Paving the way for application of next generation risk assessment to safety decision-making for cosmetic ingredients

Next generation risk assessment (NGRA) is an exposure-led, hypothesis-driven approach that has the potential to support animal-free safety decision-making. However, significant effort is needed to develop and test the in vitro and in silico (computational) approaches that underpin NGRA to enable confident application in a regulatory context. A workshop was held in Montreal in 2019 to discuss where effort needs to be focussed and to agree on the steps needed to ensure safety decisions made on cosmetic ingredients are robust and protective. Workshop participants explored whether NGRA for cosmetic ingredients can be protective of human health, and reviewed examples of NGRA for cosmetic ingredients. From the limited examples available, it is clear that NGRA is still in its infancy, and further case studies are needed to determine whether safety decisions are sufficiently protective and not overly conservative. Seven areas were identified to help progress application of NGRA, including further investments in case studies that elaborate on scenarios frequently encountered by industry and regulators, including those where a ‘high risk’ conclusion would be expected. These will provide confidence that the tools and approaches can reliably discern differing levels of risk. Furthermore, frameworks to guide performance and reporting should be developed.

Tree mode of death and mortality risk factors across Amazon forests

The carbon sink capacity of tropical forests is substantially affected by tree mortality. However, the main drivers of tropical tree death remain largely unknown. Here we present a pan-Amazonian assessment of how and why trees die, analysing over 120,000 trees representing > 3800 species from 189 long-term RAINFOR forest plots. While tree mortality rates vary greatly Amazon-wide, on average trees are as likely to die standing as they are broken or uprooted-modes of death with different ecological consequences. Species-level growth rate is the single most important predictor of tree death in Amazonia, with faster-growing species being at higher risk. Within species, however, the slowest-growing trees are at greatest risk while the effect of tree size varies across the basin. In the driest Amazonian region species-level bioclimatic distributional patterns also predict the risk of death, suggesting that these forests are experiencing climatic conditions beyond their adaptative limits. These results provide not only a holistic pan-Amazonian picture of tree death but large-scale evidence for the overarching importance of the growth-survival trade-off in driving tropical tree mortality.

Standardisation of defined approaches for skin sensitisation testing to support regulatory use and international adoption: position of the International Cooperation on Alternative Test Methods

Skin sensitisation is the regulatory endpoint that has been at the centre of concerted efforts to replace animal testing in recent years, as demonstrated by the Organisation for Economic Co-operation and Development (OECD) adoption of five non-animal methods addressing mechanisms under the first three key events of the skin sensitisation adverse outcome pathway. Nevertheless, the currently adopted methods, when used in isolation, are not sufficient to fulfil regulatory requirements on the skin sensitisation potential and potency of chemicals comparable to that provided by the regulatory animal tests. For this reason, a number of defined approaches integrating data from these methods with other relevant information have been proposed and documented by the OECD. With the aim to further enhance regulatory consideration and adoption of defined approaches, the European Union Reference Laboratory for Alternatives to Animal testing in collaboration with the International Cooperation on Alternative Test Methods hosted, on 4-5 October 2016, a workshop on the international regulatory applicability and acceptance of alternative non-animal approaches, i.e., defined approaches, to skin sensitisation assessment of chemicals used in a variety of sectors. The workshop convened representatives from more than 20 regulatory authorities from the European Union, United States, Canada, Japan, South Korea, Brazil and China. There was a general consensus among the workshop participants that to maximise global regulatory acceptance of data generated with defined approaches, international harmonisation and standardisation are needed. Potential assessment criteria were defined for a systematic evaluation of existing defined approaches that would facilitate their translation into international standards, e.g., into a performance-based Test Guideline. Informed by the discussions at the workshop, the ICATM members propose practical ways to further promote the regulatory use and facilitate adoption of defined approaches for skin sensitisation assessments.

Cobalt oxide as a selective co-catalyst for water oxidation in the presence of an organic dye

In photobiocatalytical processes involving the simultaneous oxidation of water and reduction of specific organic molecules (e.g., cofactors), the lack of physical separation of the redox half-reactions adversely affects the product stability. This is largely because organic molecules are generally less stable within harsh oxidative environments. In general, surface co-catalysts are able to improve the selectivity of photocatalysts towards water oxidation. However, harsh oxidative environments reduce the chemical stability of the organic molecules. Herein, we show that the use of Co₃O₄ as a surface co-catalyst on silver orthophosphate improve water photo-oxidation in the presence of organic dye molecules, such as methylene blue, that typically exhibits susceptibility toward photodegradation. The presence of Co₃O₄ on the photocatalyst surface prevents the adsorption of the organic dye, thus reducing its degradation rate. These findings provide a promising scenario for the visible light-driven reduction of organic molecules using water as an electron donor.

[Elevated incidence of cognitive impairment in patients with asymptomatic carotid stenosis]

INTRODUCTION

Stroke is one of the main causes of mortality and functional disability in developed countries. Carotid stenosis (CS) is considered the reason for 20-30% of strokes. However, the studies that have gone into depth on the cognitive status of these patients are limited.

AIM

To investigate the cognitive performance of CS patients and its relationship with clinical variables (carotid obstruction, lifestyle).

PATIENTS AND METHODS

33 CS patients were evaluated using a broad neuropsychological protocol, and were divided into two groups: symptomatic CS and asymptomatic CS.

RESULTS

50-57% of CS patients showed deficits in processing speed and visual memory (immediate recall). 41.9% showed altered performance in semantic fluency, whereas the percentage was 30% in digits subtest. The percentage of altered performance was 20-27% in verbal memory (learning curve, delayed recall) and visual memory (delayed recall). No significant differences were found between the symptomatic CS and asymptomatic CS groups. Cognitive performance correlated significantly with lifestyle scale factors, but not with the percentage of carotid obstruction.

CONCLUSION

A high percentage of CS patients showed a clinically altered performance in different cognitive domains, regardless of suffering vascular neurological symptoms (symptomatic vs asymptomatic CS). A close relationship was found between lifestyle and cognitive status of CS patients.

Pattern of neuropsychological impairment in the early phase of relapsing-remitting multiple sclerosis

To investigate the neuropsychological profile in the first few years post-onset of relapsing-remitting multiple sclerosis (MS) we carried out a comprehensive neuropsychological evaluation of 33 patients characterized by very short evolution of this disease, minimal levels of neurological disability and preserved general cognition. Thirty-three individually pair-matched controls were also evaluated. Patients performed as well as controls on many of the cognitive exploration measures. Nevertheless, the group of patients evinced a general slowness that affected motor execution and cognitive processing. Memory functions were characterized by preservation of working memory, retrieval or storage of information and a deficit at the acquisition phase in (verbal and visual) supraspan tasks. In addition, significant correlations were observed between some measures of information processing speed and memory. These results highlight the importance of studying cognitive deficits not only in the different subtypes of MS but also in different phases of the disease.

Long-term decline of the Amazon carbon sink

Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.

Managing knee ostheoarthritis: efficacy of hyaluronic acid injections

Osteoarthritis (OA) is the most common form of chronic arthritis worldwide. The etiology of pain in osteoarthritis is multifactoral, and includes mechanical and inflammatory processes. The use of intra-articular viscosupplementation in the nonoperative management of patients with osteoarthritis has become quite popular. Recent clinical data have demonstrated that the anti-inflammatory and chondroprotective actions of hyaluronic acid viscosupplementation reduce pain, from 4 to 14 weeks after injection, while improving patient function. Viscosupplements are comparable in efficacy to systemic forms of active intervention, with more local reactions but fewer systemic adverse events, and hyaluronic acid has more prolonged effects than IA corticosteroids. Although several randomized controlled trials have established the efficacy of this treatment modality, additional high quality randomized control studies with appropriate comparison are still required to clearly define the role of intra-articular hyaluronic acid injections in the treatment of osteoarthritis. We review the basic science and development of viscosupplementation and discuss the mounting evidence in support of its efficacy and safety profile.

Trauma, stressful life events and depression predict HIV-related fatigue

Despite the fact that fatigue is a common and debilitating symptom among HIV-infected persons, we know little about the predictors of fatigue in this population. The goal of this cross-sectional study was to examine the effects of early childhood trauma, recent stressful life events and depression on intensity and impairment of fatigue in HIV, over and above demographic factors and clinical characteristics. We studied 128 HIV-infected men and women from one southern state. The median number of childhood traumatic events was two and participants tended to have at least one moderate recent stressful event. Multiple regression findings showed that patients with less income, more childhood trauma, more recent stressful events and more depressive symptoms had greater fatigue intensity and fatigue-related impairment in daily functioning. Recent stresses were a more powerful predictor of fatigue than childhood trauma. None of the disease-related measures (e.g. CD4, viral load, antiretroviral medication) predicted fatigue. Although stress and trauma have been related to fatigue in other populations, this is the first study to examine the effects of traumatic and recent stressful life events on fatigue in an HIV-infected sample.

Measuring fatigue in people living with HIV/AIDS: psychometric characteristics of the HIV-related fatigue scale

In the era of life-prolonging antiretroviral therapy, chronic fatigue is one of the most prevalent and disabling symptoms of people living with HIV/AIDS, yet its measurement remains challenging. No instruments have been developed specifically to describe HIV-related fatigue. We assessed the reliability and construct validity of the HIV-Related Fatigue Scale (HRFS), a 56-item self-report instrument developed through formative qualitative research and designed to measure the intensity and consequences of fatigue as well as the circumstances surrounding fatigue in people living with HIV. The HRFS has three main scales, which measure fatigue intensity, the responsiveness of fatigue to circumstances and fatigue-related impairment of functioning. The functioning scale can be further divided into subscales measuring impairment of activities of daily living, impairment of mental functioning and impairment of social functioning. Each scale demonstrated high internal consistency (Cronbach's alpha=0.93, 0.91 and 0.97 for the intensity, responsiveness and functioning scales, respectively). The HRFS scales also demonstrated satisfactory convergent validity when compared to other fatigue measures. HIV-Related Fatigue Scales were moderately correlated with quality of nighttime sleep (rho=0.46, 0.47 and 0.35) but showed only weak correlations with daytime sleepiness (rho=0.20, 0.33 and 0.18). The scales were also moderately correlated with general mental and physical health as measured by the SF-36 Health Survey (rho ranged from 0.30 to 0.68 across the 8 SF-36 subscales with most >0.40). The HRFS is a promising tool to help facilitate research on the prevalence, etiology and consequences of fatigue in people living with HIV.

[Verbal fluency in school-aged Spanish children: normative data and analysis of clustering and switching strategies]

INTRODUCTION

Verbal fluency tasks are highly sensitive to the presence of brain pathology. The use of verbal fluency tasks in paediatric clinical neuropsychology requires knowing how the execution progresses across age. Developmental changes in children's verbal fluency were explored in this study.

SUBJECTS AND METHODS

Participants were 79 school-aged children divided into three age groups. Phonemic (FAM) and semantic (animals) fluency task were administered. Three scores were obtained for qualitative analyses: number of clusters, switches and mean cluster size.

RESULTS

Children in older groups generated more words in phonemic fluency than children in 6-7 years group. In semantic fluency differences were significant only between the 10-11 years group and the youngest group. In both tasks year-group effects were found in number of clusters and number of switches. High positive correlations were found between total production and number of cluster and number of switches.

CONCLUSIONS

Results suggest that the development of the capability to generate words is related to the maturation of frontal component of the task. That means, that it is related to development of a greater cognitive flexibility that allows more efficient strategic search processes. Data obtained, although preliminary, may be useful to evaluate the executive functions in Spanish speaking paediatric population.

Progression to AIDS, a clinical AIDS condition and mortality: psychosocial and physiological predictors

BACKGROUND

The primary aim of this study is to examine prospectively the association of stressful life events, social support, depressive symptoms, anger, serum cortisol and lymphocyte subsets with changes in multiple measures of human immunodeficiency virus (HIV) disease progression.

METHODS

Ninety-six HIV-infected gay men without symptoms or anti-retroviral medication use at baseline were studied every 6 months for up to 9 years. Disease progression was defined in three ways using the Centers for Disease Control (CDC) classifications (e.g. AIDS, clinical AIDS condition and mortality). Cox regression models with time-dependent covariates were used, adjusting for control variables (e.g. race, age, baseline, CD4 T cells and viral load, number of anti-retroviral medications).

RESULTS

Higher cumulative average stressful life events and lower cumulative average social support predicted faster progression to both the CDC AIDS classification and a clinical AIDS condition. Higher anger scores and CD8 T cells were associated with faster progression to AIDS, and depressive symptoms were associated with faster development of an AIDS clinical condition. Higher levels of serum cortisol predicted all three measures of disease progression.

CONCLUSIONS

These results suggest that stressful life events, dysphoric mood and limited social support are associated with more rapid clinical progression in HIV infection, with serum cortisol also exerting an independent effect on disease progression.

Production and characteristics of Debaryomyces hansenii killer toxin

The optimal conditions for the production of the killer toxin of Debaryomyces hansenii CYC 1021 have been studied. The lethal activity of the killer toxin increased with the presence of NaCl in the medium used for testing the killing action. Production of the killer toxin was stimulated in the presence of proteins of complex culture media. Addition of nonionic detergents and other additives, such as dimethylsulfoxide enhanced killer toxin production significantly. Killer toxin secretion pattern followed the growth curve and reached its maximum activity at the early stationary phase. Optimal stability was observed at pH 4.5 and temperatures up to 20 degrees C. Above pH 4.5 a steep decrease of the stability was noted. The activity was hardly detectable at pH 5.1.

(1-->6)-Beta-D-glucan as the cell wall binding site for Debaryomyces hansenii killer toxin

AIMS

The aims of this study were to characterize the cell wall binding site of Debaryomyces hansenii killer toxin to provide a simple purification method and to determine some characteristics of this toxin.

METHODS AND RESULTS

Various linear (1-->6)-beta-D-glucans of different origins were effective competitive inhibitors of the toxin action. Periodate oxidation and 1H-NMR was used to determine the receptor nature. Affinity chromatography on pustulan-Sepharose column was used to purify D. hansenii killer toxin, probably a 23-kDa protein. The killer toxin character was cureless.

CONCLUSIONS

The investigation revealed that the killer toxin was mainly adsorbed by (1-->6)-beta-D-glucans. This is a low molecular weight protein, probably encoded by chromosomal genes.

SIGNIFICANCE AND IMPACT OF THE STUDY

The specificity of the killer toxin for its receptor provides an effective means to purify the killer toxin. This study is the first to identify the cell wall binding site of this killer toxin, a toxin with properties of industrial relevance.

In the field with the Beck depression inventory

Qualitative methods are typically and formally used only in the earliest phases of instrument development to generate items. Once these items are generated, instrument development usually then moves into the testing phases, where quantitative methods prevail. The achievement of psychometric credibility is presumed to depend largely on quantitative measures of reliability and validity. Or if qualitative methods are employed, their use is masked, unfocused, and/or unplanned. The planned use of qualitative methods is critical in every phase of instrument use and in all studies that depend for their results on instruments, and their use is critical in illuminating problems with existing instruments. The authors illustrate these points by drawing on the first author's experiences in the field with the Beck Depression Inventory in her research program on managing fatigue in persons with HIV/AIDS.

[Study of brain asymmetry with neurologically normal subjects: visual procedures]

OBJECTIVES

We present a revision of the technique of visual lateralization of stimuli as one approach to the study of brain asymmetry with regard to language. At the same time, we present a summary of the research carried out by our group using these techniques, reflecting not only the main results but also the most relevant methodological aspects.

DEVELOPMENT

Brain asymmetry is a basic characteristic of the organization of the nervous system. In most of the principal psychological processes there exists a greater or lesser degree of hemispheric differentiation. Among these, language is possibly one of the processes most noticeably lateralized. One of the main approaches in this field is the study of neurologically normal subjects using techniques of visual lateralization of stimuli. Appropriate use of this technique requires a knowledge of the basic principles involved and of the methodological requirement, as well as the different types of tasks and stimuli, which can be adapted to these requirements.

CONCLUSIONS

The technique of lateralization of visual stimuli has a long tradition as a procedure for the study of cerebral asymmetry for language and is within the possibilities of most laboratories. However, ensuring correct lateralization requires rigorous controls and this has to be taken into consideration in the selection and adaptation of the experimental paradigm to be used. Several of these paradigms are used in our research and our results provide evidence of the relative character of cerebral asymmetry and of the participation of the right hemisphere in lexico-semantic processing.

Comparison between African-American and white women in their beliefs about breast cancer and their health locus of control

The purpose of this study was to examine the health beliefs of African-American and white women about breast cancer and locus of control, using the health belief model and the health locus of control construct. The Health Screening Questionnaire, developed by Sugarek, Deyo, and Holmes, was used to collect self-report data about health beliefs related to breast cancer and health locus of control. Participants included 197 white and 152 African-American women, between the ages of 19 and 93, recruited from various settings in central Florida. Significant differences were found between the two groups on all of the health beliefs about cancer items. The African-American women were significantly more likely to believe in chance, or to depend on powerful others for their health. Perceived susceptibility to cancer, doubts about the value of early diagnosis, and beliefs about the seriousness of breast cancer all were significantly associated with powerful other scores among African-American women. There was no relation between health beliefs and years of education for African-American women, but for white women, those with the least education were more likely to believe that death was inevitable with a cancer diagnosis. These results add to the information needed for the development of effective programs aimed at increasing breast cancer screening among African-American women.

[Neuropsychological assessment in multiple sclerosis]

OBJECTIVE

Over the past 20 years great advances have been made in understanding the neuropsychological changes in multiple sclerosis. In this paper we review the nature of mental deterioration in multiple sclerosis and the procedures used for its evaluation.

DEVELOPMENT

First we give a short summary of present knowledge of the involvement of different functions and the instruments most generally used to evaluate it. We then consider the different approaches to neuropsychological assessment, the use of broad guidelines as opposed to screening techniques, bearing in mind their advantages and disadvantages in the clinical field and in investigation. Similarly we mention the current trends in the evaluation and treatment of multiple sclerosis.

CONCLUSIONS

The general profile of neuropsychological alterations in multiple sclerosis is characterized by the presence of changes in secondary memory and speed of thought, although the nature of this defect is still not clear. Changes are also seen in other neuropsychological functions, although less frequently and more controversially. Our knowledge of the prevalence of these changes comes from the use of guidelines for thorough examination. However, the current tendency is to seek instruments for evaluation which combine diagnostic efficiency, clinical usefulness and brevity. In this respect, although progress is being made, there are still questions to be answered.

Metasynthesis of qualitative research on living with HIV infection

Qualitative studies of people living with HIV infection are crucial for providing direction for practice and research because they provide the emic perspective. As more of these qualitative studies are conducted, researchers are challenged to develop ways to synthesize the findings for research and clinical practice. The purpose of the metasynthesis described in this article was to understand the experience of adults living with HIV infection as described in published research. Findings from the studies were categorized into six overarching metaphors: (a) finding meaning in HIV/AIDS, (b) shattered meaning, (c) human connectedness, (d) focusing on the self, (e) negotiating health care, and (f) dealing with stigma.

Hemispheric asymmetry in lexical decisions: the effects of grammatical class and imageability

It has been suggested that neural systems for lexical processing of nouns and verbs are anatomically distinct. The aim of the present study was to investigate if brain asymmetry for the processing of these two grammatical classes is also different. Neurologically intact adults performed a lateralized lexical decision task with grammatically unambiguous words of high, medium, and low degrees of imagery. For error scores a right visual field (RVF) advantage and an overall effect of imageability were obtained. For latency scores grammatical class and imageability modified visual field differences: in the noun class a RVF advantage was obtained only for low imagery nouns, while for the verbs the RVF advantage was present for both medium and low imagery verbs. These results suggest that the participation of right hemisphere neural systems in the processing of verbs is more limited than in the processing of nouns.

A review of fatigue in people with HIV infection

Fatigue is often cited by clinicians as a debilitating symptom suffered by the many who are infected with HIV. This article provides a review of HIV-related fatigue, including research on possible physiological causes such as anemia, CD4 count, impaired liver function, impaired thyroid function, and cortisol abnormalities. Psychological causes of fatigue, particularly depression, are reviewed as well. Measurement issues, such as the use of inappropriate tools, the problem of measuring the presence or absence of fatigue, and the use of tools developed for other groups of patients, are reviewed. The need for a comprehensive fatigue tool that is appropriate for people with HIV is discussed. Current treatment research, including thyroid replacement, hyperbaric oxygen, and dextroamphetamine, is presented. Finally, the implications for further research, including the need for qualitative studies to learn more about the phenomenon, develop an instrument to measure fatigue, and examine variables together to get a complete picture of this complex concept, are reviewed.

Long-term nonprogressors with HIV disease

BACKGROUND

Although biomedical research is being conducted on long-term nonprogressors with HIV disease, there is relatively little research on the psychosocial factors influencing this phenomenon.

OBJECTIVE

To describe the perceptions of long-term nonprogressors of their HIV disease and its course.

METHOD

A naturalistic study design was used to elicit information from 25 men and women who were long-term nonprogressors (HIV positive for 7 or more years, CD4 count > 500, and free of opportunistic infections and/or AIDS-defining illnesses). Audiotaped interviews were transcribed verbatim, and content analysis and constant comparison were used to elicit themes.

RESULTS

Themes include viewing HIV as a manageable illness, taking care of my physical health, human connectedness, taking care of my emotional/mental health, and spirituality. Specific ways of adapting to HIV are identified within each theme.

CONCLUSIONS

The results of this study can be used by nurses who work with HIV positive individuals in an effort to help them adopt strategies that may assist them in maintaining their health. However, longitudinal studies that follow this group over time and that include biomedical markers of disease progression would provide knowledge that would assist in the refinement of these interventions.

Social support and long-term survivors of AIDS

A naturalistic study design using ethnographic interviews was employed to elicit data about the phenomenon of being a long-term survivor of AIDS from 14 men and 6 women. Data were generated through multiple intensive open-ended interviews, demographic data sheets, and self-reported CD4 counts. Data were analyzed using latent and manifest content analysis techniques and the method of constant comparison. One of the dimensions that emerged from the data was "being in relation to others," the complex set of interpersonal relationships that have been renegotiated to maintain the reconstructed life. Specific ways of being in relation to others included dealing with one's family, renegotiating the friendship group, helping others with HIV, and developing a relationship with a higher power. The results of this study have implications for counseling people with HIV disease, and for nursing actions to enhance social support in this vulnerable group.

Focusing on living: attitudinal approaches of long-term survivors of AIDS

This naturalistic study reports the attitudinal approaches of long-term survivors of AIDS. Ethnographic interviewing techniques were employed to interview a purposive sample of 14 men and 6 women who had had AIDS for at least 3 years and who were living in the Tampa/St. Petersburg, FL, area. As part of a larger study on the phenomenon of surviving AIDS, participants reconstructed their lives within the context of AIDS. There were five dimensions involved in becoming a long-term survivor, and this article reports on the attitudinal dimension, labelled "focusing on living." Components of this dimension include having a positive attitude, planning for the future, and having a focus for one's energies. Implications for practice, theory, and research are discussed, and specific strategies are suggested for nurses to assist people in all stages of HIV disease.

Individual and combined effects of triptoreline and gestrinone on experimental endometriosis in rats

OBJECTIVES

To evaluate the effects of triptoreline, gestrinone, and both, on experimental endometriosis in rats.

STUDY DESIGN

Experimental endometriosis was surgically induced in 225 Wistar rats. Of these, 202 rats showed at least one grown implant, 22 of which composed the control group, while 180 were treated with triptoreline, gestrinone, or both, for 28 days. The implants were evaluated again after 25 days.

RESULTS

There were no changes in size in the control group. About 73% of the implants treated with triptoreline showed a high reduction (> 50%), vs. 51% with gestrinone (P < 0.0005) and 65% with both (P < 0.005). Triptoreline caused macroscopic resolution in 40% of the implants vs. 31% for gestrinone (not significant) and 26% for both substances (P < 0.05). In the triptoreline group, the mean size of the implants decreased by 65% between the 25th and 28th days, 58% between the 29th and the 35th, and 39% after the 36th day. This reduction was 51%, 36%, and 33%, respectively, in gestrinone group.

CONCLUSIONS

Triptoreline was more effective than gestrinone, but perhaps not in the long run. Their association did not improve the results.

Self-care activities of long-term survivors of acquired immunodeficiency syndrome

The article reports the self-care activities of long-term survivors of acquired immunodeficiency syndrome (AIDS). A naturalistic, descriptive study design using ethnographic interviewing techniques was employed to interview 14 men and 6 women who had AIDS for at least 3 years. The self-care activities reported were globally labeled as taking care of oneself. Discontinuing negative health habits, undertaking health-promoting activities, being responsible for one's health, and decreasing stress were reported by participants as behaviors allowing them to survive and thrive with AIDS. This study offers nurses strategies to assist people in all stages of human immunodeficiency virus disease to find health within the context of their illness.

Hemispheric specialization for word classes with visual presentations and lexical decision task

In the present paper we study the possible RH capabilities for the processing of adjectives and verbs of high frequency and medium imagery using a lexical decision task and a horizontal display. In the analysis of both RTs and mean errors, a RVF advantage is obtained. The interaction VF x Word Class did not reach significance. Therefore, we did not find evidence of differences in the visual-field effect for any syntactic class. These results support a LH superiority for the processing of both adjectives and verbs. For the nonword conditions (pseudoverbs and pseudoadjectives), no visual field differences were observed in either group. Methodological aspects are also discussed.

Semantic capabilities of the left and right cerebral hemispheres in categorization tasks: effects of verbal-pictorial presentation

Two lateral tachistoscopic experiments were carried out to test semantic capabilities of the left and right cerebral hemispheres through categorization tasks with verbal and pictorial presentations. RVF advantages were obtained for verbal presentations in both category-membership and category-matching tasks. However, no significant visual-field differences were found for any pictorial presentation. We also found a higher degree of sensitiveness of the positive judgements for the detection of hemispheric differences and sex differences in patterns of functional asymmetries with a greater lateralization in males.

Behavioral lateralization in rats and dopaminergic system: Individual and population laterality

Recently, we reported that practice facilitates the expression of the behavioral asymmetry in rats at individual and population levels. In the present study we investigated the side preference in the performance of four different tasks during 10 successive days. The practice increased individual laterality and internal consistency in all tasks. In addition, practice facilitated the expression of marked population laterality in two tasks (78.1% and 63.3% for right bias). The influence of dopaminergic systems on these behaviors was evaluated with apomorphine and with 6-hydroxydopamine lesions ipsi- and contralateral to the side preference. The results suggest that there is a presynaptic dominance contralateral to the side preference in the four tests. However, as influences of dopaminergic systems were different in each task and because the tests were unrelated, the results suggest that the behavioral laterality in rats, as in humans, is a phenomenon caused by different and relatively independent systems.

Localization of uricase in mycorrhizas of Ophrys lutea Cav

Infected roots of Ophrys lutea present nymerous peroxisome profiles identified by diaminobenzidine (DAB) staining. The presence of uricase in these peroxisomes could also be recognized cytochemically. The activities of catalase and uricase, assayed using a crude fraction of peroxisomes, reached 0·8 μkat min^-1 protein-1 and 1·73 nakat min^-1 mg protein^-1 respectively. The role of uricase in purine metabolism is discussed in terms of host/endophyte interactions in O. lutea mycorrhzas.

COATED VESICLES IN THE CYTOPLASM OF THE HOST CELLS IN OPHRYS LUTEA CAV. MYCORRHIZAS (ORCHIDACEAE)

The host cells from endomycorrhizas of Ophrys lutea Cav. contain many coated vesicles associated with dictyosomes, with a membrane system (probably partially coated reticulum) and with the host's sequestration plasmalemma. The contents of coated vesicles stain with neither the PATAg test for polysaccharides nor with ruthenium red. The involvement of coated vesicles in the host/endophyte interactions during the establishment of O. lutea endomycorrhizas is discussed.

Lateralization in male rats and dopaminergic system: evidence of right-side population bias

Recent studies have reported population right-biased lateralization in rats, although with low percentages (between 54-59%). The present study investigated the spatial preference of rats in an electrified T-maze during successive days and the influence of ascending dopaminergic systems using apomorphine, a dopamine agonist, as well as ipsilateral and contralateral lesions on the side preference. Results showed a marked right-biased lateralization at both individual and population levels (85.71% of the rats presented a behavioral asymmetry, being 80% right-biased and 20% left-biased within the lateralized group). Also, the results suggest that there is a presynaptic dominance in the contralateral dopaminergic system to the spatial preference in the T-maze and postsynaptic dominance in the ipsilateral side.

Mechanism of the pulmonary edema induced by intravenous injection of scorpion toxin in the rat

The intravenous injection of purified scorpion toxin (tityustoxin, TsTX) into unanesthetized rats induces a severe systemic hypertension followed by a hemorrhagic edema of the lungs. The edema is focal or diffuse, whereas the hemorrhage is always focal and less prominent than the edema. Anesthesia of the rats prevents the appearance of pulmonary edema. It seems likely that this protective action of the anesthesia is due, at least in part, to an interference with the hypertension induced by TsTX. The pulmonary edema is prevented by bilateral adrenalectomy, guanethidine or phenoxybenzamine. It is suggested that the edema depends on a sympathetic-adrenal discharge and that catecholamines released by TsTX act on alpha adrenergic receptors. The mean kininogen content of the rat plasma, 1 h after TsTX injection, is not significantly different from that found in the control animals. The possible role played by kinins and other mediators in the early phases of the pulmonary edema induced by TsTX is under investigation.