Showing papers on "Ultraviolet light published in 1986"

Structural and functional changes of normal aging skin

Abstract: Solar-induced cutaneous changes are more prevalent and profound in older persons and, thus, are often inappropriately attributed to the aging process, per se. Structural and functional alterations caused by intrinsic aging and independent of environmental insults are now recognized in the skin of elderly individuals. Structurally the aged epidermis likely becomes thinner, the corneocytes become less adherent to one another, and there is flattening of the dermoepidermal interface. The number of melanocytes and Langerhans cells is decreased. The dermis becomes atrophic and it is relatively acellular and avascular. Dermal collagen, elastin, and glycosaminoglycans are altered. The subcutaneous tissue is diminished in some areas, especially the face, shins, hands, and feet, while in others, particularly the abdomen in men and the thighs in women, it is increased. The number of eccrine glands is reduced and both the eccrine and apocrine glands undergo attenuation. Sebaceous glands tend to increase in size but paradoxically their secretory output is lessened, The nail plate is generally thinned, the surface ridged and lusterless, and the lunula decreased in size. There is a progressive reduction in the density of hair follicles per unit area on the face and scalp, independent of male-pattern alopecia. The hair shaft diameter is generally reduced but in some areas, especially the ears, nose, and eyebrows of men and the upper lip and chin in women, it is increased as vellus hairs convert to cosmetically compromising terminal hairs. Functional alterations noted in the skin of elderly persons include a decreased growth rate of the epidermis, hair, and nails, delayed wound healing, reduced dermal clearance of fluids and foreign materials, and compromised vascular responsiveness. Eccrine and apocrine secretions are diminished. The cutaneous immune and inflammatory responses are impaired, particularly cell-mediated immunity. Clinical correlates of these intrinsic aging changes of the skin include alopecia, pallor, xerosis, an increased number of benign and malignant epidermal neoplasms, increased susceptibility to blister formation, predisposition to injury of the dermis and underlying tissues, delayed onset and resolution of blisters and wheals, persistent contact dermatitis, impaired tanning response to ultraviolet light, increased risk for wound infections, prolongation of therapy necessary for onychomycosis, and thermoregulatory disturbances.

Far ultraviolet surgical and dental procedures

Abstract: A method and apparatus are described for photoetching organic biological matter without requiring heat as the dominant etching mechanism. Far-ultraviolet radiation of wavelengths less than 200 nm are used to selectively remove organic biological material, where the radiation has an energy fluence sufficiently great to cause ablative photodecomposition. Either continuous wave or pulse radiation can be used, a suitable ultraviolet light source being an ArF excimer laser having an output at 193 nm. The exposed biological material is ablatively photodecomposed without heating or damage to the rest of the organic material. Medical and dental applications include the removal of damaged or unhealthy tissue from bone, removal of skin lesions, cutting or sectioning healthy tissue, and the treatment of decayed teeth.

Waterproof sunscreen compositions

Abstract: An effective aesthetic water-proof sunscreen composition which includes ultraviolet light protection to the skin includes water in an amount from 15% up to about 95% by weight, from about 1% to about 30% by weight of an active sunscreen agent, from about 0.1% to about 6.0% by weight of ethylcellulose, from about 0.01% to about 12% of weight by a surface active agent, and from about 0.03% to about 5.0% by weight of an alkaline dispersion promoting agent. The composition may optionally contain up to about 25% by weight of water-soluble organic liquids; up to about 20% by weight of water-insoluble emollients; up to about 20% by weight of suspended particulate matter; up to 8% by weight of plasticizers; up to 5% by weight of a thickening agent; and up to about 3% by weight of fragrance oil.

Spectrometer with combined visible and ultraviolet sample illumination

Abstract: In an optical instrument, a fiber optic probe is provided to irradiate a sample with visible NIR and ultraviolet light. Glass fibers carry the visible and NIR light to the probe from a visible and NIR light source and quartz fibers carry ultraviolet light to the probe from an ultraviolet source. Glass fibers carry visible and NIR light emanating from the sample to a spectrometer having a fixed grating and an array of photodetectors to receive the spectrum dispersed by the grating within the spectrometer housing. Amplifiers are also contained in the spectrometer housing severally connected to the photodetectors to amplify the output signals of the photodetectors. The probe is provided with a standard white sample pivotal into position to receive the light from the visible light source. A computer is programmed to provide automatic calibrating whenever the temperature within the housing changes more than a predetermined small amount. The automatic calibration is carried out by pivoting the white standard into position and computing calibration values from the resulting photodector outputs. Automatic calibration is also provided when the ratio of output signals from selected ones of the photodetectors changes by more than a predetermined small percentage.

Symbiotic filter-sterilizer

Abstract: This invention relates to a device including a combination of a porous filter and ultraviolet light source, that is for purifying fluid media. The porous filter filtering out particles suspended in the fluid medium and the ultraviolet germicidal lamp killing germs in the fluid medium are arranged in a combination in such a way that the porous filter distributes the fluid flow in a pattern that exposes the fluid medium to the germicidal radiation uniformly and thoroughly, while the ultraviolet germidical light destroys the bacteria and other germs contaminating the fluid medium, and at the same time cleans the porous filter continuously by oxidizing the organic particles clogging the porous filter wherein the oxidizing process utilizes oxygen naturally dissolved in the fluid medium or that artificially injected into the fluid medium.

Ultraviolet radiation purification system

Abstract: A fluid purification system includes an elongated ultraviolet radiation emitting tube and independent fluid flow-controlling conduits. Each conduit is transparent to allow ultraviolet light emitted by the tube to enter the conduit, and defines a continuous, aand is helically wound closely about the tube to insure that fluid flow through the conduits is exposed to the ultraviolet light. The system includes a filter having inlet and outlet ports. An end of each conduit is connected to one of the inlet and outlet ports of the filter. The system thus exposes the fluid to ultraviolet radiation both before and after the fluid is filtered.

Method and apparatus for making a plastic lens

Abstract: A method and apparatus for making a plastic lens and a plastic lens made thereby are provided, the method comprising the steps of disposing a lens forming material comprising a liquid monomer and a photosensitive initiator into a mold cavity defined in part between a pair of spaced apart mold members each having a lens forming surface facing the cavity and an outer opposed surface, directing rays of ultraviolet light from a source thereof against the outer surface of at least one of the mold members so as to pass therethrough to act on the lens forming material in the cavity to produce the lens therefrom, and forming the outer surface of the one mold member with structure to cause the ultraviolet light directed thereagainst to be substantially evenly distributed throughout the lens forming material in the cavity in order to tend to prevent optical distortions in the lens being formed therefrom.

Method and apparatus utilizing waveguide and polarized light for display of dynamic images

Abstract: A visual display device is disclosed in which a liquid crystal cell is adjacent a light waveguide. Electrodes in the liquid crystal cell alter the dielectric constant therein to change the critical angle defined by the two media of the cell and the waveguide to regulate the amount and location of light which may escape from the waveguide. Color display can be obtained with visible light by providing a dyed layer and with ultraviolet light by providing colored ultraviolet phosphors. A shaped mirror or contoured reflective layer is provided with a visible light device to cause the displayed light to scatter in desired directions.

The C-C (6-4) UV photoproduct is mutagenic in Escherichia coli

Abstract: Mutation induced by ultraviolet light is predominantly targeted by UV photoproducts. Two primary candidates for the premutagenic lesion are the cyclobutane pyrimidine dimer and the less frequent (by a factor of 10) pyrimidine-pyrimidone (6-4) photoproduct. Methylation of the 3'-cytosine in the sequence 5' CCAGG 3' reduces the yield of (6-4) lesions, but not of cyclobutane dimers, at these sites. By taking advantage of mutants deficient in cytosine methylation, we show here that at the three sites in the lacI gene of Escherichia coli having this sequence, the specific increase in the formation of the (6-4) photoproducts is accompanied by a concomitant increase in mutation. At each site, a G X C to A X T transition results in an amber mutation. In the unmethylated state, these sites become among the most frequent nonsense mutations recovered. We conclude that the (6-4) photoproduct constitutes a major premutagenic lesion in E. coli.

Stereoselective photoaffinity labelling of the purified 1,4-dihydropyridine receptor of the voltage-dependent calcium channel.

Abstract: The voltage-dependent calcium channel from guinea-pig skeletal muscle T-tubules has been isolated with a rapid, two-step purification procedure. Reversible postlabelling of the channel-linked 1,4-dihydropyridine receptor and stereoselective photolabelling as a novel approach were employed to assess purity. A 135-fold purification to a specific activity of 1311 ± 194 pmol/mg protein (determined by reversible equilibrium binding with (+)-[3H]PN200-110) was achieved. Three polypeptides of 155 kDa, 65 kDa and 32 kDa were identified in the purified preparation. The 155-kDa band is a glycoprotein. The arylazide photoaffinity probe (−)-[3H]azidopine bound with high affinity to solubilized membranes (Kd= 0.7 ± 0.2 nM) and highly purified fractions (Kd= 3.1 ± 2 nM), whereas the optical antipode (+)-azidopine was of much lower affinity. Irradiation of (−)-[3H]azidopine and (+)-[3H]azidopine receptor complexes with ultraviolet light led to preferential incorporation of the (−) enantiomer into the 155-kDa polypeptide in crude solubilized and purified preparations. The pharmacological profile of irreversible labelling of the 155-kDa glycoprotein by (−)-[3H]azidopine is identical to that found in reversible binding experiments. Specific photolabelling of the 155-kDa band by (−)-[3H]azidopine per milligram of protein increases 150-fold upon purification, whereas incorporation into non-specific bands in the crude solubilized material is identical for both, (−) and (+)-[3H]azidopine.

Fluence dependence of the ultraviolet-light-induced accumulation of chalcone synthase mRNA and effects of blue and far-red light in cultured parsley cells

Abstract: The fluence dependence of the time course of accumulation of chalcone synthase mRNA in ultraviolet (UV)-light-irradiated cell suspension cultures of parsley (Petroselinum crispum) and the additional effects of blue and far-red light have been investigated. Variations of the UV fluence had no detectable influence on the initial rate of increase in mRNA amount or translational activity, nor on the preceding lag period of approximately 3 h, but strongly influenced the duration of the transient increase. The effects were the same whether the fluence rate or the time of irradiation was varied to obtain a given fluence. Blue-light pretreatment of the cells resulted in increased amounts of mRNA and abolished the apparent lag period. This effect remained cryptic without the subsequent UV-light treatment. Irradiation with long-wavelength far-red light following UV-light pulses shortened the duration of the mRNA accumulation period. This effect was not altered by a preceding blue-light treatment. Thus, three photoreceptors, a UV-B receptor, a blue-light receptor and phytochrome, participate in the regulation of chalcone synthase mRNA accumulation in this system.

Sodium arsenite potentiates the clastogenicity and mutagenicity of DNA crosslinking agents

Abstract: To see if sodium arsenite enhances the clastogenicity and the mutagenicity of DNA crosslinking agents, Chinese hamster ovary (CHO) cells and human skin fibroblasts were exposed to cis-diamminedichloroplatinum (II) (cis-Pt(II)) or 8-methoxypsoralen (8-MOP) plus long-wave ultraviolet light (UVA) and then to sodium arsenite. The results indicate that the clastogenicity of cis-Pt(II) and 8-MOP plus UVA are enhanced by the post-treatment with sodium arsenite. Chromatid breaks and exchanges are predominantly increased in doubly treated cells. Furthermore, the mutagenicity of cis-Pt(II) at the hypoxanthine-guanine phosphoribosyl transferase locus is also potentiated by sodium arsenite in CHO cells.

Flexible printed circuit board having integrated circuit die or the like affixed thereto

Abstract: A flexible printed circuit board assembly having an integrated circuit die bonded directly thereto. A first layer of the flexible printed circuit board assembly includes a plurality of conductive paths and geometrical patterns on each of its surfaces. The conductive patterns include pads for mounting the integrated circuit die and connecting the wires from the integrated circuit. Additional intermediate layers of the flexible printed circuit board assembly, having an aggregate thickness greater than the height of the integrated circuit die and associated leads bonded thereto, surround the integrated circuit die. The top layer of the flexible printed circuit board provides for total encapsulation of the integrated circuit die for protection thereof. In the preferred embodiment that portion of the top layer which covers the integrated circuit die is opaque to prevent the passage of ultraviolet light which might otherwise cause damage to the integrated circuit.

Osteoid-osteoma: intraoperative tetracycline-fluorescence demonstration of the nidus.

Abstract: Nine patients with a clinical and radiographic diagnosis of osteoid-osteoma received 750 to 4,000 milligrams of tetracycline preoperatively. Immediate examination of the surgically removed specimens under ultraviolet light demonstrated fluorescence of the nidus in all nine patients. Reactive and normal bone did not fluoresce. This simple technique permits quick, easy, economical, and sure verification that the nidus has been excised.

Increased uterine vascular permeability at the time of embryonic attachment in the pig.

Abstract: The temporal relationship between embryonic attachment and endometrial vascular permeability was investigated in the gilt. Light and electron microscopy failed to reveal structural differences between Day 10 cycling and pregnant maternal epithelia, including evidence of blastocyst contact. Chorionic adhesion was preserved at mesometrial regions in 3 of 5 Day 13 pregnant animals and appeared to be related to localized differentiation of the underlying maternal epithelium. In order to study uterine vascular permeability, 44 gilts between Days 11 and 19 of the cycle and pregnancy were injected i.v. with a 0.5% solution of Evans Blue (2.5 ml/kg body weight). Examination of excised uteri under ultraviolet light revealed a well-defined zone of endometrial fluorescence corresponding to extravascular content of the dye. Exclusive to pregnant gilts, this response appeared in conjunction with blastocyst elongation at Day 12, and was consistently confined to areas of embryonic membrane contact thereafter. The changes in endometrial morphology and vascular permeability suggest involvement of some embryonic factor(s) acting in a localized manner. Increased histotrophe production is probably facilitated by the flux of plasma constituents to maternal epithelial cells. Coincidence of increased uterine vascular permeability at the site of attachment with elevated blood flow would enhance transport of nutrients toward the conceptus and allow access of blastocyst-induced products to the maternal circulation.

Psoralens potentiate ultraviolet light-induced inhibition of epidermal growth factor binding

Abstract: The psoralens, when activated by ultraviolet light of 320-400 nm (UVA light), are potent modulators of epidermal cell growth and differentiation. Previously, we reported that, in mammalian cells, these compounds bind to specific saturable high-affinity cellular receptor sites. In the present studies, we demonstrate that binding of psoralens to their receptors followed by UVA light activation is associated with inhibition of epidermal growth factor (EGF) receptor binding. Inhibition of EGF binding, which required UVA light, was rapid and dependent on the dose of UVA light (0.5-2.0 J/cm2), as well as the concentration of psoralens (10 nM to 1 microM). Higher doses of UVA light (2.0-6.0 J/cm2) by themselves were also inhibitory, indicating that psoralens potentiate the UVA-induced inhibition of EGF binding. A number of biologically active analogs of psoralen, including 8-methoxypsoralen, 5-methoxypsoralen, and 4,5',8-trimethylpsoralen, when activated by UVA light, were found to be inhibitors of binding. Inhibition of EGF binding by psoralens was observed in a variety of human and mouse cell culture lines known to possess psoralen receptors. In the epidermal-derived line PAM 212, at least two populations of receptors with different affinities for EGF were found. Psoralens and UVA light selectively inhibited binding to the higher-affinity EGF receptors, an effect analogous to that of the phorbol ester tumor promoters. As observed with phorbol esters, photoactivated psoralens appeared to inhibit EGF binding by an indirect mechanism. These data demonstrate that the psoralens and UVA light have direct biological effects on cell-surface membranes. Since EGF is a growth-regulatory peptide, the ability of psoralens and UVA light to inhibit EGF binding may underlie the biologic effects of these agents in the skin.

Clinical pharmacokinetics of methoxsalen and other psoralens.

Abstract: The psoralen derivative methoxsalen and to a lesser extent some other furocoumarin congeners, including bergapten and trioxsalen, have acquired a place in the treatment of psoriasis and other dermatoses. They are inactive after oral or topical administration unless combined with irradiation with long-wave ultraviolet light (UVA). This combination is referred to as photochemotherapy or PUVA (psoralen plus UVA). Usually a standard dose of methoxsalen (0.5 to 0.7 mg/kg) is given 2 hours prior to irradiation, and the light dose is assessed individually. Differences in response are often due to the unpredictable pharmacokinetic behaviour of the drug. Reversed-phase high-performance liquid chromatography is the method of choice for determining methoxsalen concentrations in body fluids, but gas chromatography with electron capture detection and thin-layer chromatography with fluorescence densitometry also give favourable results. The absorption of methoxsalen, and hence clinical response, is affected by concomitant food ingestion and by differences in drug formulation. A liquid preparation in soft gelatin capsules or a microenema give higher and more rapidly appearing maximum serum concentrations (Cmax) than crystalline methoxsalen in tablets or capsules. With a standard dose of tablets, Cmax is in the range of 50 to 250 µg/L and appears between 1 and 2 hours after ingestion. The drug has a high, but variable, intrinsic metabolic clearance and is almost completely metabolised. Serum elimination half-life is in the order of 0.5 to 2 hours. There is a large interpatient variability in the clearance of methoxsalen (40 to 650 L/h); the relative distribution volume ranges between I and 9 L/kg. Concentrations in suction blister fluid (sbf) are approximately one-third of Cmax in serum and remain relatively constant as long as the plasma concentration exceeds the suction blister fluid level. Individuals with a high methoxsalen clearance and low Cmax usually show less biological sensitivity to PUVA (in terms of minimal phototoxic dose of UVA) than low-clearance patients and frequently a less favourable clinical response. Hence Cmax can be used for the purpose of therapeutic drug monitoring and, in practice, this may be determined by measuring serum concentrations at least at 1, 2, and 3 hours after ingestion. Bergapten is somewhat less active than methoxsalen but has similar pharmacokinetic characteristics. The bioavailability of trioxsalen is poor after oral intake and this drug is mainly administered topically.

Polyacrylated oligomers in ultraviolet curable optical fiber coatings

Abstract: @ An ultraviolet curing liquid coating composition is disclosed which, when cured with ultraviolet light in the presence of an appropriate photoinitiator, provides buffer coatings for optical glass fiber having adequate strength at room or expected elevated temperature and stability at such elevated temperature, a high index of refraction above 1.48, and a low tensile modulus which remains low to resist microbending difficulties down to around -60°C. This coating composition consists essentially of a linear polyacrylate-terminated polyurethane or polyurea oligomer having a room temperature tensile modulus of at least 100 psi., and a tensile modulus at -60°C. which is less than 175,000 psi., when capped with 2-hydroxyethyl acrylate and cured with ultraviolet light, in admixture with a liquid acrylate-functional material which does not increase the low temperature hardness and which provides the liquidity needed for coating application. The oligomer is instead capped with a monohydric polyacrylate to provide improved cure speed without eliminating resistance to low temperature microbending.

Induction of yeast Ty element transcription by ultraviolet light

Abstract: Gene expression induced in response to DNA damage is now well characterized in Escherichia coli (reviewed in ref. 1), and the functions of the proteins encoded by some of these genes are also understood. Physiological evidence has implicated similar responses in eukaryotes2–9, and recently DNA sequences whose transcription can be induced by ultraviolet (UV) irradiation have been identified and cloned from the yeast Saccharomyces cerevisiael0–12. With the exception of the Ustilago maydis Recl protein, however13, no inducible eukaryotic proteins have been characterized with respect to their role in post-irradiation DNA metabolism. Using differential colony hybridization methods, we have described the cloning of four S. cerevisiae DNA sequences whose transcript levels increase ∼10-fold after a dose of UV irradiation which was previously shown to induce two novel proteins in yeast12,14. Although they possess different restriction enzyme maps, these sequences did share elements of homology as defined by cross-hybridization experiments. We show here that all four sequences possess homology with yeast Ty elements. These elements comprise a family of heterogeneous, dispersed and moderately repetitive transposable DNA sequences which are present as ∼30 copies per haploid genome in laboratory strains and whose archetypal structure is shown in Fig. 1 (refs 15,16 and reviewed in ref. 17). We also show directly that the 5.7-kilobase (kb) major Ty transcript, initiated in one terminal direct repeat sequence (δ) and terminated in the other18, is induced by UV irradiation.