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Background: Palliative care is a priority for health systems worldwide, yet equity in access remains unknown. To shed light on this issue, this study compares populations' driving time to specialized palliative care services in three countries: Ireland, Spain, and Switzerland., Methods: Network analysis of the population's driving time to services according to geolocated palliative care services using Geographical Information System (GIS). Percentage of the population living within a 30-min driving time, between 30 and 60 minutes, and over 60 min were calculated., Results: The percentage of the population living less than thirty minutes away from the nearest palliative care provider varies among Ireland (84%), Spain (79%), and Switzerland (95%). Percentages of the population over an hour away from services were 1.87% in Spain, 0.58% in Ireland, and 0.51% in Switzerland., Conclusion: Inequities in access to specialized palliative care are noticeable amongst countries, with implications also at the sub-national level.

Introduction  The middle cranial fossa approach is performed by fewer neurotologists owing to a reduced number of indications. Consistent landmarks are mandatory to guide the surgeon in a narrow field. Objectives  We have evaluated the incus and malleus head and the incudomalleal joint (IMJ) as a key landmark for identifying the superior semicircular canal (SSC) and to get oriented along the floor of the middle cranial fossa. Methods  A combination of 20 temporal bone dissections and CT imaging were utilized to test and describe these landmarks. Results  The blue line of the SSC is consistently identified along the prolongation of a virtual line through the IMJ and the angulation toward the root of zygoma. The mean distance from the zygoma toward the IMJ ranged from 1.60 to 1.90cm. Once the IMJ was identified, the blue line of the SSC was consistently found along the virtual line through the IMJ within 5 to 9mm. Conclusions  The IMJ is a safe and consistent anatomical marker in the surgical approach to the middle cranial fossa floor. Opening the tegmen 1.5 to 2cm medial to the root of the zygoma and identifying the joint allows to trace a virtual line toward the SSC within 5 to 9mm. Knowledge of the close relationship between the direction of the IMJ and the superior canal can be used in all transtemporal approaches, thus orienting the surgeon in a rather narrow field with limited retraction of the dura and brain., Competing Interests: Conflict of Interests The authors have no conflict of interests to declare., (Fundação Otorrinolaringologia. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commecial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ).)

Purpose: The present study aimed to compare the outcomes of combined phacoemulsification and 360-degree endocyclophotocoagulation with and without goniotomy using a Kahook Dual Blade in patients with glaucoma., Patients and Methods: We enrolled 37 patients, 21 of whom underwent combined phacoemulsification with 360-degree endocyclophotocoagulation and goniotomy using a Kahook Dual Blade (tri-modal therapy (T-MT) group). The remaining 16 patients underwent phacoemulsification with endocyclophotocoagulation (bi-modal therapy (B-MT) group). Visual acuity, intraocular pressure, and number of glaucoma medications were recorded before the study and postoperatively on the first day, at week 1, and at 1, 3, 6, 9, and 12 months. Surgical success was defined as an IOP ≤12 mmHg and ≥6 mmHg or an at least 20% reduction in IOP from baseline with (qualified success) or without medications (complete success)., Results: Forty-nine eyes were included. Baseline mean IOP was 16.96±3.66 mmHg and 15.64±4.88 mmHg in the T-MT and B-MT groups (p=0.122), respectively. At the 12-month follow-up, mean IOP values were 11.44±2.15 mmHg and 12.45±1.90 mmHg (p=0.031) in the T-MT and B-MT groups, respectively. Complete success rates were 37% in the T-MT group and 31% in the B-MT group, while qualified success rates were 74% and 50%, respectively. Glaucoma medications decreased from 2.0±1.4 to 0.8±1.0 (p<0.001) in the T-MT group and from 1.5±1.3 to 1.0±1.5 in the B-MT group (p=0.032). Similar improvements in visual acuity were observed in both groups. Complications were mild and resolved without intervention., Conclusion: The tri-modal treatment is safe and may be more effective in reducing IOP and glaucoma medication requirements than bi-modal treatment., Competing Interests: The authors report no conflicts of interest related to this work., (© 2021 Izquierdo et al.)

Background: Glaucoma surgery have been developed to lower intraocular pressure in a less invasive manner than traditional glaucoma surgery. The purpose of this article is to determine the outcome of using combined phacoemulsification technique, ab-interno trabeculectomy dual blade and endoscopic cyclophotocoagulation (ECP) surgeries in patients with primary open angle glaucoma., Methods: A retrospective case series was performed on 27 consecutive eyes with both primary open-angle glaucoma (POAG) and cataract; each eye was treated with combined phacoemulsification, ab-interno trabeculectomy-Kahook Dual Blade and Endocyclophotocoagulation at Instituto de ojos Oftalmosalud, Lima, Peru, between April 2017 and May 2017., Inclusion Criteria: 1) Patients with uncontrolled mild to advanced POAG (according to Glaucoma Grading Scale HODAPP) 2) cataract condition 3) treatment with two or more glaucoma medications due to rapid progression in the visual fields (at least two in a short period of time). Intraocular pressure (IOP), best corrected visual acuity (BCVA) logMAR and number of glaucoma medications were recorded prior to the study, at day 1, week 1, and 1,3,6 and 9 months after surgery. Primary outcome measure was surgical success defined in terms of IOP < 14 mmHg either with no medications (complete success) or with medications (qualified success)., Results: A total of 27 eyes from 27 patients were included. The mean basal IOP was 17.0 ± 3.7 mmHg and postoperatively was 11.6 ± 1.9 mmHg and 11.4 ± 1.8 mmHg (P < 0.001) at 6 and 9 months respectively. Glaucoma medications decreased from 1.9 ± 1.4 to 0.56 ± 1.05 at 9 month follow-ups (P < 0.001). Preoperative best corrected visual acuity (BCVA) showed and improvement from 0.4 ± 0.4 LogMAR to 0.2 ± 0.4 logMAR at 9 months. The main complication was blood reflux intra-operatively (66.7%), which resolved without re-operation. The mean IOP was reduced by 32.9% from baseline and the surgical success was 92,6%, (complete success 70,3% and qualified success 29,6%) at 9 months., Conclusions: In patients with POAG, combined treatment with phacoemulsification, ab-interno trabeculectomy and endoscopic cyclophotocoagulation effectively reduced IOP and glaucoma medication dependence.

Background: Thyroid hormone has been shown to be involved in carcinogenesis via its effects on cell proliferation pathways. The objective of this study is to determine the association between subclinical hypothyroidism (SCH) and the risk of incident cancer and cancer mortality via systematic review., Methods: A systematic search was performed on Medline and Pubmed to identify relevant studies. Randomized controlled trials, and observational studies assessing SCH or its treatment and the risk of incident cancer or cancer mortality were identified., Results: A total of 7 cohort and 2 case-control studies met our inclusion criteria. In general, these studies were of medium to good quality. Overall, studies revealed no association between SCH and breast and prostate cancer. One study found that untreated SCH may be associated with an increased risk of colorectal cancer (adjusted odds ratio [OR]: 1.16; 95% confidence interval [CI]: 1.08-1.24). One study showed an increased risk in thyroid cancer incidence (adjusted OR: 3.38; 95% CI: 2.05-5.59) associated with elevation of a thyroid stimulating hormone (TSH) of > 1.64mIU/L. Two studies found an increase in cancer mortality among patients with SCH compared to euthyroid individuals; in contrast one study found no association between subclinical hypothyroidism and cancer mortality among aging men., Conclusion: The number of studies examining thyroid dysfunction and cancer risk and mortality is limited. Future studies assessing the association between thyroid dysfunction and cancer risk and mortality are needed, which will further address the need to treat subclinical hypothyroidism.

The purpose of the method is to generate an immunological synapse (IS), an example of cell-to-cell conjugation formed by an antigen-presenting cell (APC) and an effector helper T lymphocyte (Th) cell, and to record the images corresponding to the first stages of the IS formation and the subsequent trafficking events (occurring both in the APC and in the Th cell). These events will eventually lead to polarized secretion at the IS. In this protocol, Jurkat cells challenged with Staphylococcus enterotoxin E (SEE)-pulsed Raji cells as a cell synapse model was used, because of the closeness of this experimental system to the biological reality (Th cell-APC synaptic conjugates). The approach presented here involves cell-to-cell conjugation, time-lapse acquisition, wide-field fluorescence microscopy (WFFM) followed by image processing (post-acquisition deconvolution). This improves the signal-to-noise ratio (SNR) of the images, enhances the temporal resolution, allows the synchronized acquisition of several fluorochromes in emerging synaptic conjugates and decreases fluorescence bleaching. In addition, the protocol is well matched with the end point cell fixation protocols (paraformaldehyde, acetone or methanol), which would allow further immunofluorescence staining and analyses. This protocol is also compatible with laser scanning confocal microscopy (LSCM) and other state-of-the-art microscopy techniques. As a main caveat, only those T cell-APC boundaries (called IS interfaces) that were at the right 90° angle to the focus plane along the Z-axis could be properly imaged and analyzed. Other experimental models exist that simplify imaging in the Z dimension and the following image analyses, but these approaches do not emulate the complex, irregular surface of an APC, and may promote non-physiological interactions in the IS. Thus, the experimental approach used here is suitable to reproduce and to confront some biological complexities occurring at the IS.

Objective: To assess the influence of clinical features and laboratory test results on the determination of fever of unknown origin (FUO) by means of 18F-FDG PET/CT., Methods: Retrospective and longitudinal analysis, including all the PET/CT studies requested for FUO. Reference standard was established by serology, cultures or biopsy with other laboratory tests or clinical follow-up when necessary. Clinical variables, inflammation markers, protein analysis, serology and culture results close to the PET scan were obtained. The final diagnosis was classified into three groups attending to the etiology; group 1: infection or neoplasm, group 2: vasculitis, autoimmune disease or non-infectious inflammatory disease and group 3: auto-limited fever or persistent fever without diagnosis. PET/CT scans were classified as positive or negative and helpful or not in the diagnosis of the fever origin. The effect of clinical features and laboratory variables on the PET/CT results was analyzed., Results: Sixty-seven patients were evaluated. The final diagnosis was: Group 1 (25), Group 2 (20) and Group 3 (22). 89.6% of patients had a positive inflammation marker, 28.4% proteinogram alterations and 20.9% positive cultures. PET/CT was positive in 52/67 patients. PET/CT helped in the establishment of the fever origin in 35 cases and was especially helpful in groups 1 and 2. Sensitivity, specificity and accuracy of PET/CT were: 84, 31 and 61%. PET results shown significant relations with the final diagnosis (p = 0.035) and culture results (p = 0.037). No significant relations were observed with the rest of clinical or laboratory variables., Conclusions: 18F-FDG PET/CT had a high sensitivity but a low specificity in the diagnosis of the fever origin, probably due to the high rate of diffuse and auto-limited aetiologies. Patients who are most likely to benefit from the PET/CT study would be those with several positive inflammation markers, reflecting a higher pre-test probability of active disease.

Objectives: Proton-pump inhibitors (PPIs) have shown antihyperglycemic effects by stimulating insulin secretion. The aim of this study was to analyze the effect of PPIs on glucose metabolism in general and any potential antidiabetes effects in patients with type 2 diabetes., Methods: A systematic search was conducted in MEDLINE, Embase, Cochrane and PubMed. Studies using PPIs as interventions and reporting glucose levels, glycated hemoglobin (A1C) levels and insulin levels were selected. Weighted-mean differences (WMDs) were calculated for all outcomes. A random-effects model was used for moderate and high heterogeneity and a fixed-effects model for low heterogeneity data., Results: The research included 9 studies have involving 320 patients in total. Among patients with type 2 diabetes, those exposed to PPIs did not see significant reductions in A1C levels; WMD -0.36, 95% confidence interval (CI) -0.87, 0.15; p=0.17. Pantoprazole resulted in a statistically significant reduction in A1C levels in patients with type 2 diabetes when compared to control interventions; WMD -0.93, 95% CI -1.49, -0.37; p=0.001. There was no statistically significant difference in other outcomes (p≥0.05)., Conclusions: This meta-analysis demonstrates that PPIs, in general, do not decrease A1C levels in patients with type 2 diabetes. However, pantoprazole produced significant reductions in A1C levels in patients with type 2 diabetes. Given the limitations and the presence of bias in the primary studies, larger and better-quality studies are warranted., (Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.)

Background: Inadequate perioperative fluid therapy impairs gastrointestinal function. Studies primarily evaluating the impact of goal-directed fluid therapy on primary postoperative ileus are missing. The objective of this study was to determine whether goal-directed fluid therapy reduces the incidence of primary postoperative ileus after laparoscopic colorectal surgery within an Enhanced Recovery After Surgery program., Methods: Randomized patient and assessor-blind controlled trial conducted in adult patients undergoing laparoscopic colorectal surgery within an Enhanced Recovery After Surgery program. Patients were assigned randomly to receive intraoperative goal-directed fluid therapy (goal-directed fluid therapy group) or fluid therapy based on traditional principles (control group). Primary postoperative ileus was the primary outcome., Results: One hundred twenty-eight patients were included and analyzed (goal-directed fluid therapy group: n = 64; control group: n = 64). The incidence of primary postoperative ileus was 22% in the goal-directed fluid therapy and 22% in the control group (relative risk, 1; 95% CI, 0.5 to 1.9; P = 1.00). Intraoperatively, patients in the goal-directed fluid therapy group received less intravenous fluids (mainly less crystalloids) but a greater volume of colloids. The increase of stroke volume and cardiac output was more pronounced and sustained in the goal-directed fluid therapy group. Length of hospital stay, 30-day postoperative morbidity, and mortality were not different., Conclusions: Intraoperative goal-directed fluid therapy compared with fluid therapy based on traditional principles does not reduce primary postoperative ileus in patients undergoing laparoscopic colorectal surgery in the context of an Enhanced Recovery After Surgery program. Its previously demonstrated benefits might have been offset by advancements in perioperative care.

Background: Residence at high altitude has been associated with lower obesity rates probably due to hypoxia conditions. However, there is no evidence of this association in a free-living population., Objectives: We assessed the association between the altitude where each participant of a Spanish cohort (the SUN Project) was living and the incidence of overweight/obesity., Methods: The SUN Project is a dynamic, prospective, multipurpose cohort of Spanish university graduates with a retention rate of 89%. We included in the analysis 9 365 participants free of overweight/obesity at baseline. At the baseline questionnaire, participants reported their postal code and the time they had been living in their city/village. We imputed the altitude of each postal code according to the data of the Spanish National Cartographic Institute and categorized participants in tertiles. We used Cox regression models to adjust for potential confounding variables., Results: During a median follow-up of 10 years, we identified 2 156 incident cases of overweight/obesity. After adjusting for sex, age, time of residence at current city, baseline body mass index, physical activity, sedentarism and years of education (≤ 3 years, ≥ 4 years, Master/PhD), those participants in the third tertile (>456 m) exhibited a statistically significant 14% reduction in the risk of developing overweight/obesity in comparison to those in the first tertile (<124 m) (adjusted HR = 0.86; 95% CI: 0.77, 0.96)., Conclusions: Living in cities of higher altitude was inversely associated with the risk of developing overweight/obesity in a cohort of Spanish university graduates., Competing Interests: The authors have declared that no competing interests exist.

Background: Anti-dengue virus (DENV) immunoglobulin M (IgM) seroconversion has been the reference standard for dengue diagnosis. However, paired specimens are rarely obtained, and the interval for this testing negates its usefulness in guiding clinical case management. The presence of DENV viremia and appearance of IgM during the febrile phase of dengue provides the framework for dengue laboratory diagnosis by using a single serum specimen., Methods: Archived paired serum specimens (n = 1234) from patients with laboratory-confirmed dengue from 2005 through 2011 were used to determine the diagnostic performance of real-time reverse transcription polymerase chain reaction (RT-PCR), for detection of DENV serotypes 1-4, and enzyme-linked immunosorbent assays (ELISAs), for detection of DENV nonstructural protein 1 (NS1) antigen and anti-DENV IgM., Results: During 1-3 days after illness onset, real-time RT-PCR and NS1 antigen testing detected 82%-69% and 90%-84% of cases, respectively, as viremia levels declined, while anti-DENV IgM ELISA detected 5%-41% of cases as antibody appeared. Over the 10-day period of the febrile phase of dengue, the cumulative effect of using these 3 types of tests in a diagnostic algorithm confirmed ≥90% of dengue cases., Conclusions: The use of molecular or NS1 antigen tests to detect DENV and one to detect anti-DENV IgM in a single serum specimen collected during the first 10 days of illness accurately identified ≥90% of dengue primary and secondary cases., (Published by Oxford University Press for the Infectious Diseases Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Objective: To compare axonal regeneration in an animal model after the repair of facial nerve defects with pre-degenerated (PD) and non-PD (NPD) great auricular nerve grafts., Materials and Methods: The buccal branch of the facial nerve was completely sectioned in 18 New Zealand rabbits, which were randomized to 3 treatment groups: PD great auricular nerve graft repair (PD group), NPD great auricular nerve graft repair (NPD group), and immediate end-to-end repair (control group). Axonal regeneration was examined using optical microscopy to assess the following variables: total number of myelinated axons and regenerating sprouts (MARS) that crossed the distal anastomosis, numbers of intra and extrafascicular MARS, and area of myelinated axons., Results: The total number of myelinated axons (p = 0.008) and intrafascicular axons (p = 0.02) that crossed the distal anastomosis significantly differed between the NPD and control group. No significant differences were observed between the PD and control group or between the PD and NPD groups., Conclusion: Nerve repair with PD grafts could be an alternative treatment in the management of injuries resulting in facial nerve gaps.

Purpose: To determine the effect of conjunctival incision location on the long-term efficacy of nonvalved glaucoma drainage devices., Materials and Methods: We conducted a retrospective review of patients ≥18 years of age with uncontrolled glaucoma [intraocular pressure (IOP) ≥18 mm Hg] who underwent glaucoma drainage device implantation. A comparison was made of a limbal-based (LB-BGI) versus fornix-based (FB-BGI) conjunctival flap during placement of a 350-mm Baerveldt glaucoma implant (AMO, Santa Ana, CA) in subjects with at least 1 year of follow-up data. The primary outcome measure was IOP; secondary outcome measures were medication burden, visual acuity, and surgical complications., Results: One hundred sixty eyes of 147 glaucoma patients were included. Two years after surgery, the IOP in the LB-BGI group was 14.3±5.3 mm Hg and in the FB-BGI group 13.1±4.7 mm Hg (P=0.47). Overall success of IOP control was achieved at the final visit (range 1 to 5 y) in 90% of the LB-BGI group and 87% of the FB-BGI group (P=0.63). The medication burden of the 2 groups at 1 and 2 years after surgery was not statistically significantly different. Worsening of visual acuity by more than 2 lines was not statistically different between the groups 2 years after the surgery and at the final visit (P=0.47, P=0.60, respectively). A greater number of eyes developed endophthalmitis and were more likely to undergo subsequent tube revision in the FB-BGI group, but the differences were not significant., Conclusions: Both incision techniques were equally effective in controlling IOP. Each surgical approach has its advantages and this study suggests that either technique may be used safely and effectively.

Background: The Spanish Palliative Care Strategy recommends an intermediate level of training for primary care physicians in order to provide them with knowledge and skills. Most of the training involves face-to-face courses but increasing pressures on physicians have resulted in fewer opportunities for provision of and attendance to this type of training. The effectiveness of on-line continuing medical education in terms of its impact on clinical practice has been scarcely studied. Its effect in relation to palliative care for primary care physicians is currently unknown, in terms of improvement in patient's quality of life and main caregiver's satisfaction. There is uncertainty too in terms of any potential benefits of asynchronous communication and interaction among on-line education participants, as well as of the effect of the learning process.The authors have developed an on-line educational model for palliative care which has been applied to primary care physicians in order to measure its effectiveness regarding knowledge, attitude towards palliative care, and physician's satisfaction in comparison with a control group.The effectiveness evaluation at 18 months and the impact on the quality of life of patients managed by the physicians, and the main caregiver's satisfaction will be addressed in a different paper., Methods: Randomized controlled educational trial to compared, on a first stage, the knowledge and attitude of primary care physicians regarding palliative care for advanced cancer patients, as well as satisfaction in those who followed an on-line palliative care training program with tutorship, using a Moodle Platform vs. traditional education., Results: 169 physicians were included, 85 in the intervention group and 84 in the control group, of which five were excluded. Finally 82 participants per group were analyzed. There were significant differences in favor of the intervention group, in terms of knowledge (mean 4.6; CI 95%: 2.8 to 6.5 (p = 0.0001), scale range 0-33), confidence in symptom management (p = 0.02) and confidence in terms of communication (p = 0.038). Useful aspects were pointed out, as well as others to be improved in future applications. The satisfaction of the intervention group was high., Conclusions: The results of this study show that there was a significant increase of knowledge of 14%-20% and a significant increase in the perception of confidence in symptom management and communication in the intervention group in comparison with the control group that received traditional methods of education in palliative care or no educational activity at all. The overall satisfaction with the intervention was good-very good for most participants.This on-line educational model seems a useful tool for palliative care training in primary care physicians who have a high opinion about the integration of palliative care within primary care. The results of this study support the suggestion that learning effectiveness should be currently investigated comparing different Internet interventions, instead of Internet vs. no intervention.

Purpose: To measure foveal thickness and macular volume in patients with oculocutaneous albinism (OCA) using optical coherence tomography (OCT) technology and to evaluate the possible association between albinism type and OCT retinal findings., Methodology: The authors measured retinal structures such as foveal thickness and macular volume of patients and obligate carriers of the various types of OCA using OCT technology., Results: Participants with OCA (all types included) have thicker foveas (P = 0.0009) and less macular volume (P = 0.0022) than the general population. Carriers of mutations leading to OCA (all types included) have normal foveal thicknesses and higher macular volumes (P = 0.0009) than the general population. Participants with Hermansky-Pudlak syndrome (HPS)-Type 1 have thicker foveas but less macular volume (P = 0.0468) than the general population., Conclusions: Results of this study suggest that patients with OCA (all types included) and patients with HPS-1 have thicker foveas than the general population. This may be due to the absence of foveal pit as part of foveal hypoplasia associated with OCA. Conversely, participants have lower macular volumes than the general population. This finding is compatible with loss of retinal nuclear layers in patients with OCA.

Introduction: Vision and eye related problems are common among computer users, and have been collectively called the Computer Vision Syndrome (CVS)., Methods: An observational study in order to identify the risk factors leading to the CVS was done. Twenty-eight participants answered a validated questionnaire, and had their workstations examined. The questionnaire evaluated personal, environmental, ergonomic factors, and physiologic response of computer users. The distance from the eye to the computers' monitor (A), the computers' monitor height (B), and visual axis height (C) were measured. The difference between B and C was calculated and labeled as D. Angles of gaze to the computer monitor were calculated using the formula: angle=tan-1(D/A). Angles were divided into two groups: participants with angles of gaze ranging from 0 degree to 13.9 degrees were included in Group 1; and participants gazing at angles larger than 14 degrees were included in Group 2. Statistical analysis of the evaluated variables was made., Results: Computer users in both groups used more tear supplements (as part of the syndrome) than expected. This association was statistically significant (p < 0.10). Participants in Group 1 reported more pain than participants in Group 2. Associations between the CVS and other personal or ergonomic variables were not statistically significant., Conclusions: Our findings show that the most important factor leading to the syndrome is the angle of gaze at the computer monitor. Pain in computer users is diminished when gazing downwards at angles of 14 degrees or more. The CVS remains an under estimated and poorly understood issue at the workplace. The general public, health professionals, the government, and private industries need to be educated about the CVS.

Presently, in the Globally Harmonised System of Classification and Labelling of Chemicals the classification of substances for long-term effects to aquatic life is based on acute toxicity in combination with degradation and/or bioaccumulation potential. Recently an OECD Working Group was created to develop the classification scheme to accommodate chronic toxicity data related to aquatic organisms for assigning a chronic hazard category. This study focuses on a new approach for setting chronic toxicity cut-off values based on Chemicals Toxicity Distributions (CTDs). A CTD is obtained through statistical fitting of the data used by regulatory bodies for setting hazard-based classifications. The CTDs were made using the lowest aquatic NOEC value of each chemical. A review of different toxicological sources reporting acute aquatic toxicities was carried out. Initially, the data were arranged according to the specific source and distributions for key taxonomic groups (i.e. fishes, crustaceans and algae) were evaluated separately. In most cases, no significant departures from normality were observed. Thereafter, a compiled database containing >900 values was developed and the CTDs were constructed for each taxonomic group. Significant deviation from normality (P < 0.05) was observed in the fishes and crustaceans' CTDs. However, this deviation was apparently produced by the presence of only seven values with NOECs <1 x 10(-5) mg l(-1), while high correlation between the data and the normal scores (r-values>or= 0.989) indicated that the data were samples from normal distributions. From these observations, potential cut-off values would allow quantitative estimations of the percentage of chemicals falling into each specific category. This approach results in a simple classification hazard scheme where most chemicals are covered in one of the categories, allowing a clear distribution of the chemicals among three categories for chronic toxicity.

Introduction: Vision and eye related problems are common among computer users, and have been collectively called the Computer Vision Syndrome (CVS)., Methods: An observational study in order to identify the risk factors leading to the CVS was done. Twenty-eight participants answered a validated questionnaire, and had their workstations examined. The questionnaire evaluated personal, environmental, ergonomic factors, and physiologic response of computer users. The distance from the eye to the computers' monitor (A), the computers' monitor height (B), and visual axis height (C) were measured. The difference between B and C was calculated and labeled as D. Angles of gaze to the computer monitor were calculated using the formula: angle=tan(-1)(D/ A). Angles were divided into two groups: participants with angles of gaze ranging from 0 degrees to 13.9 degrees were included in Group 1; and participants gazing at angles larger than 14 degrees were included in Group 2. Statistical analysis of the evaluated variables was made., Results: Computer users in both groups used more tear supplements (as part of the syndrome) than expected. This association was statistically significant (p<0.10). Participants in Group 1 reported more pain than participants in Group 2. Associations between the CVS and other personal or ergonomic variables were not statistically significant., Conclusions: Our findings show that most important factor leading to the syndrome is the angle of gaze at the computer monitor. Pain in computer users is diminished when gazing downwards at angles of 14 degrees or more. The CVS remains an under estimated and poorly understood issue at the workplace. The general public, health professionals, the government, and private industries need to be educated about the CVS.