1,25(OH)2-vitamin D3 mediated changes in mRNA for c-myc and 1,25(OH)2D3 receptor in HL-60 cells and related subclones

The aim of this study was to clarify the change of the gastric mucosa following inoculation with Helicobacter pylori (H. pylori). Two pairs of cynomolgus monkeys received either H. pylori of human origin (group A) or H. pylori of monkey origin (group B) by intragastric inoculation at a dose of 10(9) CFU. After inoculation, endoscopical observation and biopsies were done every 7 days for one month. The bacteria in the biopsy samples were cultured quantitatively. The content of intracellular PAS-AB positive substance was quantitatively analyzed with the image analyzing system. Results were as follows: 1) Before inoculation, the gastric mucosa was endoscopically normal and free from H. pylori. 2) The quantity of H. pylori varied from 0 to 10(3) CFU/0.1 g tissue in group A and from 10 to 10(6) CFU/0.1 g tissue in group B. 3) Severe erosion was seen in group B, while mild mucosal erythema and erosion were observed in group A. 4) There was a correlation between the quantity of H. pylori and histological activity (Rauws' gastritis score). 5) The PAS-AB positive substance in H. pylori-positive mucosa was less than that in H. pylori-negative mucosa. In conclusion, gastric mucosal changes of varying degrees were brought about after inoculation of H. pylori depending on the quantity of bacilli in the gastric tissue.     

Distribution and metabolism of F6-1,25(OH)2 vitamin D3 and 1,25(OH)2 vitamin D3 in the bones of rats dosed with tritium-labeled compounds

26,26,26,27,27,27-Hexafluo-1,25(OH)2 vitamin D3, the hexafluorinated analog of 1,25(OH)2 vitamin D3, has been reported to be several times more potent than the parent compound regarding some vitamin D actions. The reason for enhanced biologic activity in the kidneys and small intestine appears to be related to F6-1,25(OH)2 vitamin D3 metabolism to ST-232, 26,26,26,27,27,27-hexafluoro-1 alpha, 23S,25-trihydroxyvitamin D3, a bioactive 23S-hydroxylated form that is resistant to further metabolism. Since F6-1,25(OH)2 vitamin D3 is considered to prevent osteoporotic decrease in bone mass by suppressing bone turnover, we here compared the distribution and metabolism of [1 beta-3H]F6-1,25(OH)2 vitamin D3 and [1 beta-3H]1,25(OH)2 vitamin D3 in bones of rats by autoradiography and radio-HPLC. In the dosed groups, radioactivity was detected locally in the metaphysis, the modeling site in bones. As compared with the [1 beta-3H]1,25(OH)2 vitamin D3 case, [1 beta-3H]F6-1,25(OH)2 vitamin D3 was significantly retained in this site, and moreover, it mainly persisted as unchanged compound and ST-232. These findings indicate that the reason for the higher potency of F6-1,25(OH)2 vitamin D3 than 1,25(OH)2 vitamin D3 in bones are linked with increased distribution and reduced metabolism.     

Anti-tumor effects of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) in seborrheic keratosis

1,25-dihydroxyvitamin D3 (1,25(OH)2D3) is a drug with potent antiproliferative action on keratinocytes that have nuclear receptors for 1,25(OH)2D3. We investigated the effects of 1,25(OH)2D3 on widespread seborrheic keratoses in 51 patients with these tumors. The data indicated that resolution of these tumors was dependent on both tumor size and dose of 1,25(OH)2D3. Among 15 patients treated with a high dose (0.5 microgram/d) of oral 1,25(OH)2D3, the lesions of widespread seborrheic keratoses changed from brown-black papules to brownish papules with erythema and/or crust as early as 2 wk after the start of treatment. The tumors finally developed into an atrophic scar or brownish pigmented macule. Histologically, vacuolation of the spinous cells, vesicle formation, and liquefaction degeneration of the basaloid cells were observed. Numerous lymphocytes had infiltrated in the papillary dermis. Among 36 patients treated with a low dose (0.25 microgram/d) of 1,25(OH)2D3, brownish papules became pale to normal in color and reduced in size, without erythematous change. Histologically, acanthosis of the epidermis was reduced, but degenerative change of the tumor cells was not observed. These data suggest that oral therapy of 1,25(OH)2D3 is an acceptable method well suited to the removal of seborrheic keratoses, especially those that are predominantly small tumors.     

Toxicity and dose-response studies of 1,25-(OH)2-16-ene-23-yne vitamin D3 in transgenic mice

The vitamin D3 analogue 1,25-(OH)2-16-ene-23-yne vitamin D3 (16,23-D3) in doses with low systemic toxicity has been demonstrated to inhibit retinoblastoma growth in transgenic mice. This study examines the dose-dependent response for inhibition of tumor growth in transgenic mice with retinoblastoma and evaluates the in vivo toxicity of 16,23-D3 in nontransgenic mice. Transgenic 8-10-week-old mice with retinoblastoma (n = 119) were randomly assigned to groups receiving 1.0, 0.75, 0.5, 0.35, 0.2, or 0.05 microg of 16,23-D3 and a vehicle alone (control) group i.p. five times a week for 5 weeks. An additional control group received no injection. Eyes were enucleated one week after the end of treatment, and tumor areas were measured. To determine the toxic dose, transgene-negative littermates received 0.5, 1.0, 1.5, 2.5, 3.5, 4.5, or 5.0 microg of 16,23-D3, and control groups received vehicle alone, 5 days a week for 5 weeks. Serum calcium levels were measured, and necropsies were performed on animals from each group. In the dose-response study, tumor growth inhibition was greatest in the group receiving 0.35 microg (55% inhibition; P = 0.0056) and was also significant in the group receiving 0.5 microg (42% inhibition; P = 0.036). The systemic toxic effects due to hypercalcemia occurred at doses of > or =1.0 microg. 16,23-D3 inhibits tumor growth at doses > or =0.35 microg and shows toxic effects at doses > or =1.0 microg related to hypercalcemia in mice fed an unrestricted diet. No toxicity was observed with lower doses.     

Arachidonic acid is an autocoid mediator of the differential action of 1,25-(OH)2D3 and 24,25-(OH)2D3 on growth plate chondrocytes

Prior studies have shown that 24,25-(OH)2D3 and 1,25-(OH)2D3 regulate protein kinase C (PKC) in costochondral chondrocytes in a cell maturation-dependent manner, with 1,25-(OH)2D3 affecting primarily growth zone (GC) cells and 24,25-(OH)2D3 affecting primarily resting zone (RC) cells. In addition, 1,25-(OH)2D3 has been shown to increase phospholipase A2 activity in GC, while 24,25-(OH)2D3 has been shown to decrease phospholipase A2 activity in RC. Stimulation of phospholipase A2 in GC caused an increase in PKC, whereas inhibition of phospholipase A2 activity in RC cultures increased both basal and 24,25-(OH)2D3-induced PKC activity, suggesting that phospholipase A2 may play a central role in mediating the effects of the vitamin D metabolites on PKC. To test this hypothesis, RC and GC cells were cultured in the presence and absence of phospholipase A2 inhibitors (quinacrine and oleyloxyethylphosphorylcholine [OEPC]), phospholipase A2 activators (melittin and mastoparan), or arachidonic acid alone or in the presence of the target cell-specific vitamin D metabolite. PKC specific activity in the cell layer was determined as a function of time. Phospholipase A2 inhibitors decreased both basal and 1,25-(OH)2D3-induced PKC activity in GC. When phospholipase A2 activity was activated by inclusion of melittin or mastoparan in the cultures, basal PKC activity in RC was reduced, while that in GC was increased. Similarly, melittin and mastoparan decreased 24,25-(OH)2D3-induced PKC activity in RC and increased 1,25-(OH)2D3-induced PKC activity in GC. For both cell types, the addition of arachidonic acid to the culture media produced an effect on PKC activity that was similar to that observed when phospholipase A2 activators were added to the cells. These results demonstrate that vitamin D metabolite-induced changes in phospholipase A2 activity are directly related to changes in PKC activity. Similarly, exogenous arachidonic acid affects PKC in a manner consistent with activation of phospholipase A2. These effects are cell maturation- and time-dependent and metabolite-specific.     

1,25(OH)2D3-modulated calcium induced keratinocyte differentiation

The purpose of this study was to provide optometrists with suggested base curves and powers for initial lens choice based on the infant's age. A retrospective chart review of 16 congenital cataract patients fitted at U.C. Davis Eye Clinic between July 1987 and May 1993 was performed. Patients with associated ocular pathologies were excluded. All patients were fitted with a Bausch & Lomb Silsoft lens, a Silicone Elastomer, set at a 3.00 D myopic posture, which was decreased with the child's increasing age and activity. This study provides a graphical approach to pediatric aphakic silicone elastomer contact lens fitting. Best-fit regression lines for both graphs have an r squared value better than 0.9. Optometrists will now be able to reference the Base Curve vs. Age and Power vs. Age graphs to determine the initial lens choice when keratometry is unachievable. Furthermore, the data suggest a need for an increased range of powers provided by the Silicone elastomer lens in order to approximate normal visual development.     

Sex difference in resistance to dexamethasone-induced apoptosis in NOD mice: treatment with 1,25(OH)2D3 restores defect

The purpose of the study was to evaluate the association between smoking during pregnancy and preterm birth. The overall rate of preterm delivery was 4.3%. Smokers had a 40% higher risk of preterm birth compared to non-smokers. A dose response relationship was found between smoking and risk of preterm birth. Adjustment for women's height, pre-pregnant weight, age of the mother, marital status, education, occupational status, and alcohol intake did not change the results. Among women with an intake of less than 400 mg of caffeine per day no difference in the risk of preterm birth between smokers and non-smokers was found. However, among women with an intake of more than 400 mg of caffeine per day, the risk of preterm birth was increased almost threefold among smokers compared to non-smokers. Furthermore, among women with a high intake of caffeine a dose response relationship was found between smoking and risk of preterm delivery.     

Effect of 1,25 (OH)2 vitamin D3 on glomerulosclerosis in subtotally nephrectomized rats

In the past, there has been considerable concern that treatment with active vitamin D might accelerate progression independent of hypercalcemia and hypercalcuria. Nevertheless, 1,25(OH)2D3 has known antiproliferative properties and has also been shown to inhibit renal growth. Since glomerular growth is a permissive factor for the development of glomerulosclerosis, we reasoned that 1,25(OH)2D3 might even attenuate progression. To test this working hypothesis we performed two experiments of 8 and 16 weeks duration, respectively, to compare subtotally nephrectomized (SNX) rats treated with ethanol and SNX treated with 1,25(OH)2D3. Control animals were sham operated and pair-fed with SNX animals. 1,25(OH)2D3 (3 ng/100 g body wt/day) was administered by osmotic minipump. 1,25(OH)2D3 had no significant effect on systolic blood pressure and only a transient effect on weight gain. SNX reduced the number of glomeruli (left kidney) from an average of 3.3 x 10(4) to 1.2 x 10(4) per kidney. Mean glomerular volume was 3.87 +/- 0.71 x 10(6) microns 3 in sham operated animals and significantly (P < 0.05) higher (10.1 +/- 1.75 x 10(6) microns 3) in untreated animals 16 weeks after SNX. Glomerular volume was significantly (P < 0.05) less in 1,25(OH)2D3 treated SNX [10.1 +/- 1.75 in ethanol vs. 7.04 +/- 1.78 in 1,25(OH)2D3 treated SNX]. In parallel, there was significantly (P < 0.01) less glomerulosclerosis [glomerulosclerosis index 1.16 +/- 0.14 in the ethanol treated SNX vs. 0.80 +/- 0.16 in SNX treated with 1,25(OH)2D3] in the eight week experiment. Albuminuria was significantly (P < 0.01) lower in 1,25(OH)2D3 treated than in ethanol treated SNX (mean 0.785 mg/24 hr, range 0.43 to 1.80, vs. 3.75 mg/24 hr, 1.29 to 14.2). The morphological data were directionally analogous in a second 16 week experiment. Only slight changes of the vascular sclerosis index and tubulointerstitial index were seen in SNX and were not affected by 1,25(OH)2D3 further. To prove that the effect of 1,25(OH)2D3 was independent of PTH, parathyreoidectomized SNX rats without or with 1,25(OH)2D3 treatment were examined seven days post-SNX. PCNA staining showed suppression of cell proliferation. Furthermore, in situ hybridization for transforming growth factor-B (TGF-beta) showed less vascular and tubular expression in 1,25(OH)2D3 treated rats. We conclude that 1,25(OH)2D3 has antiproliferative actions during the compensatory growth of nephrons in response to subtotal nephrectomy. These effects are independent of PTH. The data document that 1,25(OH)2D3 reduces renal cell proliferation and glomerular growth as well as glomerulosclerosis and albuminuria as indicators of progressive glomerular damage.     

Effect of vitamin D3 and 1,25(OH)2D3 on growth of neoplastically derived cell lines and their alkaline phosphatase activity

Inhibitory effects of 1,25(OH)2D3 and D3 on growth of four neoplastically derived cells were observed in human acute leukemia cell culture CEM-C-1 and CEM-C-7, human cervical carcinoma cell lines C-4-1 and human epithelioid carcinoma cells of cervix HeLa S3K. Concurrently, in dexamethasone-responsive cells C-4-1 and HeLa S3K there was a 1,25(OH)2D3 and D3 induced elevation of alkaline phosphatase with 1,25(OH)2D3 showing the greater effects. It is supposed that vitamins D3-induced alkaline phosphatase activity in malignant cells, which is proposed to be a possible marker of cell differentiation, can be associated with the membrane effects of these vitamins.     

Antisense oligonucleotides targeted against protein kinase Cbeta and CbetaII block 1,25-(OH)2D3-induced differentiation

It is now recognized that protein kinase C (PKC) plays a critical role in 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) promotion of HL-60 cell differentiation. In this study, the effects of phosphorothioate antisense oligonucleotides directed against PKCalpha, PKCbeta, PKCbetaI, and PKCbetaII on HL-60 promyelocyte cell differentiation and proliferation were examined. Cellular differentiation was determined by nonspecific esterase activity, nitro blue tetrazolium reduction, and CD14 surface antigen expression. Differentiation promoted by 1,25-(OH)2D3 (20 nM for 48 h) was inhibited similarly in cells treated with PKCbeta antisense (30 microM) 24 h prior to or at the same time as hormone treatment (86 +/- 9% inhibition; n = 4 versus 82 +/- 8% inhibition; n = 4 (mean +/- S.E.), respectively). In contrast, cells treated with PKCbeta antisense 24 h after 1, 25-(OH)2D3 were unaffected and fully differentiated. PKCalpha antisense did not block 1,25-(OH)2D3 promotion of HL-60 cell differentiation. Next, the ability of PKCbetaI- and PKCbetaII-specific antisense oligonucleotides to block 1,25-(OH)2D3 promotion of cell differentiation was examined. PKCbetaII antisense (30 microM) completely blocked CD14 expression induced by 1, 25-(OH)2D3, whereas PKCbetaI antisense had little effect. Interestingly, PKCbetaII antisense blocked differentiation by 87 +/- 7% (n = 2, mean +/- S.D.) but had no effect on 1,25-(OH)2D3 inhibition of cellular proliferation. These results indicate that the effects of 1,25-(OH)2D3 on HL-60 cell differentiation and proliferation can be dissociated by blocking PKCbetaII expression.     

Intravenous calcitriol therapy restores reduced antigen-induced T-lymphocyte response in 1,25-(OH)2D3-deficient hemodialysis patients

Phosphatidylinositide-specific phospholipase Cs (PI-PLCs) catalyze the calcium-dependent hydrolysis of phosphatidylinositides in response to diverse stimuli in higher eukaryotes. Mammalian PI-PLCs contain divergent regulatory regions, but all share three conserved regions: an N-terminal pleckstrin homology (PH) domain, X, and Y. We report the high-level expression and characterization of a recombinant "catalytic core" of rat PI-PLC delta 1 that contains the catalytically essential X and Y regions, but not the PH domain. The expressed protein, PI-PLC delta delta 1-134, is catalytically active versus phosphatidylinositol 4,5-bisphosphate in deoxycholate micelles with a K(m) of 182 microM and a Vmax of 27 mumol/min/mg. PI-PLC delta delta 1-134 is monomeric and monodisperse as judged by dynamic light scattering. Far-UV CD indicates a structure with approximately 35% alpha-helix. A reversible change in the near-UV CD spectrum is observed on addition of calcium, suggesting that calcium can bind PI-PLC delta delta 1-134 in the absence of phospholipid. Triclinic crystals of PI-PLC delta delta 1-134 have been obtained that diffract beyond 2.4 A resolution under cryogenic conditions. Based on Vm = 2.72 Da/A3 and on the self-rotation function, there are two PI-PLC delta delta 1-134 molecules per asymmetric unit that are related to each other by a noncrystallographic axis of approximate twofold symmetry parallel to a.     

Identification of 7-dehydrocholesterol, vitamin D3, 25(OH)-vitamin D3 and 1,25(OH)2-vitamin D3 in Solanum glaucophyllum cultures grown in absence of light

1. Mouse fibroblasts (NIH3T3) transfected with the full-length coding region of the Mel1a melatonin receptor stably expressed the receptor, coupled to a pertussis toxin-sensitive G-protein(s) and exhibiting high affinity and adequate pharmacological profile. 2. The receptor protein had the tendency of a strong coupling to the G-protein and therefore low-affinity state was induced by uncoupling the receptor from its G-protein in presence of high concentrations of NaCl (500-700 mM) and/or GTPgammaS (100 microM). Thereafter, the affinity of a series of melatonin analogues was determined to both, high- and low-affinity receptor states, thus providing a basis for the prediction of their efficacy, according to the ternary complex model. 3. The cells were subsequently used to study the agonist-induced G-protein activation, determined by calculating the rate of GDP-GTP exchange measured in presence of 35S-labelled GTPgammaS. The natural ligand melatonin induced a significant increase in the GDP-GTP exchange rate, the presence of GDP and NaCl being necessary to observe this effect. 4. The full agonists 2-phenylmelatonin, 2-bromomelatonin and 6-chloromelatonin equally induced an increase of the GDP-GTP exchange. 5-Hydroxy-N-acetyltryptamine activated the GTP-GDP exchange to a much lesser extent (53%) than melatonin, thus behaving as a partial agonist. As predicted by the model, the melatonin antagonist (N-[(2-phenyl-1H-indol-3-yl)ethyl]cyclobutanecarboxamide) was without effect on basal G protein activation. Coincubation of this compound with melatonin induced a dose-dependent rightward shift in the melatonin concentration-effect curve, thus exhibiting the behaviour of a competitive and surmountable antagonist. 5. Using the equation proposed by Venter (1997) we were able to determine that there were no 'spare' receptors in the system. Therefore, the approach proposed in the present work can be successfully used for the determination of 'drug action' at the level of the human Mel1a melatonin receptor and evaluation of the efficacy of new selective melatonin analogues.     

Influence of metabolic acidosis on serum 1,25(OH)2D3 levels in chronic renal failure

Metabolic acidosis has been shown to alter vitamin D metabolism. There is also evidence that calcium may modulate 1,25(OH)2D3 by a parathyroid hormone (PTH)-independent mechanism. To investigate the effect of rapid correction of chronic metabolic acidosis on serum 1,25(OH)2D3 levels by free calcium clamp in chronic renal failure, 20 patients with mild to moderate metabolic acidosis (mean pH 7.31 +/- 0.04) and secondary hyperparathyroidism (mean intact PTH 156.47 +/- 84.20 ng/l) were enrolled in this study. None had yet received any dialysis therapy. Metabolic acidosis was corrected by continuous bicarbonate infusion for 3-4 h until plasma pH was around 7.4, while plasma ionized calcium was held at the preinfusion level by calcium solution infusion during the entire procedure. The plasma pH, bicarbonate, total CO2, sodium, and serum total calcium levels were significantly increased while serum concentrations of alkaline phosphatase and albumin were significantly decreased after bicarbonate infusion. The plasma ionized calcium, potassium, serum magnesium, inorganic phosphorus, and 25(OH)D levels showed no significant change before and after bicarbonate infusion. The serum 1,25(OH)2D3 levels were significantly increased (38.66 +/- 11.77 vs. 47.04 +/- 16.56 pmol/l, p < 0.05) after correction of metabolic acidosis. These results demonstrate that rapid correction of metabolic acidosis raises serum 1,25(OH)2D3 levels in vitamin D-deficient chronic renal failure patients, and may underline the importance of maintaining normal acid-base homeostasis in the presence of secondary hyperparathyroidism in chronic renal failure.     

Liposomal 1,25 (OH)2 vitamin D3 compounds block proliferation and induce differentiation in myelomonocytic leukaemia cells

Using the giant patch technique, we combined two fast relaxation methods on excised patches from guinea pig cardiomyocytes to compare the rate constants of the involved reaction steps. Experiments were done in the absence of intra- or extracellular K+. Fast ATP concentration jumps were generated by photolysis of caged ATP at pH 6.3 with laser flash irradiation at a wavelength of 308 nm and 10 ns duration, as described previously. Transient outward currents with a fast rising phase, followed by a slower decay and a small stationary current, were obtained. Voltage pulses were applied to the same patch in the presence or absence of intracellular ATP. Subtraction of the voltage jump-induced currents in the absence of ATP from those taken in the presence of ATP yielded monoexponential transient current signals, which were dependent on external Na+ but did not differ between intracellular pH (pHi) values 6.3 or 7.4. Rate constants showed a characteristic voltage dependence, i.e., saturating at positive potentials (approximately 200 s-1, 24 degrees C) and exponentially rising with increasing negative potentials. Rate constants of the fast component from transient currents obtained after an ATP concentration jump agree well with rate constants from currents obtained after a voltage jump to zero or positive potentials (pHi 6.3), and the two exhibit the same activation energy of approximately 80 kJ.mol-1. For a given membrane patch, the amount of charge that is moved across the plasma membrane is roughly the same for each of the two relaxation techniques.     

In vivo treatment with calcitriol (1,25(OH)2D3) reverses age-dependent alterations of intestinal calcium uptake in rat enterocytes

The vitamin D endocrine system has been involved in the impairment of intestinal calcium absorption during aging. Alterations in the nongenomic mechanism of calcitriol (1,25-dihydroxy-vitamin D3; [1, 25(OH)2D3] have been recently evidenced. In enterocytes isolated from aged rats, 1,25(OH)2D3 stimulation of Ca2+ channels through the cAMP/PKA pathway is blunted. We have now investigated whether in vivo administration of calcitriol to senescent rats reverses the absence of hormonal effects in isolated intestinal cells. In enterocytes from 20-24-month-old rats given 1,25(OH)2D3 for 3 days (30 ng/100 g bw/day), calcitriol (10(-10) M, 3-5 minutes) stimulated Ca2&plus uptake and intracellular cAMP to the same degree and protein quinase A (PKA) activity to a lesser degree than in enterocytes from young animals. Significantly higher basal levels of cAMP and PKA detected in enterocytes from old rats were not affected by prior injection of animals with 1,25(OH)2D3. When the aged rats were injected with 25(OH)D3, similar Ca2+ influx, cAMP, and PKA responses to in vitro stimulation with calcitriol were obtained. 1, 25(OH)2D3-dependent changes in Ca2+ uptake by enterocytes from both young and old rats treated with calcitriol were totally suppressed by the cAMP antagonist Rp-cAMPS, whereas the response to the agonist Sp-cAMPS was markedly depressed in aged animals. These results suggest that intestinal resistance to nongenomic 1,25(OH)2D3 stimulation of duodenal cell Ca2+ uptake develops in rats upon aging and show that in vivo administration of 1,25(OH)2D3 or its precursor to senescent rats restores the ability of the hormone to stimulate duodenal cell calcium influx through the cAMP messenger system.     

Expression of a human homeobox-containing gene is regulated by 1,25(OH)2D3 in bone cells

The seasonal variation in the nutrient composition of Enhydra fluctuans and Marsilea quadrifolia, two edible semi-aquatic plants, was studied in order to promote their consumption as green leafy vegetables. Both plants had a high crude protein content throughout all harvesting seasons. Enhydra fluctuans had a low ash content and was a good source of beta-carotene (3.7 to 4.2 mg/100 g on a fresh weight basis). Marsilea quadrifolia exhibited wide fluctuations between seasons and was not very promising in nutrient composition when compared to other commonly used green leafy vegetables.     

5-(5-溴-3-碘-2-吡啶偶氮)-2,4-二氨基甲苯的合成及其与铑(III)显色反应的探讨

以5-溴-3-碘-2-氨基吡啶和2,4-二氨基甲苯为主要原料,设计合成新试剂5-(5-溴-3-碘-2-吡啶偶氮)-2,4-二氨基甲苯(5-Br-3-I-PADAT),用红外光谱和核磁共振波谱对其结构进行了表征,并研究了试剂与铑(III)的反应。结果表明,在pH 4.8的HAc-NaAc缓冲体系中,铑(III)与5-Br-3-I-PADAT可形成棕红色的络合物,该络合物在536nm和576nm处有两个吸收峰,铑(III)的质量浓度在0.04~0.70μg/mL时符合比尔定律,方法检出限为0.010μg/mL,表观摩尔吸光系数为2.18×10⁵ L·mol^-1·cm^-1。方法用于铑炭催化剂中铑的测定,测定值和参考值相一致,结果的相对标准偏差(RSD,n=6)为0.88%,回收率分别为98%和96%。     

1,25(OH)2-vitamin D3 stimulation of phospholipases C and D in muscle cells involves extracellular calcium and a pertussis-sensitive G protein

In an open study, 172 male and female adult patients with acute uncomplicated bacterial cystitis were randomly allocated to three treatment groups. Two groups received brodimoprim 200 mg tablets as follows: a single dose of two 200 mg tablets on day 1, followed by one tablet per day on days 2 and 3 (58 patients); or a single daily dose of two tablets, for 2 days (63 patients). The third group received a single dose of pefloxacin, as two 400 mg tablets, for 1 day (51 patients). Complete urinalysis, sediment and urine culture examinations were carried out before treatment and 10 days after the last dose. Evaluation also comprised, at the time of enrolment and 48 h after the last dose, measurement of corporal temperature and assessment of symptoms (dysuria, pollakiuria, strangury, suprapubic pain, burning sensation during urination and urgency) on a 4-point scale. The eradication rate for the pathogen concerned was 98.3% and 96.7% in the groups receiving brodimoprim for 3 and 2 days, respectively, and 92.8% in the pefloxacin group (between-group comparison n.s.). There was significant regression of symptoms (P < 0.001) in the three groups (between-groups comparison n.s.). Mainly gastrointestinal adverse events occurred in 3 patients receiving brodimoprim for 2 days and in 4 patients from each of the other two groups.