Studies on curcumin and curcuminoids. XLVI. Photophysical properties of dimethoxycurcumin and bis-dehydroxycurcumin.

The steady-state absorption and fluorescence, as well as the time-resolved fluorescence properties of dimethoxycurcumin and bis-dehydroxycurcumin dissolved in several solvents differing in polarity and H-bonding capability are presented. The singlet oxygen generation efficiency of the two compounds relative to curcumin is estimated. The photodegradation quantum yield of the former compound in acetonitrile and methanol is determined. The dimethoxycurcumin and bis-dehydroxycurcumin decay mechanisms from the S (1) state are discussed and compared with those of curcumin, dicinnamoylmethane and bis-demethoxycurcumin.

Revision of an unstable HELICA endoprosthesis with a Zurich cementless total hip replacement.

A six-year-old, female, spayed Labrador Retriever was evaluated for progressive lameness of one year duration, ending in non-weight-bearing of the right hindlimb. The dog had a history of severe coxarthrosis of both hip joints, and had a HELICA hip prosthesis implanted in the right hip 18 months before. On survey radiographs, the acetabular and femoral components appeared unstable, with a large void in the proximal femur and a lacy periosteal reaction on the trochanter. Arthrocentesis was performed to rule out septic loosening. As culture samples were negative, the dog underwent surgery. We report the successful revision of an unstable HELICA screw hip prosthesis with a Zurich cementless total hip replacement. The patient had a good clinical and radiological outcome seven months postoperatively.

Ground reaction force profiles after partial and pancarpal arthrodesis in dogs.

OBJECTIVES: To evaluate and compare long-term functional outcome after partial carpal arthrodesis and pancarpal arthrodesis in dogs using kinetic gait analysis. METHODS: Fourteen dogs with 19 partial carpal or pancarpal arthrodeses were retrospectively examined and underwent force-plate gait analysis. Mean times since surgery were 29.4 and 24.4 months for pancarpal and partial carpal arthrodesis respectively. Vertical and braking-propulsive ground reaction force profiles were compared between treatment groups, and to those of normal dogs (control group) using Kruskal-Wallis one-way analysis of variance. RESULTS: With the exception of time to vertical peak that occurred earlier in dogs with pancarpal than in dogs with partial carpal arthrodesis (p <0.01), there was no difference between the two treatment groups. Several parameters differed significantly between operated and healthy dogs (p <0.01): vertical impulses were significantly lower in both treatment groups, braking forces and impulses were also reduced after both techniques. Propulsive forces and impulses were only reduced in dogs with pancarpal arthrodesis. When comparing gait parameters of sound limbs of unilateral operated dogs to those of control dogs, braking forces and impulses (p <0.01; p <0.05) were significantly higher in the sound legs of unilateral operated dogs. CLINICAL SIGNIFICANCE: Long-term outcome after partial carpal and pancarpal arthrodesis is good and comparable to each other. Propulsive action may be altered more in dogs with pancarpal arthrodesis.

Alternaria spores at different heights from the ground.

BACKGROUND: Alternaria tenuis (Alt) is one of the main allergens in pediatric age. In temperate climates, airborne Alt spores are detectable from May to November with peaks in late summer and autumn. Sensitized children display symptoms even in the absence of airborne Alt spores. Alt spore concentration, as well as pollen, is usually detected by fixed devices located on the roof of a building at a height of 10-20 m. The aim of the current study is to find out whether ground-level (50 cm) Alt spore concentrations are different from those at roof-top level, even during low-concentration periods. METHODS: Alt samples were taken simultaneously using a Hirst fixed volumetric collector (FVC) placed on a 15 m-high roof and by a portable volumetric collector (PVC). Firstly, the results of FVC and PVC, both placed on the roof-top, were compared to verify the correlation coefficient of the two samplers. Subsequently, the PVC was placed 50 cm above the ground in a courtyard (30 samplings) and in private green areas (50 samplings). The results were compared by statistical analysis (Student's t-test or K-S test). RESULTS: The values of the 20 samples taken jointly in summer time (FVC 195 +/- 134 spores/m(3); PVC = 134 +/- 131 spores/m(3)) showed a good correlation between the two samplers (r = 0.850; P < 0.01), with a correction factor equal to 1.177. 1. Thirty samples obtained in summer and winter when the PVC was positioned in an enclosed courtyard directly below the FVC showed no significant difference (PVC, 181 +/- 194 spores/m(3); FVC, 152 +/- 145 spores/m(3); P = 0.221). 2. Fifty samples taken by PVC placed in private green areas in a low-concentration period, showed significantly higher concentrations than by FVC: PVC, 531 +/- 925 spores/m(3); FVC, 25 +/- 51 spores/m(3) (K-S test: P < 0.0001). In particular, 33 samples taken in winter when Alt counts by FVC were <10 spores/m(3) still demonstrated highly significant differences: PVC, 398 +/- 961 spores/m(3); FVC, 2.0 +/- 2 spores/m(3) (K-S test: P < 0.0001). CONCLUSION: Our results lead to the conclusion that Alt spore concentration is significantly higher at ground level in the presence of vegetation, even when the spore concentration is very low (<10 spores/m(3)). These results further suggest that the individual's exposure to Alt, especially in the case of children, is underestimated by samples taken at roof-top level by FVC.

Real-time holograms generated by second-harmonic cross correlation of object and reference optical wave fields.

Three-dimensional holographic images of extended diffusing objects are simultaneously recorded and reconstructed by optical cross correlation in a second-order nonlinear crystal. An interaction geometry in which the phase-matched object and reference fields propagate slightly noncollinearly is particularly convenient for producing these second-harmonic-generated holograms.

Combinational tasks performed by second-harmonic-generated holograms.

Second-harmonic-generated holograms directly provide the outputs of logical gates AND and NAND operating on optical bits encoded as amplitude modulations in the object and reference wave fronts. By use of a Nd:YAG laser and a beta-barium borate crystal, we realized a real-time half-adder of two one-digit binary numbers. The feasibility of highly parallel operation is also discussed.

Group-velocity control in the mixing of three noncollinear phase-matched waves.

A model of three-wave parametric interactions is presented, in both type I and type II noncollinear phase-matching conditions, in which the group velocities of the interacting pulses are suitably linked to each other. We consider two conditions for group velocities that are significant in the parametric generation/amplification of femtosecond pulses and determine the interaction geometry required to fulfill them in uniaxial crystals. The results are compared with those for collinear phase matching and are used to interpret the behavior of ultrabroadband parametric sources.

Kinetic transport analysis of daunorubicin by LoVo and LoVo/DX cells.

We describe a fluorometric technique for the measurement of transport parameters of fluorescent drugs through cellular membranes. Unlike other procedures, this method gives an accurate measure of drug accumulated in the cells and measures the fraction of free and bound drug in the cell. The kinetic parameters of transport through cellular membranes are determined using a simple three-compartment model combined with fluorescence measurements performed on the extracellular medium and on Triton-permeabilized cells during daunorubicin incorporation. With this technique we found that LoVo cells have a greater daunorubicin uptake, a similar input rate constant and a lower output rate constant than the drug-resistant LoVo/DX cells.

Matching of group velocities by spatial walk-off in collinear three-wave interaction with tilted pulses.

We demonstrate that, for tilted pulses, the contribution to group velocity that is due to spatial walk-off can compensate for the group-velocity mismatch in three-wave interactions. With 100-fs, 0.4-Zmicrom pump pulses in beta-barium borate, we obtained efficient parametric generation of collinear superfluorescence tunable in the range from 0.456 to 3.25 microm.

Visible pulses of 100 fs and 100 µJ from an upconverted parametric generator.

Upconversion by sum-frequency and second-harmonic generation of pulses from a Ti:sapphire-pumped parametric generator provides 50-120 µJ, sub-100 fs, bandwidth-limited pulses at 470-700 nm.

Involvement of brain catecholamines and acetylcholine in growth hormone hypersecretory states. Pathophysiological, diagnostic and therapeutic implications.

Secretion of growth hormone (GH) is excessive in acromegaly, but also in a number of other pathological states such as anorexia nervosa, insulin-dependent diabetes mellitus (IDDM), liver cirrhosis, depression, renal failure and GH-insensitivity syndrome. Abnormalities in the neuroendocrine control of GH secretion and/or a state of insensitivity to GH contribute to hypersecretion of GH in these states, with the possible exception of acromegaly, which appears to be a primary pituitary disease. GH hypersecretion may also occur in neonates or adolescents with tall stature, thus reflecting particular physiological or paraphysiological conditions. In the cohort of brain neurotransmitters, catecholamines and acetylcholine reportedly play a major role in the control of neurosecretory GH-releasing hormone (GHRH) and somatostatin (SS)-producing neurons, and hence GH secretion. Activation of alpha 2-adrenoceptors or of muscarinic cholinergic receptors in the hypothalamus stimulates GH release, probably through stimulation of GHRH and inhibition of SS release, respectively. Activation of dopamine receptors likewise stimulates GH release, while activation of beta-receptors inhibits GH release through stimulation of hypothalamic SS function. This review discusses the involvement of brain catecholamines and acetylcholine in GH hypersecretory states, including anorexia nervosa, acromegaly, IDDM, liver cirrhosis, depression, renal failure and GH insensitivity syndrome, with a view to providing a fuller understanding of their pathophysiology and, whenever possible, diagnostic and therapeutic implications.

Fluorochromes with long-lived fluorescence as potential labels for pulsed laser immunocytofluorometry: photophysical characterization of pyrene derivatives.

An apparatus for laser-induced time-resolved fluorescence measurements, in conjunction with pyrene derivatives endowed with long-lived excited singlet states, was employed for immunocytofluorometric measurements. N-(1-pyrene)maleimide, 1-pyrenesulfonyl chloride and 1-pyreneisothiocyanate were conjugated with immunoglobulin, antimouse-IgG, and the fluorescence decays of both free and conjugated forms were investigated. Bi-exponential decays were obtained in all cases with time constants of the short-lived component in the range 3-4.7 ns and the long-lived one in the range 20-55 ns. Only the spectral distribution of the two components is essentially affected upon conjugation. The persistence of the long-lived component, well above the lifetime of autofluorescence, and of the antibody specificity, as shown by immunodiffusion tests, upon conjugation indicates that this technique could be advantageously adopted in immunocytofluorometry.

Laser photosensitization of cells by hypericin.

Administering a light dose of 90 J/cm2 at 599 nm during incubation with hypericin to a highly differentiated normal epithelial cell line (FRTL-5), derived from Fisher rat thyroid, and to a neoplastic cell line (MPTK-6), derived from the lung metastases of a thyroid carcinoma induced in Fisher rats, produces cell kill at drug doses 1000 times lower than those necessary to cause the same mortality in the dark. The photocytocidal activity of this polycyclic quinone drug on neoplastic cells is superior to that of antitumor anthraquinone drugs, such as daunomycin and mitoxanthrone, and to the photosensitized antiviral activity previously reported for hypericin.

Corticotrophin-releasing hormone does not inhibit growth hormone-releasing hormone-induced release of growth hormone in control subjects but is effective in patients with eating disorders.

Previous studies have shown that corticotrophin-releasing hormone (CRH) inhibits GH secretion in response to GH-releasing hormone (GHRH) in normal women and men, and animal studies suggest that this effect is mediated by an increased release of somatostatin from the hypothalamus. It has been reported that there are abnormalities in the neuroendocrine regulation of the hypothalamo-pituitary-somatotrophic axis and the hypothalamo-pituitary-adrenocortical axis in patients with eating disorders. The present study therefore investigated the ability of CRH to inhibit the GH response to GHRH in eight young women with anorexia nervosa (AN) and in seven young women with eating disorders which were not otherwise specified (NOS). We also compared the effect of CRH in the patients with the response it caused in ten control women. In contrast to a previous report, combined i.v. administration of 50 micrograms human CRH (hCRH) and 50 micrograms GHRH(1-29) caused a GH response in control women which was higher, although not significantly so, than that induced by GHRH alone (area under the curve (AUC) 988.5 +/- 506.0 compared with 1568.4 +/- 795.6 (S.E.M.) ng/ml per 120 min for GHRH alone and GHRH plus hCRH respectively). Conversely, the administration of hCRH given together with GHRH markedly inhibited the GH response induced by the latter in both AN patients (AUC 2253.0 +/- 385.7 compared with 1224.4 +/- 265.7 ng/ml per 120 min for GHRH and GHRH plus hCRH respectively; P < 0.005 and NOS patients (AUC 2827.4 +/- 281.1 compared with 308.5 +/- 183.4 ng/ml per 120 min for GHRH and GHRH plus hCRH respectively; P < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Fluorometric determination of the kinetics of anthracyclines uptake by cells.

Fluorometric measurements on extracellular medium are shown to allow kinetic parameters of in vitro anthracycline uptake by cells to be calculated. The method provides influx and efflux rates, as well as the time dependence of both influx and efflux. It is applied to a normal thyroid epithelial cell line (FRTL-5) and a cell line (MPTK-6) derived from the lung metastases of a thyroid carcinoma exposed to daunorubicin at concentrations within the range of 250 to 1000 ng/ml. The results show that the number of cells influences the dependence of the kinetics upon the extracellular drug concentration and that the MPTK-6 cells are endowed with very efficient efflux mechanisms.

Enhanced response to daunomycin of normal, tumor and metastatic cell lines via drug photoactivation.

We have compared the cytotoxicity of daunomycin in vitro to highly differentiated normal epithelial cells (Fisher rat thyroid cells, FRTL-5) and to two neoplastic cell lines, a thyroid carcinoma (TK-6) and its lung metastasis (MPTK-6). Whereas the cell lines are equally sensitive to the drug in the dark, if irradiated during incubation with daunomycin (86 J/cm2 at 488 nm), they become more and differently sensitive. Namely, the drug doses producing 50% mortality decrease by factors of about 22, 28 and 16 for FRTL-5, TK-6 and MPTK-6 cell lines, respectively. This result correlates with differences in drug uptake and resistance observed in the normal and neoplastic cell lines.