Nitrosalicyl-imine-chitosan hydrogels based drug delivery systems for long term sustained release in local therapy

The paper focuses on the synthesis and characterization of new drug delivery systems for local therapy. They were prepared by in situ hydrogelation of chitosan biopolymer with nitrosalicylaldehyde in the presence of a model drug, varying the crosslinking density. The structural, supramolecular and morphological characteristics of the systems were studied by FTIR spectroscopy, X-ray diffraction and, POM and SEM microscopy. In vitro release of the drug has been explored in simulated physiological conditions and in vivo release was investigated by the somatic pain model on rats. Information on the biodegradation of the systems was gain by simulating experiments of enzymatic degradation. The systems were biodegradable and showed a prolonged drug release, assuring an in vivo efficient therapeutic effect over 5 days, with no systemic toxicity. All these findings demonstrated that the new hydrogels based on nitrosalicyl-imine-chitosan provides a practical approach for sustained drug delivery for local chemotherapy.

Ketoprofen-liposomes formulation for clinical therapy

Lipid (L-α-phosphatidylcholine) was used in liposome-ketoprofen formulation to obtain vesicles systems characterized by a net positive charge along the liposomal surface. A careful analysis of vesicles formation and systems stability was made. Dynamic stability and specificity of liposomes disruption and prolonged release of ketoprofen was provided by steric effect accomplished on the vesicle surface by chitosan molecules, which were introduced into the system additionally. The retardation effect of the liposomes containing ketoprofen was tested in vitro and in vivo. The studies have shown that the liposomes containing ketoprofen obtained are characterized by a net positive charge and an average diameter of 1,287 nm for dialyzed solutions (pH 7.40). This formulation presents in vivo significant antinociceptive effects starting at 90 min, with a maximum intensity between 2 and 8 h, prolonged more than 10 h, and an analgesic activity within 3-4 h.

Research ethics I: Responsible conduct of research (RCR)--historical and contemporary issues pertaining to human and animal experimentation

PURPOSE

In this series of articles--Research Ethics I, Research Ethics II, and Research Ethics III--the authors provide a comprehensive review of the 9 core domains for the responsible conduct of research (RCR) as articulated by the Office of Research Integrity. In Research Ethics I, they present a historical overview of the evolution of RCR in the United States then examine the evolution of human and animal experimentation from the birth of scientific medicine through World War II to the present day.

METHOD

They relied on authoritative documents, both historical and contemporary, insightful commentary, and empirical research in order to identify current issues and controversies of potential interest to both faculty and students.

CONCLUSIONS

The authors have written this article from a historical perspective because they think all readers interested in RCR should appreciate how the history of science and all the good--and harm--it has produced can inform how researchers practice responsible research in the 21st century and beyond.

Objective measures of health and well-being in laboratory rhesus monkeys (Macaca mulatta)

BACKGROUND

Non-human primates are an invaluable part of biomedical research. Strict regulations insure animals have a maximum likelihood of well-being and optimum health during the course of experimental procedures. Objective assessment of well-being is a critical component of these assurances.

METHODS

Here we describe an objective and quantitative system we used to identify two well-being concerns in laboratory rhesus monkeys (Macaca mulatta). We provide a series of indicators for use by laboratory personnel to promote laboratory primate well-being. The indicators measure (1) potentially life threatening clinical concerns, (2) developing clinical issues, (3) atypical behaviors, and (4) laboratory performance. We include specific criteria to facilitate veterinary intervention.

RESULTS

The assessment, applied to two case studies reported here, enabled swift veterinary intervention returning the animals to a healthy state.

CONCLUSIONS

The measures described here provide a battery of observable and objective measures across multiple dimensions that can further ensure both excellent science and veterinary care.

Does experimental pain response vary across the menstrual cycle? A methodological review

The findings on sex differences in human experimental pain research are inconsistent. One possible factor contributing to the inconsistent findings is the female hormonal cycle, as hormone levels may affect pain sensitivity. A number of studies suggest that women's responses to experimentally evoked pain vary across the menstrual cycle. However, at least an equal number of studies suggest a lack of variability. The purpose of this article is to review the literature with emphasis on what we believe could be the reasons for the inconsistent findings, namely, differences in populations sampled, timing of experimental sessions across the menstrual cycle, and nomenclature used to identify the time (phases) in the cycle when measurements were done, nature of the pain stimuli chosen, and outcomes measured. These inconsistencies and other methodological problems associated with most experimental pain studies make it difficult to draw inferences from this literature. For the science to improve, replication of significant findings using standardized timing of sessions, pain stimulus procedures, outcomes, and hormonal assessment is necessary.

Effect of the analgesic butorphanol on activity behaviour in turkeys (Meleagris gallopavo)

During fattening, the bodyweight of modern broad-breasted turkeys increases considerably within a very short space of time. In particular, the breast muscles increase disproportionately. This leads to a disadvantageous distribution in weight, and as a consequence, to a disturbed leg position and skeletal deformations like antitrochanteric degeneration, tibial dyschondroplasia, bending, twisting and rotation of the tibia, osteochondrosis, osteomyelitis, rickets, and epiphyseolysis of the femoral head increases. This cases of degenerative joint disease cause severe pain in humans and there are indications that this is also true for turkeys. The purpose of this study was to determine if behaviour indicative of such pain in turkeys of the B.U.T. Big 6 breeding line could be attenuated by administering a quick-acting analgesic, butorphanol. Twelve pairs of turkeys were tested at the ages of 7 and 12 weeks. One bird in each pair received an analgesic opioid injection, while the other one received a control injection of physiologically balanced saline solution. The time the birds spent putting weight on their legs, i.e., 'walking' and 'standing' and the distance covered by the birds were recorded during the 30 min periods before and after the application of the drug. At week seven the treated birds spent significantly more time putting weight on their legs than control birds. At week 12, the same tendency was observed. No significant differences were found in the distances covered by the animals. It is concluded that fattening turkeys reduce the time they are putting weight on their legs because these behaviours may be associated with pain.

Nursing staff members' perceptions of pain indicators in persons with severe dementia

OBJECTIVES

The aims of this study were to (1) identify behaviors that occur in noncommunicative nursing home residents that are perceived by nurses to be indicators of pain, (2) determine factors affecting the differentiation of pain behaviors from similar behaviors due to other causes, and (3) assess nurses' perceptions of the prevalence and importance of specific indicators of pain as well as barriers to the detection of pain in this population.

SETTING AND PATIENTS

Seventy-two staff members of three nursing homes were interviewed and surveyed about specific behaviors associated with pain. Focus groups were conducted with staff to validate pain indicators and investigate perceptions of their own ability to identify pain.

RESULTS

Nursing staff members agreed on a core group of behaviors that they perceive as pain indicators in elderly persons suffering from dementia. These indicators include specific physical repetitive movements, vocal repetitive behaviors, physical signs of pain, and changes in behavior from the norm for that person. The nursing staff members' level of familiarity with the residents was reported to have a significant effect on staff members' ability to identify and differentiate pain behaviors from other behaviors of impaired residents. Barriers to the detection of pain pertain to staff issues, resident behaviors, and resident-staff relationships.

CONCLUSIONS

The study of pain among the noncommunicative elderly and, in particular, the development of a tool that can be used to assess their pain may greatly improve the quality of life of the estimated 20% to 35% of nursing home residents who cannot adequately express their needs.

Benefits, Necessity and Justification in Animal Research

The cost–benefit assessment in the Animals (Scientific Procedures) Act 1986 is said to ensure that animals are only used in experiments which are justified and necessary. The way in which the Home Office Inspectorate derives the cost–benefit assessment is explained in the Report of the Animal Procedures Committee for 1993. However, evaluation of both costs and benefits is largely subjective, as are concepts such as “necessity” and “justification”. These concepts mean different things to different people in different places and at different times, depending on the pressures to which they are subject. These include the socio-economic climate and the context in which the proposed research is to be carried out. Animal use cannot, therefore, be said to be necessary and/or beneficial unless serious questions are answered with respect to who or what the research is necessary for, who or what will benefit from it and who defines the criteria used in the justification process. Retrospective analysis of whether the proposed benefit was actually achieved and applied is also important. Discussion regarding the necessity, benefits and justification of individual research projects, and of overall research goals or directions, tends to be obscured by the polarised debate over the morality and scientific validity of animal experiments as a whole. This paper raises some of the issues that could be discussed in a wider view of the cost–benefit assessment, with reference to selected areas of animal use as examples.

Ethics in dental research. Ethical use of animals

Based on old nursery rhymes, which are still in vogue, it is apparent that children from an early age receive ambivalent messages concerning relationships with animals. It is also apparent that we as a society have placed a hierarchical structure on animals; it is clear that we value a dog or a cat more than a mouse or a rat. Enormous strides in the prevention and treatment of disease have been made directly or indirectly as a result of experiments carried out on animals. Persons who conduct investigations using animals have an obligation to ensure that valid scientific questions are being explored, and that the minimum numbers of animals are used compatible with achieving a valid scientific result. Animals must always be cared for properly. Research involving induction of pain must receive particular attention. Finally, it is incumbent upon all scientists who use animals in their investigations to ensure that the public is kept fully informed of all scientific advances made by the use of animals.

Weight bearing as an objective measure of arthritic pain in the rat

This study compares two methods for evaluating pain-related behavior in an animal model with carrageenan-induced monoarthritis. Rats injected with lambda-carrageenan into the right tibio-tarsal joint were videofilmed at various times after injection and later scored regarding their stance. Immediately after each videorecording session the animals were tested in a box constructed to register the weight load exerted by the hindpaws by means of force plates inserted in the floor. Following carrageenan injection (300 micrograms in 50 microL) the load on the injected paw fell from a control value of 39.3% +/- 0.4% of the body weight (mean +/- SEM, n = 6) to a minimum of 5.1% +/- 1.8% at 6 hr and then slowly increased to approach control levels at 72 hr. The weight load on the contralateral paw increased from a control value of 38.9% +/- 0.6% to 52.4% +/- 1.4% at 6 hr, whereafter it gradually decreased. The video-based stance scores also showed a maximal impairment at 4-6 hr, with a gradual return towards control values at 72 hr. However, the results based on the force plate measurements were less variable and more graded. Morphine inhibited the carrageenan-induced effect in a dose-dependent manner in both paradigms. In conclusion, the present results indicate that measurement of weight bearing as described in the present paper is a practical, useful, and objective method to assess the degree of arthritic pain in the rat.