These studies demonstrate that treatment of human U‐937 cells with ionizing radiation (IR) is associated with activation of a cytoplasmic myelin basic protein (MBP) kinase. Characterization of the kinase by gel filtration and in‐gel kinase assays support activation of a 40 kDa protein. Substrate and inhibitor studies further support the induction of protein kinase C (PKC)‐like activity. The results of N‐terminal amino acid sequencing of the purified protein demonstrate identity of the kinase with an internal region of PKC delta. Immunoblot analysis was used to confirm proteolytic cleavage of intact 78 kDa PKC delta in control cells to the 40 kDa C‐terminal fragment after IR exposure. The finding that both IR‐induced proteolytic activation of PKC delta and endonucleolytic DNA fragmentation are blocked by Bcl‐2 and Bcl‐xL supports an association with physiological cell death (PCD). Moreover, cleavage of PKC delta occurs adjacent to aspartic acid at a site (QDN) similar to that involved in proteolytic activation of interleukin‐1 beta converting enzyme (ICE). The specific tetrapeptide ICE inhibitor (YVAD) blocked both proteolytic activation of PKC delta and internucleosomal DNA fragmentation in IR‐treated cells. These findings demonstrate that PCD is associated with proteolytic activation of PKC delta by an ICE‐like protease.

Up-regulation of maternal islet function is essential to accommodate the increased demand for insulin during pregnancy. Previously, we suggested that lactogenic activity regulates islet function during pregnancy. However, this hypothesis was based on the effect of homologous PRLs on islets, since the homologous placental lactogens (or islets) were unavailable. In this study we examine the direct effects of homologous placental lactogens (PL), PRL, and GH on insulin secretion and B-cell division in rat, mouse, and human islets in vitro. Neonatal rat islets were cultured for 8 days in the presence of 0-1000 ng/ml rat PL-I (rPL-I), rPRL, or rGH. Media were changed daily, and the insulin concentration was determined. rPL-I and rPRL (500 ng/ml) treatment resulted in a 2-fold increase in insulin secretion. rGH (1000 ng/ml) elicited a 30% increase in insulin secretion. Similarly, cell replication, as indicated by BrdU incorporation into B-cells, was increased 4-fold in the presence of rPL-I and rPRL. The ED50 for insulin secretion and 5'-bromo-2'-deoxyuridine (BrdU) incorporation was 70 ng/ml for rPL-I and 150 ng/ml for rPRL. Similarly, in adult rat islets, insulin secretion was increased 1.6-fold, and B-cell replication increased 3-fold in the presence of the lactogenic hormones. Neonatal mouse islets were cultured for 8 days in the presence of 500 ng/ml mouse (m) PL-I, mPL-II, mPRL, or mGH. mPL-I, mPL-II, and mPRL treatment resulted in a 2-fold increase in insulin secretion. mGH elicited a 30% increase in insulin secretion. BrdU incorporation into B-cells was increased 3-fold in the presence of mPL-I and mPRL and 2-fold in the presence of mPL-II. Adult human islets were cultured for 8 days in the presence of 1 microgram/ml human (h) PL, hPRL, or hGH. For human islets isolated from six pancreata obtained from females, hPL (138 +/- 10%), hPRL (133 +/- 9%), and hGH (117 +/- 3%) significantly increased insulin secretion compared to that from control islets. This study compares the direct effects among homologous PLs, PRLs, and GHs on insulin secretion and B-cell division in rat, mouse, and human islets. The results indicate that placental lactogen directly regulates islet function in several species and is probably the principal hormone responsible for the increased islet function observed during normal pregnancy.

BACKGROUND: Unresectable intrahepatic cholangiocarcinoma has a poor prognosis, with a median survival of 5 to 8 months without treatment. Response and survival after chemoembolization were evaluated. METHODS: Lobar or segmental chemoembolization with cisplatinum, doxorubicin, mitomycin-C, ethiodol, and polyvinyl alcohol particles was performed at monthly intervals for 1-4 sessions until the entire intrahepatic tumor burden was treated. Cross-sectional imaging and clinical and laboratory evaluation were performed before treatment, 1 month after treatment, and then every 3 months. A second cycle of treatment was performed for intrahepatic recurrence. Toxicity was assessed using NCI CTC v.3.0. Response was evaluated using RECIST criteria, and survival was estimated with Kaplan-Meier analysis. RESULTS: Sixty-two patients were treated. Thirty-seven had pathologically proven cholangiocarcinoma, and 25 had poorly differentiated adenocarcinoma of unknown primary, likely cholangiocarcinoma. One hundred and twenty-two total procedures were performed during the initial cycle of treatment (mean, 2.0 per patient). Twenty patients received a second cycle, for a total of 165 procedures. There were 5 major complications. Thirty-day diseasespecific mortality was 0%. Forty-five of 62 patients were evaluable for morphologic response after completion of their initial cycle: 11% (n ¼ 5) partial responses, 64% (n ¼ 29) stable, and 24% (n ¼ 11) progressed. Median time to progression from first chemoembolization was 8 months, with 28% free of progression at 12 months. Median survival from time of diagnosis was 20 months, with 1-, 2-, and 3-year survival of 75%, 39%, and 17%, respectively. Median survival from time of first chemoembolization was 15 months, with 1-, 2-, and 3-year survival of 61%, 27%, and 8%, respectively. There was no statistically significant difference in survival between patients with cholangiocarcinoma and those with poorly differentiated adenocarcinoma. Patients who also received systemic chemotherapy had improved overall survival (median 28 vs 16 months, P ¼ .02; HR, 1.94; 95% CI, 1.13-3.33). CONCLUSIONS: Chemoembolization provided local disease control (PR þ SD) of intrahepatic cholangiocarcinoma and adenocarcinoma of unknown primary in 76%. Overall survival after chemoembolization showed the best outcomes for those receiving multidisciplinary integrated liver-directed and systemic therapies.

The possible role of the conceptus in stimulating the onset of maternal behavior through its secretion of placental lactogens and their passage into the brain was investigated in female rats. In the first study, significant mitogenic activity in the Nb₂ lymphoma cell bioassay was detected in cerebrospinal fluid (CSF) samples collected by push-pull perfusion from rats on days 12–21 of pregnancy, coincident with the establishment of placental function. In contrast, mitogenic activity was absent from CSF in lactating and gonadectomized, virgin females. In a second study the mitogenic activity in day 12 pregnant samples was neutralized 71% with antibodies to rat placental lactogen-I (rPL-I) and > 90% with a combination of antibodies to rPL-I plus rPL-II. In contrast, activity on day 21 of pregnancy, 1 day prepartum, was reduced by antibodies to rPL-II (>85%), but not by antibodies to rPL-I, indicating that the predominant lactogen in the CSF prepartum is rPL-II. The behavioral actions of placental secretions were assessed in the third experiment by infusing recombinant rPL-I and purified rPL-II directly into the medial preoptic area of the brain of steroid-primed, nulliparous rats. Latencies to respond maternally to foster young were significantly reduced in rPL-I- and rPL-II-treated rats (2- to 3-day latencies) when compared with latencies in control females (5- to 6-day latencies). Thus, the conceptus through its secretion of rPLs which apparently gain access to the CSF helps to prime the pregnant female’s brain to respond maternally at the end of gestation. This endocrine communication between the developing conceptus and pregnant female appears to be an important part of the biological system which helps to establish successful maternal care.

A radioimmunoassay (RIA) has been developed to the species of lactogenic hormone (rPL) present in late pregnant rat placenta. Partially purified rPL calibrated against oPRL in the rat liver receptor assay (RRA) was used as standard. None of the PL's, PRL's, and GH's from other species cross-reacted in the RIA when tested at 1000 ng/ml. Rat serum PL levels remained stable in samples stored at -70C but not at -20C. In previous studies, using RRA, two peaks of rPL were found in rat serum, one at Day 11-13 and one at Day 20. By RIA, however, only the 20,000 dalton species of rPL present in late pregnant serum was immunoreactive. The RIA did not detect the larger, 40-50,000 dalton molecular species of rPL predominant in mild-pregnant serum, thus revealing the presence of two possibly unrelated forms of rPL. Serum rPL concentrations at Day 21 of pregnancy increased exponentially as the number of fetuses increased until a maximum of nine fetus.