Phase II study of etoposide (VP-16) in patients with thyroid cancer with no prior chemotherapy: an Eastern Cooperative Oncology Group Study (E1385)

This study of etoposide in thyroid cancer was designed to determine the activity and toxicity of etoposide in a variety of inoperable, thyroid hormone insensitive, and radio-iodine resistant primary cancers of the thyroid. The patients were required to have an ECOG performance status of at least 3 and no previous exposure to chemotherapy. The etoposide was given at a dose of 140 mg/m² daily for 3 days and every 3 weeks until progression. The study was closed after 18 months because of poor accrual. There were no responses seen among the 10 patients accrued. The toxicity was primarily hematologic. There was no evidence of activity of etoposide in thyroid carcinoma, although this study lacked significant power because of the poor accrual.     

Effect of D-serine on a delayed match-to-place task for the water maze

The effect of the amino acid d-serine, a partial NMDA receptor agonist, on a delayed match-to-place task in the water maze was examined. Twenty-four male rats were first trained to attain baseline measurements, then administered D-serine or saline. Rats administered D-serine (100 mg/kg, i.p.) before swim trials did not show a decrease in escape latencies, but did show an increase in swim time spent within the previous days' escape platform location.     

Follicular administration of a cyclooxygenase inhibitor can prevent oocyte release without alteration of normal luteal function in rhesus monkeys

BACKGROUND: Prostaglandins (PG), produced by the follicle just before ovulation, appear to act locally to promote follicle rupture and oocyte release. METHODS: To determine whether administration of PG synthesis inhibitor directly into the primate follicle would prevent ovulatory events, serum estradiol was used to predict the day of the ovulatory LH surge in rhesus monkeys. On the day before or the day of the LH surge, vehicle (n = 9), the PG synthesis inhibitor indomethacin (10(-6) or 10(-5) mol/l final concentration; n = 8), or 10(-5) mol/l indomethacin + 1 micro g/ml PGE(2) (n = 3) was injected into the follicular fluid of the pre-ovulatory follicle. In some animals, luteal phase estrogen and progesterone were measured in daily serum samples. Other animals were ovariectomized 3 days after follicle injection; ovaries were examined for verification of follicle rupture and oocyte release. RESULTS: Follicle injection of indomethacin [10(-6) mol/l (n = 4) or 10(-5) (n = 4) mol/l final concentration] or vehicle (n = 6) did not alter luteal function. Examination of serial sections of removed ovaries confirmed follicle rupture and the absence of oocytes in vehicle-injected follicles (n = 3). Trapped oocytes were observed in 4/8 indomethacin-injected follicles, though several ovaries with trapped oocytes had experienced follicle rupture. Oocytes were not detected in the ruptured, luteinizing follicles from indomethacin + PGE(2)-injected monkeys (n = 3). CONCLUSIONS: Follicular administration of indomethacin can prevent oocyte release without inhibition of follicle rupture or disruption of subsequent luteal function. The ability of PGE(2) to prevent indomethacin-induced ovulatory failure suggests a critical role for locally produced PGE(2) in the process of oocyte release in primates.     

Going the distance: Developing shared web-based learning programmes

Despite a high demand for continuing professional education, it is becoming more challenging to provide education in a resource-limited environment that meets the varied needs of learners. The advent of user-friendly, interactive communication technology led the University of British Columbia in Canada to explore the feasibility of developing a web-based distance learning programme shared by undergraduate and practising therapists to address this problem. Potential benefits and challenges of distance learning, undergraduate web-learning, pilot-test results and an assessment of therapists’ interests and needs are profiled.     

Calorie restriction in nonhuman primates: mechanisms of reduced morbidity and mortality

Long term chronic calorie restriction (CR) of adult nonhuman primates significantly reduces morbidity and increases median age of death. The present review is focused upon an ongoing study of sustained adult- onset calorie restriction, which has been underway for 15 years. Monkeys, initially calorie restricted at about 10 years of age, are now approximately 25 years old. The median life span of these restricted monkeys is increasing, now exceeding that of ad libitum (AL)-fed monkeys. In our laboratory, maximum life span for AL-fed monkeys appears to be about 40 years. Thus, whether CR can also increase maximal life span, as it does in rodents, cannot be determined for at least another 15 years. The earliest detectable positive benefit on morbidity in these monkeys was previously reported as the prevention of obesity. Current evidence, as reviewed here, suggests that much obesity- associated morbidity is also mitigated by sustained calorie restraint in nonhuman primates. Furthermore, probably because of the prevention of obesity, diabetes has also been prevented. Recent findings include the identification of extraordinary changes in the glycogen synthesis pathway, and on the phosphorylation of glycogen synthase in response to insulin. This calorie restriction-induced prevention of morbidity does not require excessive leanness, but is clearly present when body fat is within the normal range of 10 to 22%, and this is likely to be true in humans as well.      

Results of the 1988-1989 Patterns of Care Study process survey for Hodgkin's disease

PURPOSE: To document national standards of care for patients receiving radiotherapy as part of curative treatment for Hodgkin's disease. MATERIALS AND METHODS: A national survey was conducted of 61 institutions treating 275 patients with Stages I-III Hodgkin's disease and representing six facility type strata. Pretreatment evaluation, radiotherapy treatment parameters, and use of combined modality therapy were assessed. RESULTS: Ann Arbor stage for the 275 patients was as follows: IA, 69 (25%); IB, 7 (3%); IIA, 123 (45%); IIB, 36 (13%); IIIA 23 (8%), IIIB, 14 (5%); unknown, 3 (1%). Pretreatment evaluation included complete blood count for 93%, sedimentation rate in 29%, chest CT in 88%, abdominal CT scan in 87%, and bone marrow biopsy in 81%. Lymphangiograms were obtained in 50% of cases; laparotomy was performed in 46%. The yield of positive findings in the spleen at laparotomy was 6.5 % overall. Facility differences with respect to staging were seen only for the use of gallium scans, which were more commonly used in academic centers (44% vs. 15-23% elsewhere, p<0.001). Radiotherapy was delivered with a linear accelerator in 94% of cases. Treatment simulation was performed for 94% and individualized blocks constructed for 95% overall; however, freestanding facilities had a lower rate of performance of these procedures (78% vs. 98-99% for simulation and 88% vs. 96-99% for customized blocking, p<0.001). The mean supradiaphragmatic dose was 36.74 Gy and the mean subdiaphragmatic dose was 33.81 Gy. Planned combined modality therapy was given in 36% of patients. The use of combined modality therapy by stage was as follows: IA, 11%; IB, 43%; IIA, 30%; IIB, 68%; IIIA, 57%; IIIB, 100%. Chemotherapy was completed prior to radiation in 80% of cases and generally consisted of ABVD (32%), an alternating regimen (25%), or MOPP (22%). Among Stage I/II patients, use of chemotherapy was associated with reduced radiation doses (mean supradiaphragmatic dose 34.53 Gy vs. 38.43 Gy and mean subdiaphragmatic dose 31.27 Gy vs. 34.51 Gy), and reduced volumes of treatment (87% vs. 28% treated to one side of the diaphragm only). Laparotomy was not associated with decreased supra- or subdiaphragmatic radiation doses or decreased volumes of treatment. CONCLUSIONS: With the exception of gallium scans, pretreatment evaluation is relatively uniform across facility strata. Increased understanding of prognostic factors in Hodgkin's disease and greater use of planned combined modality therapy for higher risk patients appears to have contributed to a decreased use of and low yield of positive findings for laparotomy. Laparotomy was not associated with reduced radiation volumes or doses. Freestanding radiation facilities had a lower rate than other facility types for the performance of treatment simulation and customized patient blocking.     

A Poissonian explanation for heavy tails in e-mail communication

Patterns of deliberate human activity and behavior are of utmost importance in areas as diverse as disease spread, resource allocation, and emergency response. Because of its widespread availability and use, e-mail correspondence provides an attractive proxy for studying human activity. Recently, it was reported that the probability density for the inter-event time τ between consecutively sent e-mails decays asymptotically as τ^−α, with α ≈ 1. The slower-than-exponential decay of the inter-event time distribution suggests that deliberate human activity is inherently non-Poissonian. Here, we demonstrate that the approximate power-law scaling of the inter-event time distribution is a consequence of circadian and weekly cycles of human activity. We propose a cascading nonhomogeneous Poisson process that explicitly integrates these periodic patterns in activity with an individual's tendency to continue participating in an activity. Using standard statistical techniques, we show that our model is consistent with the empirical data. Our findings may also provide insight into the origins of heavy-tailed distributions in other complex systems.