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Biomedical subjects

J Mansell

Publications and source records attributed to J Mansell.

35 records · Page 2Linked to original sources
PubMed1985

Time sampling and measurement error: the effect of interval length and sampling pattern.

The accuracy of momentary time-sampling was evaluated for behaviors occurring for different proportions of time, for different momentary time-samples and for sessions of different lengths. For 1-hr sessions, momentary time-samples of 10, 20 or 30 see intervals between observations yielded 90% of estimates within 10% of the comparison standard, for behaviours of 25%, 50% and 70%. Behaviours occurring for 2% of the session were not accurately recorded even at 10-sec momentary time-samples. For a 5-min momentary time-sample, this criterion was only approached when 8 hr data was averaged to give a single score for each individual, for behaviours of 25% or more. The 5-min momentary time-sample was also compared with a 1 in 5-min cluster sample; although less accurate, cluster-sampling might be a useful strategy in some settings.

Behavior↗
PubMed1985

Fast neutrons and misonidazole for malignant astrocytomas.

Twenty-five patients with biopsy proven malignant supratentorial astrocytomas were entered into a Phase I/II study of misonidazole combined with neutron radiation at Fermilab Neutron Therapy Facility (NTF) between August 1979 and April 1981. The main objectives were to determine tissue tolerance in terms of acute and late effects, and to estimate tumor clearance and survival rates. The total dose was 18.0 Gy given in weekly fractions of 3.0 Gy over 39 days. Four hours before each irradiation, 2.5 gm/m2 misonidazole was administered orally. Patients' ages ranged from 28-69 years. Karnofsky status for most patients was 80 or 90; the lowest grade was 60. The majority of patients had glioblastoma multiforms. Most were already on steroids prior to initiation of therapy. The median survival for the whole group was 12.0 months; 25% were alive at 18 months with some neurological compromise. The median survival remained unchanged for subgroups of patients with ages between 40-60 years and with Karnofsky performance status above 80. Among the 19 patients with glioblastoma multiforme, the median survival was 10 months. Acute toxicity was within tolerable limits. Details of toxicity and tissue analysis from post mortems and second craniotomy samples are presented.

Adult↗
PubMed1985

Tolerance of the human spinal cord to high energy p(66)Be(49) neutrons.

The risk of post irradiation myelopathy was evaluated in 76 patients followed for 1-5 years after neutron irradiation of the cervical and thoracic regions. No overt myelopathy was observed. Forty-six patients received doses (central cord dose) in excess of 10 Gy, 9 received doses in excess of 12 Gy, and 5 received doses between 13 and 17 Gy, all without any evidence of spinal cord injury. On careful questioning, a subjective transient neuropathy (a tingling sensation in one extremity) was reported by 6 patients, but this was apparently unrelated to dose. A review of available literature revealed a total of 14 patients with myelopathy, 13 of whom received doses in excess of 13 Gy delivered with relatively low energy neutrons generated by the deuteron + beryllium reaction. It is concluded from these studies that the tolerance limit for the human spinal cord irradiated with high energy [p(66)Be(49)] neutrons is close to 15 Gy, above which the risk of cord injury becomes significant. Central cord doses of 13 Gy or less appear to be well tolerated with little, if any, risk of myelopathy. These conclusions are valid for a treatment time of 4 weeks or more with two or more fractions per week (9 or more fractions). The RBE for the human spinal cord irradiated under the above conditions compared with conventionally fractionated photon therapy does not exceed 4.0.

Adult↗
PubMed1984

Response of epidermoid and non-epidermoid cancers of the head and neck to fast neutron irradiation: the Fermilab experience.

One hundred and six patients with locally advanced cancers of the head and neck were treated with neutrons at the Fermilab Neutron Therapy Facility. Of these, 44 patients were previously untreated, 33 were recurrent following attempted surgery and 29 patients had previously received a full course of radiation therapy with conventional radiation. Results were analyzed to study the influence of stage, previous management, site of origin and tumor histology on local control of the disease. The most significant factor determining the outcome in this series of patients is the histological type. For epidermoid carcinoma, long term local control was achieved in 17/35 patients (49%) in the previously unirradiated group. With non-epidermoid tumors (adenocarcinoma, cylindroma, muco-epidermoid carcinoma), the local control rate was 28/39 (72%). Disease-free survival analysis also shows a survival advantage in non-epidermoid lesions treated with neutrons. It is concluded that neutron beam therapy may probably be the treatment of choice for non-resectable or recurrent non-epidermoid cancers of the head and neck and requires a clinical trial to establish this observation.

Adenocarcinoma↗
PubMed1984

Response of sarcomas of bone and of soft tissue to neutron beam therapy.

A total of 51 patients were treated at Fermilab for sarcoma of bone (25 patients) and soft tissue (26 patients). Neutrons were delivered in twice weekly fractions over 6-7 weeks to total doses between 18 and 26 Gy. Long-term local control (greater than 2 years) was achieved in 24 patients (47%). Overall local control rates were 44% in the bone sarcomas and 50% in the soft tissue tumors. Chondrosarcoma appeared relatively more responsive with 9 out of 16 (56%) controlled, compared to osteogenic sarcoma with 2 out of 9 (22%) controlled. Among the soft tissue tumors, liposarcoma (5/7 controlled) and neurogenic sarcoma (3/3 controlled) appear to be more responsive than other tumors. The overall survival rate was 40% in the entire series. These results are comparable with international experience in neutron therapy of sarcomas of bone and soft tissues. Out of 263 soft tissue sarcomas treated with neutrons only to full dosage throughout the world, 152 (58%) were locally controlled. Similarly out of 74 sarcomas of bone so treated, 44 (60%) were controlled.

Bone Neoplasms↗
PubMed1975

The ultrastructure and biomechanical significance of the tidemark of articular cartilage.

Thirty specimens of human articular cartilage obtained at surgery were examined by scanning electron microscopy to determine the ultrastructure of the tidemark, the junction of the non-calcified and calcified portions of mature articular cartilage. Three distinct variations of the collagen framework of the tidemark were observed: (1) A band of randomly oriented compacted fibrils that appeared to be continuous with those of the non-calcified and calcified zones. (2) A band of flattened fibrils paralleling the undulating surface of the calcified cartilage. (3) A band of perpendicularly oriented fibrils having a distinct continuous transition between the non-calcified and calcified zones, the amount of calcified material applied about the fibrils rapidly increasing as the fibrils entered the calcified zone. The tidemark may serve to provide a tethering mechanism for the relatively flexible and perpendicularly oriented collagen fibrils of the deepest portion of the non-calcified articular cartilage and may prevent them from being sheared at their point of anchorage to the calcified zone. The undulating pattern of the tidemark affords a strong geometric pattern in providing resistance to the shearing action of articulation. Small gaps present in the tidemark may provide pathways for the passage of nutrients into the deep non-calcified zone of articular cartilage from the subchondral bone.

Biomechanical Phenomena↗
PubMedDate not supplied

Specialized group homes for persons with severe or profound mental retardation and serious problem behaviour in England.

Thirteen people with severe or profound mental retardation identified by their local service agencies as presenting the most serious problem behaviour were transferred from institutional care to specialized group homes. A multiple time-series design and direct observation were used to evaluate whether there was any change in their level of participation in meaningful activity; social interaction and problem behaviour were also observed. Participation increased significantly on transfer and included a wider range of activities. The majority of participants did not increase their major problem behaviour. The results support the view that individualised community-based placements can replace institutions for this group of clients.

Activities of Daily Living↗
PubMedDate not supplied

A Wessex home from home.

Explore the source record for details and available documents.

Activities of Daily Living↗