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At least 829 records · Page 46Linked to original sources
PubMed2003

Treatment of bulbar urethral strictures a review, with personal critical remarks.

This is a review article on treatment of bulbar urethral strictures with personal critical remarks on newer developments. As a treatment of first intention there exists 4 options : dilatation, urethrotomy, end to end anastomosis and free graft, open urethroplasty. Success rate of dilatation and visual urethrotomy after 4 years is only 20 en 40% respectively. Laser urethrotomy could not fulfill expectations. End to end anastomosis obtains a very high success rate but is only applicable for short strictures. Free graft urethroplasty obtains success rates of +/- 80%. There is considerable debate on the best material for grafting. Buccal mucosa graft is the new wave, but this is not based on scientific data. Whether this graft should be used dorsally or ventrally is also a point of discussion. In view of the good results published with both techniques it is probably of no importance. Intraluminal stents are not indicated for complicated cases and give only good results in those cases which can easily be treated with other techniques. Metal self-retaining urethral stent, resorbable stents and endoscopic urethroplasty is briefly discussed. Redo's and complicated urethral strictures need often other solutions. Here skin flap from the penile skin and scrotal flap can be used. Advantages and drawbracks of both are discussed. There is still a place for two-stage procedures in complicated redo"s. The two-stage mesh-graft urethroplasty offers advantage over the use of scrotal skin. Some other rare techniques like substitution with bowel and pudendal thigh flap, to cover deep defects, are also discussed.

Humans↗
PubMedDate not supplied

Simplification of three-dimensional density maps.

We consider scientific data sets that describe density functions over three-dimensional geometric domains. Such data sets are often large and coarsened representations are needed for visualization and analysis. Assuming a tetrahedral mesh representation, we construct such representations with a simplification algorithm that combines three goals: the approximation of the function, the preservation of the mesh topology, and the improvement of the mesh quality. The third goal is achieved with a novel extension of the well-known quadric error metric. We perform a number of computational experiments to understand the effect of mesh quality improvement on the density map approximation. In addition, we study the effect of geometric simplification on the topological features of the function by monitoring its critical points.

Algorithms↗
PubMed2001

A pain in the fetus: toward ending confusion about fetal pain.

Are fetuses, at any stage of their development, capable of feeling pain? In his paper, "Locating the Beginnings of Pain," Stuart Derbyshire argues that they are not. We argue that he reaches this conclusion by way of conceptual confusion, a misreading of the available scientific data and the inclusion of irrelevant data. Despite his assertion to the contrary, the work of most scientists in the area supports the conclusion that fetuses can feel pain. At the outset we examine the concept of pain and distinguish it from the allied concept of nociception, with which it is sometimes confused. With the relevant conceptual framework in place, we elucidate the problem of determining when, in its development, a human becomes capable of feeling pain. We then examine the available data showing how, on balance, it tends more to support than undermine the claim that fetuses of around 28 to 30 weeks' gestation are capable of feeling pain.

Central Nervous System↗
PubMed2005

Colourants in transferable picture tattoos for the skin.

Transferable picture tattoos for the skin are popular among children. There is however very little knowledge about the colourants that may be present in the picture tattoos and thus of the risk of contact allergic reactions. In the present investigation, 36 picture tattoos were analysed for the content of 129 organic colourants listed in the Cosmetic Directive, to which these products should comply as they are used on the skin. Only 11 of the cosmetic colourants could be identified in the analysed samples. Allergenic potential of 7 of these colourants (CI 15850, CI 11920, CI 45220, CI 75300, CI 13015, CI 45100 and CI 15525, maximum concentration 35-4479 p.p.m.) was evaluated on the basis of published scientific data. Only scarce information regarding contact allergy to these substances was found in the available literature. Most information in the literature regarding contact allergy has concerned CI 75300, curcumin, which is reported to have caused a few cases of contact allergy as a colourant in food or in disinfectants used prior to surgery. In no case, allergic reactions to any of the colourants have been verified from transferable picture tattoos. On the basis of this investigation, the risk of allergic reactions from the colourants in the transferable picture tattoos seems to be limited.

Allergens↗
PubMed2004

The contrast between risk assessment and rules of evidence in the context of international trade disputes: can the US experience inform the process?

Risk assessment provides a formalized process to evaluate human, animal, and ecological responses associated with exposure to environmental agents. The purpose of risk assessment is to answer two related questions: - How likely is an (adverse) event to occur? - If it does, how severe will the impact be? In the United States, the science of risk assessment has evolved out of the necessity to make public health decisions in the face of scientific uncertainty. Its basic propositions have been established over the past three decades and its applications have impacted virtually every aspect of public health and environmental protection in many countries, including the United States. More recently, the World Trade Organization's (WTO) dispute-settlement process has provided additional incentive for the reliance on risk assessments internationally through the requirement that member countries be able to provide scientific justification, based on a risk assessment, for public health and environmental regulatory measures that are challenged. The purpose of this article is to review the history of risk assessment in the United States, emphasizing the development of both its scientific and policy aspects, as one example of the development of institutional capacity for risk assessment. This article discusses the importance of the social, political, and economic contexts of risk assessment and risk management in shaping the approaches taken while highlighting the reality that the analytic or risk assessment part of the decision-making process, in the absence of scientific data, can be completed only by inserting inferences, or policy judgments, which may differ among countries. This article recognizes these differences, and the consequent difference between risk assessment that incorporates public health protective assumptions and the rules of evidence that seek to answer questions of causality, and discusses implications for the WTO dispute-settlement process. It further explores the value of country-specific risk assessment guidelines to facilitate consistency within a country along with the appropriateness and feasibility of international risk assessment guidelines.

Animals↗
PubMed1992

Mechanisms of local, low-dose UVB-induced immunosuppression in contact hypersensitivity.

Preirradiation of contact sensitizing sites to low-dose ultraviolet B (UVB) renders animals unresponsive to challenge reaction. This unresponsiveness is known as local, low-dose UVB-induced immunosuppression. Although researchers in this area have developed theories, the exact mechanisms of UVB-induced immunosuppression are still a matter of controversy. This article reviewed various scientific data on UVB-induced immunosuppression, categorizing them into individual sequential steps in the whole cascade.

Animals↗
PubMed2006

Review article: complementary and alternative therapies for inflammatory bowel disease.

Complementary and alternative medicine includes a wide range of practices and therapies outside the realms of conventional western medicine. Despite a lack of scientific data in the form of controlled trials for either efficacy or safety of complementary and alternative medicine, use by patients with inflammatory bowel disease, particularly of herbal therapies, is widespread and increasing. There is limited controlled evidence indicating efficacy of traditional Chinese medicines, aloe vera gel, wheat grass juice, Boswellia serrata and bovine colostrum enemas in ulcerative colitis. Encouraging results have also been reported in small studies of acupuncture for Crohn's disease and ulcerative colitis. Contrary to popular belief, natural therapies are not necessarily safe: fatal hepatic and irreversible renal failure have occurred with some preparations and interactions with conventional drugs are potentially dangerous. There is a need for further controlled clinical trials of the potential efficacy of complementary and alternative approaches in inflammatory bowel disease, together with enhanced legislation to maximize their quality and safety.

Clinical Trials as Topic↗
PubMed2006

Target proteins in inherited and acquired blistering skin disorders.

Maintenance of an intact epidermis depends on secure adhesion between adjacent keratinocytes, and between basal keratinocytes and the underlying epidermal basement membrane. The major adhesion units that achieve this are the hemidesmosomes and desmosomes, but when these structures are disrupted, e.g., by gene mutations or autoantibodies, the resilience of the epidermis is lost and blisters develop. Recently, there have been considerable advances in our knowledge of the proteins and glycoproteins that contribute to maintaining keratinocyte adhesion via hemidesmosomes and desmosomes, as well as new insights into the molecular pathogenesis of several inherited and autoimmune blistering skin diseases. These new basic scientific data are clinically relevant, helping to improve patient management and to provide a rationale for developing better and more specific treatments for patients with inherited or acquired blistering skin diseases. In addition, there have also been improvements in our understanding of the organization and assembly of these adhesion structures, and their involvement in signalling pathways, intricately linked to skin development, wound healing and tumour invasion. This review provides an update on the structure and organization of hemidesmosomes and desmosomes, and on the molecular pathology of their various components that result in bullous skin diseases.

Autoimmune Diseases↗
PubMed1985

Pooled cells versus individual screening cells in pre-transfusion testing.

Pooling of screening red cells used in pre-transfusion testing has been discouraged by many workers since it might lead to the failure to detect alloantibodies. However, there is minimal scientific data to support this view and in the UK a high proportion of blood transfusion laboratories were still using pooled red blood cells for antibody screening in 1982-1983. In order to solve the dilemma of sensitivity of serological tests when using pooled versus individual screening cells, a comparative evaluation of both approaches was carried out. One hundred and five sera known to contain weak, warm-reacting clinically significant alloantibodies were tested by the three same standard sensitive techniques using samples of individual screening cells and a pool of the same cells in parallel. Our results show that when pooled cells were used, 12% of the selected alloantibodies were undetectable and a further 23% were only detectable microscopically. All antibodies examined were easily detectable macroscopically when individual screening cells were used. It is concluded that the sensitivity of pre-transfusion screening tests is reduced when pooled red cells are employed as opposed to individual samples of screening cells and that the use of pooled cells should be discouraged in routine pre-transfusion and antenatal antibody screening.

Blood Transfusion↗
PubMed1995

An overview of sleepiness and accidents.

This paper reviews the association between neurobiologically-based sleepiness/fatigue and human-error related accidents. It concludes that fatigue contributes to human error and accidents in technology-rich, industrialized societies in terms of human, environmental and economic impacts. The cultural utilization of time as expressed in 24-h work operations, combined with the widespread use of automation, will continue to escalate in the next century, further increasing the risks of fatigue-related accidents, as more people conduct vigilance-based activities at times other than the traditional daytime work hours. Fatigue management and prevention of fatigue-related catastrophes need to become a sustained priority for government, industries, labour, and the public. Scientific data are urgently needed on the most likely areas in which sleepiness-related performance failures contribute to accidents, and on the effectiveness of a wide range of potentially useful countermeasures.

Journal Article↗
PubMed1991

The effect of intravenous immunoglobulin on placental transfer of a platelet-specific antibody: anti-P1A1.

The isolated perfused lobule of human placenta was used as an in-vitro model to study the effect of intravenous immunoglobulin (IVGG) on the placental transfer of a human platelet-specific antibody (anti-P1A1). Normal human IgG was shown to transfer from the maternal to the fetal circulation of the placental model after a lag period of 2-3 h. IVGG also transferred across the placenta but only after a longer lag period (3-4 h) than normal human IgG at the same concentration, which suggests that IVGG may contain a factor that inhibits the transfer of its own component IgG. The sensitive Western immunoblotting technique was used to demonstrate progressive transfer of anti-P1A1 antibody to the fetal circulation after a 2-3 h lag period. When IVGG and anti-P1A1 antibody were added simultaneously to the maternal circulation, the transfer of platelet-specific antibody was strongly inhibited by IVGG. The inhibitory effect of IVGG on anti-P1A1 antibody transfer was consistent for three different batches of the same IVGG product (Sandoglobulin). These studies provide the first scientific data to support the use of IVGG to inhibit antiplatelet antibody transfer as part of the antenatal management of neonatal alloimmune thrombocytopenia.

Antibodies↗
PubMed2006

Isotretinoin and the controversy of psychiatric adverse effects.

Isotretinoin is a synthetic oral retinoid that has great efficacy against severe, recalcitrant, nodulocystic acne. Since its introduction to the market, it has been associated with a variety of adverse psychiatric effects, including depression, psychosis, mood swings, violent behavior, suicide, and suicide attempts. A MEDLINE review was performed to compile all case reports, case series, adverse drug event reportings, and prospective and retrospective studies relating psychiatric adverse events to isotretinoin. In addition, literature linking a biological mechanism for psychiatric adverse events to retinoid signaling pathways was also reviewed. Although a variety of anecdotal and epidemiologic studies are available, the overall lack of concrete scientific data limits any conclusion that can be drawn about a causal relationship between istotretinoin and psychiatric adverse events. Several lines of evidence link retinoid signaling to theorized psychiatric pathogenesis, but are limited in their applicability to adult neurophysiology.

Acne Vulgaris↗
PubMed2004

Post-natal stem cells as participants in complex systems and the emergence of tissue integrity and function.

This issue of Pediatric Diabetes contains articles with scientific data, their interpretation, and a discussion of the respective field of stem cells and diabetes - its achievements and controversies. Through our daily laboratory activities, we employ a reductionist approach and often a deterministic interpretation of data. We would like to make this contribution a means of adding a somewhat different perspective to this collection of essays. This conceptual piece is merely intended to be an invitation to further thoughts and discussions.

Animals↗
PubMed1990

Marketing authorisation of fish drugs--current status and future intentions.

The main purpose of the German drug law (August 24, 1976) is to guarantee quality, efficacy and safety of drugs for use in man and animals. The present particular situation for fish is as follows: 1. Several drugs (including antibiotics and antiparasitics) have been authorised before 1978. An application for prolonged authorisation has to be made before the end of 1989. For decisions on these applications, the Federal Health Office requires further scientific data of the active ingredients as a basis. 2. Certain chemicals (including malachite green) are subject to a simplified standard procedure for authorisation. Requirements concerning quality, restrictions of use etc. are published in monographs. 3. New drugs will be authorised according to the present national drug law until the establishment of EEC regulations. 4. Future decisions under EEC legislation shall consider potential risks for the environment (proposals to be included in the EEC directive 81/852) and more data specific for fish.

Animals↗
PubMedDate not supplied

Etanercept treatment of renal amyloidosis complicating rheumatoid arthritis.

Rheumatoid arthritis and juvenile arthritis represent the commonest diseases complicated by AA amyloidosis in developed countries. Up to 5% of patients with rheumatoid arthritis will develop AA amyloidosis, with renal failure being the commonest cause of mortality. To date, treatment of this condition has focused on suppressing the underlying inflammatory condition with drugs such as cyclophosphamide and chlorambucil, but both these drugs are associated with myelotoxicity, leukaemia and sterility. Tumour necrosis factor-alpha (TNF-alpha) is thought to be involved in amyloid deposition. The efficacy of anti-TNF-alpha therapy (etanercept) in the treatment of renal amyloidosis complicating rheumatoid arthritis is demonstrated here and the current scientific data on this subject are presented.

Amyloidosis↗
PubMed2005

Gestational diabetes: dilemma caused by multiple international diagnostic criteria.

AIMS: To highlight the variation in the diagnosis of gestational diabetes (GDM) as defined by six well-accepted international expert panels. METHODS: Two thousand, five hundred and fifty-four pregnant women underwent a 75-g oral glucose tolerance test for routine, antenatal GDM screening. They were classified using the criteria of the American Diabetes Association, Australasian Diabetes in Pregnancy Society, the Canadian Diabetes Association, the European Association for the Study of Diabetes, the New Zealand Society for the study of Diabetes and the World Health Organization (WHO). RESULTS: Between any two criteria, both the GDM prevalence (range; 7.9-24.9%) and the women classified differently [range; 70 (2.7%)-454 (17.8%) women], was significant (P<0.001). The most inclusive criteria, i.e. Australasian, despite generating the highest prevalence of GDM, did not pick up all the women identified by the most restrictive criteria, i.e. Canadian. The Australasian and the WHO criteria were associated with an increase in the number of Caesarean sections [odds ratio (OR); 1.64, 1.45, respectively] while the American, Canadian and New Zealand criteria identified an increase in macrosomia (birthweight>or=4000 g) incidence (OR; 2.09, 2.01, 1.92, respectively). CONCLUSIONS: The guidelines of the various professional committees, being based on consensus and expert opinion, show major discrepancies in their ability to identify women with GDM and their capacity to predict adverse pregnancy outcome. Only evidence-based criteria derived from reliable and consistent scientific data will eliminate the confusion caused in clinical practice.

Adolescent↗
PubMed1994

Assessment of medical treatments for menorrhagia.

Although usually not life-threatening, dysfunctional uterine bleeding (DUB) can cause discomfort and disruption to life for many women. It has been poorly researched in the past, primarily because of difficulties in trying to accurately measure blood loss and response to treatment. There are several different therapies currently available but, for many, actual evidence of their efficacy is lacking from scientific data. Progestogens are the most frequently prescribed drugs for the treatment of DUB. Data support their use in anovulatory women but a number of comparative trials have shown that an overall reduction in blood loss of only 20% is achieved in ovulatory women. Their use, therefore, must be questioned as the first line of treatment. Combined oral contraceptives were at one time popular but whether the low-dose, current generation pills are equally effective awaits appropriate trials. Prostaglandin synthetase inhibitors can be useful, with up to a third of women with menorrhagia benefiting from a reduction of between 25% and 35% in blood loss. A proportionally greater reduction is seen in women with more excessive bleeding. Antifibrinolytic drugs have been shown to reduce menstrual blood loss in DUB by 50% and would be useful in women in whom oestrogens are contraindicated. Gonadotrophin-releasing hormone analogues are highly effective because of their ability to induce amenorrhoea, but long-term use is contraindicated because of their hypo-oestrogenic effects. One other effective therapy for menorrhagia has been danazol.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2002

A double-blind, randomised, placebo controlled study on the influence of carbohydrate solution intake during labour.

OBJECTIVE: Although there has been much debate on whether women should be allowed to eat and drink during labour, little scientific data are available on the effects of caloric intake on the course of labour. DESIGN: Double-blind, randomised, placebo controlled. SETTING: Leyenburg Hospital, The Hague, The Netherlands. POPULATION: Two hundred and one consecutive nulliparous women, pregnant of a single fetus in cephalic presentation. METHODS: All women were included in early labour (2cm-4cm of cervical dilatation) and were allowed to drink at will. MAIN OUTCOME MEASURES: The duration of labour, the need for augmentation and pain medication and the incidence of abdominal and vaginal instrumental deliveries. RESULTS: Drinking of carbohydrate solutions was well tolerated, but did not show any beneficial effects regarding labour outcome when compared with the control group. In the carbohydrate group, a higher caesarean section rate was observed (RR 2.9, 95% CI 1.29-6.54). CONCLUSIONS: Women in the carbohydrate group had worse labour outcome. It is unclear whether a statistical coincidence, a negative effect of the carbohydrate intake or an incorrect carbohydrate intake strategy is responsible for these results. Further studies are necessary before any definite conclusion can be drawn.

Adult↗