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The psychological complexity of predictive testing for late onset neurogenetic diseases and hereditary cancers: implications for multidisciplinary counselling and for genetic education.

Increasing knowledge about the human genome has resulted in the availability of a steadily increasing number of predictive DNA-tests for two major categories of diseases: neurogenetic diseases and hereditary cancers. The psychological complexity of predictive testing for these late onset diseases requires careful consideration. It is the main aim of the present paper to describe this psychological complexity, which necessitates an adequate and systematic multidisciplinary approach, including psychological counselling, as well as ongoing education of professionals and of the general public. Predictive testing for neurogenetic diseases--in an adequate counselling context--so far elicits optimism regarding the short- and mid-term impact of the predictive test result. The psychosocial impact has been most widely studied for Huntington's disease. Longitudinal studies are of the utmost importance in evaluating the long-term impact of predictive testing for neurogenetic diseases on the tested person and his/her family. Given the more recent experience with predictive DNA-testing for hereditary cancers, fewer published scientific data are available. Longitudinal research on the mid- and long-term psychological impact of the predictive test result is essential. Decision making regarding health surveillance or preventive surgery after being detected as a carrier of one of the relevant mutations should receive special attention. Tailoring the professional approach--inside and outside genetic centres--to the families' needs is a continuous challenge. Even if a continuous effort is made, several important questions remain unanswered, last but not least the question regarding the best strategy to guarantee that the availability of predictive genetic testing results in a reduction of suffering caused by genetic disease and in an improvement of the quality of life of families confronted with genetic disease.

Counseling↗

Patellofemoral malalignment: looking beyond the viewbox.

A clear understanding of the pathophysiology of anterior knee pain is inhibited by the use of imprecise, poorly defined, and often interchanged words, such as malalignment, patellar alignment, maltracking, subluxation, dislocation, and congruence. The literature is filled with articles regarding the diagnosis, "malalignment of the patella," most of which give no precise diagnosis. This article presents a definition of malalignment and a plea for rational descriptive and scientific analysis. Much of what is described is based on theory, not facts. These ideas are supported by clinical experience and logical analysis, but very little in the way of scientific data. Most of the data involve radiographic images, which present only one piece of the puzzle.

Humans↗

The FEMA GRAS assessment of pyrazine derivatives used as flavor ingredients. Flavor and Extract Manufacturers Association.

This is the fifth 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 taking into account the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of pyrazine derivatives as flavoring ingredients is evaluated.

Animals↗

Safety assessment of allylalkoxybenzene derivatives used as flavouring substances - methyl eugenol and estragole.

This publication is the seventh 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 flavouring substances under conditions of intended use. In this review, scientific data relevant to the safety evaluation of the allylalkoxybenzene derivatives methyl eugenol and estragole is critically evaluated by the FEMA Expert Panel. The hazard determination uses a mechanism-based approach in which production of the hepatotoxic sulfate conjugate of the 1'-hydroxy metabolite is used to interpret the pathological changes observed in different species of laboratory rodents in chronic and subchronic studies. In the risk evaluation, the effect of dose and metabolic activation on the production of the 1'-hydroxy metabolite in humans and laboratory animals is compared to assess the risk to humans from use of methyl eugenol and estragole as naturally occurring components of a traditional diet and as added flavouring substances. Both the qualitative and quantitative aspects of the molecular disposition of methyl eugenol and estragole and their associated toxicological sequelae have been relatively well defined from mammalian studies. Several studies have clearly established that the profiles of metabolism, metabolic activation, and covalent binding are dose dependent and that the relative importance diminishes markedly at low levels of exposure (i.e. these events are not linear with respect to dose). In particular, rodent studies show that these events are minimal probably in the dose range of 1-10 mg/kg body weight, which is approximately 100-1000 times the anticipated human exposure to these substances. For these reasons it is concluded that present exposure to methyl eugenol and estragole resulting from consumption of food, mainly spices and added as such, does not pose a significant cancer risk. Nevertheless, further studies are needed to define both the nature and implications of the dose-response curve in rats at low levels of exposure to methyl eugenol and estragole.

Animals↗

The FEMA GRAS assessment of alicyclic substances used as flavour ingredients.

For over 35 years, an independent panel of expert scientists has served as the primary body for evaluating the safety of flavour ingredients. This group, the Expert Panel of the Flavor and Extract Manufacturers' Association (FEMA), has achieved international recognition from the flavour industry, government regulatory bodies including the Food and Drug Administration, and the toxicology community for its unique contributions. To date, the Expert Panel has evaluated the safety of more than 1700 flavour ingredients and determined the vast majority to be "generally recognized as safe" (GRAS). Elements that are fundamental to the safety evaluation of flavour ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavour ingredients are evaluated individually taking into account the available scientific information on the group of structurally related substances. The elements of the GRAS assessment program as they have been applied by the Expert Panel to the group of 119 alicyclic substances used as flavour ingredients, and the relevant scientific data which provide the basis for the GRAS status of these substances, are described herein.

Animals↗

The FEMA GRAS assessment of trans-anethole used as a flavouring substance. Flavour and Extract Manufacturer's Association.

This publication is the fourth in a series of safety evaluations performed by the Expert Panel of the Flavour and Extract Manufacturers' Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavouring substances under conditions of intended use. In this review, scientific data relevant to the safety evaluation of trans-anethole (i.e. 4-methoxypropenylbenzene) as a flavouring substance is critically evaluated by the FEMA Expert Panel. The evaluation uses a mechanism-based approach in which production of the hepatotoxic metabolite anethole epoxide (AE) is used to interpret the pathological changes observed in different species and sexes of laboratory rodents in chronic and subchronic dietary studies. Female Sprague Dawley rats metabolize more trans-anethole to AE than mice or humans and, therefore, are the most conservative model for evaluating the potential for AE-induced hepatotoxicity in humans exposed to trans-anethole from use as a flavouring substance. At low levels of exposure, trans-anethole is efficiently detoxicated in rodents and humans primarily by O-demethylation and omega-oxidation, respectively, while epoxidation is only a minor pathway. At high dose levels in rats, particularly females, a metabolic shift occurs resulting in increased epoxidation and formation of AE. Lower activity of the "fast" acting detoxication enzyme epoxide hydrolase in the female is associated with more pronounced hepatotoxicity compared to that in the male. The continuous intake of high dose levels of trans-anethole (i.e. cumulative exposure) has been shown in dietary studies to induce a continuum of cytotoxicity, cell necrosis and cell proliferation. In chronic dietary studies in rats, hepatotoxicity was observed when the estimated daily hepatic production of AE exceeded 30 mg AE/kg body weight. In female rats, chronic hepatotoxicity and a low incidence of liver tumours were reported at a dietary intake of 550 mg trans-anethole/kg body weight/day. Under these conditions, daily hepatic production of AE exceeded 120 mg/kg body weight. Additionally, neither trans-anethole nor AE show any evidence of genotoxicity. Therefore, the weight of evidence supports the conclusion that hepatocarcinogenic effects in the female rat occur via a non-genotoxic mechanism and are secondary to hepatotoxicity caused by continuous exposure to high hepatocellular concentrations of AE. trans-Anethole was reaffirmed as GRAS (GRASr) based on (1) its low level of flavour intake (54 microg/kg body weight/day); (2) its metabolic detoxication pathway in humans at levels of exposure from use as a flavouring substance; (3) the lack of mutagenic or genotoxic potential; (4) the NOAEL of 120 mg trans-anethole/kg body weight/day in the female rat reported in a 2 + -year study which produces a level of AE (i.e. 22 mg AE/kg body weight/day) at least 10,000 times the level (0.002 mg AE/kg body weight day) produced from the intake of trans-anethole from use as a flavouring substance; and (5) the conclusion that a slight increase in the incidence of hepatocellular tumours in the high dose group (550 mg trans-anethole/kg body weight/day) of female rats was the only significant neoplastic finding in a 2+ -year dietary study. This finding is concluded to be secondary to hepatotoxicity induced by high hepatocellular concentrations of AE generated under conditions of the study. Because trans-anethole undergoes efficient metabolic detoxication in humans at low levels of exposure, the neoplastic effects in rats associated with dose-dependent hepatotoxicity are not indicative of any significant risk to human health from the use of trans-anethole as a flavouring substance.

Allylbenzene Derivatives↗

Resuscitation in shock associated with burns. Tradition or evidence-based medicine?

OBJECTIVE: To summarize the present standards and guidelines for fluid treatment of shock associated with burns, and to evaluate their scientific support in the literature. DESIGN: Nonsystematic, critical review of the literature regarding the indications for crystalloid and colloid fluid treatment, invasive monitoring and the use of resuscitation end points in shock associated with burns. SUMMARY POINTS: Crystalloid fluid resuscitation of patients with burns is traditionally managed using empirical resuscitation formulae, with the efficacy monitored by vital signs and urinary output The value of these end points has been questioned by recent studies, which have suggested that such noninvasive parameters may be inadequate for detecting malperfusion. No consensus exists regarding appropriate assessment of adequate resuscitation, and the impact on survival of invasive measures has still to be proven in controlled randomized trials. Generally, a significantly higher fluid requirement has been demonstrated when resuscitation is based on invasive cardiorespiratory monitoring. Colloid resuscitation in burns patients is controversial. Published reports suggest that colloid infusion should be started between 6 and 36 h following thermal injury. A recent meta-analysis highlighted the shortcomings of albumin in patients with burns, and this, together with restrictions for the use of plasma products, has obscured the choice of colloid solution. The effect of colloid resuscitation on survival remains to be proven in burned patients. CONCLUSION: The current standards for monitoring fluid therapy in patients with large burns are not supported by scientific data. Further randomized, controlled trials are indicated, and should help establish general guidelines regarding monitoring and treatment end points in these patients.

Clinical Medicine↗

The sensitivity of biological tissue to ultrasound.

Mammalian tissues have differing sensitivities to damage by physical agents such as ultrasound. This article evaluates the scientific data in terms of known physical mechanisms of interaction and the impact on pre- and postnatal tissues. Actively dividing cells of the embryonic and fetal central nervous system are most readily disturbed. As a diagnostic ultrasound beam envelopes a small volume of tissue, it is possible that the effects of mild disturbance may not be detected unless major neural pathways are involved. There is evidence that ultrasound can be detected by the central nervous system; however, this does not necessarily imply that the bioeffect is hazardous to the fetus. Biologically significant temperature increases can occur at or near to bone in the fetus from the second trimester, if the beam is held stationary for more than 30 s in some pulsed Doppler applications. In this way, sensory organs that are encased in bone may be susceptible to heating by conduction. Reports in animals and humans of retarded growth and development following frequent exposures to diagnostic ultrasound, in the absence of significant heating, are difficult to explain from the current knowledge of ultrasound mechanisms. There is no evidence of cavitation effects occurring in the soft tissues of the fetus when exposed to diagnostic ultrasound; however, the possibility exists that such effects may be enhanced by the introduction of echo-contrast agents.

Animals↗

Current laparoscopic practice patterns in urology: results of a survey among urologists in Germany and Switzerland.

OBJECTIVES: A survey was performed to assess the current practice patterns in laparoscopy among urologists in Germany and Switzerland. METHODS: Using the database directory of the German and Swiss Urological Association urological departments were identified. A detailed questionnaire was designed and sent by postal service. Responding questionnaires were analyzed. RESULTS: The overall response rate was 64%. Fifty-four percent of respondents in Germany and 33% in Switzerland already perform laparoscopy; another 50% and 56% are planning to introduce laparoscopy. Thirty-six percent think that laparoscopy is economical and 77% await shortening of hospital stay. Major concerns are: Economical aspects, lengthy learning curve, investment, and lack of scientific data. The number of laparoscopic procedures during 12 months was registered for 19 indications. More than 40 procedures for one indication are performed by only 6% of the departments. CONCLUSIONS: The survey reveals an increasing number of departments performing laparoscopy and broad acceptance of the technology but combined with some major concerns. Currently only a minority of the departments perform more than 40 procedures for one indication suggesting that at present laparoscopy is mainly a center-based technology.

Data Collection↗

Application of molecular biological techniques for detection of epizootic hemorrhagic disease virus (EHDV-318) recovered from a sentinel calf in central Sudan.

Epizootic hemorrhagic disease virus (EHDV), isolate 318 (EHDV-318), an untyped virus recovered from a sentinel calf herd at the Khartoum University farm in central Sudan, was characterized using molecular biological techniques. With dot blot hybridization technique, a cDNA probe derived from genome segment 6 of EHDV-2 (Alberta strain) hybridized with RNA from EHDV-318. Application of serogroup-specific EHDV polymerase chain reaction (PCR) to EHDV-318 RNA resulted in specific amplification of a 387 bp PCR product. Amplification product was visualized on ethidium bromide-stained agarose gel. Specificity of the PCR products was confirmed by chemiluminescent hybridization with a non-radiolabelled internal probe. No amplification product or hybridization signal was detected when the serotype-specific EHDV-1 or EHDV-2 PCR-based assays were applied to RNA from EHDV-318. The scientific data presented in this study indicated that cDNA probes and serogroup-specific PCR-based assay can be used to classify the virus as a member of EHDV serogroup, and as serotypically distinct from EHDV-1 and EHDV-2.

Animals↗

Transmission of classical swine fever virus by artificial insemination.

Classical swine fever (CSF) virus was introduced into an artificial insemination centre during the CSF epizootic of 1997-1998 in the Netherlands. The risk of further spread of CSF virus via contaminated semen was recognised, but could not be assessed because scientific data on this issue were not available. An animal experiment was performed to determine whether CSF virus could be transmitted via artificial insemination with contaminated semen. Three boars were inoculated with a CSF virus field isolate and from Day 5 till Day 18 thereafter, ejaculates were collected and prepared for insemination. Ruttish sows were inseminated with the extended semen from Day 5 till Day 18 after inoculation of the boars. All the inoculated boars remained healthy throughout the experiment and developed CSF neutralising antibodies between 14 and 21 days after inoculation. Virus was isolated from several semen samples collected from 5 till 11 days after inoculation. Two out of six sows inseminated with CSF contaminated semen seroconverted after insemination. All the other sows remained seronegative. In the foetuses of both the seropositive sows, CSF virus was detected at approximately 35 days post insemination. These results demonstrate that adult boars infected with CSF virus can excrete virus with semen and can, subsequently, transmit the virus to sows and their foetuses via artificial insemination.

Animals↗

The development of preterm infants' breastfeeding behavior.

Extensive scientific data are available on the development of sucking in term infants, but corresponding knowledge about preterm infants has been lacking. The aim was to describe the development of preterm infants' behavior at the breast, according to postmenstrual and postnatal age. Mothers co-operated as data collectors using the Preterm Infant Breastfeeding Behavior Scale for observations. Seventy-one singletons (born after 26.7-35.9 gestational weeks) were studied prospectively. Mothers received regular advice about breastfeeding and guidance about interaction and appropriate stimulation. Breastfeeding was initiated at a postmenstrual age (PMA) of 27.9-35.9 weeks. Mothers provided 4321 records of infants' behavior, 70% of the total breastfeeding sessions during the infants' hospital stay. Irrespective of PMA, the infants responded by rooting and sucking on the first contact with the breast. Efficient rooting, areolar grasp and latching on were observed at 28 weeks, and repeated bursts of > or = 10 sucks and maximum bursts of > or = 30 sucks at 32 weeks. Nutritive sucking appeared from 30.6 weeks. Sixty-seven infants were breastfed at discharge. Fifty-seven of them established full breastfeeding at a mean PMA of 36.0 weeks (33.4-40.0 weeks). Their early sucking behavior is interpreted as the result of learning, enhanced by contingent stimuli. We therefore suggest that guidelines for initiation of breastfeeding in preterm infants should be based on cardiorespiratory stability, irrespective of current maturity, age or weight.

Adolescent↗

Hygienic aspects of storage and use of semen for artificial insemination.

The artificial insemination (AI) industry has developed over the last 50 years to the extent that it is used in almost every country in the world. One of the main factors contributing to its success is the confidence of the farmers that germplasm is not associated with pathogens, so that AI can be performed without risks. This has been achieved as a result of a considerable amount of research based on sound scientific data that has identified the major risk pathogens. A summary of these studies, given in this section, shows that despite the large number of agents that could be transmitted via the semen, there are cost-effective means to prevent such hazards. One of the basic rules is that the males should be housed in strictly protected semen collection centres (SCCs). Such centres should be approved by the veterinary authorities based upon specific criteria, which include special housing and operating specifications. This also includes specific means of monitoring the health of individual males through regular clinical examinations, assessment of semen and testings for various diseases. Two new challenges can now be identified, one relevant to so-called emerging diseases the impact of which on the status of the semen donors should always be assessed, and the second, relates to endangered genetic resources which may become extinct without active conservation programmes. The experience gained by the AI industry over the last 50 years should help to solve those problems. Currently, the use of semen derived from approved SCCs warrants their disease-free status.

Animal Diseases↗

Aspects of progestin activity on the breast. European Progestin Club.

On 9-11 May 1997, the second Meeting of the European Progestin Club was held in Turin, Italy. Aspects of progestin use on the breast were discussed, based on the currently available scientific data. The paper covers topics addressed at the meeting and summarizes the recommendations which could be agreed on by the participants.

Breast↗

Effects of Sclerocarya birrea (A. rich) hochst (anacardiaceae) leaf extracts on calcium signalling in cultured rat skeletal muscle cells.

Sclerocarya birrea is a plant used widely to treat many diseases in Burkina Faso, although no scientific data has been reported about its mechanism of action. In the present study the effects of its leaf extracts were investigated on calcium signalling in rat cultured skeletal muscle cells. The results show that the different extracts (crude decoction, aqueous, ethanolic and chloroformic extracts) have significant antagonistic effect on caffeine-induced calcium release from sarcoplasmic reticulum. Crude decoction is the most active followed by ethanolic, aqueous and chloroformic extracts in dose-dependent manner and can partly justify the use of the plant in traditional medicine.

Animals↗

Intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) represents a significant fraction of all strokes and causes a disproportionate amount of stroke related morbidity and mortality, especially in young blacks. While diagnosis of this disorder has greatly improved in the CT era, morbidity and mortality remain essentially unchanged. Not one currently utilized therapeutic modality has been clearly associated with a beneficial effect on long term outcome in small prospective randomized treatment trials for ICH. In spite of the lack of scientific data regarding therapy, patients often require aggressive medical and surgical intervention because of the life-threatening presentation of many patients. Recent clinical and experimental ICH research has identified a number of potentially effective new therapeutic strategies, and time to treatment is likely to be very important as it is for ischemic stroke. Large prospective, randomized, placebo controlled trials to examine the judicious application of current therapeutic modalities, and to investigate the potential benefit of proposed new treatment modalities, are long overdue.

Cerebral Hemorrhage↗

Management of fever in infants and children.

There is no question that fever is a source of great consternation for parent and physician alike; however, it is impossible to predict with certainty the outcome of every febrile illness. Inherent in the words diagnostic impression is a degree of uncertainty. The only question remaining is how much uncertainty is in the best interest of the child. Physicians try to use the existing scientific data to best determine the prevalence of disease and outcome. At the same time, they must recognize the limitations of both the data and their ability to be generalized to every population. Everything clinicians do has risks and costs, which they must balance against the incidence of complications and the benefits of testing. To take away clinical judgment makes physicians technicians not clinicians.

Anti-Bacterial Agents↗

Outcomes analysis in hand surgery patients--get your project started!

Once there are answers to the research questions, the results must be used in clinical practice to alter treatment plans, giving patients the most appropriate choices and the highest quality outcomes based on scientific data. Daily clinical practice can be improved by applying the results of outcomes studies to alternative treatment options. This in turn helps lead the clinician to choose the path to the best outcome for the patient. Because most practitioners recognize the need and the importance for conducting outcomes research, finding alternative avenues for them to be successful in the process is essential.

Data Collection↗