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PubMed2005

The FEMA GRAS assessment of hydroxy- and alkoxy-substituted benzyl derivatives used as flavor ingredients.

This publication is the ninth in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of hydroxy- and alkoxy-substituted benzyl derivatives as flavoring ingredients is evaluated. The group of hydroxy- and alkoxy-benzyl derivatives was reaffirmed as GRAS (GRASr) based, in part, on their self-limiting properties as flavoring substances in food; their rapid absorption, metabolic detoxication, and excretion in humans and other animals; their low level of flavor use; the wide margins of safety between the conservative estimates of intake and the no-observed-adverse effect levels determined from subchronic and chronic studies and the lack of significant genotoxic and mutagenic potential. This evidence of safety is supported by the fact that the intake of hydroxy- and alkoxy-substituted benzyl derivatives as natural components of traditional foods is greater than their intake as intentionally added flavoring substances.

Alcohols↗
PubMed2005

Review of the toxicology of carbonyl sulfide, a new grain fumigant.

Carbonyl sulfide (COS) is a new grain fumigant which has been developed to replace methyl bromide, being phased out due to its ozone depletion properties, and to supplement phosphine gas which is experiencing increased insect resistance. Treatment of commodities with COS, a highly effective fumigant, results in residues that are near or indistinguishable to natural background levels of this compound. COS is a naturally occurring gas, being the predominant sulfur moiety in the atmosphere, occurs naturally in food and is a normal by-product of mammalian aerobic metabolism. COS has low acute inhalational toxicity but with a steep dose response curve; COS is neither genotoxic nor a developmental toxicant but does reversibly impair male fertility. Prolonged, repeated exposure to COS is likely to present similar neurotoxicity hazards to that of the structurally and toxicologically related compound carbon disulfide. Although the occupational risks presented by COS as a fumigant of bulk grain are significant, these are, as they have been for a considerable time for phosphine and methyl bromide, manageable by good occupational safety practices. Consideration may need to be given to scrubbing of ventilated COS and its breakdown product hydrogen sulfide, at the completion of fumigation to minimise worker and bystander exposure. In terms of classical regulatory toxicology studies, the available database for COS is deficient in many aspects and registration in most jurisdictions will depend on sound scientific argument built upon the totality of the existing scientific data as there are strong arguments supporting the registration of this compound.

Animals↗
PubMed2005

Influence of orange juice in the levels and in the genotoxicity of iron and copper.

World consumption of natural juices is increasing as a consequence of the human search for a healthier life. The juice production industry, especially for orange juice, is expanding in several countries and particularly in Brazil. Despite scientific data reporting beneficial properties derived from juice consumption, some components of juices have been identified as mutagenic or carcinogenic. Carcinogenic or genotoxic effects may be mediated by the interaction of juice components with transition metals or by sub-products of juice auto-oxidation. In this study, the mutagenic potential of orange juice and two metallic agents used in dietary supplementation, FeSO(4) and CuSO(4), were investigated using the comet assay in mouse blood cells (in vivo). Both metal compounds were genotoxic for eukaryotic cells after 24h treatment at the doses used. Significant damage repair was observed after 48h of treatment with the same compounds. Orange juice had a modulating effect on the action of metallic sulfates. In the case of iron treatment, the presence of the orange juice had a preventive, but not restorative, effect. On the other hand, in the case of copper treatment, the effects were both preventive and restorative. PIXE (particle induced X-ray emission) analysis indicated a positive correlation between DNA damage and the hepatic levels of iron and a negative correlation between whole blood copper and DNA damage. A negative correlation between hepatic iron and whole blood copper content was also seen in the treatment with both ferrous and cupric sulfates.

Analysis of Variance↗
PubMed2006

Neurotoxicity of Coscinium fenestratum stem, a medicinal plant used in traditional medicine.

Coscinium fenestratum is a common medicinal plant widely used in the Indochina region, but scientific data on its safety is very limited. This study aimed to observe the effect of this plant on neurotoxicity and neurobehavior. Oral administration of plant alcoholic extract at dosages of 5, 10 and 20 mg/kgBW for 14 days increased the rats body weight and decreased the neuron density in the cerebral cortex, hippocampus and striatum. The plant extract significantly increased stereotyped behavior in licking but did not cause anxiolytic activity, anti-depression, sensory motor co-ordination impairment and ataxia. It is concluded that the plant possesses neurotoxicity and is able to induce neurobehavioral changes in rats. Therefore, the application of this plant as either drug or supplementary food should be reconsidered.

Animals↗
PubMed2004

Tools for making correct decisions regarding hormone therapy. part I: background and drugs.

OBJECTIVE: To review existing scientific data related to the biology of estrogen in the aging process of women, and to understand the pharmacology, physiology, and diversity of sex hormones. DESIGN: A MEDLINE computer search was performed to identify relevant articles. RESULT(S): Estrogen and progesterone have been prescribed for postmenopausal women over the last 60 years. Various formulations have had divergent properties, which are related to dissimilarities in the molecule structure, metabolism, plasma carrier, distribution, receptor binding, and the specific localizations of the different receptors in the various organs. CONCLUSION(S): Extensive data are available on the various characteristics of sex-hormone formulations, which are related to clinical consequences. The drugs and means of application have resulted in fundamental differences in activity, such as variance between oral and transdermal applications resulting in different forms of liver involvement. This information could assist in understanding why certain formulations may either prove harmful or beneficial to specific women.

Administration, Cutaneous↗
PubMed2005

Angiographic diagnosis and endovascular management of nonvariceal gastrointestinal hemorrhage.

Diagnostic angiography still plays an essential role in the diagnosis of patients,particularly those with acute lower GI bleeding. Transcatheter therapy appears to be a viable treatment alternative in selected patients with GI bleeding. Many interventionists today believe embolotherapy to be more effective initially and to have better long-term results, specifically less rebleeding, than vasopressin infusion with at least equal complication rates. Unfortunately, direct comparison of the two techniques in a randomized, controlled fashion has not been performed. Small patient series, such as those summarized here, suggest that the results of the two techniques are essentially equal, and ischemic complications appear more prevalent with embolotherapy. The use of embolotherapy--either empirically based on endoscopic or surgical findings or directed against a site found to have contrast extravasation-represents the current intervention of choice in the case of upper GI bleeding refractory to endoscopic intervention. Head-to-head studies directly comparing the efficacy, morbidity, and mortality associated with endovascular or surgical correction of bleeding from the upper GI tract is needed. Although the current tide favors embolotherapy in the lower GI tract, infusion of vasoconstricting agents deserves more attention. To that end, there is a great need for scientific data regarding the safety and efficacy of transcatheter therapy for upper and lower GI bleeding.

Angiography↗
PubMed2005

[Diagnostic hysteroscopy and risk of peritoneal dissemination of tumor cells].

Questions have been raised about the safety of diagnostic hysteroscopy preceding surgical treatment of endometrial carcinoma. Several studies showed that the risk of a positive cytology among patients presenting endometrial adenocarcinoma was increased after diagnostic hysteroscopy, suggesting a peritoneal dissemination of tumor cells due to the exploration. We studied this hypothesis on the basis of a systematic review of the scientific data. Five studies fulfilling inclusion criteria have been selected and have been introduced into a fixed model of meta-analysis. On a total of 756 studied patients, 79 presented a positive peritoneal cytology. The diagnostic hysteroscopy did not increase significantly the risk of abdominal dissemination of tumor cells, the peritoneal cytology being positive among 38 patients in the group having undergone this intervention vs 41 patients in the control group (OR = 1,64; 95% CI: 0,96-2,80). In conclusion, no formal evidence is currently available concerning the role of diagnostic hysteroscopy on the frequency of peritoneal dissemination of tumor cells, or on the vital prognosis of the patients presenting with endometrial carcinoma. From the data available, there is not any reason to avoid diagnostic hysteroscopy in the initial workup of endometrial cancer.

Adenocarcinoma↗
PubMed2006

[Poisons for reproduction in work environment].

This article describes the lawful bases of the reprotoxic risk management in work environment, and sets out the recommendations of the French Société de Médecine du Travail (occupational medicine) for the medical supervision of pregnant wage-earners exposed to toxic substances as far as foetal development is concerned. We start with the description of the lawful bases, clarifying the various types of classification of toxic substances for reproduction, the particular regulation applying to reprotoxic categories 1 and 2, particularly with regard to the labelling of these products, the prohibition of availability to the general public, the principles of prevention and the guarantees of remuneration of the pregnant women exposed to this risk. Then, we present the recommendations worked out by the Société Française de Médecine du Travail, with regard to the medical supervision of pregnant wage-earners. They include: evaluation of the risk on the work place, evaluation of exposure, be it external or internal, presentation of methods of calculation of values guides and of recommendations transmitted to occupational doctors, before and during the pregnancy of their patients. To conclude, it is important to remain rigorous with this reprotoxic risk, by referring to the lawful bases at our disposal and supporting the scientific bases following epidemiologic studies. Adequate information must be given to women but also men pf procreation age. In spite of a well-defined lawful framework, watchfulness is required with the new products put on the market and the new scientific data.

Female↗
PubMed2004

Should patients with recent-onset polyarthritis receive aggressive treatment?

The diagnostic and therapeutic management of rheumatoid arthritis has benefited considerably in recent years not only from the introduction of new treatments (including new disease-modifying antirheumatic drugs, new combinations of these drugs, and TNF inhibitors), but also from the development of new concepts. Important new concepts include the use of novel diagnostic approaches, very early management within the first 3-6 months of symptom onset, periodic assessments of clinical disease activity based on objective clinical criteria and radiographic progression, and earlier use of aggressive treatments. The goal is to induce a clinical remission, thereby preventing radiographic deterioration. These concepts are firmly supported by sound scientific data. At present, patients at risk for progression to severe rheumatoid arthritis must be identified early on, and disease activity and progression must be monitored closely. This should enable patients with highly progressive disease to receive aggressive treatment (e.g., a combination of disease-modifying antirheumatic drugs or biological therapy) very early on with the goal of minimizing joint destruction and subsequent functional impairments.

Antirheumatic Agents↗
PubMed2004

The antioxidant potential of Sutherlandia frutescens.

One of the best-known multi-purpose medicinal plants in Southern Africa, Sutherlandia frutescens subsp. microphylla (family: Fabaceae/Leguminosa), is used for a wide range of conditions, including cancer, viral diseases and inflammatory conditions. Little scientific data has been documented on the mechanism by which Sutherlandia frutescens acts on the immune system. Phagocyte derived reactive oxygen species, such as hydrogen peroxide and superoxide radicals, are responsible for the pathogenesis of various inflammatory conditions. Anti-inflammatory properties of various medicinal-plant extracts have been explained, at least in part, by their antioxidant activities. We investigated the effects of a hot water extract of Sutherlandia frutescens on both luminol and lucigenin enhanced chemiluminescence of neutrophils stimulated with L-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) as well as its superoxide and hydrogen peroxide scavenging properties in a cell free system. The results indicate that Sutherlandia frutescens extract possesses superoxide as well as hydrogen peroxide scavenging activities at concentrations as low as 10 microg/ml, which could account for some of the anti-inflammatory properties that have been described.

Antioxidants↗
PubMed2005

Patients' and relatives' perceptions about intravenous and subcutaneous hydration.

Hydration during palliative care is a controversial topic. Most of the arguments are based on anedoctal reports that have not been substantiated with scientific data. Given that the choice is problematic from a clinical perspective, preferences of patients and family should dictate whether intravenous fluids are administered. The aim of this study was to evaluate patient and family perceptions about hydration and two modes of providing hydration. Fifty-four consecutive patients admitted to an acute pain relief and palliative care unit who required hydration completed a questionnaire regarding their perceptions on hydration and modes of hydration. Similarly, the principal family carer was chosen and similar questions were posed. For most items, patients and relatives agreed, considering hydration as a useful medical treatment that is able to provide some nutrition. The intravenous route was considered able to improve the clinical condition and to have a positive psychological meaning, representing an acceptable burden. The subcutaneous route was considered less effective, and not less bothersome than the intravenous route. Most patients and relatives agreed with continuing hydration at home, if necessary, preferring the intravenous route. Other than technical considerations, which can be variable according to the clinical setting, the perceived benefits of artificial hydration by the caregivers and patients are central to the ethical, emotional, and cultural considerations involved in their decision making. Most patients and relatives surveyed accepted and were in favor of intravenous hydration.

Adult↗
PubMed2005

Fundamentals of surgical research course: research presentations.

BACKGROUND: The effective communication of research outcomes is a skill that can be learned. To make the greatest impact, it is imperative to know your audience. METHODS: Oral communication is a highly effective means for dissemination of new information. The preparation of a research presentation requires significant time. The researcher must determine the key messages to be delivered and plan the presentation accordingly. High quality visual aids can impress your audience and, in combination with a succinct oral presentation, can increase retention of the material. CONCLUSIONS: In addition to the communication of the raw scientific data and results, the importance of stance, appearance, voice, and eye contact necessary to engage your audience should not be overlooked.

Audiovisual Aids↗
PubMed2005

Chlorinated pesticides and PCBs in the sea-surface microlayer and seawater samples of Singapore.

Sea-surface microlayer (SML) and seawater samples collected from Singapore's coastal marine environment were analyzed for selected chlorinated pesticides and polychlorinated biphenyls (PCBs). The SML is a potential site of enrichment of persistent organic pollutants (POPs) compared to the underlying water column. The concentration ranges of SigmaHCH, SigmaDDT and SigmaPCB in subsurface (1 m depth) seawater were 0.4-27.2 ng/l (mean 4.0 ng/l), 0.01-0.6 ng/l (mean 0.1 ng/l) and 0.05-1.8 ng/l (mean 0.5 ng/l) respectively. In the SML, the concentration ranges of SigmaHCH, SigmaDDT and SigmaPCB were 0.6-64.6 ng/l (mean 9.9 ng/l), 0.01-0.7 ng/l (mean 0.2 ng/l) and 0.07-12.4 ng/l (mean 1.3 ng/l) respectively. High spatial and temporal distribution was observed for all POPs measured. However, overall levels measured in the SML were lower than levels reported in the literature for SML samples from temperate coastal regions-possibly due to loss of semi-volatile compounds in the tropical climate of Singapore. Atmospheric wet deposition during the monsoon season may be an important source of POPs to the SML. This study provides the first scientific data on POP concentrations and enrichment factors in the SML for Southeast Asia.

Environmental Monitoring↗
PubMed2003

Progestins and their effects on the breast.

Nowadays, when the available scientific data on the in vivo effects of progestins on mammary gland tissue remain controversial, it is of utmost importance to establish adequate criteria to evaluate their actions. One of the reasons for this situation is that a variety of progestins have been studied using a number of different study designs. In addition, data relating to the effects of progestins on breast tissue have been interpreted differently from country to country. Recent data indicate that some progestins clearly oppose the favourable effects of estrogens on a number of important metabolic processes, e.g. influencing insulin-like-growth-factor (IGF)-1 serum levels. IGF-1 is a mitogenic and antiapoptotic peptide involved in growth regulation of breast epithelial cells. Circulating IGF-1 exerts endocrine action, it regulates growth hormone secretion by a negative feedback mechanism. In the past few years, both laboratory investigations and epidemiologic studies provided strong evidence that the IGF-1/growth hormone axis is involved in human cancer risk [Maturitas 29 (1998) 61; Horm. Res. 51 (1999) 34; Eur. J. Cancer 36 (2000) 1224; Maturitas 41 (2002) 299] Some progestins also have effects on the enzymes in breast tissue that are responsible for the local synthesis of estradiol. Thus, whilst progestins without androgenic action have been found to markedly inhibit these enzymes, an equivalent degree of inhibition is not achieved with testosterone-derivatives. Therefore, special attention should be paid to the various partial actions of the different progestins and their effects on breast tissue. Furthermore, factors such as the duration of breast tissue exposure to progestin activity, the influence of different regimens on protective apoptotic mechanisms in the breasts, as well as dose levels and the degree of mammary gland tissue differentiation throughout treatment, should also be considered.

Apoptosis↗
PubMed2005

[Adaptive behaviors to HIV risk of transmission in different populations].

Since the beginning of the HIV epidemic in France, surveys aimed at better understanding risk perceptions of HIV infection and preventive sexual behaviors have been implemented in the general population, and in populations such as IVDU and homosexual men, more concerned by risks of HIV transmission. The objective of this article is to describe these surveys, to present their main results and to assess what has been the overall impact of prevention campaigns on the adoption of preventive sexual behaviors in these populations. The results show that very early after the beginning of the AIDS epidemic, both general and homosexual populations have adopted preventive sexual behaviors, mainly increasing condom use and implementing other preventive strategies. However, with the introduction of HAART in 1996, a slackening of these preventive behaviors is noted. The use of condom is less frequent, especially in the youngest generations of both general and homosexual populations. On the opposite, among IVDU, the use of sterile syringes increased dramatically as soon as over-the-counter sales of syringes was authorized in 1987, as well as the adoption of ways other than intravenous to take drugs. Both have contributed to almost stop the HIV epidemic in this specific group. The results of these surveys show that the benefits of prevention campaigns are different between populations and are reversible. It is necessary to renew the messages, campaigns and programs of prevention with the renewal of generations. It is also necessary to adapt these messages to the new scientific data, and to the evolution of social and individual representations of the disease.

Antiretroviral Therapy, Highly Active↗
PubMed2005

Epilepsy and psychiatry: automatic psychic paroxysms.

This study analyzes diverse psychic phenomena which, although always occurring with very characteristic clinical features, are sometimes diagnosed as epilepsy and sometimes as symptoms of different psychiatric disorders depending on the availability of an electroencephalogram. It is posited that these phenomena, whenever they are accompanied by the features characteristic of an epileptic consciousness (suddenness, automatic nature, great intensity and a strong sensation of strangeness) should be diagnosed as partial seizures with a psychic content, regardless of the availability of an EEG. The co-occurrence of these four clinical signs, which are relatively simple to objectivize, is a more reliable clinical criterion for diagnosis than a transcraneal electroencephalogram, which, as is known, is of little value in measuring the electrical activity of partial seizures. Moreover, an interpretation of this type makes it possible to reconcile scientific data from various neurosciences which thus far have seemed contradictory.

Anticonvulsants↗
PubMed2006

Medical papyri describe the effects of the Santorini eruption on human health, and date the eruption to August 1603-March 1601 BC.

Egyptian medical papyri date the Santorini eruption, and reconcile the hitherto perceived dichotomy between archaeological/historical and scientific data. The medical documentation describes ailments, which can only have arisen from a volcanic source: ash fallout, rain acidified by ash, and a plume. Furthermore, the Egypt described by the medical texts matches the one in the series of so-called biblical plagues. This match in turn provides the length of time, 19 months, between the initial and final phases of the eruption, each phase contributing to the otherwise odd accumulation of sulfates spread over two consecutive biennia (1603-1600 BC) in Greenland's ice core. As a result, the initial phase of the eruption can be dated to August 21, 1603 BC, and the final one to March 1601 BC, in full agreement with the radiocarbon data (1627-1600 BC) based on the outermost ring on the branch of an olive tree killed by the eruption.

Archaeology↗
PubMed2004

Approaches for the development of occupational exposure limits for man-made mineral fibres (MMMFs).

Occupational exposure limits (OELs) are an essential tool in the control of exposure to hazardous chemical agents, and serve to minimise the occurrence of occupational diseases associated with such exposure. The setting of OELs, together with other associated measures, forms an essential part of the European Community's strategy on health and safety at work, upon which the legislative framework for the protection of workers from risks related to chemical agents is based. The European Commission is assisted by the Scientific Committee on Occupational Exposure Limits (SCOEL) in its work of setting OELs for hazardous chemical agents. The procedure for setting OELs requires information on the toxic mechanisms of an agent that should allow to differentiate between thresholded and non-thresholded mechanisms. In the first case, a no-observed adverse effect level (NOAEL) can be defined, which can be the basis for a derivation of an OEL. In the latter case, any exposure is correlated with a certain risk. If adequate scientific data are available, SCOEL estimates the risk associated with a series of exposure levels. This can then be used for guidance, when setting OELs at European level. Man-made mineral fibres (MMMFs) are widely used at different worksites. MMMF products can release airborne respirable fibres during their production, use and removal. According to the classification of the EU system, all MMMF fibres are considered to be irritants and are classified for carcinogenicity. EU legislation foresees the use of limit values as one of the provisions for the protection of workers from the risks related to exposure to carcinogens. In the following paper, the research requirements identified by SCOEL for the development of OELs for MMMFs will be presented.

Humans↗