Age of lens use onset in a myopic sample of office-workers

PURPOSE: The present study was developed to assess prevalence of myopic refractive error and the relative percentages of youth- and adult- onset myopia in a Caucasian adult population. METHODS: Subjects were office-workers sent consecutively from their workplace for a general health check-up, without refractive selection. Each subject received a questionnaire about academic achievement and family history of myopia. Subsequently, an ophthalmologist performed the vision examination. Although age of initial lens use is not necessarily the same as age of onset of myopia, it was considered to be so for this paper. A subject was considered an adult-onset myope if lens use began at age 18 or later. RESULTS: Subjects (n=349) had a mean age of 37.6 +/- 9.3 years. One hundred seventeen subjects (33.5% prevalence) had myopic spherical equivalent refraction. Further analysis comprises only subjects with simple myopia (astigmatism <1 diopter, n=95). Nearly half of the simple myopic subjects were of adult-onset (47.8%). There was no difference in family history of myopia between youth- and adult-onset myopes (at least one myopic parent in 53.1% and 47.8% respectively, p=0.53), and no clear cut-off point separated the two myopic subgroups with respect to the age of lens use onset. However, adult-onset myopes had myopia of lower diopter amount than youth-onset myopes. CONCLUSIONS: Adult-onset myopes comprised nearly half of the simple myopic subjects, and their family history of myopia was similar to that of youth-onset myopes. There is no clear cut-off point between both myopic subgroups when age of onset is the variable considered.     

Dynamics of cytochrome P450 inducers in polluted sites of São Paulo city reservoirs

The first analysis of water pollutants using biomarkers at the Guarapiranga Reservoir, which supplies water for one-third of the population of the S?o Paulo megalopolis (Brazil), is reported. Studies were performed before and after the start of water pumping to the Guarapiranga from the highly polluted Billings reservoir. Billings's water was purified by passing through the natural wetland located near Guarapiranga. Liver enzymes of Oreochromis niloticus (tilopias) obtained from both reservoirs served as biomarkers of pollution in a comparison with animals obtained from a reference site. Enhanced levels of total cytochromes P450 (3.4 times) and b5 (2.7 times) and activity of cytochrome c (P450) reductase (2.2 times) were observed in specimens collected near the water influx from the Billings before the pumping started. However, these parameters were significantly decreased 3 months later. This effect is probably due to dilution of pollutants because of the increased level of water in the Guarapiranga.     

Dual effect of ethanol on cell death in primary culture of human and rat hepatocytes

AIMS: In-vivo and in-vitro studies have shown that ethanol induces hepatocyte damage. The aim of the present study was to evaluate the effect of a broad range of ethanol concentrations on apoptosis and necrosis in primary culture of human and rat hepatocytes. METHODS: Human and rat hepatocytes were isolated from human hepatectomies and male Wistar rats (200-250 g) using the classical collagenase perfusion method. After stabilization of cell culture, ethanol (0-10 mmol/l) was administered and the parameters were measured 24 h after ethanol addition. Apoptosis was studied by DNA fragmentation, iodide propidium-DNA staining, caspase-3 activity and annexin V binding in hepatocytes. Necrosis was evaluated by lactate dehydrogenase (LDH) release. Malondialdehyde (MDA) and GSH/GSSG were used as parameters of oxidative stress. RESULTS: Ethanol enhanced dose-dependently all the parameters associated with apoptosis in human and rat hepatocytes. Low or high ethanol concentrations induced an opposite action against cell necrosis in cultured hepatocytes. Low concentrations of ethanol (1-2 mmol/l) reduced LDH release from human and rat hepatocytes. However, the highest ethanol concentration (10 mmol/l) induced a sharp increase in cell necrosis. The effect of ethanol on cell necrosis was related to lipid peroxidation in hepatocytes. CONCLUSIONS: Ethanol differentially regulates apoptosis or necrosis in cultured hepatocytes. Although ethanol exerted a dose-dependent induction of apoptosis, low ethanol concentrations were able to reduce basal lipid peroxidation and necrosis in hepatocytes. The highest ethanol concentration (10 mmol/l) induced apoptosis and necrosis in human and rat cultured hepatocytes.     

Use of Fatty Acids to Explain Variability of Organochlorine Concentrations in Eggs and Plasma of Common Terns (Sterna hirundo)

We have studied the breeding parameters, organochlorine compounds (OCs) concentrations, and fatty acid (FA) composition of egg yolks (n = 47) and plasma (n = 90) of common terns (Sterna hirundo) from two colonies (Banya and Fangar) in the Ebro delta, NE Spain. Terns from Banya tend to have smaller clutch size and lower hatching success than terns from Fangar. p,p'-DDE and polychlorinated biphenyls (PCBs) concentrations were almost 2-fold higher in yolks from Banya in 1998 than from Fangar in 1999, and the percentage of n-6 PUFA was positively correlated with these contaminants. Differences between samplings in OCs concentrations in plasma were less evident, and were affected by breeding chronology. The highest OCs concentrations in yolks from Banya may be explained by two processes involving the increased deposition of n-6 PUFA: (1) higher mobilization of endogenous fat due to lower food resources, or (2) differences in the diet between colonies. Birds from Banya may have been feeding at a higher degree on discards of trawling fisheries composed of demersal and benthic fish species that are more exposed to contaminants from sediment and have lower n-3/n-6 ratio, whereas birds from Fangar would feed mostly on pelagic species of small clupeiformes that are less polluted and have higher n-3/n-6 ratios.     

The impact of mid-treatment MRI on defining boost volumes in the radiation treatment of glioblastoma multiforme

Radiation therapy is a central modality in the treatment of glioblastoma multiforme (GBM). Integral to adequate radiation therapy delivery is the appropriate determination of tumor volume and extent at the time treatment is being delivered. As a matter of routine practice, radiation therapy treatment fields are designed based on tumor volumes evident on pre-operative or immediate post-operative MRIs; another MRI is generally not obtained for planning boost fields. In some instances the time interval from surgery to radiotherapy initiation is up to 5 weeks and the boost or "cone-down phase" commences 4-5 weeks later. The contrast enhanced T1 MRI may not be a totally reliable indicator of active tumor, especially in regions where such blood-brain barrier breakdown has not occurred. Moreover, these volumes may change during the course of treatment. This may lead to a geographic miss when mid-treatment boost volumes are designed based on a pre-radiotherapy MRI. The goal of this study is to examine how a mid-treatment MRI impacts the delineation and definition of the boost volume in GBM patients in comparison to the pre-treatment MRI scan, particularly when the tumor-specific agent Motexafin-Gadolinium is used.     

Sclerosing stromal tumor of the ovary in a premenarchal female

Sclerosing stromal tumor (SST) is a rare benign ovarian neoplasm of stromal origin with less than 100 cases reported in the literature. Unlike the other stromal tumors, thecomas and fibromas, which tend to occur in the fifth and sixth decades, sclerosing stromal tumors predominantly affect females in the second and third decades. Computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound findings have been described, but have not been reported previously in the pediatric literature. We present a case of SST of the ovary in a 10-year-old premenarchal female, the youngest patient to our knowledge reported in the literature, and describe the ultrasound and CT findings with pathologic correlation.     

A1 adenosine receptors accumulate in neurodegenerative structures in Alzheimer disease and mediate both amyloid precursor protein processing and tau phosphorylation and translocation

Immunostaining of adenosine receptors in the hippocampus and cerebral cortex from necropsies of Alzheimer disease (AD) patients shows that there is a change in the pattern of expression and a redistribution of receptors in these brain areas when compared with samples from controls. Adenosine A1 receptor (A1R) immunoreactivity was found in degenerating neurons with neurofibrillary tangles and in dystrophic neurites of senile plaques. A high degree of colocalization for A1R and betaA4 amyloid in senile plaques and for A1R and tau in neurons with tau deposition, but without tangles, was seen. Additionally, adenosine A2A receptors, located mainly in striatal neurons in controls, appeared in glial cells in the hippocampus and cerebral cortex of patients. On comparing similar samples from controls and patients, no significant change was evident for metabotropic glutamate receptors. In the human neuroblastoma SH-SY5Y cell line, agonists for A1R led to a dose-dependent increase in the production of soluble forms of amyloid precursor protein in a process mediated by PKC. A1R agonist induced p21 Ras activation and ERK1/2 phosphorylation. Furthermore, activation of A1R led to and ERK-dependent increase of tau phosphorylation and translocation towards the cytoskeleton. These results indicate that adenosine receptors are potential targets for AD.     

Mechanisms of Moisture Sorption in Barrier Polymers Used in Food Packaging: Amorphous Polyamide vs. High‐Barrier Ethylene‐Vinyl Alcohol Copolymer Studied by Vibrational Spectroscopy

The nature of the association between sorbed water and two high‐barrier hydrophilic polymers used in oxygen‐sensitive food packaging, and exhibiting opposite oxygen barrier behavior in the presence of moisture, has been studied by FT‐Raman and FT‐Infrared spectroscopy. The polymers considered in this work were an ethylene‐vinyl alcohol copolymer with superior oxygen barrier properties (32 mol‐% of ethylene EVOH) and an amorphous polyamide (aPA). The results revealed that for the latter glassy amorphous polymer, water molecules associate with the C?O and N? H groups of the ca. 10% “free” amide moieties, being the excess sorbed water self‐associated in clusters; thus, moisture sorption does not appear to disrupt the originally present hydrogen‐bonded amide groups. This “unusual” behavior leads to an overall increase in the extension of the hydrogen‐bonding, which may help explain the lower oxygen permeability displayed by the aPA with increasing relative humidity on the basis of the known free‐volume competing mechanism. Differently, water sorption appears to progressively disrupt the strong polymer self‐association present in the very efficient high‐barrier semicrystalline EVOH material by hydrogen‐bonding to hydroxyl groups, hence leading to the well‐known highly plasticized rubbery structure with much lower intermolecular cohesion and oxygen barrier.

FT‐IR spectra of severely dried, dry (dotted), and water‐equilibrated (thicker line) aPA in the range 2 600–3 800 cm^?1.     

In utero diagnosis of bladder perforation with urinary ascites. A case report

Prenatal sonographic diagnosis of fetal obstructive uropathy is relatively common. However, the complication of spontaneous rupture of the obstructed bladder in utero causing fetal urinary ascites is extremely rare. This case report describes an unusual case of congenital bladder perforation and urinary ascites diagnosed in utero. The pertinent literature is reviewed.