Human gastric carcinogenesis: a multistep and multifactorial process--First American Cancer Society Award Lecture on Cancer Epidemiology and Prevention. Evidence from pathology and epidemiology studies has been provided for a human model of gastric carcinogenesis with the following sequential stages: chronic gastritis; atrophy; intestinal metaplasia; and dysplasia. The initial stages of gastritis and atrophy have been linked to excessive salt intake and infection with Helicobacter pylori. The intermediate stages have been associated with the ingestion of ascorbic acid and nitrate, determinants of intragastric nitrosation. The final stages have been linked with the supply of beta-carotene and with excessive salt intake. Nitrosating agents are candidate carcinogens and could originate in the gastric cavity or in the inflammatory infiltrate.


Down-regulation of c-MYC antigen expression in lymphocytes of Emu-c-myc transgenic mice treated with anti-c-myc DNA methylphosphonates. In transgenic mice bearing a murine immunoglobulin enhancer/c-myc fusion transgene (Emu-myc), it was found that antisense DNA methylphosphonates targeted against c-myc mRNA inhibited production of c-MYC protein in peripheral lymphocytes. The decrease in protein was measured 3-4 h after i.v. administration of a 300-nmol dose. c-MYC was detected by immunofluorescence of fixed cells stained with an anti-c-MYC antiserum. In addition, DNA methylphosphonates did not induce acute toxicity following i.v. administration of a 300-nmol dose. An identically administered scrambled sequence oligomer did not decrease c-MYC protein or induce toxicity. Finally, recovery of DNA methylphosphonates from the blood plasma of treated mice indicated that the oligomers remained intact up to 3 h, while their concentrations decreased rapidly for the first h, then slowly decreased over the next 2 h. This is the first demonstration of sequence-specific antisense DNA methylphosphonate inhibition of gene expression in the bloodstream of an animal model.


Phase I and pharmacokinetic study of the novel platinum analogue CI-973 on a 5-daily dose schedule. CI-973, a platinum(II) derivative with a 2-methyl-1,4-butanediamine carrier ligand, has activity in cisplatin-resistant tumor models in vitro and in vivo. In a Phase I pharmacokinetic study, 31 patients were treated with CI-973 (24 to 50 mg/m2/day for 5 days; 28-day cycles) given i.v. over 30 min without routine antiemetic prophylaxis or hydration. Of the 29 patients evaluable for maximum tolerated dose determination, most had a performance status of 0 or 1, and most had received prior chemotherapy. Neutropenia was dose limiting at 40 and 50 mg/m2/day. Recovery from neutropenia was generally rapid with nadir counts and recovery usually occurring by Days 15 and 22, respectively. Drug-associated thrombocytopenia was uncommon and never severe, even in patients with Grade 4 neutropenia. Anemia was common, but did not appear dose related. Drug-related nausea and vomiting and changes in renal function were relatively infrequent and mild. No clinically evident ototoxicity was reported, although changes in audiograms were noted in several patients. CI-973 concentrations were measured in plasma ultrafiltrate and urine by high-pressure liquid chromatography. The harmonic mean terminal half-life was 2.0 h. The mean CI-973 renal and nonrenal clearance values were 42.3 and 37.4 ml/min/m2, respectively. The mean recovery of CI-973 in urine was 53% of the administered dose. The mean ratio of CI-973 renal clearance to creatinine clearance was 0.92. Total clearance correlated with creatinine clearance (r2 = 0.63). A relationship between toxicity, expressed as the percentage of reduction in absolute granulocyte count, and area under the CI-973 plasma concentration-time curve was found in a subgroup of "good-risk" patients. This relationship, described well by a sigmoidal Emax pharmacodynamic model, did not hold for patients with extensive prior therapy or poor performance status. A model for toxicity prediction based on dose and creatinine clearance has been derived and will be validated in future studies. The recommended Phase II dose of CI-973 is 30 mg/m2/day for 5 days.


Biological and immunological features of humanized M195 (anti-CD33) monoclonal antibodies. Human-mouse chimeric immunoglobulins G1 and G3 (IgG1 and IgG3) (ChG1, ChG3) and "complementarity-determining region"-grafted, humanized IgG1 and IgG3 (HuG1, HuG3) constructs of the mouse monoclonal antibody (mAb) M195 were characterized. M195 is a murine immunoglobulin G2a (IgG2a), anti-CD33 mAb, specifically reactive with acute myelogenous leukemia cells, that is active as an antileukemia agent in humans. The new mAb constructs maintained specificity and biological function, including rapid internalization after binding to the cell surface, which has been important for delivery of therapeutic isotopes in patients. Although previously reported complementarity-determining region-grafted mAbs had reduced avidities, the HuG1 and HuG3 M195 showed up to an 8.6- and 4-fold higher binding avidity, respectively, than the original murine mAb. All constructs were effective at mediating rabbit complement-mediated cytotoxicity against HL60 targets. Fibroblasts transfected with CD33 genes and expressing high levels of CD33 antigen were also lysed in the presence of human complement, but HL60 cells or fibroblasts with lower CD33 levels were not killed. Thus, the inability of M195 and constructs to kill HL60 targets with human complement is due to the much lower antigen density on HL60 cells compared to CD33+ fibroblasts. Unlike the murine M195, the chimeric and humanized M195 demonstrated antibody-dependent cell-mediated cytotoxicity using human peripheral blood mononuclear cells as effectors. Because the chimeric and humanized M195 have improved avidities as compared to the original M195 and have, in addition, the potential to avoid human anti-mouse antibody responses and to recruit human effector functions, these new constructs may be useful therapeutically, either alone or conjugated to toxins or isotopes, in the treatment of acute myelogenous leukemia.


High molecular weight transforming growth factor beta is excreted in the urine in active nodular sclerosing Hodgkin's disease. To measure the in vivo secretion of high molecular weight (HMW) transforming growth factor (TGF)beta by Reed-Sternberg cells from patients with nodular sclerosing Hodgkin's disease, we studied the urine samples from untreated patients. The urinary proteins did not promote the proliferation of NIH-3T3 cells in monolayer culture and contained similar amounts of total TGF activity when compared with normal controls. Urinary proteins from 24 different control and test urines were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. Either of two primary antibodies were used for immunoblot detection: (a) affinity column purified polyclonal anti-TGF beta 1 prepared against platelet TGF beta 1 or (b) monoclonal anti-HMW-TGF beta prepared against HMW-TGF beta secreted by cloned L-428 Reed-Sternberg cells. All patients with active nodular sclerosing Hodgkin's disease had a detectable HMW-TGF beta (approximately 300,000) which cross-reacted with both anti-TGF beta 1 and anti-HMW-TGF beta. Purification demonstrated HMW-TGF beta which was active at physiological pH. Twelve control urine samples from healthy adults and 5 follow-up samples from the Hodgkin's patients after successful treatment contained no detectable urinary HMW-TGF beta. The in vivo production of HMW-TGF beta in untreated nodular sclerosing Hodgkin's disease supports the conclusion that this growth factor is secreted in large amounts by Reed-Sternberg cells or cells stimulated by Reed-Sternberg cells.


Pharmacokinetics and therapeutics of sterically stabilized liposomes in mice bearing C-26 colon carcinoma. Three different liposome types were compared for blood clearance and tissue uptake in mice bearing C-26 colon carcinoma growing either s.c. or in liver. Therapeutic experiments were performed with the liposome preparation showing the highest tumor uptake. Liposomes were composed of solid-phase phosphatidylcholine, either distearoyl phosphatidylcholine or hydrogenated soy phosphatidylcholine, and cholesterol at a 2:1 molar ratio. These liposomes were compared with similar but sterically stabilized liposomes (SL) which, in addition, contained either GM1 ganglioside or phosphatidylethanolamine derivatized with poly(ethylene glycol). Pharmacokinetic analysis of drug disposition was based on the areas under the curve for liposome-entrapped 67Ga uptake per gram of tissue up to 96 h following i.v. injection. The highest tissue area under the curve values with both liposome types were obtained in spleen, liver, and tumor. However, the sterically stabilized liposomes gave an area under the curve value 2-3-fold higher in the s.c. tumor and about 2-fold lower in liver and spleen. The therapeutic efficacy of doxorubicin (DOX) and epirubicin (EPI) encapsulated in poly(ethylene glycol)-derivatized phosphatidylethanolamine-containing liposomes was compared with that of free drug at two doses, 6 and 9 (or 10) mg/kg animal weight. Liposomes containing drug were injected either as a single dose, at different times following tumor implantation, or as three weekly doses starting 10 days after implantation. When injected as a single dose, liposome-encapsulated DOX had the maximal effect on tumor growth when injected 6 to 9 days after tumor implantation. When injected as three weekly doses, with treatment starting with a delay of 10 days, tumors which had grown to a size of approximately 0.05-0.1 cm3 regressed in groups of animals treated with either liposome-encapsulated drug (SL-DOX or SL-EPI) but continued to grow unabated in untreated mice and in mice receiving either of the free drugs. Survival of tumor-bearing animals treated with either SL-EPI or SL-DOX was significantly prolonged. Animals receiving saline, EPI, or DOX survived a mean of 50, 62, and 49 days, respectively, following tumor implantation. Eight of nine and nine of 10 animals receiving 6 and 9 mg/kg SL-EPI, respectively, survived to 120 days. Ten of 10 animals in both groups receiving 6 and 9 mg/kg SL-DOX survived to 120 days. None of the surviving animals in the SL-EPI and SL-DOX group showed any histological evidence of tumor at the conclusion of the experiment (120 days).(ABSTRACT TRUNCATED AT 400 WORDS)


alpha-Difluoromethylornithine alters calcium signaling in platelet-derived growth factor-stimulated A172 brain tumor cells in culture. alpha-Difluoromethylornithine (DFMO), an irreversible inhibitor of the polyamine biosynthetic enzyme ornithine decarboxylase, inhibits the growth of brain tumor cell lines and is undergoing clinical trials as a treatment for brain tumors. Platelet-derived growth factor (PDGF) is thought to regulate the growth and development of precursors of both normal and neoplastic astrocytic cells; calcium signaling is thought to play a role in the transduction of PDGF signals. Using laser fluorescence image cytometry, flow cytometry, and spectrofluorometry, we studied the effect of DFMO on the calcium signals induced by PDGF in A172 human glioblastoma cells. Four days of treatment with 5 mM DFMO substantially shortened PDGF-induced calcium signals. The effect was reversed more than 10 h but less than 24 h after putrescine treatment, even though polyamines were repleted 4 h after putrescine and spermidine were added. DFMO did not substantially affect intracellular calcium release or the timing of the opening and closing of plasma membrane calcium channels. These findings support the notion that calcium signaling may be a target for inhibitors of polyamine metabolism.


Modulation of cisplatin resistance in human malignant melanoma cells. Previous studies have shown that the combination of dacarbazine, carmustine, cisplatin (DDP), and tamoxifen (TAM) produced a 53% overall response rate in patients with disseminated melanoma. Deletion of TAM from the regimen resulted in a fall in the response rate to 10%, and reincorporation of TAM returned the response rate to 52%, suggesting an important role for TAM. Using the human melanoma cell line T-289, we examined the nature of the interaction between TAM and each member of this combination in clonogenic assays in soft agar. The combination of TAM with DDP was highly synergistic as demonstrated by median effect analysis, whereas TAM was antagonistic with carmustine and an activated form of dacarbazine. The mean combination index at 50% kill was 0.26 +/- 0.02 (mean +/- SD) for TAM and DDP. This marked synergism was observed at concentrations of TAM that are clinically achievable. TAM had no effect on the uptake of the DDP analogue [3H]dichloro(ethylenediamine)platinum(II). There was no effect on the formation or repair of DDP intrastrand DNA adducts. Similarly, there was no effect demonstrated on the intracellular concentrations of glutathione or metallothioneins. We conclude that the interaction between TAM and DDP is truly synergistic in this cell line and is accomplished through none of the four mechanisms commonly associated with DDP resistance.


Resistance of murine lung tumors to xenobiotic-induced cytotoxicity. Studies were performed to test the hypothesis that urethane-induced murine lung tumors exhibit xenobiotic resistance and alterations in pulmonary cytochrome P-450 enzymes. 1,1-Dichloroethylene, naphthalene, and paraquat were administered to tumor-bearing and control mice to elicit acute lung cytotoxicity, and responses were evaluated in tumors (papillary and solid), uninvolved surrounding tissue, and untreated control lung. 1,1-Dichloroethylene (125 mg/kg, i.p.) and naphthalene (225 mg/kg, i.p.) caused preferential necrosis of Clara cells in control lungs and uninvolved tissue of tumor-bearing lungs. In contrast, papillary and solid tumors were both resistant to 1,1-dichloroethylene-induced cytotoxicity. Paraquat (10, 20 mg/kg, i.v.) elicited Clara cell damage in control lungs and uninvolved lung tissue of tumor-bearing mice, with minor disruption of the alveolar epithelium. Neither papillary nor solid tumors sustained any apparent cell damage from paraquat. Immunoblots of P-450 enzymes confirmed constitutive expression of CYP2B1 in control lung and uninvolved lung tissue of tumor-bearing mice, but this P-450 enzyme was not detected in either adenomas or carcinomas. Lung CYP1A1 was inducible by beta-naphthoflavone in non-tumor-bearing mice and uninvolved tissue of tumor-bearing mice; however, inducibility was decreased in adenomas and abolished in carcinomas. These results demonstrate resistance of lung tumor cells to chemically induced cytotoxicity and diminished expression of cytochrome P-450 enzymes in tumors.


Clonal growth of hepatitis B virus-integrated hepatocytes in cirrhotic liver nodules. A total of 83 cirrhotic nodules (pseudolobules) individually collected from 11 cirrhotic livers of hepatitis B virus carrier patient were analyzed for the frequency and mode of hepatitis B virus integration as well as histological features. Southern blot analysis disclosed discrete bands at higher molecular weight region in 26 of 83 nodules (31.3%), indicating a clonal growth of hepatocytes with viral integration. Considerable variation (0-75%) existed in the positive rates for discrete bands in nodules among livers. Molecular cloning revealed the sequence flanking an integrated viral sequence to be host DNA and thus confirmed true integration. Histological analysis, however, did not reveal any neoplastic-appearing foci of growth within nodules, despite the fact that the detection sensitivity would predict clones of more than 10(5) cells to give rise to clonal integration patterns on Southern blot analysis. The question of whether clonal expansion of hepatocytes reflects any viral integration-associated growth advantage and/or a preneoplastic condition awaits future studies.


Lower heat shock factor activation and binding and faster rate of HSP-70A messenger RNA turnover in heat sensitive human leukemias. Normal bone marrow progenitors and some leukemic cells develop only a limited amount of thermotolerance. Further, once developed, thermotolerance decays at a faster rate than that normally observed in cells of nonhemopoietic origin. Thermotolerance induction and maintenance correlates with reduced levels of expression of various M(r) 70,000 heat shock proteins (HSP-70) mRNAs after heat shock. We have now compared the accumulation of HSP-70 proteins in heat-shocked human leukemic cells KG-1, HL-60, and K562 to that in Ht1080, a colon carcinoma cell line. We have found reduced accumulation of HSP-70 proteins in all leukemic cells. The rate of decay of HSP-70A mRNA, measured following heat shock by using actinomycin D treatment to inhibit further RNA synthesis, was more rapid in KG-1 and HL-60 cells compared to Ht1080 cells. The half-life of HSP-70A mRNA was 2 h in KG-1 and HL-60 cells while in Ht1080 cells it was > 7 h. HSP-70A mRNA is known to decay with a half-life of 2 h in unheated cells; this is increased to > 7 h following heat shock. We therefore postulate that leukemic cells lack the mechanism to stabilize HSP-70A mRNA after heat shock. One postulated mechanism for HSP-70 mRNA decay rate is known to be due to the nucleotide sequences at the 3'-untranslated region. We examined the 3'-untranslated region in leukemic cells. No sequence variations, however, were observed at either the genomic or the complementary DNA levels between leukemic or nonleukemic tumor cells. Heat shock factor activation and binding by gel retardation assays showed that KG-1 and HL-60 cells had a reduced heat shock factor binding to the heat shock element when compared to K562 and Ht1080 cells. Furthermore, HSF-1 mRNA was found to be expressed at relatively lower levels in HL-60 cells when compared to Ht1080 or KG-1 cells. In conclusion, reduced HSP synthesis and accumulation of leukemic cells after heat shock correlates with the reduction in heat shock factor-heat shock element binding and a faster HSP-70A mRNA decay rate that is observed in these cells.


Effects of ketoconazole on the proliferation and cell cycle of human cancer cell lines. The growth-inhibitory effects of ketoconazole, an antifungal agent which inhibits arachidonic acid lipoxygenases and cytochrome P-450 enzymes, were tested in human colon and breast cancer cell lines. In the serum independent HT29-S-B6 colon cell clone, ketoconazole reduced cell proliferation and [3H]thymidine incorporation in a dose-dependent fashion, with a 50% inhibitory concentration of approximately 2.5 microM. Flow cytometry showed an accumulation of cells in the G0-G1 phase of the cell cycle and a concomitant decrease of the percentage of cells in S phase. Ketoconazole also inhibited [3H]thymidine incorporation in the hormone-independent breast cancer cells MDA-MB-231 and Evsa-T, with respective 50% inhibitory concentration of approximately 13 and 2 microM. The mechanism of action of ketoconazole is unknown. However, another lipoxygenase inhibitor, BW755C, inhibited only weakly [3H]-thymidine incorporation and accumulated the cells in S and G2. Conversely, clotrimazole and SKF525A, inhibitors of cytochrome P-450 enzymes, had effects similar to those of ketoconazole on HT29-S-B6 cells whereas metronidazole and secnidazole, other azole derivatives which do not inhibit cytochrome P-450 enzymes, had no effect. The results suggest that cytochrome P-450 enzyme(s) activity(ies) could be implicated in the antiproliferative effects of ketoconazole.


Isolation and characterization of a highly malignant variant of the SW480 human colon cancer cell line. We found that the human colon cancer cell line SW480 consists of two distinct subpopulations which we have designated E-type (epithelial) and R-type (round). Pure cultures of each type were obtained by subcloning, and both have maintained their characteristic phenotypes for at least 1 year (40 passages). E-type cells are the major (> 98%) type in the parental SW480 cell line. They form flat epithelial-like colonies. In contrast, R-type cells, which constitute a minor fraction (< 2%) of the parental cell line, have a rounded shape and grow in clusters of piled-up cells. Compared to E-type cells or the parental SW480 cells, isolated R-type cells display decreased doubling time, loss of contact inhibition, less adhesiveness to culture plates, higher anchorage-independent growth in soft agar, and a much more aneuploid karyotype. When injected s.c. into nude mice, R-type cells produce much larger tumors within the same period of time than E-type cells, and the tumors are less differentiated than those produced by the E-type cells. Cell fusion experiments between R-type and E-type cells revealed that the R-type phenotype is dominant, and the results suggest that this is due to one or a few genetic changes. Taken together, these findings suggest that the R-type cells represent a more malignant variant of the E-type cells. They may be useful, therefore, for studying mechanisms involved in tumor progression.


Overexpression of metallothionein in Chinese hamster ovary cells and its effect on nitrogen mustard-induced cytotoxicity: role of gene-specific damage and repair. Overexpression of metallothionein in mammalian cells has been associated with protection from cytotoxic chemicals and acquired resistance of tumors to cytotoxic drugs. The mechanism of this effect, however, remains unclear. We have explored whether cytotoxicity of the bifunctional alkylating agent nitrogen mustard was correlated with the extent of DNA damage formation and repair in the metallothionein gene regions in Chinese hamster ovary cells. The DNA damage and repair were examined in metallothionein-overexpressing, cadmium-resistant Chinese hamster ovary cells, Cdr200T1, with or without zinc-induced transcriptional activation, and in the parental CHO-met- cell line. The zinc-induced Cdr200T1 cells tolerated significantly higher doses of nitrogen mustard than did the uninduced Cdr200T1 variant. The parental CHO-met- cells, which did not have any detectable metallothionein expression, were even more resistant to nitrogen mustard than the zinc-induced Cdr variants. Nitrogen mustard-induced N-alkylpurines were formed with a higher frequency in inactive genomic regions than in the active genes. The removal of N-alkylpurines was similar in the active MT I gene region in Cdr200T1 and the silent MT I gene region in the parental cells, and the expression of these genes was determined by Northern assay. The MT II gene-containing region was repaired less efficiently than the MT I gene, independently of zinc induction. Further, preferential repair of nitrogen mustard-induced N-alkylpurines were detected in a single copy of the essential active dihydrofolate reductase gene as compared to a downstream noncoding region. This preferential repair was unaffected by the presence of zinc. Neither damage formation nor repair kinetics in the MT gene regions seemed to parallel the observed spectrum of sensitivity to HN2.


Identification of a protein factor secreted by 3T3-L1 preadipocytes inhibitory for the human MCF-7 breast cancer cell line. The 3T3-L1 cell line is a preadipocyte cell line derived from the Swiss 3T3 mouse fibroblast cell line. We have compared the effect of 3T3-L1 conditioned medium (3T3-L1 CM) and Swiss 3T3 conditioned medium (3T3 CM) on the growth of normal mouse mammary cells (NMMG) and the human MCF-7 breast carcinoma cell line. 3T3 CM increased the growth of both NMMG and MCF-7 cells by 19 +/- 2% (SD) and 24 +/- 3%, respectively, and increased thymidine incorporation by 74 +/- 4% and 104 +/- 8%, respectively. Conditioned medium from 3T3-L1 cells stimulated the growth of NMMG cells by 64 +/- 2%; in contrast, 3T3-L1 CM inhibited the growth of MCF-7 cells by 36 +/- 1%. In parallel with these growth studies, thymidine incorporation increased by 20 +/- 4% in NMMG cells and decreased by 72 +/- 5% in the MCF-7 cells. Moreover, a similar effect was also noted in NCI H630 colon cancer cells, where 3T3-L1 CM produced a 58 +/- 4% decrease in growth and a 82 +/- 6% decrease in thymidine incorporation. Heating the 3T3-L1 CM at 100 degrees C for 30 min destroyed all inhibitory activity. Several known inhibitory growth factors (fibroblast growth factor, 20 ng/ml; interleukin 6, 1000 units/ml; tumor necrosis factor alpha, 15 ng/ml; transforming growth factor beta, 1 ng/ml) were tested for activity in the MCF-7 cells. Tumor necrosis factor alpha and transforming growth factor beta produced a 97% and 67% inhibition of thymidine uptake, respectively, whereas interleukin 6 and fibroblast growth factor had no effect. Neither transforming growth factor beta nor tumor necrosis factor alpha activity was detectable in 3T3-L1 CM using an enzyme-linked immunosorbent assay. High-performance liquid chromatography fractionation of the 3T3-L1 CM revealed that the inhibitory activity eluted at a molecular weight of 67,000; moreover, silver staining of these eluates on a denaturing polyacrylamide gel revealed that M(r) 69,000 peptide was the predominant protein band in the inhibitory fractions. Thus 3T3-L1 CM stimulates the growth of normal breast epithelial cells and inhibits the growth of MCF-7 breast cancer cells. This inhibitory activity appears to be due to a protein secreted by 3T3-L1 preadipocytes.


Inability of leucovorin to rescue a naturally methotrexate-resistant human soft tissue sarcoma cell line from trimetrexate cytotoxicity. A human lymphoblastoid line (RPMI-1788), a methotrexate-sensitive human fibrosarcoma cell line (HT-1080), and a naturally resistant mixed mesodermal human sarcoma cell line with impaired methotrexate polyglutamylation (HS-42), recently established in our laboratory, were used to compare the ability of leucovorin to prevent trimetrexate cytotoxicity. Growth inhibition and an in situ thymidylate synthesis activity assay showed that inhibitory effects of trimetrexate (1 to 10 microM), 24-h exposure, were prevented by 10 microM leucovorin in the RPMI-1788 and HT-1080 cell lines but not in the HS-42 cell line. Total intracellular reduced folates increased about 2-fold in the three cell lines after exposure to leucovorin (10 microM) for 4 h, and after a 6-hour efflux remained elevated (1.5- and 1.3-fold of control levels) in RPMI-1788 and HT-1080 cells but decreased to 80% of control levels in HS-42 cells. Although uptake of leucovorin and levels of N5,N10-methylenetetrahydrofolate achieved after leucovorin administration were similar in RP-MI-1788 and HS-42 cells, polyglutamylate forms of this coenzyme were less in the HS-42 cells as compared to RPMI-1788 cells. Based on these studies, the combination of trimetrexate with leucovorin should be further investigated as a way to increase the therapeutic index in some patients with soft tissue sarcomas.


Regulation of smooth muscle alpha-actin promoter in ras-transformed cells: usefulness for setting up reporter gene-based assay system for drug screening. Oncogenic activation of ras results in changes in the transcription of several genes leading to uncontrolled cell growth. In this paper, we demonstrate that transformation of fibroblast cells by the ras oncogene leads to transcriptional repression of the smooth muscle alpha-actin promoter. Transient transfection analysis of plasmids containing the 5' upstream region of the human alpha-actin gene fused to human growth hormone or bacterial chloramphenicol acetyltransferase coding sequences into Rat-2 and ras-transformed Rat-2 (HO6) cells indicates that alpha-actin promoter is repressed in ras-transformed cells. In addition, stable rat fibroblast cell lines expressing human growth hormone or beta-galactosidase under the control of alpha-actin promoter exhibit repressed reporter gene activity following transformation by the ras oncogene. alpha-Actin promoter-driven beta-galactosidase activity is derepressed in revertants of ras-transformed stable cell lines. This revertant cell line expresses elevated levels of ras p21 protein and is resistant to retransformation by Ki and Ha-ras oncogenes. The revertant may have either a defective target protein whose activity is essential for the transforming activity of ras or an activated tumor suppressor gene which can suppress the activity of ras. These results indicate that smooth muscle alpha-actin promoter activity is a sensitive marker to follow phenotypic changes following transformation by ras and subsequent reversion. The advantages of this alpha-actin promoter-reporter gene assay system to screen for drugs that inhibit the transforming activity of ras, either directly or indirectly, are discussed.


Relationship of cellular glutathione to the cytotoxicity and resistance of seven platinum compounds. The role of glutathione (GSH) in the effectiveness of and resistance to 7 platinum compounds [5 Pt(II) and 2 Pt(IV) drugs] was evaluated in a 8.6-fold cisplatin (CDDP)-resistant human small cell lung cancer cell line (GLC4/CDDP), the parent GLC4 line, a 3.7-fold CDDP-resistant human embryonal carcinoma cell line (Tera-CP), and the parent Tera line (NTera2/D1). Resistance factors for both CDDP-resistant cell lines were determined after continuous incubation (4 days) with CDDP. Continuous incubation with the other studied platinum drugs revealed complete cross-resistance for carboplatin (CBDCA) and zeniplatin but less for enloplatin (ENLO) and iproplatin in both models. Tetraplatin and lobaplatin showed, respectively, partial and complete cross-resistance in GLC4/CDDP but no cross-resistance in Tera-CP. GSH level, but not glutathione S-transferase activity, of the 4 cell lines correlated with platinum drug concentrations inhibiting cell survival by 50% after continuous incubation (r = 0.86, P < 0.05). GSH depletion by DL-buthionine-S,R-sulfoximine (BSO) increased sensitivity, as measured after a 4-h exposure to the drugs, of GLC4/CDDP for CDDP 2.0-fold, for CBDCA 1.7-fold, for zeniplatin 1.7-fold, and almost to the level of the sensitive GLC4 for ENLO, whereas no effect was observed for lobaplatin and the Pt(IV) compounds iproplatin and tetraplatin. BSO-modulating effect was higher in the sensitive GLC4 line for most compounds; therefore reduction of resistance could be achieved only for CDDP and ENLO. In contrast to GLC4, no modulation occurred in Tera. In Tera-CP BSO increased sensitivity for CDDP 1.5-fold, for CBDCA 1.9-fold, and for zeniplatin 1.2-fold; no effect was observed for ENLO, lobaplatin, and the Pt(IV) compounds. Reduction of CDDP resistance by BSO was known to occur with identical cellular platinum levels and higher Pt-DNA binding in GLC4/CDDP. However, pretreatment with BSO followed by 4 h ENLO incubation increased cellular platinum levels in both GLC4 and GLC4/CDDP while Pt-DNA binding remained unchanged. In conclusion, GSH reflected sensitivity to platinum-containing drugs. However, since the involvement of GSH differed between the models and the various platinum drugs, the effect of modulation with BSO was unpredictable.


Inhibition of 12-O-tetradecanoylphorbol-13-acetate-caused tumor promotion in 7,12-dimethylbenz[a]anthracene-initiated SENCAR mouse skin by a polyphenolic fraction isolated from green tea. Our laboratory has been studying cancer chemopreventive effects of polyphenolic fraction isolated from green tea (GTP). In prior studies we have shown that (a) GTP possesses antigenotoxic effects in various test systems; (b) topical application of GTP protects against UV radiation and chemical carcinogen-induced tumorigenesis in murine skin; and (c) feeding of GTP in drinking water p.o. to mice protects against carcinogen-induced forestomach and lung tumorigenesis. Recently, we showed that in a dose-dependent manner GTP inhibits tumor promoter-caused induction of epidermal ornithine decarboxylase activity in SENCAR mice (R. Agarwal et al., Cancer Res., 52: 3582-3588, 1992). In the present study, we assessed the effect of GTP on TPA-induced skin tumor promotion in 7,12-dimethylbenz(a)anthracene-initiated SENCAR mouse. Topical application of varying doses of GTP (1-24 mg) 30 min prior to that of each TPA application resulted in highly significant protection against skin tumor promotion in a dose-dependent manner. The animals pretreated with GTP showed substantially lower tumor body burden such as decrease in total number of tumors per group, number of tumors per animal, tumor volume per mouse, and average volume per tumor, as compared to the animals that did not receive GTP. Since TPA-induced epidermal cyclooxygenase and lipoxygenase activities and edema and hyperplasia are conventionally used markers of skin tumor promotion, we also assessed the effect of preapplication of GTP on these parameters. As quantitated by the formation of prostaglandin and hydroxy-eicosatetraenoic acid metabolites from, respectively, cyclooxygenase- and lipoxygenase-catalyzed metabolism of arachidonic acid, skin application of GTP to SENCAR mice resulted in significant inhibition of TPA-caused effects on these 2 enzymes. Prior application of GTP to mouse skin also resulted in 30-46% inhibition of TPA-induced epidermal edema and hyperplasia. The results of the present study suggest that GTP possesses anti-skin tumor-promoting effects, and that the mechanism of such effects may involve inhibition of tumor promoter-induced epidermal ornithine decarboxylase, cyclooxygenase and lipoxygenase activities, edema, and hyperplasia. Further studies are in progress to define which component present in GTP is responsible for its anti-skin tumor-promoting effects.


Novel expression of gastrin (cholecystokinin-B) receptors in azaserine-induced rat pancreatic carcinoma: receptor determination and characterization. Many reports have emphasized the role of gastrin as a growth factor for normal gastrointestinal mucosa and gastrointestinal cancers. Recent studies have pointed out that this peptide acts also as a growth factor for the pancreatic cancer cell line AR42J. This effect is mediated by gastrin [cholecystokinin (CCK)-B] receptors. In the present study, we investigated gastrin (CCK-B) receptor expression in the azaserine-induced rat pancreatic carcinoma DSL-6, comparing it to normal rat pancreas, and we also characterized CCK receptor subtypes in this tumor. The results showed that there is extensive gastrin binding to the DSL-6 pancreatic carcinoma. No evidence of specific gastrin binding to normal pancreas was found. Analysis of the ability of gastrin-17-I to inhibit 125I-gastrin-I binding demonstrated that gastrin bound to a single class of receptors with a Kd of 0.21 +/- 0.04 nM and a binding capacity of 184 +/- 29 fmol/mg protein. 125I-Gastrin-I binding was inhibited by the specific CCK-B receptor antagonist L365,260 approximately 40 times more effectively than by the specific CCK-A receptor antagonist L364,718. Analysis of the ability of cholecystokinin octapeptide (CCK-8) to inhibit 125I-Bolton-Hunter-CCK-8 binding revealed two CCK binding sites, i.e., a high affinity site and a low affinity site. The observed binding affinities of CCK-8 were then introduced into the computer analysis of the dose-inhibition curve of the ability of gastrin-17-I to inhibit binding of 125I-Bolton-Hunter-CCK-8, which was significantly better fit by a three-site model than by a two-site model. The three sites meet the criteria for CCK-B, high affinity CCK-A, and low affinity CCK-A receptors. The binding capacity of CCK-B receptors constitutes 34% of the total high affinity CCK binding sites. This study demonstrated that DSL-6 pancreatic carcinoma expresses three subtypes of CCK receptors. Gastrin (CCK-B) receptors, which were not detected in normal rat pancreas, constitute about one third of the total high affinity CCK receptors. We suggest that novel expression of gastrin (CCK-B) receptors may be generated by gene mutation or amplification during carcinogenesis and may play an important role in promoting tumor growth.


Immunogenicity and safety of a recombinant vaccinia virus vaccine expressing the carcinoembryonic antigen gene in a nonhuman primate. We have previously reported the development of a recombinant vaccinia virus vaccine expressing the human carcinoembryonic antigen (CEA) gene, designated rV(NYC)-CEA. This construct has been shown to elicit specific anti-CEA immune responses and an antitumor effect in a murine tumor model. In the studies reported here, the safety and immunogenicity of this recombinant vaccinia virus were evaluated in a rhesus monkey model. Human CEA is a M(r) 180,000 glycoprotein expressed in approximately 90% of gastrointestinal carcinomas and in some breast and non-small cell lung carcinomas. This family also includes normal cross-reacting antigen (NCA). Rhesus monkeys, like humans, have some NCA on the surface of their granulocytes. Eight monkeys were immunized 3 or 4 times by skin scarification with the recombinant CEA vaccine and four monkeys received wild-type vaccinia virus as control. After three vaccinations, all rV(NYC)-CEA-vaccinated animals exhibited a strong anti-CEA antibody response as measured by enzyme-linked immunosorbent assay. The functional ability of these antibodies to mediate lysis of a CEA-bearing tumor cell was demonstrated using human effector cells. This response could be enhanced by interleukin 2. Cellular immunity to CEA was measured by delayed-type hypersensitivity upon intradermal challenge with purified CEA. Only those animals receiving the recombinant vaccine displayed significant anti-CEA responses. Furthermore, peripheral blood mononuclear cells from immunized monkeys were found to proliferate in response to CEA stimulation. All vaccinated monkeys developed local skin irritation at the site of the vaccination, regional lymphadenopathy, and low-grade fevers after immunization. Following immunization with rV(NYC)-CEA, the response was consistent with the usual constitutional symptoms seen with human smallpox virus immunization. Blood counts, differentials, and hepatic and renal chemistries remained normal in all animals throughout the study and for up to 1 year following the primary vaccination. No evidence of immunological cross-reactivity to NCA was found by either a fall in the granulocyte count or analyses for anti-NCA antibodies. Thus, the rV(NYC)-CEA vaccine appears to be safe in rhesus monkeys. The administration of a CEA recombinant vaccine to rhesus monkeys induces both a humoral and a cell-mediated immune response directed against human CEA.


Potent and specific inhibition of p60v-src protein kinase both in vivo and in vitro by radicicol. A fungal metabolite, radicicol, with a macrocyclic ring induced the reversal of transformed phenotypes of v-src-transformed fibroblasts (Rous sarcoma virus-transformed 3Y1 rat fibroblast) at a quite low concentration of 0.1 microgram/ml. Actin stress fibers reappeared in the transformed cells after treatment with radicicol. Radicicol reduced the intracellular level of autophosphorylation of p60v-src as well as the level of other tyrosine-phosphorylated proteins in a dose-dependent manner. In vitro kinase assay revealed that radicicol effectively inhibited not only autophosphorylation but also transphosphorylation activities of purified p60v-src with a concentration producing 50% inhibition of 0.1 microgram/ml. However, radicicol showed no inhibitory effect on protein kinase C or protein kinase A. These results suggest that radicicol is a novel and specific protein-tyrosine kinase inhibitor and that the decreased level of tyrosine kinase activity of p60v-src causes reversion of transformed phenotypes of Rous sarcoma virus-transformed 3Y1 rat fibroblast. Furthermore, differentiation of Friend leukemia cells, which is one of the known characteristic phenomena associated with the inhibition of tyrosine kinase, was also induced in the concentration range of 0.05-0.5 microgram/ml, suggesting that the agent is useful for the analysis of differentiation as well as the kinase-mediated signal transduction.


Carcinogenicity studies of fluoxetine hydrochloride in rats and mice. The antidepressant drug fluoxetine HCl was tested for carcinogenicity in three well designed and controlled studies in Fischer rats and C57BL/6 x C3H F1 mice. The compound was administered to the animals for 24 months at dietary doses of approximately 0, 0.5, 2.0, or 10.0 mg/kg body weight in rats and 1.0, 5.0, or 10.0 mg/kg in mice. The highest dose tested was a maximum tolerated dose for both species as evidenced by clinical signs (rats and mice) and some mortality (mice) referable to central nervous system pharmacological effects, decreased weight gain (rats), and histopathological changes of phospholipidosis (rats) and hepatic fatty change (mice). There was no evidence of an increased incidence of any type of unusual or commonly occurring spontaneous neoplasm in either rats or mice. There were statistically significant decreases in a few commonly occurring neoplasms. The data reported herein provide convincing evidence that fluoxetine is neither a complete carcinogen nor a tumor promoter.


Expression of the protooncogene bcl-2 in the prostate and its association with emergence of androgen-independent prostate cancer. The significance of apoptosis in relation to the development and progression of prostate cancer remains largely undefined. bcl-2 is an oncogene that functions by overriding apoptosis. bcl-2 expression was localized to the basal epithelial cells in the normal human prostate with the use of immunohistochemistry. Androgen-dependent and androgen-independent prostate carcinomas were evaluated immunohistochemically for bcl-2 expression. bcl-2 was undetectable in 13 of 19 cases of androgen-dependent cancers. In contrast, androgen-independent cancers displayed diffuse, high levels of bcl-2 staining (P < 0.01). In rats, steady-state levels of bcl-2 mRNA, assessed by S1 assays, reached maximum levels 10 days following castration. Addition of exogenous testosterone with, or without, flutamide demonstrated that the increased bcl-2 mRNA resulted from androgen ablation. Our findings indicate that bcl-2 expression is augmented following androgen ablation and is correlated with the progression of prostate cancer from androgen dependence to androgen independence.


Consistent disruption of the AML1 gene occurs within a single intron in the t(8;21) chromosomal translocation. The AML1 gene on chromosome 21 was rearranged by the t(8;21) chromosomal translocation in acute myeloid leukemia (AML). Southern blot analysis of 21 AML patients with t(8;21), including three with complex translocations, t(8;V;21), demonstrated that all the breakpoints occurred at random within a single intron between two coding exons of AML1. Clustering of the breakpoints in the restricted intron suggests the formation of a unique fusion gene between the AML1 gene and a presumable counterpart gene on chromosome 8. Nucleotide sequencing of the breakpoint region revealed that the translocation event was accompanied by deletion of a short stretch of nucleotides.


Immunohistochemical staining for transforming growth factor beta 1 associates with disease progression in human breast cancer. The transforming growth factor beta s (TGF-beta) comprise a family of M(r) 25,000 pluripotent growth factors which have been implicated in the development and progression of human breast cancer. Conflicting data suggest that TGF-beta has the potential to either inhibit or promote the progression of mammary neoplasia. We therefore examined a pathological library of malignant breast biopsy specimens to determine the prevalence and distribution of immunoreactivity with antibodies specific for the three mammalian isoforms of TGF-beta (beta 1, beta 2, and beta 3). We found that intense staining for TGF-beta 1 was positively associated with rate of disease progression, and that this was independent of age, stage, nodal status, or estrogen receptor status (P = 0.009).


Disruption of mitochondrial function by suramin measured by rhodamine 123 retention and oxygen consumption in intact DU145 prostate carcinoma cells. Suramin, an antiparasitic drug, has shown antitumor activity in humans. This may occur in part through disruption of energy balance, which is believed to be part of its antiparasitic action. Suramin disrupts mitochondrial function in intact DU145 prostate carcinoma cell monolayers as seen by its causing the release of rhodamine 123 from prestained cells beginning at about 10 microM in 96-well microtiter plates measured with a fluorescent plate scanner. This effect was similar to the ionophore carbonyl cyanide m-chlorophenylhydrazone, dissolved in ethanol at 0.01 N and indicates that suramin acts as a respiratory poison or an ionophore. This effect was confirmed by studies of oxygen consumption with a Clark oxygen electrode and cellular ATP content which demonstrated uncoupling of oxidative phosphorylation by 100 microM suramin, a clinically achievable plasma drug level.


Growth suppression mediated by transfection of p53 in Hut292DM human lung cancer cells expressing endogenous wild-type p53 protein. This study was undertaken to analyze the effect of wild-type p53 transfection on the growth potential of a human lung cancer cell line Hut292DM expressing endogenous wild-type p53. Transfection efficiencies obtained with either the wild-type or a mutant p53 complementary DNA revealed a significant decrease in the number of colonies obtained with the wild-type p53 as compared to the mutant p53 complementary DNA (27%) or control vector DNA only (20%), suggesting that wild-type p53 inhibited the growth of Hut292DM cells. A series of wild-type and mutant p53 transfection clones were then analyzed for the presence and expression of the exogenous p53 gene. Polymerase chain reaction amplification revealed that 98% of mutant p53 transfection clones analyzed contained the exogenous p53 gene as opposed to 47% for wild-type p53 clones. The majority of mutant p53 clones expressed high levels of exogenous p53 mRNA and protein as analyzed by Northern and Western blots, respectively. In contrast, all wild-type p53 clones analyzed failed to express exogenous p53 mRNA transcript or protein of a normal size. Aberrant-size p53 mRNA was detected in two wild-type p53 clones (X833.W2 and W18), and Western blot analysis revealed that these clones expressed truncated p53 proteins (M(r) 45,000 and 33,000 respectively). No difference in proliferation rates in vitro or in tumorigenic potential in nude mice were observed between mutant p53 clones or control cell lines. In contrast, a wild-type p53 clone (X833.W2) exhibited a significantly reduced tumorigenic potential in nude mice, whereas its in vitro proliferation rate was comparable to parental Hut292DM cells. The data indicate that exogenous expression of wild-type p53 is incompatible with Hut292DM lung cancer cell proliferation in vitro and suggest that p53-mediated growth control in vitro and in vivo may be dissociated and exerted by separate domains of the p53 protein.


Expression and regulation of the leukemia inhibitory factor/D factor gene in human T-cell leukemia virus type 1 infected T-cell lines. The expression of the leukemia inhibitory factor/D factor (LIF) gene in human T-cell leukemia virus type 1 infected T-cell lines was examined. Human T-cell leukemia virus type 1 infected T-cell lines MT-1, MT-2, H89-59, H89-79, and H109 expressed LIF mRNA, but the T-cell lines MOLT-4 and TALL-1 did not. LIF mRNA expression was enhanced by interleukin 2 or 12-O-tetradecanoylphorbol-13-acetate in MT-2 cells. The biological activity of LIF was detected in culture medium enhanced by interleukin 2 in MT-2 cells. The expression of LIF mRNA was suppressed by 1 alpha,25-dihydroxyvitamin D3 and dexamethasone. These results imply that the expression of the LIF gene is involved in the development of hypercalcemia and abnormalities of the immune system observed in patients with adult T-cell leukemia.


Differential display and cloning of messenger RNAs from human breast cancer versus mammary epithelial cells. Identification of the genes that are specifically expressed in tumor cells but not in normal cells (oncogenes), or vice versa (tumor suppressor genes), is important for understanding the molecular basis of cancer. The differential display technique was applied to compare mRNAs from normal and tumor-derived human mammary epithelial cells, cultured under the same conditions. Complementary DNA fragments corresponding to several apparently differentially expressed mRNAs were recovered and sequenced. They exhibit characteristics of the 3' end of eukaryotic mRNA, as predicted by the method. A complementary DNA fragment seen only in the normal cell was used as a probe to isolate its corresponding complementary DNA clone from a library. Northern analysis confirmed its differential expression. Thus, this method can be used for detecting, cloning, and sequencing of genes that are unique to a host of biological and disease processes.


A functional screen for germ line p53 mutations based on transcriptional activation. Germ line p53 mutations represent a genetic predisposition for cancer development. At the present time, their detection requires extensive work and their functional significance must be documented. Therefore, we have designed a simple biological assay which detects functionally significant germ line p53 mutations. This assay is based on the cloning of the patient's p53 complementary DNA into a eukaryotic expression vector followed by the cotransfection into human cells of the recombinant vector with a reporter plasmid for the transcriptional activity of p53. This assay potentially offers a powerful method to screen fibroblasts or lymphocytes from patients for germ line mutations which inactivate the p53 tumor suppressor gene.


Lack of T-cell immunity in humans with preexisting anti-mouse immunoglobulin reactivity. We have identified five normal individuals without known exposure to mouse immunoglobulin with "preexisting" human anti-mouse antibody (HAMA) against a panel of four mouse monoclonal antibodies and polyclonal mouse IgG. Competitive inhibition by polyclonal mouse IgG of HAMA binding to monoclonal antibody coated beads demonstrates the mouse constant region specificity of these sera. Lack of such inhibition by polyclonal human IgG eliminates polyclonal rheumatoid factors as an explanation. Lymphoblastic transformation studies in these five persons failed to demonstrate a memory T-cell response to the four mouse monoclonals or polyclonal mouse IgG. Positive controls included T-cell responses to streptolysin O in these five individuals as well as responses to monoclonal antibody D612 in three patients following treatment with that antibody. This lack of T-cell immunity to mouse IgG suggests that "preexisting" HAMA is the product of inadvertent cross-reactivity with murine constant region by antibodies directed against other antigens. Therefore, "preexisting" HAMA should pose no risk of anamnestic or allergic response in patients considered for murine monoclonal therapy.


Observations on electrical stimulation of lumbosacral nerve roots in children with and without lower limb spasticity. Selective functional posterior rhizotomy (SFPR) is a popular operation for the treatment of spasticity in children with cerebral palsy, but the physiologic basis of the procedure is poorly understood. As part of SFPR operations in 60 consecutive children, the responses to electrical stimulation of posterior lumbosacral roots and rootlets, and the corresponding anterior roots were studied. In addition, similar electrical stimulation of posterior roots was performed in four nonspastic "control" children. Sustained responses to 50 Hz stimulation, one of the criteria used to signify abnormality in the spastic children, was found frequently in the "control" children. Contralateral spread to the lower limb muscles and suprasegmental spread to the upper limbs, face, and neck were determined to be the most valid criteria which differentiated abnormal from normal responses. Stimulation of anterior nerve roots at 50 Hz caused sustained responses and ipsilateral lower limb spread, at a low threshold compared to that of corresponding posterior roots. The results of this study bring into question the validity of some of the criteria that are used to select abnormal posterior rootlets in the SFPR procedure, and suggest criteria that may be more valid based on findings in nonspastic children.


Central neurocytoma: its differentiation from intraventricular oligodendroglioma. Two patients with intraventricular tumours are presented. Both had similar features on light microscopic examination. On the basis of the specific immunohistochemical staining patterns and the ultrastructural findings, one was diagnosed as a central neurocytoma while the other was diagnosed as an intraventricular oligodendroglioma. The possibility of central neurocytoma should be considered in all young patients including children presenting with an intraventricular lesion. Definitive diagnosis requires electron microscopic and immunohistochemical studies.


Congenital spinal cord astrocytomas.

Congenital spinal cord astrocytomas. Congenital spinal cord astrocytomas have only rarely been reported. We report two additional cases and a review of the literature on these infrequent tumors. The congenital cord astrocytomas can have obscure initial presentations, including fever and irritability, leading to delays in diagnosis. Magnetic resonance imaging is the diagnostic procedure of choice, allowing noninvasive delineation of the lesion. The congenital tumors are similar in location and pathology to astrocytomas of the cord in older children. As in older patients, initial treatment should include attempted surgical extirpation, delaying or avoiding radiation therapy with its attendant risks. Reported follow-ups of the congenital astrocytomas suggest they will behave in a fashion similar to spinal cord astrocytomas in older children.


Histological changes in the midbrain around the aqueduct in congenital hydrocephalic rat LEW/Jms. Primary aqueductal stenosis is one of the main causes of congenital hydrocephalus in humans and experimental models. The congenitally hydrocephalic rat strain LEW/Jms is one such model. In this report, we describe further detailed histological features of periaqueductal structure, including the posterior commissure, subcommissural organ (SCO), and ependyma, and discuss the changes in these structures in relation to the cause of hydrocephalus. Coronal sections of the aqueduct in normal rats showed that the usual ependyma was absent in the center of the base facing the dorsal side, which was replaced by tall columnar cells. On the other hand, in hydrocephalic rats the ependyma encircled the aqueductal cavity. In midline sagittal sections, normal and hydrocephalic rats showed the SCO, although the SCO in hydrocephalic rats was shorter than in normal rats. There was also a marked difference between normal and hydrocephalic rats in the dorsoventral dimension of the rostral midbrain. In hydrocephalus, this dimension was large in comparison with normal rats. The superior collicular commissure located caudal to the posterior commissure ran along the ventral side of the midbrain in rats with hydrocephalus, and there was a cell-depleted area just dorsal to the superior collicular commissure. The same findings were observed from the 17th day of gestation until the postnatal period. Although the role of the SCO has been widely discussed from the viewpoint of secretory function, the present study indicated that this organ might be involved in the formation of the shape of the aqueduct.


Expanding cranioplasty for craniosynostosis and allied disorders. For early correction of craniosynostosis in the newborn or in early infancy, strip craniectomy may produce satisfactory results. For late correction, however, more radical cranial reconstruction procedures are essential in order to achieve adequate remodeling of cranial deformities and normalization of intracranial pressure. Craniosynostosis presents various types of cranial deformity, and different procedures for its correction have been reported. Expanding cranioplasty is presented for the increase of cranial volume and immediate correction of the cranial deformity. This cranioplasty can be applied not only for late correction of various types of craniosynostosis but also for other cranial deformities.


Management of brain abscess in children: review of 130 cases over a period of 21 years. The data on 130 children with brain abscesses treated over 21 years (1970-1990) were analyzed retrospectively. The whole group included four infants. Chronic ear infection and cyanotic congenital heart disease were the most common predisposing factors. In infants, meningitis and/or ventriculitis were dominant in the etiopathogenesis. Cases were evaluated according to the treatment received and also according to time periods. More than half of the patients (n = 74) in this series were treated by primary or secondary excision. Computed tomography (CT) facilitated the diagnosis and helped the planning of treatment. Aspiration gained increasing credit after the advent of CT. Microorganisms could be identified in 54% of the cultured specimens. Staphylococci, streptococci and Proteus were the dominating microorganisms. Penicillin and chloramphenicol have long been the mainstay of antimicrobial therapy but have recently been replaced by third-generation cephalosporins and sulbactam-ampicillin combinations. Overall mortality was 15.5% but showed a decline from 30% in the pre-CT era to 6% in the last 5 years and to zero in the last three. Neither the location nor associated heart disease contributed to the mortality, but mortality among infants was as high as 50%.


New head-prone position for posterior fossa surgery in infants with severe hydrocephalus. A new head-prone position is described for posterior cranial fossa surgery on infants whose cerebral cortical mantle has been markedly thinned by severe hydrocephalus. The new position furnished a direct line of sight to the apex of the IV ventricle corresponding to that provided by the classic high sitting position, without the latter's risks of air embolism and of acute subdural hematoma secondary to tearing of corticodural bridging vessels due to escape of gravity-impelled CSF from the large ventricles. The anesthesiologic technique, the positioning of the patient, and the surgeon's posture presented no unusual problems.


Congenital cerebral venous dysgenesis. Decreased cerebral blood flow in deep cerebral regions revealed by SPECT. This report describes a rare case of primary cerebral venous dysgenesis in a 3-year-old child with development retardation. Angiography resulted in nonvisualization not only of deep cerebral veins but also of superficial cerebral veins. In computed tomography and in magnetic resonance imaging the collateral venous circulation appeared as a strange configuration in the pineal region. Single photon emission computed tomography using N-isopropyl-p-[I-123]-iodoamphetamine revealed decreased regional cerebral blood flow in the basal ganglia and thalamus, but cerebral infarction was not detected in the area. These features indicate that in this case, dysgenesis of deep cerebral veins, which probably occurred during prenatal life, had caused hypoperfusion in the deep cerebral regions.


Vertebrobasilar infarcts in infancy: a case report and review of the literature. We report a rare case of a child with cerebellar infarction confirmed by vertebral angiography, computed tomography and magnetic resonance imaging. The etiology of this case is unknown. The relevant literature is reviewed.


Alcohol acts to promote incidence of tumors. Alcohol is a major cancer risk factor. A variety of roles in carcinogenesis have been assigned to ethanol. Our recent studies indicate that ethanol may act as tumor promoter. Further studies suggest that ethanol may act as tumor promoter through free radicals generated during its metabolism because an increase in tumors was observed under conditions in which ethanol-induced lipid peroxidation could take place and not in which such lipid peroxidation could not occur. Other possibilities include ethanol effect on cell necrosis and cell proliferation and generation of a secondary mutagenic event through a DNA repair deficiency. The immune system, because it is a defense mechanism against carcinogenesis and because ethanol is immunosuppressive, must also play a role. Our current studies are aimed at elucidating some of these mechanisms and pointing out the complexity of the mechanisms that are affected by ethanol and that may be involved in tumor promotion.


Food habits and esophageal cancer: an overview. Cancer of the esophagus has a more varied geographical distribution and incidence than any other commonly occurring cancer. Its incidence rate is increasing in many countries, especially among males. Esophageal cancer has been found to be associated with the consumption of alcohol and tobacco, particularly when combined, and in the last decade the role of nutrition and diet in the etiology of this disease has attracted worldwide attention. Regions with a large incidence of this disease are generally located in poor parts of the world, and their inhabitants share several dietary characteristics. They subsist on a diet high in starch and almost without fresh fruit or vegetables, eat rapidly without sufficient mastication, and consume many foods (rice gruel) and drinks (tea) at very high temperatures. Hard and scratchy foods also are consumed frequently. In the high-risk region of northern Iran, where the frequency of esophageal cancer is higher among women than men, the main food during pregnancy contains strong black pepper and sharp crushed pomegranate seeds, which irritate the esophagus.


Epidemiological study of French uranium miners. An epidemiological cohort study has been carried out to demonstrate any excess cancer mortality in a group of French uranium miners who worked underground for at least 2 years. The latency period of cancer associated with this type of professional exposure was long (10 to 20 years). The first study includes miners who began underground mining between 1946-1972. The individual monthly exposure to radon and its decay products has been recorded since 1956. The exposure of the first 10 years had to be estimated retrospectively for each miner regarding the working conditions. Problems associated with these two different exposure recordings are discussed. The results revealed an excess of lung cancer mortality for miners who had begun underground mining during the years 1946-1956.


The effects of iodinated glycerol, trichlorfon, and acetaminophen on tumor progression in a Fischer rat leukemia transplant model. Sixty-day bioassays of iodinated glycerol, trichlorfon, and acetaminophen were conducted using a leukemia transplant model in 6- to 8-week-old F344 rats to investigate the potential of these chemicals to affect tumor progression. The chemicals were administered in the drinking water at doses that approximated those used in previously conducted 2-year carcinogenesis studies. Simultaneous with dose administration, half of a group of young, healthy, syngeneic rats were given subcutaneous transplants of mononuclear cells derived from spleens of leukemic donors. Variables used to quantitate tumor progression included body weight, spleen weight, white blood cell (WBC) and red blood cell (RBC) counts, packed cell volume, hemoglobin concentration, and platelet counts. Iodinated glycerol at 1.25 or 2.5 mg/ml caused a greater increase in leukocytosis in dosed transplant recipients in comparison to that experienced by undosed recipients: trichlorfon at 2.5 or 5.0 mg/ml enhanced splenomegaly and induced greater reductions in RBC parameters in dosed recipients in comparison to that experienced by undosed recipients. Acetaminophen at 3.0 and 6.0 mg/ml resulted in insignificant but dose-related increases in spleen weight and leukocytosis only in the female rat transplant recipients, as was observed in 2-year studies. Based on results from the short-term leukemia transplant model, data from 2-year carcinogenicity studies, and structure-activity considerations, exposure to iodinated glycerol and trichlorfon was more strongly associated with the expression of leukemia than exposure to acetaminophen. The potential carcinogenicity of each of these chemicals should be taken into consideration when calculating estimates of risk and decisions for their use.


Detection of N-myc gene amplification in bone marrow specimen of stage IV neuroblastoma patients. N-myc gene amplification is an unfavorable prognostic factor in neuroblastoma; therefore, its detection might have therapeutical consequences. Because of the reliability of noninvasive diagnostic methods such as X-ray examination and measurement of vanilymandelic acid and the lack of technical unavailability at most institutions, the determination of the N-myc status of neuroblastoma often is not done. In our investigation of 14 neuroblastoma patients, we could demonstrate N-myc gene amplification in the bone marrow of 5 patients with neuroblastoma stage IV disease and in bone marrow infiltration without enrichment of neuroblastoma cells. Otherwise, no information about the tumor content of N-myc gene copies at the time of initial diagnosis could be obtained. At the subsequent resection, the N-myc gene amplification was confirmed by the additional Southern blot analysis and in situ hybridization of tumor tissue. Furthermore, the N-myc status of bone marrow was analyzed during the stages of chemotherapy in three cases.


Descriptive analysis of the tumor registry experience for malignant melanoma from 1977 to 1986 at the University of Miami School of Medicine/Jackson Memorial Hospital. A descriptive analysis was performed of malignant melanoma data ascertained by the University of Miami School of Medicine/Jackson Memorial Hospital (UM/JMH) Tumor Registry. A total of 376 melanoma cases were collected and reviewed. Most of the melanoma lesions occurred on the trunk, especially in the 40- to 49- and 50- to 54-year-old age groups. Local-stage cases had the best 5-year survival--77%. The difference in survival between local-stage case and regional- and distant-stage cases was statistically significant (p = 0.0000). In males with local-stage disease, lesions on the trunk were associated with better survival than lesions at other sites (p = 0.04). In females with local-stage disease, survival was 68% for 5 years for trunk sites vs. 87% for other sites (p = 0.05). In local-stage disease, the overall 5-year survival was 85%.


Promoting dietary change in the Stockholm Cancer Prevention Program. The Stockholm Cancer Prevention Program (SCPP) is a community-based program aimed at reducing cancer incidence and mortality by reducing risk factors related to life-style: dietary habits, tobacco use, and sunbathing. The program, which came about as a result of a political initiative and commitment, has as its dietary objectives to reduce fat intake to 30% of energy and to increase fiber intake to 30 g/day. SCPP strives to achieve these goals by simultaneously affecting food supply and food demand. To date, the program collaborates with 12 municipalities and several large occupational health services and restaurant chains. It has developed cook books for caterers and the general public and has organized food fairs targeting policymakers and those working with food, education, or health promotion. SCPP emphasizes collaboration across sectors of society and has initiated contests for students studying food service technology and for retailers with the aim of promoting dietary change. The intervention is based on the principles and strategies of community organization.


Effects of opioid peptides on the tumoricidal activity of spleen cells from nude mice with or without tumors. The present study was designed to explore the effects of opioid peptides on the immune systems of intact nude mice and nude mice bearing human ovarian cancer cells (KF). When spleen cells from intact nude mice were incubated with medium alone, a significant ability of spleen cells to lyse the KF cells was not observed. However, incubation of the spleen cells with 1 microM beta-endorphin or 1 microM alpha-endorphin induced a significant lytic activity on the KF cells. The control-level lytic activity was increased significantly to about 4.5-fold by 1 microM beta-endorphin and about 3.7-fold by 10 microM met-enkephalin. These results suggest that opioid peptides play a crucial role in cellular immunity. Thus, we examined plasma levels of beta-endorphin in patients with ovarian or uterine carcinoma. The plasma beta-endorphin levels in patients with ovarian or uterine carcinoma were significantly higher (more than twofold) than those of age-matched healthy women.


Clonal karyotypic aberrations in enchondromas. Enchondromas, benign cartilaginous tumors arising within the medullary cavity of bone, are frequently difficult to differentiate from their malignant counterpart. In this study, cytogenetic analysis was performed on seven cases of solitary enchondroma. Normal karyotypes were observed in five cases. Clonal abnormalities were detected in two cases. An isochromosome of the short arm of chromosome 6 characterized one case, and t(12;15)(q13;q26) in addition to random numerical and structural abnormalities such as telomeric association was observed in the other case. An i(6p) and structural rearrangements involving 12q13 previously have been described in chondrosarcoma. Our findings suggest that similar clonal karyotypic abnormalities exist in benign and malignant cartilaginous neoplasms.


Sister chromatid exchange (SCE) frequency in lymphocytes of patients with colorectal carcinoma treated with razoxane. The increased risk of neoplasia following cytotoxic therapy for both malignant and nonmalignant disease is well known. Sister chromatid exchange (SCE) frequencies in patients receiving such chemotherapy are often elevated, and the persistence of high levels after treatment may provide an indicator for susceptibility to secondary neoplasia. The cytostatic drug razoxane has been used for the treatment of psoriasis, acute myeloid leukemia (AML), and colorectal carcinoma. Prolonged use of this drug, however, has been associated with the subsequent development of AML and, up to November 1987, 16 cases of acute leukemia following razoxane treatment have been reported. We report the SCE frequencies for 34 patients with colorectal carcinoma who were receiving or had previously been treated with razoxane. Our results show no significant increase in SCE levels in the razoxane group compared with either normal controls or untreated patients.


Immunocytochemical detection of oncoproteins in animal and human tumor lines with acquired or inherent multidrug resistance. In this presentation, we analyze the relationship between protein expression of the protooncogenes c-fos, c-erb B1, c-K-ras, and c-myc and acquired or inherent multidrug resistance (MDR) in a panel of animal (CHO, S 180, L 1210) and human (KTCTL 44, KTCTL 18, CX 1, CXF 94) tumor lines by means of immunocytochemistry. Increased expression of c-fos and c-erb B1 proteins is a constant feature of all resistant cell lines except L 1210 cells, which did not reveal any alteration in oncoprotein expression. No apparent relationship between c-K-ras and c-myc proteins and MDR was found. The immunocytochemical results were corroborated by radioimmunoassays (RIAs). The data indicate that c-fos and c-erb B1 might play a role in the development of MDR.


Early detection of colorectal cancer: a profile of current practice. This study examines the prevalence of colorectal cancer screening among individuals in the general community. The survey was undertaken as part of a large scale general population survey of health practices and attitudes. A sample of 1090 people aged 40 years and over with no previous history of colorectal cancer or other predisposing condition was interviewed. Only 56% of this group reported that they regularly checked their bowel movements, the toilet bowl, or the toilet paper for signs of rectal bleeding. Only 13% could recall a doctor ever advising them to check for rectal bleeding; and 21% could recall a doctor asking them if they had ever noticed blood in their bowel movements. More involved practitioner-based procedures, such as digital rectal examination, fecal occult blood testing, endoscopy, and barium enema, were reported by only a minority of participants. Analysis of screening rates in the 9.3% of people who reported a family history of colorectal cancer revealed that this higher risk group was no more likely to be screened than those at average risk.


Compliance with guidelines for mammography screening. The health belief model was used to identify potential variables related to intention or compliance with mammography guidelines. Scales to measure independent and dependent variables were developed from previous research and assessed for validity and reliability. A probability sample of women 35 and older (x = 50) who resided in a large metropolitan area and surrounding counties (n = 322) participated in in-home interviews. Intent to complete mammography was related to having a family history of breast cancer, perceived barriers to mammography, and perceived control over breast cancer. Compliance with mammography was influenced by general health motivation and perceived susceptibility to and seriousness of breast cancer, benefits, and control over breast cancer. In addition, knowledge about breast cancer and breast cancer detection, age, having a health care provider suggest mammography, having symptoms of breast cancer, and socioeconomic status were significantly related to actual compliance with mammography.


Combined differentiation therapy in myelodysplastic syndrome with retinoid acid, 1 alpha,25 dihydroxyvitamin D3, and prednisone. The myelodysplastic syndrome (MDPS) provides an opportunity for identifying host factors (genetic, endocrine, immune) involved in initiation and progression of preleukemia into frank acute myeloid leukemia. The aim of this study was to identify bone marrow (BM) cellular and humoral dysfunctions central to the development of MDPS and useful in therapeutic follow-up studies. Our preclinical studies have shown that (1) the characteristic stromal cell composition of the normal BM microenvironment was impaired in MDPS and in AML in 67 and 86% of the cases, respectively; (2) the 1 alpha,25(OH)2D3 concentration in BM plasma was abnormal in 50% of MDPS and 30% of AML; and (3) an inverse correlation existed in MDPS between the 1 alpha,25(OH)2D3 concentration and the frequency of F-CFU, (r = 0.41, p < 0.02), suggestive of a regulatory interaction between this secosteroid hormone and BM stromal cells. The analysis of clonal extinction of BM blast cells in response to all trans retinoic acid (RA), 1 alpha,25(OH)2D3, and colony stimulating factors (PHA-LCM), either alone or in various combinations, revealed individual patterns of responses in the cases of MDPS or AML. The results indicate the necessity for preclinical studies to select patients for combined differentiation therapy. Our ongoing clinical trials suggest that RA (Roaccutan, 20 mg/day continuously) as induction therapy, followed at weeks 6 to 8 by prednisone (40 mg/day for 15 days) and 1 alpha,25(OH)2D3 (Rocaltrol, 3 x 0.25 micrograms/day for 3 months) may induce a long-lasting hematological remission in MDPS.


The perfusion pattern in coronary artery occlusion: comparison of exercise and adenosine.p6. This study compared exercise to adenosine thallium-201 single photon emission computed tomography in detecting occlusion of left anterior descending or right coronary arteries in patients with no previous myocardial infarction. There were 41 patients who underwent adenosine thallium imaging (adenosine infusion at a rate of 140 micrograms/kg/min for 6 min), and 143 patients who underwent exercise thallium imaging. There were more patients with right coronary than left anterior descending coronary artery occlusion. Thus, in the adenosine group, there were 15 patients with left anterior descending artery occlusion, and 26 with right coronary artery occlusion, and in the exercise group, there were 46 patients with left anterior descending artery occlusion, and 97 patients with right coronary artery occlusion. In the adenosine group, the thallium images were abnormal in 41 patients (100%), while in the exercise group, the thallium images were abnormal in 125 patients (87%, P < 0.02) in the territories of the occluded arteries. ST segment depression was noted in 19 patients (46%) in the adenosine group, and 69 patients (48%) in the exercise group (P:NS). In patients with isolated single vessel occlusion, the size of the perfusion abnormality was 28 +/- 9% with adenosine, and 21 +/- 12% with exercise (P:NS). Thus, most patients with occlusion of the left anterior descending or right coronary artery have regional perfusion abnormality during stress; the different role of collaterals with each type of stress may explain the higher percentage of abnormal results with adenosine than exercise.


Use of sideholes for diagnostic coronary arteriography by Judkins technique in patients with ostial coronary stenosis. Patients with ostial left main coronary artery stenosis are at increased risk from diagnostic cardiac catheterization. In order to reduce this risk a modified Judkins coronary catheter with a sidehole 1.5-2 cm from the tip has been used in 6 patients in whom pressure damping was observed after initial use of a standard end-hole Judkins left coronary catheter. This eliminates damping and allows forceful hand injection with good proximal and distal vessel opacification. It also allows the acquisition of multiple views without the need for catheter removal after each injection, thereby reducing the risk involved in multiple cannulations of a vessel with a potentially unstable lesion at its origin. The technique has also been used for ostial lesions in a right coronary artery and a vein graft.


Cardiac catheterization laboratory survey: 1990. Society for Cardiac Angiography and Interventions, Laboratory Performance Standards Committee. A survey of 117 member cardiac catheterization laboratories was undertaken by the Society for Cardiac Angiography and Interventions. The survey included numbers and types of procedures, both diagnostic and interventional, in adult as well as pediatric age groups. Radiation safety, various laboratory policies, frequency of short stay, and outpatient procedures were tabulated. Report generation, training programs, administrative organization, and laboratory equipment were all included. The results were compared with a 1978 survey. Areas of concern in terms of safety of the patient and possible underutilization of laboratories were identified.


Early coronary artery stent restenosis: utility of percutaneous coronary angioscopy. Restenosis of an endovascular stent may be caused by thrombus, intimal hyperplasia, or extrinsic compression. Angiography may not adequately define the etiology of restenosis. We describe a patient in whom angioscopy proved important in diagnosing intimal hyperplasia obviating the need for thrombolytic therapy and prolonged anti-coagulation.


Early postoperative occlusion of a left internal mammary artery bypass graft with subsequent restoration of patency. Total occlusion of a left internal mammary artery (LIMA) bypass graft is a rare complication, and reversal of a documented occlusion has not been reported. This is a case of an early postoperative occlusion of a LIMA graft that was found to be patent 4 months later. A patient with three vessel disease (including a moderate lesion in the proximal left anterior descending artery and a severe lesion in its mid-portion) underwent coronary artery bypass grafting with a LIMA to the mid-left anterior descending artery (LAD) and saphenous vein grafts to the right coronary and left circumflex arteries. Coronary angiography 3 months after surgery revealed a totally occluded internal mammary artery and saphenous vein grafts. The patient then underwent a successful angioplasty of the more distal lesion in the LAD. She subsequently returned with recurrent angina. Repeat coronary angiography revealed rapid progression of the disease in the proximal LAD with the more distal angioplasty site being widely patent. Selective arteriography of the internal mammary artery at that time revealed a patent vessel. Thus, the internal mammary graft is a physiologically active conduit that is dependent on flow dynamics. Competitive flow through the nonobstructive native LAD in combination with impedance of flow through the internal mammary artery due to a severe lesion in the LAD distal to the anastomosis led to a functionally occluded LIMA. When the obstruction in the proximal LAD progressed and the distal obstruction was successfully angioplastied, the flow dynamics in the internal mammary improved, allowing for its dilatation and restoration of patency.(ABSTRACT TRUNCATED AT 250 WORDS)


Coronary perforation during angioplasty: angiographic detection and demonstration of complete healing. A patient is presented with localized perforation of the left anterior descending artery secondary to angioplasty balloon rupture. Despite a remarkable angiographic picture of coronary tear and dye extravasation into the surrounding pericardial tissue, the patient remained hemodynamically stable, and was medically treated. Five years later she redeveloped angina, and repeated coronary arteriography revealed complete healing of the perforation site. This case attests to the remarkable ability of the coronary artery to completely heal from a major wall trauma. Although a rare complication of coronary angioplasty, perforation can occur, and various management aspects should be considered.


Failure of endocardial biopsy from the internal jugular vein due to endocardial scar: a new indication for the femoral venous approach. Following cardiac transplantation, patients undergo serial endomyocardial biopsies to evaluate rejection, usually by the internal jugular approach. A case report and data are presented that demonstrate that this approach becomes less efficient and occasionally impossible in the third year after transplant (53% success rate per biopsy attempt) as compared to the first year after transplant (80%) probably due to the development of endocardial scar in the area sampled by the bioptome. Alternatively, one can change to the femoral venous approach which continues to have a high success rate in the third year after transplant (83%) because a different area of the interventricular septum is sampled when this approach is used.


Interpretation of cardiac pathophysiology by waveform analysis: adult congenital anomalies. Congenital anomalies are unusual in adults, but characteristic hemodynamic data facilitate precise diagnoses. A complete evaluation, including assessment for intracardiac shunts, is usually indicated in patients prior to major surgical procedures or electrophysiologic interventions.


Collagen application for sealing of arterial puncture sites in comparison to pressure dressing: a randomized trial. One hundred patients undergoing routine diagnostic or interventional catheterization were randomly assigned to receive either percutaneously applied collagen (group A; n = 50) or conventional pressure dressing (group B; n = 50) for sealing of the femoral artery. Clinical variables were comparable in both groups. The heparin dose was 100 IU/kg in 30 patients and 200 IU/kg in 20 patients of either group. The average compression time was 4.3 min in group A and 42.3 min in group B (p < .001). Bleeding was not observed in group A but was observed in 6/50 patients in group B. The time to ambulation was 6.4 hr (range, 4-12 hr) in group A and 21.6 hr (range, 10-48 hr) in group B (p < .001). Hematomas with a diameter of > 6 cm developed in 4/50 patients in group A and in 11/50 patients in group B (p < .05). Blood-transfusions or surgical interventions were not required and there was no loss of ankle pulses in either group. In conclusion, percutaneously applied collagen reduced compression time and duration of bedrest after diagnostic catheterization and PTCA. Despite earlier ambulation, the incidence of bleeding was lower with collagen than with conventional pressure dressing.


PTCA with side-by-side balloon using fixed guide wire systems: a potential alternative autoperfusion device--an in vitro study. The use of "hugging balloons" for the implementation of a coronary angioplasty is a well-known and much-written-about technique. It has not, on the other hand, ever been stressed that two inflated hugging balloons are not totally obstructive, leaving enough space, between the balloons and the arterial wall, for perfusion. The cross section of this free area can be as much as 12% of the total arterial cross section, when the side-by-side balloons are of a relatively similar size. Calculations show that similar total conduit cross sections are achieved when inflating either a 3.0 balloon or two 2.0 side-by-side balloons. An in vitro experiment compares how systems using 2.0 double balloons and a 3.0 autoperfusion balloon affect the distal flow of a 3 mm internal diameter conduit. A semi-rigid silastic tubing is perfused with a 5% glucose isotonic solution at various predetermined proximal pressure levels. Distal pressures and flows are measured at different stages: with no balloon, with deflated balloons, and with inflated balloons. Comparison shows that 1) the double balloon system offers little resistance to flow compared to the autoperfusion balloon; 2) this system's rate of perfusion run-off is hardly affected and is constantly better than with the autoperfusion balloon; 3) this difference is all the more marked, the lower the proximal perfusion. These results suggest that the use of a double balloon could, in some cases, provide an alternative solution to autoperfusion equipment. Further clinical studies are needed to test this hypothesis.


The Tracker catheter: a new vascular access system. Technologic advances in dilation equipment have been important in improving angioplasty success rates and in expanding the indications of dilation. Despite these improvements, approximately 7% to 10% of attempted dilations may ultimately fail because of inability to cross the culprit lesion. As angioplasty techniques are applied to an increasingly complex cohort of patients, the ultimate success of a given procedure depends more and more on the ability of the operator to select the appropriate equipment for a given procedure. We report the unique application of a commercially available perfusion catheter which may improve patient outcome during complex angioplasty.


Mitral balloon valvuloplasty with transesophageal echocardiography without using fluoroscopy. Balloon mitral valvuloplasty with Inoue technique was performed in two group of patients. In group I (n = 40) valvuloplasty was performed under fluoroscopy without using echocardiography, whereas in group II (n = 13) valvuloplasty was performed under the guidance of transesophageal echocardiography alone, without using fluoroscopy. Patients in two groups were comparable with regard to clinical variables and hemodynamic parameters. Two female patients in group II were pregnant. Transmitral pressure gradient decrease did not differ significantly between two groups (pressure gradient: 17 +/- 5 to 4 +/- 1 in group I and 15 +/- 4 to 3 +/- 1 mm Hg in group II). Mitral valvular area increase was also not different in two groups (1.09 +/- 0.2 cm2 to 2.3 +/- 0.5 cm2 in group I and 0.9 +/- 0.2 to 2 +/- 0.3 cm2 in group II). In 14 cases from group 1 and 2 cases from group II mitral regurgitation increased after valvuloplasty (p < .05). Left atrial perforation occurred in one patient from group 1 and 2 patients from group II. In conclusion, mitral balloon valvuloplasty under transesophageal echocardiographic guidance alone is a safe and effective procedure in the treatment of mitral stenosis.


Rotational atherectomy in anomalous coronary arteries. We describe two cases of high speed rotational atherectomy performed in patients with anomalous coronary anatomy. These procedures are performed with standard equipment requiring no modifications using a percutaneous femoral approach. We feel these cases clearly illustrate the facile application of this new technology to unusual anatomical situations.


Improved support for right coronary artery angioplasty with a new guiding catheter. Inadequate guiding catheter support is a frequent cause for failure in right coronary angioplasty (PTCA). A new guiding catheter designed to provide easy placement in the right coronary and improved stability and backup support is described. Use of this catheter for PTCA of right coronary lesions, the majority of which were considered technically difficult to dilate, in 100 patients resulted in successful dilatations in 88% of patients. Failures were due to inability to seat the guide adequately in 8 patients with narrow aortic roots or unusual coronary origins and to inability to cross a lesion in 4 patients despite good support. In 4 patients successful dilatation was achieved after failure using another presently available guide.


The TATA-binding protein and associated factors are components of pol III transcription factor TFIIIB. RNA polymerases I, II, and III require the TATA-binding protein (TBP) to initiate promoter-specific transcription. We have separated HeLa TBP into four phosphocellulose fractions that elicit polymerase specificity in supplying TBP activity to TBP-depleted pol II and pol III transcription reactions. Polymerase specificity might arise in part through distinct TBP-associated factors (TAFs), which have recently been identified in pol I and II transcription. However, the requirement for pol III TAFs has not been established. Here we show that classical pol III transcription involves a minimum of two novel TAFs: TAF-172 and TAF-L. Not only does TAF-172 activate pol III transcription, but it also inhibits the binding of TBP to the TATA box, thereby repressing pol II transcription. The TBP-TAF-172-TAF-L complex can replace TFIIIB both in transcription reactions reconstituted with TFIIIC and in template commitment assays. Thus SL1, TFIID, and TFIIIB might be functionally similar TBP-TAF complexes that direct pol I, II, and III transcription, respectively.


A TBP complex essential for transcription from TATA-less but not TATA-containing RNA polymerase III promoters is part of the TFIIIB fraction. The TATA box-binding protein TBP directs transcription by all three eukaryotic RNA polymerases. In mammalian cells, TBP is found in at least three different complexes: SL1, D-TFIID, and B-TFIID. While SL1 and D-TFIID are involved in RNA polymerase I and II transcription, respectively, no unique function has been assigned to the B-TFIID complex. Here we show that the TFIIIB fraction required for RNA polymerase III transcription contains two separable components, one of which is a TBP-containing complex that may correspond to B-TFIID. For transcription of TATA-less RNA polymerase III genes such as the VAI, 5S, and 7SL genes, this complex cannot be replaced by either TBP alone or the D-TFIID complex. In contrast, TBP alone is active for basal transcription from the TATA-containing U6 promoter. This indicates different requirements for recruiting TBP to TATA-less and TATA-containing RNA polymerase III promoters.


Mechanism of TATA-binding protein recruitment to a TATA-less class III promoter. The TATA-binding protein (TBP) is required for transcription by RNA polymerase III (pol III), even though many pol III templates, such as the adenovirus VA1 gene, lack a consensus TATA box. We show that TBP alone does not form a stable, productive interaction with VA1 DNA. However, it can be incorporated into an initiation complex if the other class III basal factors, TFIIIB and TFIIIC, are also present. TFIIIB can associate with the evolutionarily conserved C-terminal domain of TBP in the absence of DNA or TFIIIC, suggesting that TFIIIB exists in solution as a complex with TBP. The stable association of TBP with an essential component of the pol III transcription apparatus may account for the ability of TATA-less class III genes to recruit TBP.


The role of the TATA-binding protein in the assembly and function of the multisubunit yeast RNA polymerase III transcription factor, TFIIIB. The Saccharomyces cerevisiae RNA polymerase III transcription factor (TF)IIIB has been assembled from three components. An assembly pathway of these polypeptides, which specifies their interactions, has been determined. The TATA-binding protein, TBP, and the TFIIB-related BRF1 gene product BRF, together reconstitute the transcription factor activity and TFIIC-dependent DNA-binding activity of the B' component of TFIIIB. BRF alone weakly binds to a TFIIIC-tRNA gene complex; TBP greatly stabilizes this interaction. B" transcription factor activity is recovered with its previously identified 90 kd polypeptide from SDS-polyacrylamide gels. Incorporation of the 90 kd B" protein into the transcription complex requires TBP. The heparin-resistant TFIIIB-DNA complex retains all three of its constituent proteins, TBP, BRF, and B".


A Drosophila model for xeroderma pigmentosum and Cockayne's syndrome: haywire encodes the fly homolog of ERCC3, a human excision repair gene. The haywire gene of Drosophila encodes a protein with 66% identity to the product of the human ERCC3 gene, associated with xeroderma pigmentosum B (XP-B) and Cockayne's syndrome (CS). XP is a human autosomal recessive disease characterized by extreme sensitivity to ultraviolet irradiation and marked susceptibility to skin cancer. In addition, XP and CS patients often exhibit a variety of defects, ranging from central nervous system disorders to hypogonadism. Phenotypes of haywire mutants mimic some of the effects of XP. Many haywire alleles are recessive lethal, viable alleles cause ultraviolet sensitivity, and files expressing marginal levels of haywire display motor defects and reduced life span. Progeny of females carrying a maternal effect allele show central nervous system defects.


Collagenase expression in the lungs of transgenic mice causes pulmonary emphysema. Transgenic mice were generated that expressed a human collagenase transgene in their lungs under the direction of the haptoglobin promoter. Histological analysis demonstrated disruption of the alveolar walls and coalescence of the alveolar spaces with no evidence of fibrosis or inflammation. This pathology is strikingly similar to the morphological changes observed in human emphysema and therefore implicates interstitial collagenase as a possible etiological agent in the disease process. Although elastase has been proposed as the primary enzyme responsible for emphysematous lung damage, this study provides evidence that other extracellular matrix proteases could play a role in emphysema. In addition, these transgenic mice are a defined genetic animal model system to study the pathogenesis of emphysema.


Isolation of a stem cell for neurons and glia from the mammalian neural crest. We have isolated mammalian neural crest cells using a monoclonal antibody to the low affinity NGF receptor, and established conditions for the serial propagation of these cells in clonal culture to assess their developmental potential. This analysis indicates that, first, single mammalian neural crest cells are multipotent, able to generate at least neurons and Schwann cells like their avian counterparts. Second, multipotent neural crest cells generate multipotent progeny, indicating that they are capable of self-renewal and therefore are stem cells. Third, multipotent neural crest cells also generate some clonal progeny that form only neurons or glia, suggesting the production of committed neuroblasts and glioblasts. Manipulation of the substrate alters the fate of the multipotent cells. These findings have implications for models of neural crest development in vivo, and establish a system for studying the generation of cellular diversity by a multipotent stem cell in vitro.


Polymer-bound enzyme inhibitors: synthesis, properties, and physiological relevance. For the most part, the pharmacological effect of an enzyme inhibitor results from its interaction with a single target molecule--the target enzyme. In many cases, the inhibitor moiety can interact effectively with the enzyme without necessarily being released from the polymer carrier. In the simplest form, i.e., the inhibition of an extracellular enzyme, this interaction can be understood as being two macromolecules in a solution--a reaction that can be readily modeled in vitro. Thus, enzyme inhibitors are very suitable for preparing polymer-bound drugs for investigative purposes or therapeutical applications. The macromolecular properties of polymers impact on the pharmacokinetic behavior of the compound because of the controlled intercompartmental transport. The physiological significance of the polymer-bound enzyme inhibitors is considered herein regarding the factors controlling the biodistribution of polymers among the physiological compartments. Extracellular proteinases and lysosomal enzymes are the most easily approachable targets. Strategies for preparation of polymer-bound inhibitors are discussed.


Block copolymers as drug carriers.

Block copolymers as drug carriers. The main subject of this review is to describe the concept and strategy of utilizing block copolymers as drug carriers and to present a perspective for this utilization. The first section points out preferable properties of block copolymers as drug carriers with a brief survey on classifications and synthesis of block copolymers and specifies the merits of block copolymers for this purpose in the historical background of polymeric drug carriers. The second section introduces several studies using block copolymers as drug carriers. These studies contain surface modification of microspheres with block copolymers, polymeric micelles, and a conjugate of an antibody and block copolymer. In conclusion, it is determined that block copolymers possess a high potential for use as drug carriers irrespective of some difficulties in their synthesis.