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Biomedical subjects

A Day

Publications and source records attributed to A Day.

135 records · Page 8Linked to original sources
PubMed1977

Therapy of an experimental glioma with systemic or intraneoplastic methotrexate or radiation.

An intracranial mouse glioma model was used to study the effectiveness of chemotherapy with methotrexate )MTX) or radiotherapy. Maximum tolerable doses of MTX were established by toxicity studies in nontumor-bearing mice for the intraperitoneal and intracerebral routes of drug administration with and without leucovorin as an antidote. These maximum tolerable doses were then given either by the intraperitoneal route or directly into the tumor to mice bearing intracerebral tumors. The glioma model proved to be extremely useful for assessing the modalities studied, including repeated intraneoplastic injection of MTX. Dosage schedules were successfully developed for administering large amount of MTX and for preventing systemic toxicity by the administration of the antidote. Radiotherapy in single doses and 800 rads delayed the median day of death and produced several long-term survivors. Higher doses were toxic. Intraperitoneal or intraneoplastic MTX was completely ineffective as a chemotherapeutic agent for this tumor, even though very large amounts could be delivered due to the protection from systemic toxicity afforded by leucovorin. It is concluded that MTX is a poor chemotherapeutic agent for this experimental brain tumor, but that the technique of intraneoplastic administration of chemotherapeutic agents is feasible with this model system and should be studied further.

Animals↗
PubMed1977

Chemotherapy of an experimental glioma with nitrosoureas.

Chemotherapy experiments were performed with 2 nitro-sourea drugs in an experimental mouse brain tumor model. Cell suspensions of a transplantable mouse ependymoblastoma were injected i.c. by means of a stereotactic frame. The drugs used were 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea and 1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea and were given by either i.p. or by direct intraneoplastic (i.n.) injection on the fifth day after tumor cell implantation. Injections i.n. of drugs were made with the stereotactic frame. Both drugs were highly effective in increasing the median day of death and in yielding large numbers of long-term survivors. Effectiveness was evident after i.p. or i.n. injection. However, with certain dosage schedules such as every 2 hr for 5 injections daily on 2 consecutive days, i.n. injection was more effective and less toxic than i.p. injection. The reason why repeated i.n. injections produced less toxicity than repeated i.p. injections is not definitely known but may be due to local metabolism of the drugs in the tumors and surrounding brain to a less toxic form. This is the first laboratory report of direct i.n. injection of the nitrosoureas, and the authors consider these results encouraging.

Animals↗
PubMedDate not supplied

Depression and anxiety as predictors of outcome after myocardial infarction.

OBJECTIVE: The objective of this study was to investigate the significance of emotional distress immediately after a myocardial infarction as a predictor of physical, psychological, and social outcomes and resource use. METHODS: In an epidemiological survey, demographic and cardiological data were obtained for all patients from a defined geographical area who had had a myocardial infarction (according to diagnostic criteria of the Monitoring Trends and Determinants in Cardiovascular Disease [MONICA] trial). Hospital survivors were interviewed and were asked to complete self-report assessments on mental state and quality of life. Full replies were available at baseline for 347 subjects. Self-report follow-up questionnaire information was collected 3 months and 1 year later. RESULTS: Fifteen percent of patients scored as probable cases of anxiety or depression. They were more likely than noncases to report preinfarct distress and poor adjustment (as indicated on the 36-item Medical Outcome Study short form). There was an improvement at 3 months, but there was little overall or individual change after that time. Anxiety and depression did not predict subsequent mortality but did significantly predict poor outcome at 1 year on all dimensions of the 36-item short form quality-of-life measure and on specific measures of everyday activity and reports of chest pain, use of primary care resources, and secondary prevention lifestyle changes. CONCLUSIONS: Subjects who are distressed in the hospital are at high risk of adverse psychological and quality-of-life outcomes during the ensuing year. Our findings strengthen the argument for in-hospital identification and treatment of patients with depression and anxiety after myocardial infarction.

Adult↗
PubMedDate not supplied

Plasma membrane pores of the Schwann cell in Wallerian degeneration: a morphometric analysis.

Using the freeze-fracture technique, myelinated fibres were examined from the rabbit sciatic nerve at 48 h after a proximal nerve crush. Employing computer-aided morphometric techniques the distribution of Schwann cell plasma membrane pores was analysed. In both normal control and crushed nerves membrane pores were restricted to the cytoplasmic circumferential bands and longitudinal columns, which characterize the surface of the myelinated nerve fibre, and were absent from the flat plaque-like areas delimited by the bands and columns. In approximately half of the myelinated fibres from the crushed nerves there was a five-fold increase in the density of plasma membrane pores. This response of the Schwann cell was interpreted in terms of an increase in pinocytosis and related to regenerative phenomena in the peripheral nerve.

Animals↗
PubMedDate not supplied

The nurse's role in managing constipation.

Constipation is a problem that affects patients in many care settings. Although recommendations are made for specific groups of patients with constipation, such as older patients and children, there is less information available for general adult patients. Angela Day discusses the need for clinical audit to ensure that nurses are using the most effective options for managing and preventing constipation, and examines the treatment options currently available.

Acute Disease↗
PubMedDate not supplied

The LFA-1 antigen in human B lymphocyte activation.

Human tonsil B cells include a subpopulation (30 per cent) of cells which lack LFA-1 antigen. Activation of tonsil B cells by culture with anti-IgM and interleukin-4 led to an increase in staining intensities and in the proportion of cells staining, until by 48 h the majority of B cells were positive. Culture of activated cells with low-molecular weight B cell growth factor, which induces a proportion of cells to proliferate, led to a minor further increase in expression of the LFA-1 antigen. Inclusion of a monoclonal antibody against the LFA-1 beta chain in culture did not affect either proliferation or immunoglobulin secretion. The expression of LFA-1 by B cells thus changes as B cells are activated, perhaps reflecting the changing requirements of B cells for interaction with other cells and tissue components. On the other hand, our results did not provide any support for the idea that the LFA-1 antigen is directly involved in the interaction of B cells with lymphokines which control proliferation and differentiation.

Antibodies, Monoclonal↗