The MTD is thus defined in terms of the rules and a series of dose levels selected for sampling. For some trials it is desirable to have a more precise definition of the MTD, and to determine the MTD more accurately than possible with the rule-based schemes. Continuous reassessment methods (CRMs) define the MTD to be the dose at which a fixed fraction of patients experience DLT, and thus appear suited to these trials. It is shown, however, that these methods can have failure modes that in fact make them unattractive. An alternative data-driven dose-finding method is described that combines the robustness of the rule-based methods and with features of CRMs. The method has two stages. In the first stage, doses are escalated by a factor of 1.5. In the second stage, which begins at the first instance of DLT, a two-parameter logistic dose-response model estimates the MTD from the DLT experience of all patients. The model is initialized by setting the dose (d10) at which 10 per cent of patients would experience DLT to half the dose at which the first DLT was observed, and the dose (d90) at which 90 per cent would experience DLT to ten times d10. Weights are assigned such that the information at d10 and d90 is equivalent to that of one patient at each of the two doses. Cohorts of three patients are treated in both stages, and the dose for a new cohort in the second stage is the estimated MTD. The only prior information required to specify the design completely is the dose which will be given to the first cohort. Two stopping rules are investigated; among the requirements for these are that at least three (or four) DLTs be observed and at least nine patients be treated in the second stage. Simulations show that a coefficient of variation of approximately 0.4 on a target DLT probability of 0.3 is obtained over a wide variation in dose-response characteristics of the study drug. The performance of the new method is compared to that of rule-based methods.

Risk factors for hip fracture in hemodialysis patients

BACKGROUND

The incidence and mortality of hip fractures were several times greater in the patients with hemodialysis (HD) than in the general population. Although patients with end-stage renal disease develop renal osteodystrophy, few published data examined the risk factor of hip fractures in the dialysis population.

METHODS

The present study was performed to compare various indices and bone mineral density (BMD) of HD patients with or without the history of hip fractures. Moreover, we analyzed the factors which predicted hip fractures in 183 patients with chronic HD enrolled in the cross-sectional study.

RESULTS

Serum level of alkaline phosphatase was significantly higher in HD patients with hip fractures, compared to those without hip fractures. Oral calcium carbonate dose was significantly lower in HD patients with hip fractures. 1/3 radius (R)-BMD and ultradistal (UD)R-BMD were significantly lower in HD patients with hip fractures. However, lumbar spine (LS)-BMD was comparable in HD patients with or without hip fractures. Although there was no significant differences of BMD between with and without hip fractures in diabetes mellitus, UDR-BMD of patients with hip fractures was significantly lower than that of patients without hip fractures in chronic glomerulonephritis. Radial BMD was lower in female patients with hip fractures, compared to without hip fractures, although there were no significant differences in male patients. In multiple logistic regression analysis, oral calcitriol dose and 1/3R-BMD were selected as a risk factor of hip fractures in HD patients.

CONCLUSION

Radial BMD was lower in HD patients with hip fractures. However, its contribution is different, depending on gender and the original disease leading to HD. Radial BMD and oral calcitriol dose seemed to be important to predict the risk of hip fractures.

The importance of accurate dosage of topical agents: a method of estimating involved area and application to calcipotriol treatment failures

Little attention is given to accurate dosage of topical medication which is a potential source of side-effects and treatment failure. There are studies on the dosage for 'sparing' application relevant to topical steroids but not for 'liberal' application. Though calcipotriol is a first line topical treatment for psoriasis, approximately one-third of patients do not respond adequately. The aims of the present study were to define liberal dosage, to develop a method of calculation of area of involved skin and to evaluate the efficacy of calcipotriol in optimized liberal dosages, based on preliminary studies, in calcipotriol treatment failures. Weight/unit area of ointment and cream base, constituting liberal application, was determined in six normal volunteers. The area of psoriatic involvement in 24 calcipotriol non-responders was estimated by a 'fill-up' method and a modified 'hand' method. The results of the two methods were similar (Pearson correlation coefficient 0.68, P < 0.0001) but the 'hand' method proved easier in use and was the preferred method for the rest of the study. The patients applied calcipotriol at their accustomed rates for at least 2 weeks and then at the calculated liberal rates, using cream in the morning and ointment at night, for 4 weeks. The efficacy measures were Psoriasis Area and Severity Index (PASI) (primary measure), a four-point efficacy score and a visual analogue scale. As a result of the preliminary study and the actual amounts used by the patients in the psoriasis treatment study reported below, liberal application has been defined as 50 g/m2 per application for ointment base and 40 g/m2 per application for cream. At this dosage, an average individual would use approximately 100 g of medication/week to treat 10% of the body surface. During the 4-week treatment study, the psoriasis patients used an average of 39 g (SD 17 g)/m2 per application of cream and 52 g (SD 13 g)/m2 per application of ointment. All efficacy measures showed marked improvement (P < 0.0001). The frequency distribution of the PASI reduction defined responsive (70% of patients) and poorly responsive groups (30%), with mean PASI reduction of 60% and 17%, respectively.

Myelodysplasia and bone marrow fibrosis treated with calcitriol and venesection

We report a patient with myelodysplasia and bone marrow fibrosis. We managed him with regular blood transfusion for a period of 16 months. A modest dose of calcitriol (1,25-dihydroxycholecalciferol) 0.75 microg daily for 12 weeks resulted in a gradual but complete response in his haemoglobin level. There were significant bone marrow changes in that the fibrosis has completely disappeared although the marrow cytology remained dysplastic. The normal haemoglobin level persists despite an intensive venesection programme aimed at reducing iron overload. We conclude that calcitriol should be given for at least 12 weeks in patients with myelodysplasia especially if there is a fibrotic element in the bone marrow. The role of venesection in maintaining remission is a speculative.

Effect of dietary supplementation with vitamin D metabolites in an experimental model of turkey osteomyelitis complex

Supplementation with vitamin D3 was previously shown to protect Escherichia coli challenged birds that underwent two dexamethasone (DEX) treatments at 5 and 12 wk of age in an experimental model of turkey osteomyelitis complex (TOC). The purpose of the present study was to determine the effects of dietary supplementation with 10 microg of 1,25 dihydroxyvitamin D3 (1,25D)/ kg feed or 99 microg of 25-hydroxyvitamin D3 (25D)/kg feed on disease resistance in the same model. Birds were fed the supplemented diets continuously and ad libitum. Seven hundred twenty turkey poults were placed into 24 floor pens in a 3 x 2 x 2 design (three vitamin D treatments, two DEX treatments, two E. coli treatments, with two replicate pens per treatment). At 5 wk of age, half of the birds were treated with DEX, and half of the DEX-treated birds and half of the nontreated birds were challenged with E. coli. All mortalities and lame birds were necropsied. At 9 wk, all of the DEX- or E. coli-treated birds were given another series of DEX injections; 2 wk later 10 birds per pen were necropsied. At 12 wk, survivors of the previous challenges were given a third DEX treatment, and all birds were necropsied 2 wk later. After the first series of DEX injections, mortality was increased in the 25D-supplemented birds that were given the DEX treatment and the E. coli challenge. After the second series of DEX injections, the main effect mean BW was significantly lower in birds given 1,25D as compared to controls and 25D-supplemented birds. Mortality was higher in 1,25D-supplemented birds that were challenged with E. coli at 5 wk and treated with DEX at 9 wk as compared to 25D-supplemented birds. The 1,25D-treated birds that were treated with DEX at 5 and 9 wk and challenged with E. coli at 5 wk had higher mortality and air sacculitis scores as compared to controls and 25D-treated birds. The main effect mean mortality was significantly higher in birds given 1,25D as compared to controls and 25D-treated birds. The percentage of birds with TOC lesions was decreased from 27% to 0 by 25D and 1,25D in the groups given two DEX treatments and E. coli challenge. After the third DEX treatment, BW of 1,25D-suppplemented birds was decreased, and mortality and air sacculitis scores were increased. Bone strength was generally increased by supplementation with 1,25D, whereas 25D supplementation increased bone strength only in birds challenged at 5 wk and treated with DEX at Weeks 9 and 12. In this study, supplementation with vitamin D metabolites decreased TOC incidence in E. coli-challenged birds given two DEX treatments. However, toxic effects were observed in most supplemented DEX-treated birds and may be attributed to an additive effect of DEX treatment, E. coli septicemia, and vitamin D supplementation.

Calcipotriol plus short-contact dithranol: a novel topical combination therapy for chronic plaque psoriasis

The purpose of this double-blind randomised parallel-group study was to compare the efficacy and safety of short-contact treatment with dithranol ointment (2%) with its combination with calcipotriol ointment (50 microg/g) in 2 groups of in-patients with chronic plaque psoriasis. The patients of the first group (n = 23) topically applied dithranol once daily for 30 min and the vehicle of calcipotriol twice daily. The patients of the second group (n = 23) used a single topical application of dithranol for 30 min daily and additionally applied calcipotriol twice daily. The extent and the severity of psoriasis were assessed by means of psoriasis area and severity index score (PASI score) before the onset of the 6-week therapy and weekly thereafter. The difference between the two groups with regard to the mean PASI score became statistically significant already after the first week of treatment and remained so until the end of the trial. No significant differences were observed between the two groups with respect to the cutaneous adverse events. These findings indicate that the addition of calcipotriol ointment to short-contact dithranol markedly augments the therapeutic efficacy of the latter in chronic plaque psoriasis and impressively accelerates the response of psoriatic plaques to this well-tolerated regimen.

Combination of calcipotriene (Dovonex) ointment and tazarotene (Tazorac) gel versus clobetasol ointment in the treatment of plaque psoriasis: a pilot study

BACKGROUND

Both calcipotriene and tazarotene have been shown to be effective in the treatment of psoriasis. No study has evaluated the effect of using both agents simultaneously.

OBJECTIVE

Our purpose was to evaluate the effectiveness of combination treatment of psoriasis with calcipotriene ointment and tazarotene gel by comparing them with clobetasol ointment, a class I topical corticosteroid. A secondary objective was to evaluate the clinical compatibility of applying both agents at the same time.

METHODS

This pilot study was a prospective, single-center, open-label, right/left comparison of 28 lesion pairs in 15 patients. It consisted of a 2-week treatment phase, followed by a 4-week post-treatment observation phase.

RESULTS

All 15 patients completed the treatment phase of the study. At the end of the active treatment phase (end of week 2), calcipotriene- and tazarotene-treated lesions showed nearly identical reductions in scaling (P =.93), plaque elevation (P =.76), and overall lesional severity scores (P =.29) compared with their matched clobetasol-treated counterparts. Erythema improved significantly more in clobetasol-treated lesions (P <.05) during the treatment period, but differences became statistically insignificant during the post-treatment period (;P =.20). No patients had significant irritation from the treatments. During the post-treatment phase (weeks 3-6), all lesions worsened; plaque elevation returned somewhat more rapidly in calcipotriene- and tazarotene-treated lesions (P <.01), whereas changes in scaling, erythema, and overall lesional severity were not significantly different between the two treatment groups (P >.05).

CONCLUSION

The nonsteroid combination of twice-daily calcipotriene ointment and once-daily tazarotene gel was not statistically different from twice-daily application of the class I corticosteroid clobetasol ointment in reducing psoriatic scaling, plaque elevation, and overall lesional severity over a 2-week period. There does not seem to be any chemical incompatibility between calcipotriene ointment and tazarotene gel that is clinically significant.

[How I treat...pityriasis rubra pilaris]

Pityriasis rubra pilaris is a syndrome of unknown etiology. Six distinct clinical types have been described in infancy and adulthood. Oral retinoids have proven their efficacy. Emollients and topical calcipotriol may improve the clinical presentation.

Combined calcitriol-pamidronate therapy for bone hyperresorption in spinal cord injury

OBJECTIVE

To determine the biochemical effects of combined calcitriol-pamidronate therapy on bone hyperresorption in patients with spinal cord injury (SCI).

METHODS

This was a retrospective study of 21 SCI inpatients (4 women and 17 men, mean age 34 years) treated for bone hyperresorption. Initial treatment was 0.5 microg oral calcitriol once daily and 1,250 mg CaCO3 twice a day (1000 mg elemental calcium/day). On days 4 through 6 following the initial treatment, patients received 30 mg pamidronate intravenously once daily (total of 3 doses). Urinary N-telopeptide (NTx) and calcium excretion rates, and serum parathyroid hormone (PTH), 25-hydroxyvitamin D (25-D), 1,25-dihydroxyvitamin D (1,25-D), calcium, and phosphorus levels were measured within 2 weeks prior to and 2 weeks following pamidronate therapy.

RESULTS

Patients demonstrated increased urinary NTx and calcium excretion, indicative of bone hyperresorption, and suppressed PTH and 1,25-D levels as early as 9 days post-SCI. Combined calcitriol-pamidronate therapy decreased urinary NTx and calcium excretion by 71% (P < .001) and 73% (P < .001), respectively. This therapy also increased serum levels of PTH (P <.05) and 1,25-D (P < .005). Post-pamidronate hypocalcemia or hypophosphatemia was observed in 44% (P < .01) or 53% (P < .01), respectively.

CONCLUSION

Combined calcitriol-pamidronate therapy significantly inhibited bone hyperresorption in SCI patients.

Instrumental evaluation of retinoid-induced skin irritation

BACKGROUND/PURPOSE

Retinoids like tazarotene are approved for the treatment of chronic plaque psoriasis. In the beginning of topical retinoid therapy, 15-20% of the patients suffer from mild to moderate adverse reactions with burning and erythema. The aim of the study was to find predicative parameters of the individual irritative potential and to suggest options to reduce these initial irritations.

METHODS

Twenty in-patients with different skin types (1 + 2: 11, 3 + 4: 9), with chronic plaque psoriasis were included in this open study. In each patient, 7 randomized plaques on the forearm were treated for 14 days on different ways: test area 1: morning (m) and evening (e) placebo, test area 2: placebo (m) and tazarotene 0.05% (e), test area 3: placebo (m) and tazarotene 0.1% (e), test area 4: calcipotriol (m) and calcípotriol (e), test area 5: mometasone furoate (m) and tazarotene 0.05% (e), test area 6: mometasone furoate (m) and tazarotene 0,1% (e), test area 7: placebo (m) and tazarotene in increasing concentrations (e), test area 8: healthy skin for control. Before and after therapy, skin barrier function, blood flow and plaque thickness in 20-MHz sonography were assessed in different test areas intraindividually by non- invasive biophysical measurements.

RESULTS

After 14 days of therapy, tazarotene 0.05% and 0.1% produced a stronger increase of laser Doppler flow in patients with skin type 1 and 2 than in patients with skin type 3 and 4. When using the combination therapy of tazarotene and mometasone, the laser Doppler flow was significantly lower than in tazarotene as monotherapy. 20-MHz-ultrasound showed a significant decrease in the thickness of the echo-poor band in all topical therapy regimens compared to placebo. Patients of skin type 1 and 2 reached a higher density of the dermis than patients of skin type 3 and 4, meaning a stronger decrease of inflammatory infiltration and acanthosis.

CONCLUSION

Adapting retinoid therapy to the patient's skin type can reduce the initial irritative side-effects. During the first days, patients with skin type 1 or 2 should add a medium potency corticosteroid. Stronger skin irritation caused by tazarotene therapy increases therapy effects.

Differential effects of 19-nor-1,25-dihydroxyvitamin D(2) and 1,25-dihydroxyvitamin D(3) on intestinal calcium and phosphate transport

19-Nor-1,25-dihydroxyvitamin D(2) (19-norD(2)) a less calcemic and phosphatemic analog of 1,25-dihydroxyvitamin D (1,25[OH](2)D(3)), is approved for the treatment of secondary hyperparathyroidism in patients with kidney failure. We have previously demonstrated that 19-norD(2) is less active than 1,25(OH)(2)D(3) in stimulating bone resorption. In this study, we compared the potencies of 19-norD(2) and 1,25(OH)(2)D(3) in stimulating net calcium and phosphate absorption in the intestine. Mineral balance was assessed in normal rats during the last 4 days of a 14-day treatment with various daily doses of 19-norD(2) or 1,25(OH)(2)D(3). Calcium absorption increased from 16.5% +/- 7.8% in vehicle-treated rats to 27.5% +/- 7.2% in rats given 10 ng/day 1,25(OH)(2)D(3) and to 21.6% +/- 3.9%, 26.2% +/- 5.5%, and 27.4% +/- 5.1% in rats treated with 10, 50, and 100 ng/day 19-norD(2), respectively. Thus comparable stimulation of calcium transport was attained with 10 ng 1,25(OH)(2)D(3) and 100 ng 19-norD(2). Similar results were obtained for phosphate absorption, with an increase from 28.2% +/- 5.5% in vehicle-treated rats to 40.2% +/- 4.7% in rats given 10 ng/day 1,25(OH)(2)D(3) and to 32.9% +/- 2.2%, 36.2% +/- 4.5%, and 36.8% +/- 3.8% in rats given 10, 50, and 100 ng/day 19-norD(2), respectively. Vitamin D compounds are believed to increase calcium absorption by inducing a calcium channel (epithelial calcium transporter or calcium transporter-1 [CaT1]) on the luminal membrane, a calcium-binding protein (Calbindin D9k) in the cytosol, and a calcium pump (plasma membrane calcium adenosine triphosphatase-1 [PMCA1]) on the basolateral membrane. Northern-blot analysis of intestinal ribonucleic acid of vitamin D-deficient rats given seven daily injections of vehicle or 100 ng 1,25(OH)(2)D(3) or 19-norD(2) revealed that 19-norD(2) was less potent than 1,25(OH)(2)D(3) in stimulating expression of CaT1, Calbindin D9k and PMCA1. In summary, the reduced calcemic and phosphatemic activities of 19-norD(2) can be attributed to lower potency in stimulating intestinal calcium and phosphate absorption.

Regulation of renal vitamin D receptor is an important determinant of 1alpha,25-dihydroxyvitamin D(3) levels in vivo

The synthesis of 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)) is most strongly regulated by dietary calcium and the action of parathyroid hormone to increase 1alpha-hydroxylase (1alpha-OHase) and decrease 24-hydroxylase (24-OHase) in kidney proximal tubules. This study examines the hypothesis that 1,25-(OH)(2)D(3) synthesis, induced by dietary calcium restriction, is also the result of negative feedback regulation blockade. Rats fed a low calcium (0.02%, -Ca) diet and given daily oral doses of vitamin D (0, 0.5, 1.0, 2.0, 4.0, 8.0, and 16.0 microg) remained hypocalcemic despite increasing levels of serum calcium in relation to the vitamin D dose. Plasma levels of 1,25-(OH)(2)D(3) rose to high levels (1200 pg/ml) at the high vitamin D dose levels. As expected, thyroparathyroidectomy caused a rapid fall in serum 1,25-(OH)(2)D(3). In rats fed a 0.47% calcium diet (+Ca) supplemented with vitamin D (4 microg/day), exogenous 1,25-(OH)(2)D(3) suppressed renal 1alpha-OHase and stimulated the 24-OHase. In rats fed the -Ca diet, vitamin D was unable to suppress the renal 1alpha-OHase or stimulate the renal 24-OHase. In contrast, vitamin D was fully able to stimulate intestinal 24-OHase. Intestinal vitamin D receptor (VDR) was present under all circumstances, while kidney VDR was absent under hypocalcemic conditions and present under normocalcemic conditions. It appears that tissue-specific down-regulation of VDR by hypocalcemia blocks the 1,25-(OH)(2)D(3) suppression of the 1alpha-OHase and upregulation of the 24-OHase in the kidney, causing a marked accumulation of 1,25-(OH)(2)D(3) in the plasma.