Continuous full-time occlusion of the sound eye vs full-time occlusion of the sound eye periodically alternating with occlusion of the amblyopic eye in treatment of amblyopia: a prospective randomized study.

PURPOSE: To compare continuous full-time (24 hours per day) occlusion of the sound eye with full-time occlusion (24 hours per day) of the sound eye 1 day more than the years of age periodically alternating with occlusion of the amblyopic eye for 1 day, as treatments for profound strabismic amblyopia in children older than 5 years. METHODS: A total of 53 patients with visual acuity (VA) of 0.4 and less in the amblyopic eye (tested by crowded Landolt Cs) after previously being provided optimal optical correction were randomly assigned to receive either of the two patching regimens. VA and pattern reversal visual evoked potentials (PVEP) were recorded prospectively at 1-month intervals. Improvement in VA and the reduction in crowding difficulties (CD) were the main outcome measures of the treatment efficiency. RESULTS: Both treatment modalities were equally effective. Of the 51 subjects who completed the study, 21 (41.2%) were cured whereas 32 (62.7%) attained satisfactory improvement. Recovery of VA was related to age, with cure being obtained in 23.5% (4/17) and satisfactory improvement in 52.9% (9/17) of patients older than 9 years. Larger gain in VA influenced the stability of the vision over time. CONCLUSIONS: It can be concluded that in clinically monitored parameters both treatment modalities were equally effective without any statistical or clinical significance in the observed groups of patients. However, events like the ""trade-off"" effect, occurrence of occlusion amblyopia, or prolongation of PVEP latency of the sound eye indicate that full-time continuous occlusion possibly presents a more effective form of treatment.

Graves' orbitopathy as a rare disease in Europe: a European Group on Graves' Orbitopathy (EUGOGO) position statement.

BACKGROUND: Graves' orbitopathy (GO) is an autoimmune condition, which is associated with poor clinical outcomes including impaired quality of life and socio-economic status. Current evidence suggests that the incidence of GO in Europe may be declining, however data on the prevalence of this disease are sparse. Several clinical variants of GO exist, including euthyroid GO, recently listed as a rare disease in Europe (ORPHA466682). The objective was to estimate the prevalence of GO and its clinical variants in Europe, based on available literature, and to consider whether they may potentially qualify as rare. Recent published data on the incidence of GO and Graves' hyperthyroidism in Europe were used to estimate the prevalence of GO. The position statement was developed by a series of reviews of drafts and electronic discussions by members of the European Group on Graves' Orbitopathy. The prevalence of GO in Europe is about 10/10,000 persons. The prevalence of other clinical variants is also low: hypothyroid GO 0.02-1.10/10,000; GO associated with dermopathy 0.15/10,000; GO associated with acropachy 0.03/10,000; asymmetrical GO 1.00-5.00/10,000; unilateral GO 0.50-1.50/10,000. CONCLUSION: GO has a prevalence that is clearly above the threshold for rarity in Europe. However, each of its clinical variants have a low prevalence and could potentially qualify for being considered as a rare condition, providing that future research establishes that they have a distinct pathophysiology. EUGOGO considers this area of academic activity a priority.

Theoretical study of nitrodibenzofurans: A possible relationship between molecular properties and mutagenic activity.

In this study we present a theoretical investigation of the molecular properties of nitrodibenzofurans (NDFs) and dinitrodibenzofurans (DNDFs) and their relation to mutagenic activity. Equilibrium geometries, relative energies, vertical ionization potentials (IP), vertical electron activities (EA), electronic dipole polarizabilities, and dipole moments of all NDFs and three DNDFs calculated by Density Functional Theory (DFT) methods are reported. The Ziegler/Rauk Energy Decomposition Analysis (EDA) is employed for a direct estimate of the variations of the orbital interaction and steric repulsion terms corresponding to the nitro group and the oxygen of the central ring of NDFs. The results indicate differences among NDF isomers for the cleavage of the related bonds and steric effects in the active site. The results show a good linear relationship between polarizability (<α>), anisotropy of polarizability (Δα), the summation of IR intensities (ΣIIR) and the summation of Raman activities (ΣARaman) over all 3N-6 vibrational modes and experimental mutagenic activities of NDF isomers in Salmonella typhimurium TA98 strain. The polarizability changes with respect to the νsNO+CN vibrational mode are in correlation with the mutagenic activities of NDFs and suggest that intermolecular interactions are favoured along this coordinate.

Characterization of the Variation Potential in Sunflower.

A major candidate for intercellular signaling in higher plants is the stimulus-induced systemic change in membrane potential known as variation potential (VP). We investigated the mechanism of occurrence and long-distance propagation of VP in sunflower (Helianthus annuus L.) plants. Here we present evidence of the relationship among injury-induced changes in xylem tension, turgor pressure, and electrical potential. Although locally applied wounding did trigger a change in membrane potential, it evoked even faster changes in tissue deformation, apparently resulting from pressure surges rapidly transmitted through the xylem and experienced throughout the plant. Externally applied pressure mimicked flame wounding by triggering an electrical response resembling VP. Our findings suggest that VP in sunflower is not a propagating change in electrical potential and not the consequence of chemicals transmitted via the xylem, affecting ligand-modulated ion channels. Instead, VP appears to result from the surge in pressure in the xylem causing a change in activity of mechanosensitive, stretch-responsive ion channels or pumps in adjacent, living cells. The ensuing ion flux evokes local plasma membrane depolarization, which is monitored extracellularly as VP.

Both action potentials and variation potentials induce proteinase inhibitor gene expression in tomato.

Tomato plants (Lycopersicon esculentum) accumulate proteinase inhibitor 2 (pin2) mRNA in response to insect attack, crushing and flaming in leaves distant from those treated. Most earlier work suggests that the systemic wound signals are chemical; here we try to determine whether electrical or physical (hydraulic) signals can also evoke pin expression. We used a mild flame to evoke a systemic hydraulic signal and its local electrical aftermath, the variation potential (VP), and we used an electric stimulus to evoke a systemic electrical signal, the action potential (AP). We determined the kinetic parameters of both the VP and AP. Flame-wounded plants essentially always exhibited major electrical responses throughout the plant and a several-fold increase in pin2 mRNA within 1 h. Electrically stimulated plants that generated and transmitted a signal (AP) into the analyzed leaf exhibited similarly large, rapid increases in pin2 mRNA levels. Plants which generated no signal, or signals of just a few microvolts, had unchanged levels of pin2 mRNA. Since the AP and VP both arrived in the receiving leaf before accumulation of pin2 mRNA began, we conclude that, in addition to the previously shown chemical signals, both hydraulically induced VPs and electrically induced APs are capable of evoking pin2 gene expression.

Use of pralidoxime-Pd(II) complex for the spectrophotometric determination of the cholinesterase reactivator (PAM-2Cl) in the urine.

A simple and rapid method for the spectrophotometric determination of pralidoxime chloride in urine, based on complex formation with palladium(II) without preliminary mineralization of the sample, is described. The proposed method is shown to be reproducible and in good agreement with a reference method, which involved spectrophotometric determination of corresponding oximate ions in ammonium hydroxide solution at 336 nm. Our results indicate that the proposed method is reliable, rapid and of sufficient sensitivity for pralidoxime chloride analysis in urine.

Low serum alpha-1-antitrypsin specific activity in monoclonal gammopathies.

BACKGROUND: Serum alpha 1-antitrypsin (alpha 1AT) antigen concentration is elevated in malignancies as the result of acute phase reaction. In the present study, we examined whether the alpha 1AT elevation in monoclonal gammopathies was accompanied by an adequate increase of its functional activity. METHODS: In this case-control study, serum alpha 1AT concentration was measured in 187 ambulatory patients with monoclonal gammopathies and 320 healthy blood donors matched according to sex and age. The alpha 1AT antigen concentration was assayed by immunonephelometry, whereas its functional activity was measured as trypsin inhibitory capacity (TIC). The specific alpha 1AT inhibitory activity (SIA) was calculated, defined as the TIC/antigen concentration ratio. RESULTS: The alpha 1AT antigen concentrations obtained in the patients' samples were very significantly higher as compared with the corresponding values in the control group (mean +/- SD = 134 +/- 41.9% of normal, p < 0.001). However, the TIC values were higher in the patients than in the healthy controls only by 4% (104 +/- 23.8%, p < 0.05). The specific alpha 1AT activity was very significantly lower in the patients, as compared with the controls (p < 0.001), indicating that serum alpha 1AT in monoclonal gammopathies was partially inactive. CONCLUSIONS: As poor correlation between the TIC values and the antigen concentrations was obtained in the patient group as well as the decreased specific alpha 1AT activities, the TIC values in patients with monoclonal gammopathies should be interpreted with caution.

Determination of 1,3-bis(4-hydroxyiminomethylpyridinium)-propane dichloride (TMB-4) with Pd(II).

The colour reaction of TMB-4 and palladium(II) chloride has been investigated. The optimum reaction conditions, spectral characteristics, stability constant and composition of the yellow water-soluble complex have been established. A new spectrophotometric method is proposed for microdetermination of TMB-4.

Potentiometric investigation of the stability of palladium(II) complex of pralidoxime chloride in aqueous solution.

The formation of a complex between palladium(II) chloride and pralidoxime chloride (PAM-2Cl) has been studied by means of potentiometric pH measurements. The real stability constant of the complex in aqeous medium of ionic strength 0.3 M (KCl) at 25.0 degrees C was log Ks = 7.29. This value was close to that (log Ks = 7.02) obtained previously by spectrophotometric methods after appropriate correction with respect to the corresponding value of the acidic constant of PAM-2Cl (pKca = 8.05), which was also determined under the same experimental conditions.

Spectrophotometric investigation of complex formation of an oxime PAM-4Cl with palladium (II) and its analytical application.

The colour reaction of 4-hydroxyiminomethyl-1-methylpyridinium chloride (PAM-4Cl) and palladium(II) chloride has been investigated. The optimum reaction conditions, spectral characteristics, conditional stability constant and composition of the yellow water-soluble complex have been established. A new spectrophotometric method is proposed for the microdetermination of PAM-4Cl.

Spectrophotometric determination of obidoxime chloride as its Pd(II) complex in water and injections.

It has been established that obidoxime chloride reacts with palladium(II) chloride in the pH range 3.9-8.0 and forms a yellow water-soluble (1:1) complex with maximum absorbance at 355 nm. By applying the methods of Sommer, Nash and Job involving non-equimolar solutions the conditional stability constant of the complex, at the optimum pH of 6.3 and an ionic strength mu = 0.55 M, is found to be 10(5.3). The molar absorptivity at 355 nm is 3.16 x 10(4) l mol(-1) cm(-1) at pH 6.3. Beer's law is obeyed up to 20 mumol l(-1) obidoxime chloride concentration. The detection limit of the method is 0.36 mug ml(-1). The relative standard deviation (n = 10) varies over the range 1.10-2.66%. The proposed method was found to be suitable for the accurate and sensitive analysis of obidoxime chloride in water and injection solutions.

Use of palladium(II) chloride as colour-forming reagent in determination of pralidoxime chloride in water and tablets.

Pralidoxime chloride (PAM-2Cl) has been determined spectrophotometrically in Britton-Robinson buffer solution at pH = 6.45; the method is based on measurement of the absorbance of the Pd(II)-pralidoxime complex at 327 nm. Studies of the composition of the complex by Job's continuous variation method, the molar ratio method and Bent-French's method yielded a Pd(II):pralidoxime ratio of 1:1. The conditional stability constant (K') of the complex at the optimum pH of 6.45 and an ionic strength (mu) of 0.3 M was found to be 10(5.2). The molar absorptivity was 1.05 x 10(4) 1 mol(-1) cm(-1). Beer's law was obeyed at concentrations up to 60 microM. The detection limit was 0.55 microg ml(-1). The relative standard deviation (N = 10) was 0.28-1.03%. The method was accurate and sensitive for the analysis of PAM-2Cl in water and tablets.

Selection of suture material for scleral lacerations.

With a view to selecting the most suitable suture material for scleral wound management we made histological and tensiometric scar examinations after 7, 21 and 45 days on rabbits' eyes. Suture materials were also observed under the scanning electron microscope at the same intervals. Three suture materials (virgin silk 8.0, polyglycolic acid 7.0 and Nylon 8.0) were tested. Polyglycolic acid proved the most suitable suture material for this purpose.

Morphometric and biochemical characteristics of short-term effects of ethanol on rat cardiac muscle.

Alcoholism is a very important cause of congestive cardiomyopathy in man. The aim of this study was to examine a short-term effect of ethanol in rat cardiac muscle, using histologic, morphometric and biochemical methods. Experiments were carried out in Wistar male albino rats, divided into two groups: the control group consisting of eight animals receiving tap water, and the experimental group comprising eight animals received ethyl alcohol for ten days, in a single daily dose of 3 g ethanol/kg body weight, per os, using esophageal intubation. The mean volume weighted nuclear volume of cardiac myocytes was estimated by point sampled intercept method, by objective x 100. The mean cubed nuclear intercept length was multiplied by pi and divided by 3. For biochemical analysis, a 10% water tissue homogenate from the left ventricle was made. In the experimental group, the mean volume-weighted nuclear volume (15.08 +/- 5.20 microm3) was significantly lower than in the control group (51.32 +/- 7.83 microm3) (p < 0.001). The treatment of experimental animals with ethanol caused significant increase of aldolase (p < 0.0001) and aspartate transaminase (p < 0.05) activity in the rat cardiac tissue; at the same time, the enzyme activity of creatine phosphokinase, alanine transaminase and alkaline phosphatase were not changed in the experimental group compared to the control values. The amount of the glucose in the cardiac muscle was greater in the experimental group compared to the control animals. Our results suggest that there is depression of cardiomyocyte nuclei in experimental animals treated with ethanol. Alcohol intake results in the loss of Krebs cycle enzymes and as a consequence there is greater utilization of fatty acids for energy production.

Autonomic straightening of gravitropically curved cress roots in microgravity.

The typical response of plant organs to gravistimulation is differential growth that leads to organ bending. If the gravitropic stimulus is withdrawn, endogenous compensation of the graviresponse and subsequent straightening occur in some plants. For instance, autonomic straightening of Lepidium roots occurs when gravitropically-curved rootsare rotated on a clinostat (Stankovi et al., 1998a). To determine whether endogenous compensation of the graviresponse also occurs in space, microgravity-grown cress roots were laterally centrifuged in-flight and then returned to microgravity using Biorack hardware on a shuttle mission (STS-81). The cress roots were centrifuged at 4 different g-doses (0.1 x g and 1 x g for 15 or 75 min). All four treatments yielded varying degrees of root curvature. Upon removal from the centrifuge, roots in all four treatments underwent subsequent straightening in microgravity. This straightening resulted from a loss of gravitropic curvature in older regions of the root and the coordinated alignment of new growth. These results show that both microgravity and clinostat rotation on Earth are equivalent in stimulus withdrawal with respect to the induction of endogenous compensation of the curvature. Cress roots are the only plant organ shown to undergo compensation of the curvature in both microgravity and on a clinostat. The compensation of graviresponse in space rules out the hypothesis that the endogenous root straightening ("autotropism") represents a commitment to a pre-stimulus orientation with respect to gravity and instead suggests that there is a default tendency towards axiality following a withdrawal of a g-stimulus.

Seed-to-seed growth of Arabidopsis thaliana on the International Space Station.

The assembly of the International Space Station (ISS) as a permanent experimental outpost has provided the opportunity for quality plant research in space. To take advantage of this orbital laboratory, engineers and scientists at the Wisconsin Center for Space Automation and Robotics (WCSAR), University of Wisconsin-Madison, developed a plant growth facility capable of supporting plant growth in the microgravity environment. Utilizing this Advanced Astroculture (ADVASC) plant growth facility, an experiment was conducted with the objective to grow Arabidopsis thaliana plants from seed-to-seed on the ISS. Dry Arabidopsis seeds were anchored in the root tray of the ADVASC growth chamber. These seeds were successfully germinated from May 10 until the end of June 2001. Arabidopsis plants grew and completed a full life cycle in microgravity. This experiment demonstrated that ADVASC is capable of providing environment conditions suitable for plant growth and development in microgravity. The normal progression through the life cycle, as well as the postflight morphometric analyses, demonstrate that Arabidopsis thaliana does not require the presence of gravity for growth and development.

Rapid systemic up-regulation of genes after heat-wounding and electrical stimulation.

When one leaf of a tomato plant is electrically-stimulated or heat-wounded, proteinase inhibitor genes are rapidly up-regulated in distant leaves. The identity of the systemic wound signal(s) is not yet known, but major candidates include hormones transmitted via the phloem or the xylem, the electrically-stimulated self-propagating electrical signal in the phloem (the action potential, AP), or the heat-wound-induced surge in hydraulic pressure in the xylem evoking a local change in membrane potential in adjacent living cells (the variation potential, VP). In order to discriminate between these signals we have adopted two approaches. The first approach involves applying stimuli that evoke known signals and determining whether these signals have similar effects on the "model" transcripts for proteinase inhibitors (pin) and calmodulin (cal). Here we show that a heat wound almost invariably evokes a VP, while an electrical stimulation occasionally evokes an AP, and both of these signals induce accumulation of transcripts encoding proteinase inhibitors. The second approach involves identifying the array of genes turned on by heat-wounding. To this end, we have constructed a subtractive library for heat-wounded tissue, isolated over 800 putatively up-regulated clones, and shown that all but two of the fifty that we have analyzed by Northern hybridization are, indeed, up-regulated. Here we show the early kinetics of up-regulation of three of these transcripts in the terminal (4th) leaf in response to heat-wounding the 3rd leaf, about 5 cm away. Even though these transcripts show somewhat different time courses of induction, with one peaking at 30 min, another at 15 min, and another at 5 min after flaming of a distant leaf, they all exhibit a similar pattern, i.e., a transient period of transcript accumulation preceding a period of transcript decrease, followed by a second period of transcript accumulation.