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At least 1,783 records · Page 99Linked to original sources
PubMed2005

Liposomal delivery of photosensitising agents.

Photodynamic therapy is a clinically approved treatment for cancer and noncancer diseases. This modality utilises light-activatable chemicals (photosensitising agents) to capture photons and use light energy for the production of cytotoxic reactive molecular species. Most photosensitisers that are in use clinically or in preclinical development are hydrophobic and tend to aggregate in the aqueous environment, which limits their delivery and photosensitising efficiency. Liposomal delivery of photosensitisers will often overcome or decrease these problems. In addition, as with chemotherapeutic agents, liposomal formulations of photo-sensitising agents may help to achieve better selectivity for tumour tissue compared with normal tissue. Over the past years, liposomal photosensitisers have emerged as therapeutic agents in many experimental studies, and have obtained approval for clinical applications. Recent progress in liposomal technology further opens up the possibility of generating more selectively targeted photosensitisers encapsulated in liposomes. This review will cover progress in the use of liposomal photosensitisers, summarise current liposomal formulations, and project future directions for the liposomal delivery of photosensitising agents.

Biological Availability↗
PubMedDate not supplied

Evidence-based practice in provision of amplification.

Evidence-based practice (EBP) has been widely embraced in many health-care fields as a way of maintaining currency of knowledge and state-of-the-art treatment recommendations in an age of information abundance and rapid scientific progress. Although the principles of EBP are slowly entering the specialties of communication disorders, they are not well known or extensively employed as yet. In this article, the rationale for EBP is presented and differences between EBP and traditional practice are highlighted. The five-step process of EBP is described: defining the problem, searching for evidence, critically appraising the evidence, formulating a recommendation, and assessing the outcome. Critical appraisal calls for determination of the validity, clinical significance, and applicability of evidence. Each of these topics is explored with emphasis placed on the application of EBP to hearing rehabilitation. Finally some suggestions are offered for researchers and practitioners to facilitate a transition to EBP in amplification provision.

Audiology↗
PubMed1999

[Ecstasy and its "counterparts"].

RISK AWARENESS: Use of psychostimulants is spreading in France, particularly at "techno" dances. The generic term "ecstasy" covers a wide variety of molecules with variable formulations. The situation is a true public health problem, generally concerning very young subjects who must be informed of the risks involved. Knowledge of the chemical makeup of the products currently used is needed to provide valid information and reduce risks. CHEMICAL ANALYSIS: Two types of chemical analysis are used for rapid controls. A coloration test is used by the Rave mission implemented by "Médecins du Monde". More elaborate analysis methods are used to identify the active substances and quantify the compounds in the different "tablets". FINDINGS: Rapid controls give a means of quickly identifying samples containing methylenedioxyamphetamines and distinguishing them from other samples which may contain any number of substances with unknown toxicity. A precise analysis of 73 samples has shown highly variable compositions with 22% actually containing methylenedioxyamphetamines. PREVENTION: Precise analytical knowledge of the drugs circulating in "techno" dances has revealed the extreme danger of a large number of the substances used. A continuous control of ongoing consumption is required to correctly warn the users and reduce risk.

Adolescent↗
PubMed2000

Adolescents are not adults: developmental considerations in alcohol users.

Much of the work in adolescent substance abuse assessment and treatment has been a direct transport from tools and modalities used in adult substance use populations. There was a consensus among symposium participants that developmental issues are important in assessment, evaluation, and treatment of adolescents with substance use disorders. These issues directly impact outcome at all levels. Presentations from the symposium may be helpful for conceptualizing the problems of adolescent substance use as well as formulating strategies for future research. Information from the symposium may be viewed as a springboard for future research and clinical intervention in adolescent substance abuse.

Adolescent↗
PubMed1989

A study of standards for the differentiation of the urban population in China.

In China, the recent reclassification of the country into urban areas has led to an increase of urban population that is to a large extent purely administrative. To set a standard for differentiating the population into urban and rural, it is necessary to formulate a scientific standard. The author considers the problems and contradictions created by the differentiation of population according to cities and towns which are administratively established. Newly established cities and towns are comparatively large in number and their sizes are much expanded because a certain amount of agricultural population is included in the urban population. A survey of 347 cities revealed that on the average, the agricultural population accounted for 47% of the total. It is important to set the principles for standards of differentiation of the urban population with a view to the origin of the city. All the economic, social, and administrative principles have limitations, and no one set of principles can be used by itself to decide whether or not an area is urban. The standards should be based on actual conditions within China itself.

Asia↗
PubMed2003

Liposomal doxorubicin in breast cancer: new preparation. Much ado about nothing.

(1) There is no reference first-line cytotoxic chemotherapy protocol for metastatic breast cancer, but anthracycline combinations are commonly used. In addition to their myelotoxicity, anthracyclines can cause heart failure, both problems during and after treatment. (2) A liposomal formulation of doxorubicin, an anthracycline, has been developed with the aim of reducing this cardiotoxicity. The marketing terms specify that it must be used in combination with cyclophosphamide, in the first-line treatment of metastatic breast cancer. (3) According to the current evaluation file, which chiefly includes data from three comparative trials, liposomal doxorubicin is no more effective, in terms of the duration or quality of survival, than standard doxorubicin or epirubicin. (4) During comparative trials of liposomal doxorubicin, alone or in combination with cyclophosphamide, signs of cardiotoxicity, as measured by ultrasound, were slightly less frequent than with standard doxorubicin but no less frequent than with epirubicin. Given the possibility of late cardiac events, which were not studied in these trials, there is no evidence that liposomal doxorubicin is really less cardiotoxic than either standard doxorubicin or epirubicin. As regards other adverse effects, liposomal doxorubicin has no advantages over standard doxorubicin or epirubicin. (5) Liposomal doxorubicin is far more difficult to prepare than standard doxorubicin. (6) In France, liposomal doxorubicin is about 15 times more expensive than standard doxorubicin and 4 times more expensive than epirubicin. (7) In practice, standard doxorubicin can still be used, at doses appropriate for the individual patient and with cardiac monitoring.

Antibiotics, Antineoplastic↗
PubMed1999

Towards an embodied understanding of the structure/agency relationship.

Theoretical conceptualizations of the structure/agency relationship have been central to the development of the discipline, yet tend to exhibit two major limitations. First, they share a relatively disembodied view of the agent which overemphasizes cognition and marginalizes the significance of the emotional dimensions of interaction for human action and social structure. Second, most have difficulty maintaining the causal significance of both the 'people' and the 'parts' of the social system and are, therefore, unable to examine adequately their interplay. This paper suggests these problems are related, and examines the contribution recent formulations of the 'interaction order' can make toward overcoming the difficulties characteristic of this key sociological debate. The 'interaction order' identifies the embodied dimensions of interaction as consequential for, yet irreducible to, structures and agents, enables us to investigate the 'loose coupling' of interaction to individuals and social systems, but is underdeveloped in important respects. This paper addresses these limitations. It also highlights the utility for the structure/agency debate of identifying a sector of embodied interactions concerned with the maintenance of social selves, and suggests how this somatic sector of social life might be developed analytically.

Affect↗
PubMed2005

Challenges for the identification of biological systems from in vivo time series data.

Modern methods of high-throughput molecular biology render it possible to generate time series of metabolite concentrations and the expression of genes and proteins in vivo. These time profiles contain valuable information about the structure and dynamics of the underlying biological system. This information is implicit and its extraction is a challenging but ultimately very rewarding task for the mathematical modeler. Using a well-suited modeling framework, such as Biochemical Systems Theory (BST), it is possible to formulate the extraction of information as an inverse problem that in principle may be solved with a genetic algorithm or nonlinear regression. However, two types of issues associated with this inverse problem make the extraction task difficult. One type pertains to the algorithmic difficulties encountered in nonlinear regressions with moderate and large systems. The other type is of an entirely different nature. It is a consequence of assumptions that are often taken for granted in the design and analysis of mathematical models of biological systems and that need to be revisited in the context of inverse analyses. The article describes the extraction process and some of its challenges and proposes partial solutions.

Linear Models↗
PubMed1987

[Genetics of human behavior: problems, results and prospects].

In this paper, the main problems of modern behaviour genetics of man are formulated and methods for their study proposed. As a result of the Mendelian analysis of some psychometric scales of personality inventories, a major-gene mode of inheritance is found for 20% of scales of three questionnaires: MMPI, 16 PF and the Pathocharacterologic Diagnostic Inventory (PDI). Perspectives of further studies in the field of human behaviour genetics are outlined.

Genetics, Behavioral↗
PubMed1984

[Ethical principles and moral norms of psychiatric care in a socialistic society].

Ethical postulates, which are intended to serve as orientation points for personal conduct, must be formulated clearly as demands, be related to the system of values on which they are based, and point out clearly the consequences of their being ignored and must therefore be connected with moral bans. The authors have tried to formulate such postulates for the most important ethical problems facing psychiatry in the GDR. These moral guidelines, which naturally infer moral bans, offer fuel for discussion as one step towards the establishment of a comprehensive code of ethics for psychiatrists.

Ethics, Medical↗
PubMedDate not supplied

[Immune reactions and mechanisms in classical swine fever].

The authors review published data on the immune response in classical swine fever infection. Characteristics of the neutralizing antibodies, cytolytic reactions directed at elimination of infected cells, lymphocyte proliferation, and delayed-type hypersensitivity are discussed. Problems of potential theoretical and practical interest are formulated.

Animals↗
PubMed1994

Management and leadership by nurses.

Good management and leadership by nurses is essential for the achievement of health for all. Well-prepared nurses are required locally and nationally who can identify problems and needs, work on interdisciplinary teams to formulate development plans for human resources, improve working conditions, and raise the quality of care at reasonable cost.

Education, Nursing, Continuing↗
PubMedDate not supplied

Solubility principles and practices for parenteral drug dosage form development.

Solubilization of poorly water soluble or water insoluble drugs for use in intravenously administered dosage forms is a very formidable task for the parenteral formulation scientist. We have briefly reviewed pertinent literature for parenteral drug solubilization and provided tabular information to assist parenteral formulation scientists in tackling and solving their solubility problems. However, until we can better understand and predict solubility behavior in interactive solvent systems, the why's and how's for parenteral drug solubilization using acceptable (safe and regulatory compliant) approaches will largely remain an empirical effort, leaving great opportunities for scientists to get more involved in this field.

Chemistry, Pharmaceutical↗
PubMedDate not supplied

Medical expert system on fuzzy analog ganglionar lattices: explication and prospection based on sensitivity.

A reasoning method to explicate the conclusions-a posteriori- and to prospect for the next test-a priori-applied to medical expert systems based on fuzzy analog ganglionar lattices is presented. This method is founded on the sensitivity criterion of the consequent respect to the antecedents. It proves to be suited for problems of any complexity, specially when they are formulated on well-established intermediate concepts, such as syndromes, clinical finding, laboratory procedures, etc., as is usually the case in medical procedures. This type of expert system uses the structural properties of the ganglionar lattice to produce explications for its conclusions at different levels of abstraction, and to an arbitrary, but fixed, explicative degree. A measure to evaluate the consequent's achieved preciseness (certainty) is also supplied. A full example of application in the diagnosis of cardiac insufficiency with hypertensive myocardiopathy is shown, and a computational implementation of this analog procedure is described. Finally, the reasoning methods for explicating and prospecting are discussed.

Artificial Intelligence↗
PubMed2006

Mesh adaptation technique for Fourier-domain fluorescence lifetime imaging.

A novel adaptive mesh technique in the Fourier domain is introduced for problems in fluorescence lifetime imaging. A dynamical adaptation of the three-dimensional scheme based on the finite volume formulation reduces computational time and balances the ill-posed nature of the inverse problem. Light propagation in the medium is modeled by the telegraph equation, while the lifetime reconstruction algorithm is derived from the Fredholm integral equation of the first kind. Stability and computational efficiency of the method are demonstrated by image reconstruction of two spherical fluorescent objects embedded in a tissue phantom.

Algorithms↗
PubMed2002

Milk fever control principles: a review.

Three main preventive principles against milk fever were evaluated in this literature review, and the efficacy of each principle was estimated from the results of controlled investigations. Oral calcium drenching around calving apparently has a mean efficacy of 50%-60% in terms of milk fever prevention as well as prevention of milk fever relapse after intravenous treatment with calcium solutions. However, some drenches have been shown to cause lesions in the forestomacs. When using the DCAD (dietary cation-anion difference) principle, feeding rations with a negative DCAD (measured as (Na + K)-(Cl + S)) significantly reduce the milk fever incidence. Calculating the relative risk (RR) of developing milk fever from controlled experiments results in a mean RR between 0.19 and 0.35 when rations with a negative versus positive DCAD are compared. The main drawback from the DCAD principle is a palatability problem. The principle of feeding rations low in calcium is highly efficient in milk fever prevention provided the calcium intake in the dry period is kept below 20 g per day. Calculating the relative risk (RR) of developing milk fever from controlled experiments results in a very low mean RR (between 0 and 0.20) (daily calcium intake below versus above 20 g/d). The main problem in implementing the low-Ca principle is difficulties in formulating rations sufficiently low in calcium when using commonly available feeds. The use of large doses of vitamin D metabolites and analogues for milk fever prevention is controversial. Due to toxicity problems and an almost total lack of recent studies on the subject this principle is not described in detail. A few management related issues were discussed briefly, and the following conclusions were made: It is important to supply the periparturient cow with sufficient magnesium to fulfil its needs, and to prevent the dry cows from being too fat. Available information on the influence of carbohydrate intake, and on the effect of the length of the dry period and prepartum milking, is at present insufficient to include these factors in control programmes.

Animal Feed↗
PubMed2001

Pharmacokinetic study of the new cyclosporine-A formulation (Neoral) in adult allogeneic bone marrow transplant recipients.

BACKGROUND AND OBJECTIVES: A major problem encountered during oral cyclosporin-A (CsA) administration to prevent acute graft-versus-host-disease (GVHD) after allogeneic bone marrow transplantation (allo-BMT) is its irregular pharmacokinetics. The aim of this study was to evaluate the pharmacokinetics of Neoral, a new water-free microemulsion formulation of CsA. DESIGN AND METHODS: Eighteen patients aged over 18 were enrolled into the study. When able to eat normally after allo-BMT, patients received CsA orally and after 4 days a 12-hour CsA pharmacokinetic profile was constructed. Three patients received Sandimmune 10 mg/kg/day, 5 patients received Neoral 7.5 mg/kg/day and 10 patients Neoral 5 mg/kg/day. CsA concentration was analyzed on whole blood by high-performance liquid chromatography (HPLC). RESULTS: Neoral showed concentration-time profiles characterized by a smooth and faster rise to the Cmax value compared to that produced by Sandimmune. The comparison between pharmacokinetic parameters obtained in patients receiving Neoral 5 mg/kg/day or 7.5 mg/kg/day showed a proportional increase of the AUC (4776+/-1084 vs. 7746+/-2006 ng/mL h) and C(max) (1027+/-203 vs. 1514+/-231 ng/mL). In all patients to whom 7.5 mg/kg/day of Neoral were given, C(trough) levels were always above the threshold of 200 ng/mL. INTERPRETATION AND CONCLUSIONS: Our data suggest that oral administration of Neoral 7.5 mg/kg/day early after allo-BMT may represent an appropriate dose resulting in adequate CsA C(trough) levels without significant renal toxicity.

Adult↗
PubMed1992

How elderly women cope: concerns and strategies.

Forty-two elderly women were asked to describe the problems they faced with aging, and how they coped with both real-life and hypothetical problems in seven areas. Content analysis indicated that their spontaneously reported ongoing strategies were consistent with current theoretical formulations, the strategies differed by area of concern and for real-life versus hypothetical problems, and direct action strategies were related to lower levels of psychologic distress. These results have implications for nursing research and practice.

Adaptation, Psychological↗