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Plasma concentration of myeloperoxidase enzyme in pre- and post-climacterial people: related superoxide anion generation.

Neutrophil granulocytes are involved in the pathogenesis of atherosclerosis also through their free radical generation. The aim of the study was to test how extracellular levels of myeloperoxidase (MPO; a granulocyte enzyme playing role in free radical production) change by age and what effect this change has on the production of the free radical superoxide anion by neutrophils. We also wanted to examine whether the antioxidant effect of different steroid hormones is realized through the MPO. Plasma myeloperoxidase concentrations of healthy blood donors were quantified by ELISA. Superoxide anion production was measured by photometry. Myeloperoxidase concentration was significantly lower in plasmas obtained from older women and men than in those from younger subjects. Adding the MPO inhibitors 4-aminobenzoic acid hydrazide (ABAH) and indomethacin to the granulocytes, the generation of superoxide anion increased and the decreasing effect of the steroids on superoxide production was inhibited. Incubating the neutrophils with the product of the reaction catalyzed by MPO itself (hypochlorite anion), we found significant decrease in superoxide generation. According to our results MPO seems to diminish the production of superoxide anion and so probably has an antioxidant ability. Therefore, its lower plasma levels may contribute to the increasing incidence of atherosclerosis and other free radical mediated disorders in old people. Thus, after further studies MPO might become one of the indicators of cardiovascular risk and the scavenger capacity in general.

Adult↗

Near-infrared spectroscopy as a convenient analytical method for alkyl polyglycosides.

Near infrared (NIR) spectroscopy is used for the rapid determination of decyl glucopyranoside (10G1) and alkyl polyglycoside (AG) mixtures having different alkyl chain length and the number of glucose unit in aqueous solution. NIR spectroscopy is a much simpler spectroscopic analysis method compared to three analytical methods for mixture of AGs such as thin layer chromatography (TLC), high performance liquid chromatography (HPLC), and photometry method. NIR spectra of AGs between 0.030 and 0.540 mg/ml in aqueous solutions were utilized to develop a calibration model. Both raw spectra and the second derivatives of AGs were tested for the best fit. The best calibration was built with second derivative spectra by using multiple linear regression (MLR). The standard error of calibration (SEC) and the standard error of prediction (SEP) were used for the evaluation of the model. The best calibration provides an SEP of 0.052 and 0.061 mg/ml for the prediction set of 10G1 and AG mixture, respectively.

Glycosides↗

Determination of potassium ions in pharmaceutical samples by FIA using a potentiometric electrode based on ionophore nonactin occluded in EVA membrane.

A simple and rapid method was developed for the K(+) ions determination employing a flow injection system using a flow-through electrode based on the naturally-occurring antibiotic ionophore nonactin occluded in a polymeric membrane. The nonactin ionophore was trapped in poly(ethylene-co-vinyl acetate) (EVA) matrix (40% w/w in vinyl acetate) and dispersed on the surface of a graphite-epoxy tubular electrode. The plasticizer-free all-solid-state potassium-selective electrode showed a linear response for K(+) concentrations between 5.0 x 10(-5) and 5.0x10(-2) M (r=0.9995) with a near-Nernstian slope of 51.5 mV per decade, when Tris-HCl buffer (pH 7.0;0,1 M) was employed as a carrier. The potentiometric-FIA system allows an analytical frequency of 120 samples per hour with a precision of 3.6%. The relative standard deviations (R.S.D.) for K(+) determination in pharmaceuticals samples, without any previous treatment, were lower than 4.0%, comparable to those obtained by flame photometry. Ammonium is the main analytical interference and the electrode response time was 5 s at 25 degrees C. The useful lifetime of the tubular sensor is longer than 3 months in continuous use.

Anti-Bacterial Agents↗

Sodium nuclear magnetic resonance imaging of myocardial tissue of dogs after coronary artery occlusion and reperfusion.

Nuclear magnetic resonance (NMR) imaging techniques have been applied to the observation of tissue sodium-23 in normal and ischemic canine myocardium. To produce a region of ischemia and infarction in the myocardium, in six dogs a coronary artery was subjected to 1 hour of surgical occlusion followed by 1 hour of reperfusion. The dogs were then killed and sodium-23 NMR images of the excised hearts were obtained using a high field NMR imaging system. These images were compared with tissue sodium contents measured by flame photometry. The regions of ischemic damage were clearly visible as areas of increased sodium NMR signal on the three-dimensional images. A good correspondence was found between the relative intensity of the sodium signals and the sodium contents of normal myocardium and myocardium subjected to coronary artery occlusion and reperfusion. The data suggest the feasibility of NMR sodium imaging to detect the location and extent of myocardial damage in patients with coronary artery disease.

Animals↗

Implantable contact lens for high myopia.

PURPOSE: To evaluate the efficacy, safety, and biocompatibility of a collagen polymer implantable contact lens (ICL) (Staar Collamer) as a posterior chamber phakic intraocular lens (IOL) to correct high myopia. SETTING: Departments of Ophthalmology, Helsinki University Central Hospital, Helsinki, and Tampere University Hospital, Tampere, Finland. METHODS: A Staar Collamer posterior chamber phakic IOL was implanted in 38 eyes of 22 patients with a mean age of 39 years (range 24 to 54 years). The mean preoperative myopia was -15.10 diopters (D) (range -7.75 to -29.00 D). Surgical implantation was performed through a 3.0 mm clear corneal sutureless incision using paraocular anesthesia. The patients were followed clinically up to 3 years. The mean follow-up was 13.6 months (range 6 to 24 months) for refractive data and 22.3 months (range 6 to 35 months) for complications. The possible inflammatory response to the ICL was measured using a laser flare meter in 12 eyes. RESULTS: Postoperatively, all eyes had a significant increase in uncorrected visual acuity, allowing all but 3 patients (5 eyes) to manage most activities without spectacles. The mean spherical equivalent refraction at the last examination was -2.00 D +/- 2.48 (SD) (range +0.13 to -13.00 D), within +/-1.00 D of the targeted refraction in 31 eyes (81.6%) and within +/-0.50 D in 27 eyes (71.1%). In eyes in which the preoperative myopia was less than -18.00 D (n = 28), the achieved refraction was within +/-1.00 D of the intended refraction in 27 eyes (96.4%) and within +/-0.50 D in 24 eyes (85.7%). The refraction remained stable with a statistically insignificant change (P >.05) at each interval during the follow-up. The best corrected visual acuity (BCVA) improved by 1 or more lines in 23 of 32 eyes (71.9%) at 1 year. Two eyes (6.3%) lost 1 line of BCVA. Laser flare photometry showed normal aqueous flare values (11.71 +/- 6.61 photon counts/ms) in the 12 eyes measured at least 6 months after ICL implantation. Pupillary block glaucoma requiring surgical intervention occurred in 3 patients (7.9%). One patient (2.6%) developed cataract 1.5 years after ICL implantation; both ICLs were removed, and the refractive errors were corrected by lensectomy and implantation of low-power posterior chamber IOLs. One patient (2.6%) showed progression of dry macular degeneration at 17 months. CONCLUSION: At 1 year, ICL implantation had good visual and refractive results with excellent biocompatibility. Long-term follow-up is required to confirm that significant complications do not occur in most patients over time.

Adult↗

Short-term blood-aqueous barrier breakdown after implantation of the 1CU accommodative posterior chamber intraocular lens.

PURPOSE: To quantify intraocular inflammation after phacoemulsification with implantation of an accommodative posterior chamber intraocular lens (IOL). SETTING: Department of Ophthalmology, University of Erlangen-Nürnberg, Erlangen, Germany. METHODS: Twenty cataractous eyes of 20 patients without preexisting blood-aqueous barrier (BAB) deficiencies or previous intraocular surgery were included in this study. The mean age of the patients was 64.6 years +/- 16.0 (SD). A single surgeon performed phacoemulsification through a superior sclerocorneal tunnel incision and implantation of a 1CU IOL (HumanOptics AG) though a 3.2 mm incision. The haptics of the single-piece acrylic 1CU lens are designed for anterior optic movement following ciliary muscle contraction. The postoperative treatment was standardized. Postoperative BAB breakdown was quantified by laser flare photometry (FC-1000, Kowa) at 1 day, 1 and 4 weeks, and 3 and 6 months. RESULTS: The mean aqueous flare was 6.3 photons/ms +/- 3.0 (SD) (range 4.0 to 12.2 photons/ms) 1 day postoperatively, with 64% of patients having normal aqueous flare values (<8.0 photons/ms). One week after surgery, the mean aqueous flare was 5.3 +/- 2.8 photons/ms (range 2.0 to 10.5 photons/ms). Four weeks postoperatively, aqueous flare was normal in all patients and remained stable below the normal limit for up to 6 months (mean 3.3 +/- 1.2 months; range 2.0 to 5.4 months). The number of aqueous cells did not increase at any follow-up and was normal in all eyes. No postoperative complications such as fibrin formation, synechias, macrophages on the IOL optic, or endophthalmitis were observed. CONCLUSIONS: Phacoemulsification with implantation of the 1CU accommodative IOL led to minimal and short-lasting BAB alteration. No signs of persistent inflammation or pigment dispersion were detected.

Accommodation, Ocular↗

Subclinical inflammation after laser in situ keratomileusis.

PURPOSE: To determine whether laser in situ keratomileusis (LASIK) for the correction of myopia induces an anterior chamber inflammatory response measurable with laser flare-cell photometry. SETTING: Instituto Oftalmológico de Alicante, University of Alicante. Alicante, Spain. METHODS: Twenty eyes in 20 patients had LASIK to correct myopia ranging from 2.50 to 15.00 diopters (D) (mean -8.94 +/- 3.25 [SD]). Anterior chamber inflammation was measured preoperatively and 1, 3, 7, and 15 days and 1 and 3 months postoperatively using the flare mode of a laser flare-cell meter. All eyes received topical fluorometholone 0.1% drops for 2 weeks postoperatively. RESULTS: Anterior chamber flare values at 1 and 3 days and 1 week postoperatively were not significantly different from those found preoperatively. However, a significant decrease was found at 2 weeks and 1 month (P < .01 and P < .05, respectively). Flare values returned to their preoperative levels at 3 months. No significant correlations between postoperative flare values and depth of ablation were found. CONCLUSION: In this study. LASIK did not induce an inflammatory response in the anterior chamber in the myopic eye.

Adult↗

Effect of heparin in irrigating solution on inflammation following small incision cataract surgery.

PURPOSE: To study the effect of heparin-sodium added to the irrigating solution on postoperative inflammation in patients having cataract surgery. SETTING: Department of Ophthalmology, University of Giessen, Giessen, Germany. METHODS: Seventy-two patients having phacoemulsification with posterior chamber intraocular lens (IOL) implantation were randomly assigned to receive regular irrigating solution or solution with heparin-sodium (final diluted concentration 10 IU/mL). In half the patients, poly(methyl methacrylate) (PMMA) IOLs were implanted and in half, foldable silicone IOLs. The patients were examined preoperatively, on days 1 and 3, and 1 year postoperatively. Postoperative inflammation was objectively evaluated by measurement of flare and cells using laser flare-cell photometry. RESULTS: The mean postoperative flare values were significantly lower in the groups with additional heparin-sodium at days 1 and 3 (P < . 01). Flare values were not significantly different 1 year postoperatively. Cell values for the heparin-treated groups were lower, but the difference did not reach statistical significance. Flare and cells values for the two IOL materials were not significantly different during the entire follow-up. CONCLUSION: Heparin-sodium added to the infusion solution during small incision cataract surgery reduced inflammation in the early postoperative period.

Aged↗

Magnesium supplementation attenuates, but does not prevent, development of hypertension in spontaneously hypertensive rats.

This study evaluated the effects of magnesium supplementation on the development of hypertension in spontaneously hypertensive rats (SHR) and assesses the actions of magnesium on extracellular and intracellular Ca2+, Na+, and K+ status. Ten-week-old SHR (n = 72) and Wistar-Kyoto rats (WKY) (n = 60) were divided into four groups: WKY, Mg-WKY (WKY receiving 650 mg/L Mg(2+)supplementation), SHR, and Mg-SHR (SHR receiving Mg2+). Rats were studied for 17 weeks. Serum and erythrocyte Mg2+ and Ca2+ (measured by atomic absorption spectroscopy) and Na+ and K+ (measured by flame photometry) were determined every 3 or 4 weeks. From 13 weeks of age, blood pressure (BP) was significantly elevated in SHR compared with age-matched WKY. BP was reduced (P < .01) in SHR after 10 weeks of Mg2+ supplementation and at 27 weeks of age, BP in SHR was 218 (12 mm Hg v 184 +/- 9 mm Hg) in Mg-SHR. From 18 weeks of age, serum and intracellular Mg2+ levels were significantly lower (P < .05) and from 21 weeks of age, erythrocyte Ca2+ was significantly higher in SHR than in WKY. Mg2+ supplementation normalized intracellular Mg2+ and Ca2+ concentrations in SHR. BP was inversely correlated with erythrocyte Mg2+ (r = -0.74, P < .01) and positively correlated with erythrocyte Ca2+ (r = 0.78, P < .001). In conclusion, long-term Mg2+ supplementation significantly attenuates, but does not prevent, the development of hypertension in SHR. Furthermore, intracellular Mg2+ deficiency and Ca2+ overload in SHR are normalized by Mg2+ treatment.

Aging↗

Dominant role of mitochondria in clearance of large Ca2+ loads from rat adrenal chromaffin cells.

Cytosolic Ca2+ (Ca2+c) clearance from adrenal chromaffin cells was studied by whole-cell patch clamp and indo-1 Ca2+ photometry after influx of Ca2+ through voltage-dependent Ca2+ channels. We isolated the rates of Ca2+c clearance by several mechanisms using combinations of the following agents (with their expected targets): Li+ or TEA substituted for Na+ (Na(+)-Ca2+ exchange), 1 mM La3+ applied after the depolarization (Na(+)-Ca2+ exchange and plasma membrane Ca(2+)-ATPase), 1 microM thapsigargin (pumping into reticular stores), and 2 microM carbonyl cyanide m-chlorophenylhydrazone (uptake into mitochondria). Remarkably, whenever [Ca2+]c rose above approximately 500 nM, Ca2+c clearance by mitochondria exceeded clearance by either Na(+)-Ca2+ exchange or the Ca2+ pumps of the plasma and reticular membranes. As [Ca2+]c fell again, Ca2+ reemerged from mitochondria, prolonging the final return to basal levels.

Adrenal Medulla↗

Mechanistic appraisal of the effects of some protease inhibitors on ciliary beat frequency in a sequential cell culture system of human nasal epithelium.

The aim of this study was to investigate the suitability of a sequential monolayer-suspension culture system as a model to screen subacute effects of drug excipients on ciliary beat frequency (CBF). The CBF of the cultured cells was measured by computerized microscope photometry. Protease inhibitors (puromycin, bestatin, bacitracin, actinonin and thiomersal) were used as model compounds and the mechanisms of ciliary inhibition were investigated by probing the involvement of arachidonic acid metabolism, guanylate cyclase (cGMP), protein kinase C (PKC) and adenosinetriphosphate (ATP) inhibition. Bestatin concentration-dependently reduced CBF by inhibiting arachidonic acid metabolism, cGMP, PKC and endogenous ATP consumption. Thiomersal and DMSO used for dissolving actinonin reduced CBF (P<0.05) via a non-specific mechanism. Bacitracin (8 mM) and puromycin (135 mM) had no effect on CBF after acute exposure (15-30 min) (P>0.05), but significantly reduced the CBF by approximately 15.0% following daily 15-min exposure for 1 week. This study shows that (i) sequential monolayer-suspension culture system is a valid model to screen both acute and subacute effects of drug excipients on CBF; and (ii) bacitracin, puromycin and actinonin are more cilio-compatible than bestatin and thiomersal and as such are more potentially useful nasal absorption enhancer from ciliotoxicity perspective.

Cell Culture Techniques↗

Measurement of protein using an electrochemical bi-enzyme sensor.

A screen-printed three-electrode amperometric biosensor for the rapid and quantitative measurement of single protein solutions is described. A membrane immobilised protease preparation of broad specificity was used to digest sample protein liberating free amino acids that were subsequently oxidised at a working electrode by immobilised L-amino acid oxidase (L-AAO). The enzymatically generated hydrogen peroxide was determined amperometrically. The fully optimised device required 30 mU L-AAO and 3.94 U protease and had a limit of detection of 170 microg ml(-1) and linearity of response up to 1 mg ml(-1) for Casilan 90 protein. The analytical performance of the device was comparable to that of a commercially available standard photometric protein test kit and required only a 10 microl volume of sample and a single dilution step. Unlike with photometry, the sensor is able to determine the protein content of turbid samples and hence should find widespread applications. The device was simple to use, low-cost and could be mass-produced, yielding results within 4 min of sample addition with acceptable assay repeatability.

Amino Acid Oxidoreductases↗

Selective distribution of porphyrins in skin thick basal cell carcinoma after topical application of methyl 5-aminolevulinate.

Topical photodynamic therapy (PDT) of superficial basal cell carcinoma (BCC) with 5-aminolevulinic acid (ALA) has achieved promising clinical results. However, the efficacy of this therapy for thick BCC is dramatically decreased by a limited diffusion of hydrophilic ALA into the tumor. Lipophilic esters of ALA may enhance their penetration into the lesion. In this randomized, open clinical study, microscopic fluorescence photometry incorporating a light-sensitive thermo-electrically cooled charge-coupled device (CCD) camera was employed to investigate the penetration of methyl 5-aminolevulinate-induced porphyrin fluorescence in thick BCC lesions. Both the distribution pattern and the amount of porphyrins in 32 lesions of 16 patients were studied after topical application of 16, 80 or 160 mg/g of methyl 5-aminolevulinate for 3 or 18 h. A highly selective and homogeneous distribution of methyl 5-aminolevulinate-induced porphyrin fluorescence was seen in all lesions studied, with much less fluorescence in the adjacent normal skin tissues. In lesions of up to 2 mm thickness the application of 160 mg/g methyl 5-aminolevulinate for 3 h showed the highest ratio of porphyrin fluorescence depth to tumor depth (0.98+/-0.04), thus providing a biologic rationale for a clinical PDT trial with this regimen.

Administration, Topical↗

Photodynamic therapy using 5-aminolaevulinic acid for oesophageal adenocarcinoma associated with Barrett's metaplasia.

Photodynamic therapy (PDT) is a novel technique for local endoscopic treatment of gastrointestinal neoplasia. Current photosensitisers for PDT may cause prolonged skin phototoxicity. 5-Aminolaevulinic acid (ALA), a precursor of the photosensitiser protoporphyrin IX (PpIX), is more acceptable because of its short half-life and preferential accumulation in mucosa and mucosal tumour. We have treated 12 patients, median age 73 years (range 55-88) with oesophageal adenocarcinoma arising from Barrett's metaplasia (two carcinomas-in-situ, grade 0; 10 carcinomas, grade 1-11A based on endoluminal ultrasound in two and CT scanning in 10 patients). ALA (60 and 75 mg/kg body weight) was given orally in two or five equally divided doses. The PpIX distribution in stomach, normal oesophagus, Barrett's mucosa and carcinoma was measured by quantitative fluorescence photometry. PDT was performed using laser light (630 nm) delivered via a cylindrical diffuser 4-6 h after the first dose of ALA. The patients received one to four sessions of PDT. PpIX accumulation in the mucosa was two to three times that in the lamina propria. The differential distribution between carcinomatous and normal oesophageal mucosa was less marked (carcinoma:normal mucosa ratio = 1.4). Higher doses of ALA increased PpIX accumulation in all tissues but did not increase the differential PpIX distribution between tumour and normal oesophageal mucosa. After PDT using ALA (ALA/PDT), all mucosa showed superficial white necrotic changes and the histology confirmed fibrinoid necrosis. One patient with carcinoma-in-situ had the tumour eradicated after one treatment with no recurrence at 28 months. Another patient with a small T1 tumour required four ALA/PDT treatments, and died of other disease after 36 months. There was no evidence of recurrence. The tumour bulk in the other carcinomas was not significantly reduced. ALA/PDT has a potential for the eradication of small tumours but careful patient selection with endoluminal ultrasound is needed when using ALA/PDT to treat oesophageal cancer.

Adenocarcinoma↗

Primate retina: cell types, circuits and color opponency.

The link between morphology and physiology for some of the cell types of the macaque monkey retina is reviewed with emphasis on understanding the neural mechanism for spectral opponency in the light response of ganglion cells. An in vitro preparation of the retina is used in which morphologically identified cell types are selectively targeted for intracellular recording and staining under microscopic control. The goal is to trace the physiological signals from the long (L), middle (M) and short-wavelength sensitive (S) cones to identified cell types that participate in opponent and non-opponent signal pathways. Heterochromatic modulation photometry and silent substitution are used to characterize L-, M- or S-cone inputs to the receptive fields of distinct horizontal cell, bipolar cell, ganglion cell and amacrine cell types. The majority of the retinal cell types await detailed analysis, and knowledge of the mechanisms of opponency remains incomplete. However results thus far have established: (1) Horizontal cell interneurons make preferential connections with the three cone types, but cannot provide a basis for spectral opponency in the circuitry of the outer retina. (2) A morphologically distinctive bistratified ganglion cell type transmits a blue-ON yellow-OFF spectral opponent signal to the parvocellular division of lateral geniculate nucleus. The morphology of this ganglion cell type suggests a simple synaptic mechanism for blue yellow opponency via converging input from an S-cone connecting ON-bipolar cell and an L - M cone connecting OFF-bipolar cell. (3) Midget ganglion cells, whose axons project to the parvocellular layers of the lateral geniculate nucleus and are assumed to be the origin of red/green opponent signals, show a non-opponent, achromatic physiology when recorded in the retinal periphery the underlying circuitry for red green opponency thus remains controversial, and (4) recent recordings from identified bipolar and amacrine cells in macaque suggest that a more complete accounting of opponent circuitry is a realistic goal.

Animals↗

The evidential value of black cotton fibres.

Forensic scientists are faced with the problem of estimating the frequency of cotton fibres recovered in casework, in relation to those in the general population. One way of doing this is to consider the degree of spectral variation that occurs within a "block of colour". When a spectral pattern occurs very frequently, the evidential value of the fibres may be so low, that it is not worth considering them as target fibres. Using UV-visible range microspectro-photometry (MSP) spectra were recorded from 88 known black cotton dyes and 225 samples of black cotton taken from various textiles. UV-visible spectra originating from sulphur dyes and from the great majority of reactive and direct dyes can be easily recognised. Vat dyes present a little more difficulty. The degree of spectral variation and consequent discriminating power of MSP varied according to the dye class, from 0.13 for sulphur dyes to 0.93 for reactive dyes. From 99 textiles dyed with reactive dyes, the spectra could be divided into at least 40 varieties showing that these fibres have a high degree of individuality. Within the few direct dyes (11.5%) that were encountered, one basic spectral form predominated, but a number of minor variations were observed. Spectral information below 400 nm (UV-range) is important for making distinctions and is critical in the case of direct dyes.

Clothing↗

A target fibre study on seats in public houses.

A target fibre survey was conducted to assess the random occurrence of a blue wool fibre on seats in public houses throughout the United Kingdom. Fibre tape lifts were taken from 80 seats. Four seats yielded matching fibres and five of these were found on one seat. A total of 292 fibres were identified; nine fibres proved indistinguishable from the target after comparison microscopy, microspectro-photometry and attempts at thin layer chromatography, and two of these fibres were still apparently indistinguishable after TLC analysis although only one dye component was visible.

Alcohol Drinking↗

Light intensity distribution in the externally illuminated cylindrical photo-bioreactor and its application to hydrogen production by Rhodobacter capsulatus.

The light distribution in the externally illuminated cylindrical photo-bioreactor for production of hydrogen by a photosynthetic bacterium Rhodobacter capsulatus ST-410 was estimated. The estimation was performed on the basis of the Matsuura and Smith's diffuse model [1]. In the diffuse model, the incident light rays are assumed to proceed in every direction and the local intensity is calculated as the sum of the intensities of light. Since Lambert-Beer's law, extensively used in photometry, was not useful for explaining the decrease in the intensity of light by the biomass, an empirical expression was used. The measurement of the intensities from every direction was conducted in an externally illuminated cylindrical photo-bioreactor having an inner diameter of 60mm and a working volume of 550ml. The obtained results confirmed our estimation. The light distribution was applied to estimate the hydrogen production by R. capsulatus ST-410 using the same photo-bioreactor. The overall hydrogen-production rate was successfully estimated.

Journal Article↗