Biomedical subjects

J Macintosh

Publications and source records attributed to J Macintosh.

4 recordsLinked to original sources

PubMed2006

Cystic partially differentiated nephroblastoma.

Cystic partially differentiated nephroblastoma is a relatively rare tumour of the kidney usually affecting infants. Cystic Wilms' tumour and multilocular cystic nephroma should be distinguished from cystic partially differentiated nephroblastoma. Multilocular cystic nephroma is a benign tumour whereas cystic Wilms' tumour is at the malignant end of the range of classification of such tumours. Cystic partially differentiated nephroblastoma may undergo local recurrence but there is no report of metastasis.

Child, Preschool↗

PubMed2001

Analysis of toxicity of Merkel cell carcinoma of the skin treated with synchronous carboplatin/etoposide and radiation: a Trans-Tasman Radiation Oncology Group study.

PURPOSE: The acute and late toxicities of synchronous carboplatin, etoposide, and radiation therapy were prospectively assessed in a group of patients with high-risk Merkel cell carcinoma of the skin. PATIENTS AND METHODS: Forty patients from six different centers throughout Australia were entered into a Phase II study under the auspices of the Trans-Tasman Radiation Oncology Group. The trial was activated in 1996 and continues to accrue. Patients are eligible if they have disease localized to the primary site and nodes and are required to have at least one of the following high-risk features: recurrence after initial therapy, involved nodes, primary size greater than 1 cm, gross residual disease after surgery, or occult primary with nodes. Radiation was delivered to the primary site and nodes to a dose of 50 Gy in 25 fractions over 5 weeks, and synchronous carboplatin (area under curve [AUC] 4.5) and etoposide (80 mg/M(2) i.v.) were given on days 1-3 during weeks 1, 4, 7, and 10. The median age of the group was 67 years (43-78). RESULTS: The median duration of follow-up was 22 months (2-45). There were no treatment-related deaths. Grade 3 or 4 skin toxicity occurred in 63% of patients (95% CI 48, 78). The most serious acute effect was on neutrophils with Grade 3 or 4 (neutrophils < 1 x 10(9)/L), occurring in 60% (95% CI 45, 75) of cases. Complications from neutropenia (fever and sepsis) occurred in 16 patients (40% of cases). The median time for neutropenic complications was 27 days (9-35), and 10/16 (62%) cases of neutropenic fever occurred after the second cycle of chemotherapy. The probability of Grade 3 or 4 late effects on platelets (<50 x 10(9)/L) and hemoglobin (<8 g/dl) was 10% (95% CI 1, 20) and 6% (95% CI 2, 15), respectively. Of the 40 patients, 35 were able to complete 4 cycles of chemotherapy. There were no factors predictive for neutropenic toxicity at a p value < 0.05. CONCLUSIONS: The protocol has acceptable toxicity, and the treatment has been deliverable in a multi-institutional trial setting. Neutropenia is likely to occur with synchronous carboplatin/etoposide and radiation in this population of patients. The risk of a febrile neutropenia was greatest at the time of the second cycle of chemotherapy, when there was moist desquamation of skin or mucosal membranes that provided a portal for infection. This should be considered in the design of subsequent protocols with chemoradiotherapy.

Adult↗

PubMed2001

Research with homeless people uncovers a model of health.

This grounded theory research study, explored health experiences of 11 homeless persons in shelters in three New Brunswick cities and the strategies that they used to attain, maintain, or regain health. Audiotaped interviews were conducted, transcribed verbatim, and analyzed. The model that emerged from analysis consists of three pathways to health. This model of health has two central components, person and health. Person is influenced directly by family values and beliefs, and directly and indirectly by societal values and beliefs. Health is the outcome and is reached through two mediating factors of lifestyle behaviors and sector services. The first pathway to health contains the mediating factor of lifestyle behaviors, the second contains the mediating factor of sector services, and the third contains both mediating factors. Pathway strategies of choosing, accessing, and appraising appropriateness of methods influence the active participation of the person that directs the action within the model. Implications of the study include that a fragmented system of help hinders access to services intended to promote health in this population.

Adaptation, Psychological↗

PubMed1987

Technical limitations to the efficacy of radiofrequency neurotomy for spinal pain.

Prompted by clinical failures of percutaneous radiofrequency neurotomy in the treatment of back pain and neck pain, we performed a study to determine the shape and size of lesions made by radiofrequency electrodes. Experimental lesions were made in egg white and fresh meat at temperatures recommended in clinical practice. The cardinal finding was that lesions do not extend distal to the tip of the electrode. They only extend radially around the electrode tip in the shape of an oblate spheroid, with a maximal effective radius of only 2 mm. Consequently, if electrodes are directed perpendicularly onto a nerve, the nerve may not be encompassed by the lesion generated. Some of the clinical failures of percutaneous medial branch neurotomy ("facet rhizotomy") may be due to this phenomenon. We suggest modified techniques for medial branch neurotomy in which the electrodes are introduced parallel to the target nerve whereupon it is more readily encompassed by the radial spread of the lesion.

Back Pain↗