The neuroendocrine challenge paradigm in headache research

The neuroendocrine challenge paradigm provides a "window" on central neurotransmitter function in vivo. This strategy is based on the premise that the sensitivity of certain central receptors can be inferred from the magnitude of the hormonal response to specific pharmacologic probes. For example, the serotonin (5HT) receptor agonist m-chlorophenylpiperazine (m-CPP) stimulates the release of cortisol and prolactin and induces migraine-like headaches. We have previously reported that the headache and cortisol responses to m-CPP are highly correlated, which may implicate a disturbance in central serotonergic neurotransmission in the pathogenesis of migraine. As pharmacologic probes with greater specificity for 5HT receptor subtypes become available, we may be able to elucidate these mechanisms with greater precision. The neuroendocrine challenge methodology is also applicable to the study of other neurotransmitter systems and other headache disorders.     

Evaluation of radiation therapy factors in prophylactic central nervous system irradiation for childhood leukemia: A report from the Children's Cancer Study Group

The results of six different types of central nervous system (CNS) prophylaxis were studied in two successive Children's Cancer Study Group clinical trials of children with acute leukemia. Radiation therapy doses and technical factors were analyzed in relation to survival, relapse-free survival, bone marrow and CNS relapse rates, and the toxicities encountered in 656 study children. They were randomized among: (1) 2400 rad to the craniospinal axis (CS) and 1200 rad to the abdomen and gonad (2) 2400 rad CS, (3) 2400 rad to the cranium (Cr) + intrathecal methotrexate (IT/MTX), (4) IT/MTX alone, (5) 1800 rad CS, and (6) 1800 rad Cr + IT/MTX. Hematologic, gastrointestinal and infectious disease complications were highest in group 1. The patients were divided into low and high risk categories, defined as those with initial white blood cell counts below and above 20,000/cumm. for outcome analyses. No statistically significant differences were detected in the five-year rates for relapse-free survival or survival, nor for CNS or bone marrow relapse among the 5 irradiated groups when equipment variables, total doses, field arrangements, fractionation, and protraction were analyzed. These results should be interpreted in the light of the group 4 children who had the highest CNS relapse rates (e.g., 33 % for low risk patients vs. 4–16% for their counterparts in the other 5 groups), but nonetheless had a generally similar bone marrow and survival experience. Exceptions to the foregoing are the better five-year survival rates of 64 and 73 % respectively for group 3 and group 6 high-risk boys, contrasted with 25–42 % for their counterparts in the other 4 groups.     

Hepatocellular carcinoma: assessment of resectability by computed tomography and ultrasound

A retrospective review of the CT and ultrasound scans from examinations of 30 patients who had hepatocellular carcinoma (hepatoma) was undertaken with special emphasis placed on evaluation of hepatic distribution of tumor, vascular invasion, and extrahepatic spread. Although both CT and ultrasound detected hepatoma in 29 of 30 patients (96%), CT showed more extensive hepatic parenchymal involvement in eight of the patients. Vascular invasion was seen more frequently with ultrasound than with CT. Invasion into the main portal vein was seen by ultrasound in 11 of 30 patients (37%). Extrahepatic spread of tumor was much more frequently detected by CT and was present in 21 of 30 patients (70%). A reasoned approach to the diagnostic workup of hepatomas that will minimize invasive procedures and unnecessary surgery is presented.