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Biomedical subjects

D Hamilton

Publications and source records attributed to D Hamilton.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Experimental laser phototherapy of the Morris 7777 hepatoma in the rat.

The tumoricidal effect of the activation of hematoporphyrin derivative (HpD), by an argon-ion-dye-laser (wavelength 630 nm), was investigated in the Buffalo rat bearing subcutaneous implants of the Morris 7777 hepatoma. Tumor growth was monitored by measuring the tumor volume with constant force calipers. In control animals and those that were pretreated with HpD alone (10 or 20 mg per kg by i.p. injection) or laser light alone (2,000 J at 100 mW), a predictable exponential growth pattern of the cancer was observed. Animals were pretreated with HpD (10 mg per kg by i.p. injection) 48 hr prior to the fiberoptic, intratumor delivery of laser radiation (2,000 J at 100 mW), when the tumor had reached a volume greater than 1.5 cm3. Forty-eight hours after combined laser and HpD treatment, the hepatoma underwent coagulation necrosis, and the tumor volume rapidly increased from a mean value of 1.8 +/- 0.7 cm3 S.D. to a value of 5.8 +/- 1.5 cm3 S.D., compared with a mean of 3.7 +/- 0.7 cm3 S.D. in animals who had not received laser phototherapy. Rats treated with HpD and laser light survived longer (mean survival time 48 +/- 12 days S.D.) than did the other animals treated with the laser alone or HpD alone (mean survival time 31 +/- 16.5 S.D.). Tissue biodistribution studies with tritiated hematoporphyrin derivative, given with doses of 10 and 20 mg per kg of HpD, showed higher concentrations of the dye in the liver, kidneys and spleen than in the tumor at 48 hr after administration of the dye.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Identity, cognitive structure, and long-term tranquillizer use: a multidimensional approach.

The article discusses different theoretical perspectives that are relevant in analysing long-term tranquillizer use. The theories mentioned are, e.g., behavioral theory models, cognitive models, humanistic and existential models, transpersonal identity models, psychodynamic reasoning, sociological and anthropological perspectives. A multidimensional model focusing on the connection between identity structure and long-term tranquillizer use is presented. The article argues for the use of mixed methodological strategies, e.g., quantitative and qualitative methods. The implications of the 'actor-spectator paradox" for the analysis of data are also discussed in some detail.

Anti-Anxiety Agents↗
PubMedDate not supplied

Evaluation of programs for the treatment of benzodiazepine dependency.

Programs for the treatment of benzodiazepine dependency differ in a number of ways. Their outcome goals, for example, vary. In some of the programs the reduction or the elimination of benzodiazepine use is the main objective. In others a reduction in anxiety and depression among patients is regarded as much more important than decreasing benzodiazepine use. These differences in goals make comparative evaluations difficult. Further, the type of clients recruited to the programs are often dissimilar. However, it is still possible and valuable to make comparative evaluations of the numerous programs. The aims of published evaluations differ. Most evaluations are directed towards outcome data. Only in a few studies has the aim been to analyze the dynamic treatment process. To achieve more reliable and valid evaluations it is necessary to get data which describe the process and the results from both the clients' and the therapists' perspectives and combining different research strategies.

Anti-Anxiety Agents↗
PubMedDate not supplied

Toward an integrative approach in the analysis of dependency problems.

This article takes some preliminary steps towards an integrated analysis of dependency problems e.g., long-term tranquillizer use, alcohol dependence, problematic use of narcotics. It argues for the need to outline important theoretical, epistemological, and methodological prerequisites in the analysis of the complex dynamic developmental processes involved in dependency problems. The dynamic process leading to dependence can be studied by the aid of an artificial science neural network approach in combination with a mixed method strategy including a clarification of a combination of different epistemological positions. It is intended that the empirical output of this complex strategy will provide a starting point for a new theoretical analysis which, in turn, will lead to new and more relevant input variables in the neural network approach that will help us to extend our knowledge of the dynamic processes leading to dependency.

Comorbidity↗
PubMedDate not supplied

Intrathecal vincristine: an analysis of reasons for recurrent fatal chemotherapeutic error with recommendations for prevention.

PURPOSE: Accidental intrathecal vincristine instillation is usually a fatal error. The authors report an analysis of a patient and suggest means with which to reduce such errors. PATIENTS AND METHODS: A 7-year-old girl with recurrent acute lymphoblastic leukemia was inadvertently injected intrathecally with 1.5 mg vincristine. A detailed analysis of the events leading to this error and a review of all reported cases in the English literature were undertaken. RESULTS: Reasons for errors reported by us and other institutions included mistaking vincristine for an intended intrathecal drug, assuming vincristine was an additional drug to be injected, not checking physician orders, mistaken route of administration, and mislabeling of syringes. CONCLUSION: Intrathecal injection of vincristine may be the end-result of a series of systems errors. Protocol recommendations to reduce the likelihood of this error are presented.

Antineoplastic Agents, Phytogenic↗
PubMedDate not supplied

How effective are UV opaque face shields in UVB phototherapy cabins?

A few hours after servicing illuminated lamps inside a whole body ultraviolet radiation B (UVB) phototherapy cabin, a technician developed erythema to the anterior neck with subsequent peeling, despite wearing a UV-opaque face shield. Measurements using polysulphone film badges attached to various sites on the head and neck of a mannikin were carried out to explore the spatial distribution of UVB exposure. It was found that the lower face and neck can receive sufficient exposure to result in erythema, the reason being that the fluorescent lamps will extend to about 1.5 m inferior to the head of an upright person and so result in irradiation from below. It is important, therefore, that if operators or service personnel need to be in an illuminated UVB cabin for several minutes or more, adequate protection should be provided to the chin and neck, in addition to a UV-opaque face shield.

Erythema↗