Nicotiana glauca: another plant species containing vitamin D(3) metabolites.

Vitamin D(3)-related compounds have been detected in various plant species, mostly belonging to the Solanaceae. In this work we show that Nicotiana glauca, a widespread member of this taxonomic family, contains 7-dehydrocholesterol, vitamin D(3) and hydroxylated derivatives bearing precursor-product metabolic relationships in vertebrates. Leaves collected in the field and callus cultures were used.

Neurocognitive and psychological contributions to quality of life in HIV-1-infected women.

Objectives: The purpose of this study was to examine the impact of neurocognitive and emotional distress and immune system dysfunction on quality of life in women with HIV.

Methods: Thirty-six HIV-seropositive women were administered measures of mood status (Profile of Mood States), quality of life (Multidimensional Quality of Life Questionnaire for Persons with HIV) and cognitive function. CD4 cell counts were obtained as an indicator of immune system status.

Lumbar spine traction: evaluation of effects and recommended application for treatment.

Despite the widespread use of traction, little is known of the mode of effect, and application remains largely anecdotal. The efficacy of traction is also unclear because of generally poor design of the clinical trials to date, and because subgroups of patients most likely to benefit have not been specifically studied. These observations prompted this review, the purposes of which are to evaluate the mechanisms by which traction may provide benefit and to provide rational guidelines for the clinical application of traction.

Involvement of calmodulin in 1alpha,25-dihydroxyvitamin D3 stimulation of store-operated Ca2+ influx in skeletal muscle cells.

The steroid hormone 1alpha,25-dihydroxyvitamin D(3) (1, 25-(OH)(2)D(3)) rapidly modulates Ca(2+) homeostasis in avian skeletal muscle cells by driving a complex signal transduction mechanism, which promotes Ca(2+) release from inner stores and cation influx from the outside through both L-type and store-operated Ca(2+) (SOC) channels. In the present work, we evaluated the involvement of calmodulin (CAM) in 1,25-(OH)(2)D(3) regulation of SOC influx in chick skeletal muscle cells. Treatment with 10(-9) m 1,25-(OH)(2)D(3) in Ca(2+)-free medium resulted in a rapid but transient Ca(2+) rise correlated with the sterol-induced inositol 1,4,5-trisphosphate (IP(3)) production.

Role of protein kinase C in 1,25(OH)(2)-vitamin D(3) modulation of intracellular calcium during development of skeletal muscle cells in culture.

Regulation of muscle cell Ca(2+) metabolism by 1, 25-dihydroxy-vitamin D(3) [1,25(OH)(2)D(3)] is mediated by the classic nuclear mechanism and a fast, nongenomic mode of action that activates signal transduction pathways. The role of individual protein kinase C (PKC) isoforms in the regulation of intracellular Ca(2+) levels ([Ca(2+)](i)) by the hormone was investigated in cultured proliferating (myoblasts) and differentiated (myotubes) chick skeletal muscle cells. 1,25(OH)(2)D(3) (10(-9) M) induced a rapid (30- to 60-s) and sustained (>5-min) increase in [Ca(2+)](i) which was markedly higher in myotubes than in myoblasts.

Effect of aging on the mechanisms of PTH-induced calcium influx in rat intestinal cells.

We have investigated the effects of aging on parathyroid hormone (PTH) modulation of intracellular calcium homeostasis and their relationship to signal transduction pathways in isolated rat duodenal cells (enterocytes). PTH (10(-8)-10(-9) M) increased enterocyte (45)Ca(2+) influx and intracellular Ca(2+) concentration ([Ca(2+)](i)) to a greater extent (twofold and 50%, respectively) in aged (24 months) than in young (3 months) animals. The [Ca(2+)](i) response of old cells to the hormone was slower, lacking the early phase of changes in cytosolic Ca(2+).

Sphygmomanometer-induced increases in forearm and hand volume.

Swelling, or increased volume, secondary to venous congestion is thought to be a factor in some upper limb conditions. This study aimed to establish a safe, easily applied method of inducing a transitory increase in forearm and hand volume that could be used as a symptom provocation test for upper limb conditions. Using the principles of venous occlusion plethysmography, movement of blood volume into the forearm and hand of asymptomatic subjects was measured after occlusion with three different sphygmomanometer cuff pressures over four minutes.

Effect of 1,25(OH)(2)-vitamin D(3) on the activation of natural killer cells: role of protein kinase C and extracellular calcium.

As a first approach for studying the implication of PKC and the steroid hormone 1,25(OH)(2)-vitamin D(3) [1,25(OH)(2)D(3)] on natural killer cell (NK) activity, we analyzed in the YT NK cell line the expression of PKC isoforms and the effects of 1, 25(OH)(2)D(3) on BLT-esterase (a marker of NK lytic granules) activity. Western blot and RT-PCR showed a greater extent of PKC alpha, beta, delta, zeta, epsilon, theta, and lambda and lower levels of PKC mu and eta. In a dose-dependent manner 1, 25(OH)(2)D(3) induced significant increases in BLT-esterase and PKC activities and the stimulatory effect on BLT-esterase activity was mimicked and blocked, respectively, by the PKC activator phorbol ester PMA and PKC inhibitors (H7, PKC(19-36), and N-myristoylated PKC(19-31) peptides).

Participation of protein kinase C alpha in 1,25-dihydroxy-vitamin D3 regulation of chick myoblast proliferation and differentiation.

Changes in morphology and DNA synthesis in cultured myoblasts in response to 1,25-dihydroxy-vitamin D3 [1,25(OH)2D3] have previously suggested that the vitamin D hormone may affect muscle cell proliferation and differentiation. However, this interpretation was not substantiated by measurement of specific biochemical markers of myogenesis. To study the effect of 1,25(OH)2D3 on muscle development, chicken embryo myoblasts were cultured for 1-6 days in the presence or absence of 1,25(OH)2D3 (10(-9) M).

Evidence on the participation of protein kinase C alpha in the proliferation of cultured myoblasts.

There is evidence involving protein kinase C (PKC) in the signal transduction pathways that regulate the differentiation of myoblasts into mature multinucleated muscle cells (myotubes). In order to obtain information on the possible role of individual PKC isozymes in myogenesis, in the present work we investigated the differential expression of PKC isoforms alpha, beta, delta, epsilon, and zeta during muscle cell development in vitro. Chick embryo myoblasts cultured from 1 to 6 days were used as experimental model.

Rapid actions of calcitriol and its side chain analogues CB1093 and GS1500 on intracellular calcium levels in skeletal muscle cells: a comparative study.

1. The ability of synthetic analogues of the secosteroid hormone 1alpha,25-dihydroxy-vitamin-D3 [calcitriol, CT; 1,25(OH)2D3] to exert non-genomic (rapid) effects on target cells has been scarcely studied. To evaluate the pharmacological potential of the CT side-chain analogues CB1093 and GS1500, we compared their fast effects on intracellular calcium concentration ([Ca2+]i) in chick skeletal muscle cells with those elicited by the natural hormone.

Activation of a beta-adrenergic-sensitive signal transduction pathway by the secosteroid hormone 1,25-(OH)2-vitamin D3 in chick heart.

In recent studies we have established that 1 alpha, 25-dihydroxy-vitamin D3[1,25(OH)2D3] rapidly stimulates dihydropyridine-sensitive calcium channel-mediated Ca2+influx in chick cardiac muscle by a non-genomic action which is accompanied by PKA-dependent phosphorylation of a 45 kDa microsomal membrane protein. To investigate the signal transduction pathway activated by 1,25(OH)2D3 in heart, we have compared the effects of the secosteroid hormone with those of the beta-adrenergic agonist isoproterenol (IPT) by employing cultured chick embryonic cardiac cells (myocytes) and thin-slice preparations of differentiated adult heart muscle. The increases in 45Ca2+ uptake and intracellular calcium ([Ca2+]i), cyclic AMP accumulation and changes in microsomal protein phosphorylation evoked by 1,25(OH)2D3 could be reproduced by IPT.

Characterization of membrane estrogen binding proteins from rabbit uterus.

Estrogens exert fast non-genomic actions in their target tissues which may involve the participation of receptors located at the cell membrane. Studies were performed to identify and characterize membrane-associated 17beta-estradiol binding proteins in rabbit uterus. Specific and saturable [3H]17beta-estradiol binding sites of high affinity (Kd = 0.

17beta-oestradiol increases intracellular Ca2+ concentration in rat enterocytes. Potential role of phospholipase C-dependent store-operated Ca2+ influx.

The involvement of the phospholipase C (PLC) pathway in the non-genomic regulation of duodenal cell Ca2+ concentration by 17beta-oestradiol was investigated. The PLC inhibitors neomycin (0.5 mM) and U-73122 (2 microM) suppressed the stimulatory effect of 0.

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.

1alpha,25-dihydroxy-vitamin-D3-induced store-operated Ca2+ influx in skeletal muscle cells. Modulation by phospholipase c, protein kinase c, and tyrosine kinases.

In skeletal muscle cells the steroid hormone 1alpha, 25-dihydroxy-vitamin-D3 (1,25(OH)2D3) nongenomically promotes Ca2+ release from intracellular stores and cation influx through both L-type and store-operated Ca2+ (SOC) channels. In the present work we evaluated the regulation and kinetics of the 1, 25(OH)2D3-stimulated SOC influx in chick muscle cells. Stimulation with 10(-9) M 1,25(OH)2D3 in Ca2+-free medium resulted in a rapid (40-60 s) but transient [Ca2+]i rise, which correlated with sterol-dependent inositol 1,4,5-trisphosphate production.

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.

Solanum glaucophyllum contains the calciotropic hormone 1, 25-dihydroxy-vitamin D3 (1,25(OH)2D3). The metabolic pathway leading to the formation of 1,25(OH)2D3 in the plant is largely unknown. Specifically, there is controversy about the participation of a photolytic reaction in the generation of vitamin D3 and its metabolites.

Implications of failing to achieve successful long-term maintenance treatment of recurrent unipolar major depression.

This is a review article that describes current data, issues, and controversies regarding long-term maintenance treatment of depression. The authors suggest that the issues represent a public health crisis. This paper will identify the need, from both a health-care and economic perspective, for more research on the efficacy of maintenance treatment for this pernicious and lifelong disorder.

The effects of arm elevation and overnight head-up tilt on forearm and hand volume.

Methods to reduce increased fluid volume, or swelling, were evaluated as short- and long-term interventions. Forearm and hand volumes were measured in 45 fit and healthy subjects using a water displacement device with previously established reliability. Volumes were measured before and after 2 hours of recumbency and before and after overnight sleep under different conditions of arm elevation or head-up tilt.

Studies suggesting the participation of protein kinase A in 1, 25(OH)2-vitamin D3-dependent protein phosphorylation in cardiac muscle.

We have previously established that the secosteroid hormone 1alpha, 25-dihydroxy-vitamin D3 [1,25(OH)2D 3] rapidly stimulates dihydropyridine-sensitive calcium channel-mediated Ca2+ influx in chick cardiac muscle by a non-genomic action which is accompanied by phosphorylation of microsomal proteins. In the present study, we investigated the participation of the cyclic AMP/protein kinase A (PKA) signalling pathway in hormone-induced changes on protein phosphorylation in chick heart tissue. A major increase in the phosphorylation of a microsomal protein of 45 kDa, and, to a lesser extent, of a protein of 70 kDa, was observed after incubation with [gamma-32P]ATP of membranes isolated from heart thin slices (HTS) pretreated for 1-5 min with 1,25(OH)2D3.

Age-related loss of calcitriol stimulation of phosphoinositide hydrolysis in rat skeletal muscle.

We have examined the effects in vitro of calcitriol [1,25(OH)2D3], the hormonal form of vitamin D3, on the breakdown of membrane phosphoinositides in skeletal muscle from young (3 months) and aged (24 months) rats. Calcitriol (10(-9) M) induced a rapid and transient release of IP3/inositol phosphates and diacylglycerol (DAG) from muscle slices/membranes prelabeled with [3H]myo-inositol and [3H]arachidonate, respectively. Inositol phosphate release was maximal at 15 s and then declined.

Neurobehavioral functioning in asymptomatic HIV-1 infected women.

Numerous reports have assessed the neuropsychological functioning of medically asymptomatic HIV-1 infected men. However, to date there have been no published studies of the neuropsychological functioning of asymptomatic HIV-1 infected women, even though women represent the fastest-growing demographic group of HIV-1 infected individuals. In this investigation, 31 women (17 asymptomatic HIV-1 seropositive, 14 seronegative) were administered a battery of neurocognitive and neuropsychiatric instruments.

1,25(OH)2-vitamin D3 affects the subcellular distribution of protein kinase C isoenzymes in muscle cells.

Previous studies have shown the involvement of protein kinase C (PKC) in 1,25-dihydroxy-vitamin D3 [1,25(OH)2D3] regulation of DNA synthesis (long-term effect) and Ca2+ channel activity (short-term effect) in cultured myoblasts. Both events mediate stimulation of myoblast cell proliferation and growth by 1,25(OH)2D3. To characterise further the role of PKC in the hormone mode of action in muscle cells, the presence of PKC isoenzymes in chicken embryo myoblasts and changes in their total cell and subcellular levels after treatment (72 h and 5 min) with 1,25(OH)2D3 (1 nM), 12-O-tetradecanoyl phorbol 13-acetate (TPA; 100 nM) and 1,2-dioctanoyl-rac-glycerol (DOG; 50 microM) were investigated.