Degradation and plant uptake of nonylphenol (NP) and nonylphenol-12-ethoxylate (NP12EO) in four contrasting agricultural soils.

Nonylphenol polyethoxylates (NPEOs) are surfactants found ubiquitously in the environment due to widespread industrial and domestic use. Biodegradation of NPEOs produces nonylphenol (NP), an endocrine disruptor. Sewage sludge application introduces NPEOs and NP into soils, potentially leading to accumulation in soils and crops. We examined degradation of NP and nonylphenol-12-ethoxylate (NP12EO) in four soils. NP12EO degraded rapidly (initial half time 0.3-5 days). Concentrations became undetectable within 70-90 days, with a small increase in NP concentrations after 30 days. NP initially degraded quickly (mean half time 11.5 days), but in three soils a recalcitrant fraction of 26-35% remained: the non-degrading fraction may consist of branched isomers, resistant to biodegradation. Uptake of NP by bean plants was also examined. Mean bioconcentration factors for shoots and seeds were 0.71 and 0.58, respectively. Removal of NP from the soil by plant uptake was negligible (0.01-0.02% of initial NP). Root concentrations were substantially higher than shoot and seed concentrations.

Subnormal visual acuity (SVAS) and albinism in Mexican 12-13-year-old children.

BACKGROUND: In a previous study the vision of 1046 12-13-year-olds in Sweden was examined. Of those 67 had some kind of visual disturbances and in 20 no obvious cause was found. In this group, defined as children with subnormal visual acuity syndromes (SVAS), albinism was shown to be a major cause to the visual dysfunction giving a prevalence of about 1%. This is about 100 times higher than previous figures. Albinism can therefore be the cause in many cases of unexplained low visual acuity, at least in Sweden. Subnormal visual acuity is usually found in 2-4% in a pediatric population and is often called 'amblyopia'. The Swedish study showed that in many cases 'amblyopia' should be replaced by 'SVAS' and further investigation. The present Mexican study was designed identically to the Swedish study. The objective was to describe the distribution of visual acuity and the prevalence of ocular disorders, including incidence of subnormal visual acuity (SVAS) and the occurrence of albinism in a Mexican population of 12-13-year-olds. SUBJECTS AND METHODS: Altogether 1035 children, 12-13 years of age, were examined. A total number of 344 children were referred to the university pediatric eye clinic for further examination. 272 of these had simple refractive errors, 59 were diagnosed with an ophthalmological disorder and 13 children could not be pathologically classified. These were referred to a second ophthalmological examination, including VEP (Visual Evoked Potential) recordings. VEP reveals an asymmetric (right vs. left) cortical response after monocular stimulation in albinism. RESULTS: No child showed iris translucency or any other typical albinoic sign. VEP was recorded from 11 children. Three children showed an asymmetric VEP and were classified as albinos. The VEP response was normal in 8 of the children. CONCLUSIONS: The results indicate that albinism is common in Mexico, although not as common as in a similar Swedish population. A prevalence of albinism of approximately 0.3% was found in the Mexican population, compared to approximately 1% in the Swedish study group. The number of albinos was much higher in both study groups than to be expected from previous estimates. The difference between the Swedish and the Mexican figures may be explained by the general difference in pigmentation between Sweden and Mexico and thus probably by the subsequent lower number of commonly occurring albino foci in the Mexican heritage. It is emphasised that in investigations of children with SVAS, also in countries with a generally high pigmentation level, electro-physiological examinations are important, to be able to reveal albinism, but also to exclude or verify other conditions in the SVAS group, for example neurometabolic conditions.

The effects of accommodative facility training on a group of children with impaired relative accommodation--a comparison between dioptric treatment and sham treatment.

The effects of accommodative facility training were evaluated by comparing training with plano lenses and +/-2.00 D lens flipper sets. Thirteen children with symptoms and signs of accommodative dysfunction were included in the study. Seven started with 2 weeks of plano lens training before proceeding to traditional dioptric flipper training; later, one patient from this group was lost to follow-up. The remaining six children used powered flipper training from the start. The positive (PRA) and negative relative accommodation (NRA) were examined every second week. During the initial training period both the PRA and the NRA decreased in the sham treatment group (P = 0.010 and P= 0.102, respectively), while the PRA and the NRA increased during the dioptric training in both groups (P = 0.102 and P = 0.033, respectively). The result of this study indicates that accommodative facility training has a real effect on the amplitude of relative accommodation in patients with impaired relative accommodation.

Acquisition of external major histocompatibility complex class I molecules by natural killer cells expressing inhibitory Ly49 receptors.

Murine natural killer (NK) cells express inhibitory Ly49 receptors specific for major histocompatibility complex (MHC) class I molecules. We report that during interactions with cells in the environment, NK cells acquired MHC class I ligands from surrounding cells in a Ly49-specific fashion and displayed them at the cell surface. Ligand acquisition sometimes reached 20% of the MHC class I expression on surrounding cells, involved transfer of the entire MHC class I protein to the NK cell, and was independent of whether or not the NK cell expressed the MHC class I ligand itself. We also present indirect evidence for spontaneous MHC class I acquisition in vivo, as well as describe an in vitro coculture system with transfected cells in which the same phenomenon occurred. Functional studies in the latter model showed that uptake of H-2D(d) by Ly49A+ NK cells was accompanied by a partial inactivation of cytotoxic activity in the NK cell, as tested against H-2D(d)-negative target cells. In addition, ligand acquisition did not abrogate the ability of Ly49A+ NK cells to receive inhibitory signals from external H-2D(d) molecules. This study is the first to describe ligand acquisition by NK cells, which parallels recently described phenomena in T and B cells.

Screening merits of the Lang II, Frisby, Randot, Titmus, and TNO stereo tests.

PURPOSE: Previous works show a pronounced disagreement on the reliability of stereo tests as screening tools for amblyopia and strabismus. This study's aim was to compare the ability of the Lang II, Frisby, Randot, Titmus, and TNO stereo tests to detect amblyopia and strabismus with visual acuity testing and cover testing. METHODS: A total of 1035 school children aged 12 to 13 years were examined in a field study in Monterrey, Mexico. In addition to the 5 stereo tests, the examination included visual acuity, cover testing, refraction (skiascopy), and inspection of the red reflex and posterior pole. RESULTS: Sensitivity ranged from 17% to 47% (Frisby-Titmus-Lang II-Randot-TNO, in order of occurrence). Of the 60 subjects with strabismus and/or amblyopia, only 8 subjects were identified by all 5 stereo tests. A considerable number of subjects (25), the majority of whom were amblyopic (23 subjects), were not identified by any of the tests. All stereo tests showed higher sensitivities for strabismus than for amblyopia. CONCLUSION: None of the 5 stereo tests studied is suitable for screening for amblyopia or strabismus. The results of both ocularly normal subjects and subjects with strabismus and/or amblyopia are variable, and there is no way of separating normal response from abnormal response.

Subnormal visual acuity syndromes (SVAS): albinism in Swedish 12-13-year-old children.

BACKGROUND: The vision of 12-13-year-olds in Sweden was examined in a field study. The study was designed as being a part of a large European-Latin American study, the DESAMI project. The objective was to evaluate the prevalence of residual amblyopia and ocular disorders, atiologies of subnormal vision and some normal visual parameters in this group of children. The children had to be born in Sweden in 1985 in order to have the opportunity to be included in the voluntary screening visual examinations. The full results of the study will be presented elsewhere. This paper presents clinical and VEP data of those children who had visual acuity of 0.8 or below in one or both eyes which could not be increased with glasses, or other visual/eye disturbances not explained as common amblyopia, i.e., subnormal visual acuity or pathological visual states of unknown cause, SVAS (subnormal visual acuity syndromes). SUBJECTS AND METHODS: In all, 1046 children were examined: 76 had visual disturbances of such severity that they were referred to a paediatric ophthalmologist (AS). Eighteen children could not be pathologically classified, and they were referred to another ophthalmological examination and VEP (visual evoked potential) recordings. VEP reveals an asymmetric response after monocular stimulation in albinism. RESULTS: Twelve children turned up for a second examination and VEP was recorded from 10 children. Nine children showed iris translucency. Seven children showed an asymmetric VEP and were classified as albinos. The albinoic VEPs could be subdivided into two types, (1) including all parts of the response and (2) partly excluding the P1/P100 potential complex. The VEP response was normal, showing symmetry and no other abnormality, in three of the children. CONCLUSIONS: The results indicate that albinism is common in Sweden. A prevalence value of approximately 1% is about 100 times higher than previous figures. This high prevalence may indicate another form of heredity, with genetical contribution to albinism from a varying number of albino genes and varying expression in the phenotypes, in the Scandinavian population. It is emphasised that in investigations of children with SVAS, electrophysiological examinations are important, not only to reveal albinism but also to exclude or verify neurometabolic conditions, for example.

Effects of dextranation on the uptake of peptides in micrometastases: studies on binding of EGF in tumor spheroids.

Four different types of radiolabelled dextranated EGF were added to spheroids consisting of the human glioma cells U-343MGaCl2:6. Binding was analysed both in the peripheral well-nourished regions and in the deeper regions containing mainly quiescent cells. The substances had different molecular weights, and they were characterized regarding hydrophilic properties and isoelectric points. Two of the analysed conjugates, 125I-EGF-dextran (CDAP) and 125I-EGF-allyldextran-BSH, gave very low 125I binding in the deeper regions even after 24 h of incubation while better binding in these regions was found for 125I-EGF-dextran-DTPA, 125I-EGF-allyldextran and for the reference substance 125I-EGF. The molecular weight seemed not to be of major importance for the binding properties and there were no clear relationships between binding and the hydrophilic properties or the isoelectric point values. The obtained differences could not be explained by differences in molecular weight or easily measured physicochemical parameters such as hydrophilic properties or isoelectric point values. Thus, other explanations must be found.

Visual acuity, residual amblyopia and ocular pathology in a screened population of 12-13-year-old children in Sweden.

PURPOSE: To establish the distribution of visual acuity and the prevalence of residual amblyopia and other ocular disorders in a vision-screened population group of 12-13-year-old children. METHODS: In total 1046 children were examined in a field study in Sweden. The examination included visual acuity, stereopsis, cover testing, red reflex, refractive retinoscopy and examination of the posterior pole. In selected cases VEP was also performed. RESULTS: Visual acuity > or =1.0 in at least one eye was present in 98% of cases. Residual amblyopia (< or =0.5) was found in 1.1% of the population. Manifest strabismus was found in 2.7%. There were only a small number of ocular opacities and posterior pole abnormalities. Ocular albinism was found in 7 cases. In 15 children the cause of subnormal VA was unexplained. CONCLUSION: Results for visual acuity, residual amblyopia and other ocular disorders are very similar to previous Nordic, vision-screened populations.

Subnormal visual acuity syndromes (SVAS): albinism in Swedish 12-13-year-old children.

BACKGROUND: The vision of 12-13-year-olds in Sweden was examined in a field study. The study was designed as being a part of a large European-Latin American study, the DESAMI project. The objective was to evaluate the prevalence of residual amblyopia and ocular disorders, aetiologies of subnormal vision and some normal visual parameters in this group of children. The children had to be born in Sweden in 1985 in order to have the opportunity to be included in the voluntary screening visual examinations. The full results of the study will be presented elsewhere. This paper presents clinical and VEP data of those children who had visual acuity of 0.8 or below in one or both eyes which could not be increased with glasses, or other visual/eye disturbances not explained as common amblyopia, i.e., subnormal visual acuity or pathological visual states of unknown cause, SVAS (subnormal visual acuity syndromes). SUBJECTS AND METHODS: In all, 1046 children were examined: 76 had visual disturbances of such severity that they were referred to a paediatric ophthalmologist (AS). Eighteen children could not be pathologically classified, and they were referred to another ophthalmological examination and VEP (visual evoked potential) recordings. VEP reveals an asymmetric response after monocular stimulation in albinism. RESULTS: Twelve children turned up for a second examination and VEP was recorded from 10 children. Nine children showed iris translucency. Seven children showed an asymmetric VEP and were classified as albinos. The albinoic VEPs could be subdivided into two types, (1) including all parts of the response and (2) partly excluding the P1/P100 potential complex. The VEP response was normal, showing symmetry and no other abnormality, in three of the children. CONCLUSIONS: The results indicate that albinism is common in Sweden. A prevalence value of approximately 1% is about 100 times higher than previous figures. This high prevalence may indicate another form of heredity, with genetical contribution to albinism from a varying number of albino genes and varying expression in the phenotypes, in the Scandinavian population. It is emphasised that in investigations of children with SVAS, electrophysiological examinations are important, not only to reveal albinism but also to exclude or verify neurometabolic conditions, for example.

Binding of 125I after administration of 125I-EGF-dextran, 125I-EGF or 125I to human bladder cancer spheroids.

The binding of a targeting agent, 125I-EGF-dextran, to epidermal growth factor (EGF) receptors in tumour spheroids of a human bladder cancer cell line was studied. The accumulation of radioactivity was continuous up to at least 48 h in the peripheral cells of the spheroids, which in comparison with the binding pattern of 125I-EGF indicated that the cells had a limited capacity to degrade the EGF-dextran. The 125I-EGF-dextran was of two different sizes, 28 and 76 kDa, but this did not affect the binding patterns and the results were very similar. The EGF-dextran conjugates had qualities that are of interest for tumour targeting.

Myopisation: the refractive tendency in teenagers. Prevalence of myopia among young teenagers in Sweden.

PURPOSE: 1045 children between 12 and 13 years old were examined in a field study in the Göteborg area (Sweden). The aim of this study was to report the prevalence of refractive errors, with special attention to myopia, since there are no previous reports in Sweden about this age group. METHODS: The examination included visual acuity testing and refraction under cycloplegia. RESULTS: We found a prevalence of myopia (> or = -0.5D) of 49.7% and a prevalence of bilateral myopia of 39%. In the whole population, 23.3% were considered to need glasses (> or = -0.75D). We also found a prevalence of high myopia (> or = -5D) in 2.5% of the children. DISCUSSION: No statistically significant difference in myopia with respect to gender was found. The proportion of children needing glasses is considered the best indicator of the prevalence of myopia in this sample. The results confirm that this tendency towards myopisation in a teenage population in Göteborg is similar to the prevalence found in other parts of the world.

Differential effects on T cell and NK cell development by tissue-specific expression of H-2D(d) transgene.

The effect of tissue-specific expression of the MHC class I molecule H-2D(d) on T cell and NK cell specificity was studied in transgenic mice expressing the H-2D(d) gene under the control of the mouse metallothionein-I promoter. MTD mice expressed high amounts of H-2D(d) in the liver, intestine and testis, but only minute amounts in the thymus, spleen and kidney. Zinc administration resulted in a 1.5- and 8.5-fold increase in H-2D(d) expression in the liver and the intestine, respectively, but did not affect expression in the other organs tested. T cell tolerance developed towards H-2D(d) in MTD mice, even in the absence of zinc. In contrast, NK cell-mediated natural resistance against lymphoma grafts was not seen in MTD mice, despite zinc administration. NK cells in MTD mice also failed to develop self tolerance to H-2D(d). The lack of functional effects did not result from inability of NK cells in MTD mice to interact with H-2D(d), as down-regulation of Ly49A receptor expression was observed on liver NK cells in MTD mice. Our data reveal a difference between T cells and NK cells in their requirements for MHC class I molecules in specificity development.

Cellular processing of (125)I- and (111)in-labeled epidermal growth factor (EGF) bound to cultured A431 tumor cells.

Low molecular weight of epidermal growth factor (EGF) enables better intratumoral penetration in comparison with larger targeting proteins, but the cellular retention of EGF-associated radioactivity is poor for directly iodinated EGF. An attempt was made to improve intracellular retention by the use of metal-diethylenetriaminepentaacetic acid or nonphenolic linker (N-succinimidyl-para-iodobenzoate) as labeling agents. The use of nonphenolic linker did not improve retention of the radioactivity in A431 carcinoma cell line. The use of the radiometal label provided an appreciable prolongation of radioactivity residence inside the cell.

Visualization of inhibitory Ly49 receptor specificity with soluble major histocompatibility complex class I tetramers.

Murine natural killer (NK) cells are inhibited from killing their targets by the interaction between inhibitory, C-type lectin like Ly49 receptors and major histocompatibility complex (MHC) class I molecules. The receptors have overlapping specificity, and it has been difficult to analyze specific aspects of the interaction between different Ly49 receptors and their respective ligands. We have addressed this problem using tetramers of bacterially expressed, non-glycosylated, MHC class I molecules refolded with different peptides. Our results indicate that this technology is useful for analysis of Ly49 receptor specificity as well as for monitoring of NK cell subsets, with the following major conclusions emerging from this study: (1) tetramers of H-2D(d) bound the Ly49A receptor; the MHC associated glycan, previously suggested to be involved in recognition by this receptor, is thus not required for Ly49A receptor binding; (2) in support and extension of a recent report indicating peptide selectivity in the recognition of H-2K(b) by Ly49C(+) cells, H-2K(b) tetramer binding to Ly49C receptors was strongly influenced by the peptide presented by the MHC class I molecule; (3) tetramer binding allowed visualization of interactions that have not previously been detected in functional studies, such as the recognition of H-2D(b) by Ly49A and Ly49C.

The occurrence of congenital cataract in western Sweden.

PURPOSE: To estimate the occurrence of congenital cataract in a Nordic country. METHODS: In 1980, we constructed a database in the Department of Ophthalmology, Göteborg University, containing basic data from all cases in western Sweden diagnosed with congenital cataract. By collecting and processing these data from 1980 onwards, we hoped to improve the management of congenital cataract treatment and to optimize the outcome of the treatment. RESULTS: In this study, the incidence of congenital cataract in the four western counties of Sweden was evaluated. The occurrence rate of all cases with congenital cataract during the study period was 36 cases per 100,000. The occurrence rate for dense bilateral and all unilateral cases were both 14 per 10,0000 each. CONCLUSION: There were no time-related changes in incidence of congenital cataract from 1980 until today, although there was a large variation in the yearly incidence.

[Delayed vision development in 3 children with congenital cataract]. / Verzögerte Sehentwicklung bei drei Kindern mit kongenitaler Katarakt.

UNLABELLED: Within 10 years 108 children were born in Western Sweden with a congenital cataract. 22 cataracts were total and bilateral. Three out of them showed a visual development different from all the others in this group. Their visual acuity remained at a low level for a long period. Continuous improvement of 1.2 to 3 octaves did not start before the age of 7 years and could be followed up to 10 or 13 years of age. CONCLUSION: The visual system showed plasticity over a long period. This should not be neglected during the treatment and follow-up in these patients.

Conjugate chemistry and cellular processing of EGF-dextran.

Conjugates with specific binding to the epidermal growth factor receptor, EGFR, of interest for radionuclide based imaging and therapy were prepared using mouse epidermal growth factor, mEGF, and dextran. In one type of conjugate, mEGF was coupled to dextran by reductive amination in which the free amino group on the mEGF N-terminal reacted with the aldehyde group on the reductive end of dextran. The end-end coupled conjugate could be further activated by the cyanopyridinium agent CDAP, thereby introducing tyrosines to the dextran part. In the other type of conjugate, the cyanylating procedure using CDAP was applied, first to activate dextran and then allowing for the amino terminus of mEGF to randomly attach to the dextran. In the latter case, radionuclide-labelled tyrosines or glycines could be added in the same conjugation step. All types of mEGF-dextran conjugates had EGFR-specific binding since the binding could be displaced by an excess of non-radioactive mEGF. The conjugates were to a large extent internalized in the test cells and the associated radioactivity was retained intracellularly for different times depending on both the type of cells and conjugate applied. Different intracellular 'traffic routes' for the radionuclides are discussed as well as applications for both imaging and therapy.

The neonatal development of the light flash visual evoked potential.

AIMS: To follow visual development longitudinally in the normal neonate using the flash visual evoked potential (VEP) and to find indications for a relationship between potential development and visual development. METHODS: Twenty healthy infants, born at term, were included in the study. Flash and patterned flash VEPs were used. The first VEP was recorded the day of birth or just postnatally, and succeeding recordings were performed the following weeks and months. RESULTS: The data revealed different types of VEP in the neonatal period suggesting great variability in visual function on the day of birth. In the early development a potential of long latency and duration preceded the development of a more compound potential of shorter latency. The two types of responses seemed to coalesce during early development; the first late response was attenuated and was eventually integrated in the more mature VEP. At approximately five weeks of age changes in the VEP were simultaneous with the development of responsive smiling and another visual behaviour of the infants. CONCLUSIONS: The results showed many similarities between the VEP development in infants and in immature animals. In developing animals geniculo-cortical and extra-geniculate visual afferent pathways evoke two types of VEPs similar to those recorded in the present study. The early responses were also similar to previous recordings from children with lesions in the geniculo-striatal pathway or primary cortex. Our interpretation of the results was that the human VEP also consists of responses evoked by afferents running both in geniculo-cortical and extra-geniculate pathways and that the two types of responses could be separated in the VEP in the neonatal period. These findings are important for our understanding of conditions with a delay in visual maturation, for example intracranial haemorrhages, hydrocephalus, pre/dys-maturity and 'idiopathic' delayed visual maturation.

Accommodative facility training with a long term follow up in a sample of school aged children showing accommodative dysfunction.

The primary aim of this project was to study the effect of flip lens-training on the accommodative function in a group of children with accommodative dysfunction and subjective symptoms such as asthenopia, headache, blurred vision, and avoidance of near activity. We also wanted to measure the accommodative facility among the children in comparison with a control group. Another aim of the study was whether flip lens-training increased accommodative facility, and to find out if it also had a positive effect on their asthenopia and related problems also in long term. Following the training period the accommodative facility and accommodative function significantly increased and two years after finishing the training period no child had regained any subjective symptoms and the objective findings were almost the same as at the end of facility training period. These results suggest that accommodative facility training is an efficient method built on loss of symptoms among children with accommodative infacility.

Expression of epidermal growth factor receptor in urinary bladder cancer metastases.

Bladder cancers frequently exhibit an increased number of epidermal growth factor receptors (EGFR) in comparison to normal urothelium. The EGFR could potentially be a target for toxic conjugates. The aim of our study was to compare the expression of EGFR in metastases with concurrent or primary tumour in the urinary bladder using immunohistochemical techniques and a monoclonal antibody. Tumour material from 20 patients was investigated. The majority (13/20) of the metastases were homogeneously stained and showed a moderate to strong membranous staining for EGFR. The expression of EGFR in primary bladder tumours and metastases was similar. There was no indication that tumour tissue exposed to chemotherapy or radiation had a decreased number of EGFR. Targeting of the EGFR thus seems potentially applicable to metastatic disease.