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Biomedical subjects

W Temple

Publications and source records attributed to W Temple.

At least 19 recordsLinked to original sources
PubMed2006

Use of tissue expanders and pre-operative external beam radiotherapy in the treatment of retroperitoneal sarcoma.

INTRODUCTION: We report our experience of treating retroperitoneal sarcoma (RPS) using pre-operative external beam radiotherapy (EBRT) in combination with radical resectional surgery from 1990 to 2005. METHODS: Twenty-eight primary and 10 recurrent tumors were identified from a prospective database. RESULTS: The resection rate was 71% overall; 82% in primary (23/28) and 40% (4/10) in recurrent cases. EBRT was administered preoperatively in 25 patients, postoperatively in 1, and palliatively in 11. In 33 patients a saline-filled tissue expander was inserted into the abdomen before radiotherapy to displace small bowel from the radiation field. 4,500-5,000 cGy was administered in fractions of 180-200 cGy over a 5-week period; surgery followed 6-8 weeks later. Expander insertion was associated with minimal morbidity; 31/37 patients received a dose of 4,000 cGy or more (median 4,650 cGy). Median resected tumor diameter was 13 cm, and a median of three adjacent organs was resected per patient. Complete macroscopic resection was achieved in 25/27 patients (93%); R0 in 9 (33%) and R1 in 13 (48%) (microscopic margins unclear in 5). There was no postoperative mortality. Tumors were high-grade in 20 patients, low-grade in 14 and ungraded in 4. Actuarial 5- and 10-year survival for all patients was 74 and 60%. For operable primary tumors, the 5-year survival and disease-free rates were 90 and 80%. In four patients with operable recurrent tumors, median disease-free interval was 91 months (27-160). In the 11 inoperable cases, median survival after radiotherapy was 48 months (9-77). CONCLUSIONS: We conclude that a combination of pre-operative tissue expander placement, high-dose EBRT and radical resectional surgery can achieve acceptable morbidity, extended survival and low long-term recurrence in patients with RPS. STATISTICS: Median (interquartile range).

Female↗
PubMed2005

Concurrent second-order schedules: some effects of variations in response number and duration.

To examine the effects on concurrent performance of independent manipulations of response-unit duration and number, 6 hens were exposed to concurrent second-order schedules of reinforcement. Each first-order operant unit required completion of a fixed-ratio schedule within the time specified by a fixed-interval schedule, with one further response completing the fixed-interval schedule. The fixed-ratio and fixed-interval requirements comprising the first-order operant units were systematically and independently varied under three pairs of concurrent variable-interval schedules to produce differences in the first-order response and duration requirements (response and duration differentials). These manipulations produced consistent changes in response, time, and operant-unit biases. A 1:4 response differential biased the time and operant-unit measures towards the smaller fixed ratio, but to a degree less than the imposed response differential. The response-based biases favored the larger fixed ratio. Duration differentials of 4:1 and 8:1 biased the response and operant-unit measures towards the shorter fixed interval, again less than the imposed duration differential, but the time biases remained close to zero. Both sorts of differentials acted to bias operant-unit completions more systematically than the other measures, but undermatching to the differentials occurred. The undermatching appears to have arisen from a pattern of fix and sample (in which visits to the less preferred alternative involved only a single completed operant unit) under combinations of unequal operant-unit requirements and reinforcer rates. The response and time bias measures appeared to arise as by-products of the changes in operant-unit completions.

Animals↗
PubMed2001

Determination of auditory thresholds in the brushtail possum (Trichosurus vulpecula).

The auditory abilities of the brushtail possum (Trichosurus vulpecula) have been measured by cochlear potential readings, but no behavioural determinations of their auditory abilities have been published. Six experimentally naive possums were trained to perform a two-response conditional discrimination between the presence and absence of an 880-Hz tone (at 80 dB). All six possums readily learned this task. The behavioural threshold for this tone was determined using a modified tracking procedure and found to be similar to that reported using cochlear microphonic potentials. One concern with the current method was the communal nature of the experimental environment so a further threshold determination in a sound-attenuating chamber was conducted. No substantial difference was noted between the results obtained in the two threshold determinations. The success of the current method means that a full, behavioural audiogram for the brushtail possum, which would complement the existing cochlear potential data, is now possible.

Animals↗
PubMed2000

Resurgence: the role of extinction.

Three hens were trained to door push and three were trained to head bob using food as the reinforcer (Behaviour 1 training). A period of extinction followed. Each hen was then trained to perform the other behaviour (Behaviour 2) and this was followed by seven sessions of extinction. This whole sequence was repeated six times, with two sessions of extinction following Behaviour 1 training. Over the repeated extinction conditions there were decreases in responding early in extinction, for both Behaviours 1 and 2, compared with the first condition. Behaviour in the later extinction sessions could be studied for Behaviour 2 only, and it was found to increase relative to the first condition, over repeated extinction conditions. The occurrence of Behaviour 1 during the extinction following the training of Behaviour 2, that is the resurgence of Behaviour 1, both over the whole of and in the first session of each extinction phase, was variable and tended to increase over these six conditions. Thus it is possible to study resurgence using a within-subject design but the effect of repeated extinction conditions needs to be considered. The period of extinction immediately following Behaviour 1 training was then increased to nine sessions for two replications of the whole sequence. This was followed by two repeats of the sequence with no sessions of this extinction and then by another repeat, with nine sessions of this extinction phase. Over these five conditions the total resurgence of Behaviour 1 was generally greater when there were no sessions of extinction immediately following Behaviour 1 training, than when there were nine sessions. This result was more marked for the resurgence of Behaviour 1 in the first session of the extinction of Behaviour 2. Thus, these data support the hypothesis that the resurgence of Behaviour 1 is the result of the prevention of the extinction of Behaviour 1 by training Behaviour 2. At a similar point in extinction, the number of occurrences of Behaviour 1 in its own extinction was not significantly different from the number of occurrences of Behaviour 1 during the extinction of Behaviour 2. This fails to support the hypothesis that resurgence is induced by the extinction of Behaviour 2.

Journal Article↗
PubMed2000

Management of the axilla in early breast cancer: is it time to change tack?

The standard surgical treatment of the axilla in patients with early breast cancer is about to undergo a radical change. Although axillary dissection is an excellent procedure for both staging and local control, particularly in the clinically positive axilla, it has considerable morbidity and may understage a significant proportion of patients, because it will usually miss micrometastases that can occur in approximately 10% of 'node negative' patients. An increasing number of patients whose tumours are either non-invasive (ductal carcinoma in situ; DCIS), micro-invasive, tubular cancers or low-grade T1a tumours without lymphovascular invasion may be spared axillary surgery because the risk of axillary disease is 0-3%. Many studies, both prospective trials and large retrospective series, show that axillary radiotherapy alone provides similar local control rates to axillary dissection in patients with clinically negative axillas. Primary treatment of the axilla with radiotherapy alone, however, does not allow appropriate staging. Sentinel lymph node biopsy is being increasingly used in patients with breast cancer to provide this information. When a sentinel node is identified it is equal to or better than axillary dissection for staging the axilla and, if the node is positive, it will help select patients who should then proceed to further axillary surgery or axillary radiotherapy. Although sentinel lymph node biopsy is being rapidly adopted in many centres worldwide, the results of randomized controlled trials are needed before it can be recommended as the standard of care.

Axilla↗
PubMed1998

Benefit of aggressive multimodality therapy with autologous stem cell support for intra-abdominal desmoplastic small round cell tumor.

A case is described of a 19-year-old man with poor prognosis intra-abdominal desmoplastic small round cell tumor, who achieved a durable complete remission after aggressive multimodality treatment. He was diagnosed with a large peri-rectal mass and bulky metastases to the peritoneum, omentum and liver. He achieved a partial response to six courses of chemotherapy with VAC (vincristine, adriamycin, actinomycin, cyclophosphamide) and VIP (VP-16, ifosfamide, cisplatin). This was followed by resection of the omentum and cryotherapy to six of the liver lesions. He then achieved a complete response following high-dose busulfan 16 mg/kg and melphalan 140 mg/m2 with autologous stem cell support. Finally, pelvic radiotherapy was given to consolidate the remission. Twenty-six months following his diagnosis, and 19 months after the transplant, he remains well with no clinical or radiologic evidence of recurrent disease. This case report suggests a role for autologous stem cell transplantation as part of multimodality therapy for this unusual and aggressive malignancy.

Abdominal Neoplasms↗
PubMed1998

Reinforcer efficacy in a delayed matching-to-sample task.

Five domestic hens were exposed to a delayed matching-to-sample task. Conditions 1, 5, and 8 were variable-delay conditions in which five delays (0.25, 1, 2, 4, and 8 s) from the red or green sample to the presentation of the red and green comparison stimuli were presented a number of times during each session. In the fixed-delay condition (Condition 3), each delay was presented for 15 sessions under a Latin square design across birds. When improvements in accuracy across the variable-delay conditions are taken into account, the data were similar under both the variable and fixed delays. In Conditions 2, 4, 6, and 7 sample-reinforcer intervals were held at 8, 8, 4, and 2 s, respectively, while sample-choice intervals were varied within these during each session. With increasing sample-reinforcer interval, both initial discriminability (i.e., with sample-choice delay = 0) and rate of decrement in discriminability decreased. Although the former would be predicted if accuracy depends of the average sample-reinforcer interval, the latter would not. These data show that increasing the sample-choice interval had less effect on matching accuracy than increasing the sample-reinforcer interval did.

Animals↗
PubMed1998

Concordance in communication between surgeon and patient.

OBJECTIVES: To examine (1) the capability of using interactive voice response (IVR) system technology for clinical research studies involving assessment of clinician-patient interactions and (2) the concordance of surgeons and their breast cancer patients about the content of a postbiopsy pre-treatment decision meeting. DESIGN: A descriptive comparison of the perceptions of 2 volunteer groups--surgeons and their patients--using interactive voice technology. SETTING: Surgeons' offices. PARTICIPANTS: Twenty-six dyads of surgeons and their patients with newly diagnosed breast cancer. OUTCOME MEASURES: Concordance as determined through a 15-item patient questionnaire and a parallel 11-item surgeon questionnaire addressing surgical and psychosocial aspects of breast cancer treatment. RESULTS: Fifty-four percent to 100% of the 26 dyads indicated concordance about treatment preference, treatment choice, how treatment was chosen, preference for how treatment was chosen, time for discussion about treatment, and discussion about lymph-node removal. Only 27% to 50% of dyads agreed about patient understanding of lymph-node removal, the thoroughness of discussions about adjuvant treatment, the thoroughness of discussion about emotional coping, and the sufficiency of time for the discussion of patient's concerns. In these areas of disagreement surgeons often underestimated the patient's ability to understand and underestimated the patient's perception of the thoroughness of discussions about the psychosocial aspects of the illness (concerns and coping). CONCLUSION: Surgeons and patients demonstrated concordance on their perceptions of the type of treatment desired and needed but were discordant on their perceptions of the degree of patients' understanding about post-treatment and psychosocial issues.

Breast Neoplasms↗
PubMed1996

Concurrent schedules: Quantifying the aversiveness of noise.

Four hens worked under independent multiple concurrent variable-interval schedules with an overlaid aversive stimulus (sound of hens in a poultry shed at 100dBA) activated by the first peck on a key. The sound remained on until a response was made on the other key. The key that activated the sound in each component was varied over a series of conditions. When the sound was activated by the left (or right) key in one component, it was activated by the right (or left) key in the other component. Bias was examined under a range of different variable-interval schedules, and the applicability of the generalized matching law was examined. It was found that the hens' behavior was biased away from the sound independently of the schedule in effect and that this bias could be quantified using a modified version of the generalized matching law. Behavior during the changeover delays was not affected by the presence of the noise or by changes in reinforcement rate, even though the total response measures were. Insensitivity shown during the delay suggests that behavior after the changeover delay may be more appropriate as a measure of preference (or aversiveness) of stimuli than are overall behavior measures.

Journal Article↗
PubMed1996

Concurrent-schedule performance in dairy cows: persistent undermatching.

Performance of dairy cows responding under concurrent variable-interval variable-interval schedules of food delivery was examined, with results analyzed in terms of the generalized matching equation. In Experiment 1, bias measures indicated that crushed barley was preferred over meatmeal when these foods were available under the alternative schedules. For whole-session data, substantial undermatching of response and time-allocation ratios to obtained reinforcement ratios was evident. Postreinforcement pause time ratios approximately matched obtained reinforcement rates. Subtracting these times from total time-allocation values yielded net time-allocation ratios that undermatched obtained reinforcement ratios to a greater degree than did whole-session time-allocation ratios. In Experiment 2, substantial undermatching was evident when the same foods (hay for 2 cows, crushed barley for 2 others) were available under the alternative schedules. Food-related activities and other defined behavior not related to food were quantified by direct observation, and were found to occupy a substantial proportion (roughly 40% to 80%) of experimental sessions. Subtracting the time spent in these activities from the time allocated to each component schedule did not reduce the degree of undermatching obtained. Across all conditions in both experiments, slopes of regression lines relating behavioral outputs to environmental inputs characteristically were below 0.6, which agrees with prior findings and suggests that, contrary to suggestions in the literature, undermatching in dairy cows is not the result of using different foods under alternative schedules or differential pausing under those schedules.

Animals↗
PubMed1996

High-dose melphalan +/- total body irradiation and autologous hematopoietic stem cell rescue for adult patients with Ewing's sarcoma or peripheral neuroectodermal tumor.

The role of high-dose therapy and autologous stem cell transplantation (ASCT) in the treatment of patients with Ewing's sarcoma (EWS) remains uncertain. From November 1985 to September 1994, 13 patients aged 16-30 years (median 20.5) received high-dose melphalan (HDM) 140-200 mg/m2 +/- 500 cGy TBI followed by ASCT for relapsed/refractory (n = 4), metastatic (n = 2), or non-metastatic (n = 6) EWS, or for peripheral neuroectodermal tumor (PNET) (n = 1). This regimen was well tolerated with no transplant-related mortality and no toxicity requiring life sustaining measures. Three of the four patients treated for relapsed/refractory EWS had progression-free survivals (PFS) less than 5 months. The only long-term survivor of these four patients received HDM while in complete remission following pulmonary irradiation. Both patients with pulmonary metastases at presentation died just 5 and 6 months post-ASCT. All four patients with non-metastatic, bulky (> 8 cm) osseous EWS progressed at a median of 11 months (range 7-22 months) while the two patients with non-bulky EWS remain progression-free 25+ and 28+ months post-HDM/TBI + ASCT. The 19-year-old patient with a PNET of the thoracoabdominal wall relapsed 4 months post-ASCT. Overall, only three of these 13 patients remain progression-free at 25+, 28+, and 108+ months following HDM +/- TBI and ASCT. In conclusion, HDM +/- TBI did not obviously improve the outcome of these 13 patients relative to that expected following conventional dose therapy alone.

Adolescent↗
PubMed1995

Predicting and scaling hens' preferences for topographically different responses.

Six hens were exposed to several concurrent (second-order) variable-interval schedules in which the response requirements on the alternatives were varied. The response requirements were one key peck versus five key pecks, one key peck versus one door push, and five key pecks versus one door push. Response- and time-allocation ratios undermatched the obtained reinforcement ratios but were well described by the generalized matching law. Time and response bias estimates from two pairs of response requirements were used to predict bias in the third pairing. The predicted values were close to those obtained; this result supports the notion that both numerically and topographically different responses act as constant sources of bias within the generalized matching law. The differences between the response and time biases could be accounted for by the different times needed to complete each response requirement. The results also suggest that the door push is a useful operant for research with domestic hens.

Journal Article↗