[FTIR studies of compounds of 2-D networks]

Recently, there is increasing interest in the study of 2-D square network materials which have inner cavities as zeolites, expected to find applications in catalysis, sensor and absorbent. Here, the synthesis of two compounds of [[Cd(4,4'-bpy)2.2H2O](NO3)2.4H2O] and [[Cd(4,4'-bpy)2NO3H2O].NO3.(C13H11NO)2] have been reported. The FTIR spectra of those clusters and the structure-sensitive bands are studied.

Effects of prenatal exposure to cocaine on the developing brain: anatomical, chemical, physiological and behavioral consequences

Earlier studies of human infants and studies employing animal models had indicated that prenatal exposure to cocaine produced developmental changes in the behavior of the offspring. The present paper reports on the results obtained in a rabbit model of in utero exposure to cocaine using intravenous injections (4 mg/kg, twice daily) that mimic the pharmacokinetics of crack cocaine in humans. At this dose, cocaine had no effect on the body weight gain of dams, time to delivery, litter size and body weight or other physical characteristics of the offspring. In spite of an otherwise normal appearance, cocaine-exposed neonates displayed a permanent impairment in signal transduction via the D1 dopamine receptor in caudate nucleus, frontal cortex and cingulate cortex due to an uncoupling of the receptor from its associated Gs protein. This uncoupling in the caudate nucleus was shown to have behavioral consequences in that young or adult rabbits, exposed to cocaine in utero, failed to demonstrate amphetamine-elicited motor responses normally seen after activation of D1 receptors in the caudate. The cocaine progeny also demonstrated permanent morphological abnormalities in the anterior cingulate cortex due to uncoupling of the D1 receptor and the consequent inability of dopamine to regulate neurite outgrowth during neuronal development. Consistent with the known functions of the anterior cingulate cortex, adult cocaine progeny demonstrated deficits in attentional processes. This was reflected by impairment in discrimination learning during classical conditioning that was due to an inability to ignore salient stimuli even when these were not relevant to the task. The impairment in discrimination learning also occurred in an instrumental avoidance task and could be shown to be due to an impairment of cingulothalamic learning-related neuronal coding. It was proposed that the selective loss of D1-related neurotransmission in the anterior cingulate cortex prevented an appropriate activation of GABA neurons and thus a loss of inhibitory regulation that is necessary for processes involved in associative attention. Taken together, these findings suggest that the uncoupling of the D1 receptor from its G protein may be the fundamental source of the anatomic, cognitive and motor disturbances seen in rabbits exposed to cocaine in utero. Moreover, the long-term cognitive and motor deficits observed in the rabbit model are in agreement with the recent reports indicating that persistent attentional and other behavioral deficits may be evident in cocaine-exposed children as they grow older and are challenged to master more complex cognitive tasks.

Cost analysis of pancreatic carcinoma treatment

BACKGROUND

Pancreatic carcinoma is a major health issue and financial burden to society. To improve the quality and efficiency of care delivered, it is essential for health care providers to have a good understanding of the cost of treatment.

METHODS

The authors examined the facility-based costs and survival of 103 patients with pancreatic carcinoma who were treated at the Karmanos Cancer Institute between January 1992 and September 1998. Longitudinal cost data for each patient were obtained, and from those data, 6-month, 1-year, and lifetime total treatment costs were calculated.

RESULTS

The average 6-month, 1-year, and lifetime total treatment costs were $37,327, $42,218, and $48,803, respectively, and the median survival was 7 months. In univariate analyses, the disease stage at diagnosis was a highly significant predictor of total cost. Patients with metastatic disease had the lowest cost, and patients with resectable disease had the highest cost. In multivariate analyses controlling for disease stage, treatment strategies and dual insurance coverage were also important predictors of costs but patient age, race, and gender were not predictive. Disease stage also was highly predictive of survival. In a multivariate analysis controlling for disease stage, chemotherapy and radiation therapy were correlated with longer survival, whereas resection and palliative bypass surgery were not.

CONCLUSIONS

The costs of treating patients with pancreatic carcinoma are considerable, even though survival duration typically is short. Disease stage was the most dominating factor determining costs and survival. After controlling for disease stage, chemotherapy, surgery, and dual insurance coverage were also significantly associated with higher cost of care. However, in survival analyses, only chemotherapy and radiation therapy were associated with a significant increase in patient survival.

Phase II study of dolastatin-10 in patients with hormone-refractory metastatic prostate adenocarcinoma

Dolastatin-10 is a natural, cytotoxic peptide with microtubule-inhibitory and apoptotic effects. It has demonstrated in vitro and in vivo efficacy in the DU-145 human prostate cancer model. A Phase II clinical trial was designed in patients with hormone-refractory prostate cancer. Dolastatin-10 was administered at a dose of 400 microg/m2 i.v. every 3 weeks. Dose escalation to 450 microg/m2 was permitted. Toxicity evaluation was conducted every 2 weeks, and assessment of response was done at the end of every two cycles. Sixteen patients were enrolled between October 1998 to December 1999. The median age was 71 years (range, 59-79 years). Median prostate-specific antigen value was 108 ng/ml (range, 15.3-1672 ng/ml). Of the 15 eligible patients, 7 were Caucasian and 8 were African-American. Eight patients had bone-only metastases, and seven had measurable disease with or without bone metastases. A total of 56 cycles have been administered. Only 2 patients required dose adjustment because of toxicity, and in 5 patients, dose escalation was feasible to 450 microg/m2. The major toxicities observed were grade 3 and 4 neutropenia in 8 patients and grade 3 neuropathy in 1 patient. All 15 patients are evaluable for response. Three patients demonstrated stable disease; 2 of these had bone disease, and 1 had nodal metastasis. All others had disease progression. Dolastatin-10 is very well tolerated in this elderly, pretreated population but lacks significant clinical activity as a single agent.

Ssn6-Tup1 interacts with class I histone deacetylases required for repression

Ssn6-Tup1 regulates multiple genes in yeast, providing a paradigm for corepressor functions. Tup1 interacts directly with histones H3 and H4, and mutation of these histones synergistically compromises Ssn6-Tup1-mediated repression. In vitro, Tup1 interacts preferentially with underacetylated isoforms of H3 and H4, suggesting that histone acetylation may modulate Tup1 functions in vivo. Here we report that histone hyperacetylation caused by combined mutations in genes encoding the histone deacetylases (HDACs) Rpd3, Hos1, and Hos2 abolishes Ssn6-Tup1 repression. Unlike HDAC mutations that do not affect repression, this combination of mutations causes concomitant hyperacetylation of both H3 and H4. Strikingly, two of these class I HDACs interact physically with Ssn6-Tup1. These findings suggest that Ssn6-Tup1 actively recruits deacetylase activities to deacetylate adjacent nucleosomes and promote Tup1-histone interactions.

The novel silatecan 7-tert-butyldimethylsilyl-10-hydroxycamptothecin displays high lipophilicity, improved human blood stability, and potent anticancer activity

We describe the rational design and synthesis of B- and A, B-ring-modified camptothecins. The key alpha-hydroxy-delta-lactone pharmacophore in 7-tert-butyldimethylsilyl-10-hydroxycamptothecin (DB-67, 14) displays superior stability in human blood when compared with clinically relevant camptothecin analogues. In human blood 14 displayed a t(1/2) of 130 min and a percent lactone at equilibrium value of 30%. The tert-butyldimethylsilyl group renders the new agent 25-times more lipophilic than camptothecin, and 14 is readily incorporated, as its active lactone form, into cellular and liposomal bilayers. In addition, the dual 7-alkylsilyl and 10-hydroxy substitution in 14 enhances drug stability in the presence of human serum albumin. Thus, the net lipophilicity and the altered human serum albumin interactions together function to promote the enhanced blood stability. In vitro cytotoxicity assays using multiple different cell lines derived from eight distinct tumor types indicate that 14 is of comparable potency to camptothecin and 10-hydroxycamptothecin, as well as the FDA-approved camptothecin analogues topotecan and CPT-11. In addition, cell-free cleavage assays reveal that 14 is highly active and forms more stable top1 cleavage complexes than camptothecin or SN-38. The impressive blood stability and cytotoxicity profiles for 14 strongly suggest that it is an excellent candidate for additional in vivo pharmacological and efficacy studies.

The c-Myc-interacting adaptor protein Bin1 activates a caspase-independent cell death program

Cell death processes are progressively inactivated during malignant development, in part by loss of tumor suppressors that can promote cell death. The Bin1 gene encodes a nucleocytosolic adaptor protein with tumor suppressor properties, initially identified through its ability to interact with and inhibit malignant transformation by c-Myc and other oncogenes. Bin1 is frequently missing or functionally inactivated in breast and prostate cancers and in melanoma. In this study, we show that Bin1 engages a caspase-independent cell death process similar to type II apoptosis, characterized by cell shrinkage, substratum detachment, vacuolated cytoplasm, and DNA degradation. Cell death induction was relieved by mutation of the BAR domain, a putative effector domain, or by a missplicing event that occurs in melanoma and inactivates suppressor activity. Cells in all phases of the cell cycle were susceptible to death and p53 and Rb were dispensable. Notably, Bin1 did not activate caspases and the broad spectrum caspase inhibitor ZVAD.fmk did not block cell death. Consistent with the lack of caspase involvement, dying cells lacked nucleosomal DNA cleavage and nuclear lamina degradation. Moreover, neither Bcl-2 or dominant inhibition of the Fas pathway had any effect. In previous work, we showed that Bin1 could not suppress cell transformation by SV40 large T antigen. Consistent with this finding, we observed that T antigen suppressed the death program engaged by Bin1. This observation was interesting in light of emerging evidence that T antigen has roles in cell immortalization and human cell transformation beyond Rb and p53 inactivation. In support of a link to c-Myc-induced death processes, AEBSF, a serine protease inhibitor that inhibits apoptosis by c-Myc, potently suppressed DNA degradation by Bin1. Our findings suggest that the tumor suppressor activity of Bin1 reflects engagement of a unique cell death program. We propose that loss of Bin1 may promote malignancy by blunting death penalties associated with oncogene activation.

Can endothelial seeding enhance patency and inhibit neointimal hyperplasia? Experimental studies and clinical trial of endothelial seeded venous prostheses

BACKGROUND

Venous prostheses have poor long-term patency; to improve this situation, experimental studies have been carried out.

METHODS

Methods of endothelial cell harvesting, prosthetic seeding and implantation mainly in the inferior vena cava were studied in 127 dogs. Evaluations were conducted by angiography, gross appearance, light, scanning and transmission electron microscopic observations, histo-fluorescent staining, as well as radioimmunoassay.

RESULTS

It was found that at five to ten days following implantation, the prosthetic endothelialisation could be reliably achieved in the seeded group and a 100% patency of the seeded inferior vena caval prostheses was attained at 100 days. The thickness of the neointima in the seeded group at 10 and 100 days was 299 microm and 302 microm, respectively. The metabolite of PGI2 from extrinsic arachidonic acid, 6-keto PGF1a, produced by cells from seeded graft was significantly higher than that from spontaneously formed cells and the reverse found with thromboxane B2. A temporary (one week) distal (femoral) arteriovenous fistula enhanced graft patency. These results indicated that the early endothelialisation of grafts by seeding enhanced the patency and inhibited intimal hyperplasia of venous prostheses. The clinical outcome was impressively improved from our previous experience with ten of eleven venous grafts patent over a follow-up period of six to nine years. These might result from the realization of early endothelialisation and its cells derived from seeding being able to produce significantly more PGI2 and less thromboxane B2.

CONCLUSIONS

The endothelial cell seeding technique may bring us much closer to an ideal venous prosthesis.

Drosophila Cdk4 is required for normal growth and is dispensable for cell cycle progression

Complexes of D-type cyclins and cdk4 or 6 are thought to govern progression through the G(1) phase of the cell cycle. In Drosophila, single genes for Cyclin D and Cdk4 have been identified, simplifying genetic analysis. Here, we show that Drosophila Cdk4 interacts with Cyclin D and the Rb homolog RBF as expected, but is not absolutely essential. Flies homozygous for null mutations develop to the adult stage and are fertile, although only to a very limited degree. Overexpression of inactive mutant Cdk4, which is able to bind Cyclin D, does not enhance the Cdk4 mutant phenotype, confirming the absence of additional Cyclin D-dependent cdks. Our results indicate, therefore, that progression into and through the cell cycle can occur in the absence of Cdk4. However, the growth of cells and of the organism is reduced in Cdk4 mutants, indicating a role of D-type cyclin-dependent protein kinases in the modulation of growth rates.

Functional parathyroid hormone receptors are present in an umbilical vein endothelial cell line

Acute parathyroid hormone exposure induces vascular smooth muscle relaxation. In contrast, continuous infusion of parathyroid hormone leads to vasoconstriction and an elevation of blood pressure. Despite the known effects of parathyroid hormone on vascular smooth muscle, possible direct effects on the vascular endothelium have not previously been investigated. Using a human umbilical vein endothelial cell line, we found that parathyroid hormone increased both intracellular calcium and cellular cAMP content in these endothelial cells. Furthermore, exposure of these cells to increasing concentrations of parathyroid hormone stimulated both [(3)H]thymidine incorporation and endothelin-1 secretion. Parathyroid hormone/parathyroid hormone-related peptide receptor mRNA could be detected at low levels in these cells. In summary, these data demonstrate that endothelium-derived cells contain functional parathyroid hormone receptors. The potential physiological role of these receptors remains to be determined.

Synergistic inhibitor binding to Streptococcus pneumoniae 5-enolpyruvylshikimate-3-phosphate synthase with both monovalent cations and substrate

The inhibitor binding synergy mechanism of the bi-substrate enzyme Streptococcus pneumoniae 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) has been investigated with a linkage thermodynamics strategy, involving direct binding experiments of one ligand conducted over a range of concentration of the other. The results demonstrate that binding of the inhibitor glyphosate (GLP) is highly synergistic with both a natural substrate shikimate-3-phosphate (S3P) and activating monovalent cations. The synergy between GLP and S3P binding was determined to be 1600-fold and is in qualitative agreement with previous work on Escherichia coli EPSPS. The binding molar ratios of S3P and GLP were measured as 1.0 and 0.7 per EPSPS, respectively. Monovalent cations that have been shown previously to stimulate S. pneumoniae EPSPS catalytic activity and its inhibition by GLP were found here to exhibit a similar rank-order with respect to their measured GLP binding synergies (ranging from 0 to > or =3000-fold increase in GLP affinity). The cation specificity and the sub-millimolar concentrations where these effects occur strongly suggest the presence of a specific cation binding site. Analytical ultracentrifugation data ruled out GLP-binding synergy mechanisms that derive from, or are influenced by, changes in oligomerization of S. pneumoniae EPSPS. Rather, the data are most consistent with an allosteric mechanism involving changes in tertiary structure. The results provide a quantitative framework for understanding the inhibitor binding synergies in S. pneumoniae EPSPS and implicate the presence of a specific cation binding regulatory site. The findings will help to guide rational design of novel antibiotics targeting bacterial EPSPS enzymes.

Cisplatin, cytarabine, caffeine, and continuously infused 5-fluorouracil (PACE) in the treatment of advanced pancreatic carcinoma: a phase II study

Encouraging results using cisplatin, cytarabine, and caffeine for the treatment of pancreatic carcinoma prompted a phase II study using these agents and adding continuous intravenous infusion (CI) 5-fluorouracil (5-FU) (PACE). Patients with advanced pancreatic adenocarcinoma who had not received prior cytotoxic therapy were eligible. Treatment consisted of the following: on day 1, the administration of cisplatin 100 mg/m2 IV, cytarabine 2 g/m2 IV every 12 hours x 2 doses, and caffeine 400 mg/m2 subcutaneously after each cytarabine dose; and on days 3 to 21, 5-FU 250 mg/m2/day given by CI. Cycles were repeated every 28 days. Thirty eligible patients were entered in the study. The median number of cycles received was three. Grade IV neutropenia and thrombocytopenia occurred in 53% and 27% of patients, respectively. Among 30 treated patients, complete remission (CR) was seen in 2 patients and partial remission (PR) in 3 patients, for an overall response rate of 16.7% (95% confidence interval 6.8-32.4%). The median survival was 5.0 months (range: 0.3-32.4 months) and 16.7% and 10% of patients were alive at 1 and 2 years. respectively. Changes in the serum level of CA 19-9 provided an early marker of response which translated in differences in survival. Those with increasing or decreasing/stable levels of CA 19-9 after the first cycle of therapy had median survivals of 1.7 and 8.3 months, respectively (p = 0.0002). Although PACE chemotherapy produced durable responses in pancreatic cancer, the toxicity was substantial. A modification of this regimen with newer, less toxic drugs may provide better results and reduced toxicity. Also, the monitoring of the serum CA 19-9 level may provide a means to assess response and predict survival.

Two active forms of UDP-N-acetylglucosamine enolpyruvyl transferase in gram-positive bacteria

Gene sequences encoding the enzymes UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) from many bacterial sources were analyzed. It was shown that whereas gram-negative bacteria have only one murA gene, gram-positive bacteria have two distinct genes encoding these enzymes which have possibly arisen from gene duplication. The two murA genes of the gram-positive organism Streptococcus pneumoniae were studied further. Each of the murA genes was individually inactivated by allelic replacement. In each case, the organism was viable despite losing one of its murA genes. However, when attempts were made to construct a double-deletion strain, no mutants were obtained. This indicates that both genes encode active enzymes that can substitute for each other, but that the presence of a MurA function is essential to the organism. The two genes were further cloned and overexpressed, and the enzymes they encode were purified. Both enzymes catalyzed the transfer of enolpyruvate from phosphoenolpyruvate to UDP-N-acetylglucosamine, confirming they are both active UDP-N-acetylglucosamine enolpyruvyl transferases. The catalytic parameters of the two enzymes were similar, and they were both inhibited by the antibiotic fosfomycin.

[The research development of single nucleotide polymorphism]

Single nucleotide polymorphism(SNP) is a novel set of polymorphism based on the single nucleotide variations at the genomic level, which distributes widely across the human genome and has high polymorphism information content (PIC). Now, tens of thousands SNPs have been discovered among the human genome and are introduced by many biological medicine networks. With the development of identification and analysis technique for SNP, especially the combination with DNA chips, they, as the third generation of genetic markers, are gradually fitable for fine-scale mapping of diseases, especially the complex diseases susceptibility genes and will eventually substitute for the most commonly used microsatellite markers presently.

RhoB alteration is necessary for apoptotic and antineoplastic responses to farnesyltransferase inhibitors

Farnesyltransferase inhibitors (FTIs) are in clinical trials, but how they selectively inhibit malignant cell growth remains uncertain. One important player in this process appears to be RhoB, an endosomal Rho protein that regulates receptor trafficking. FTI treatment elicits a gain of the geranylgeranylated RhoB isoform (RhoB-GG) that occurs due to modification of RhoB by geranylgeranyltransferase I in drug-treated cells. Notably, this event is sufficient to mediate antineoplastic effects in murine models and human carcinoma cells. To further assess this gain-of-function mechanism and determine whether RhoB-GG has a necessary role in drug action, we examined the FTI response of murine fibroblasts that cannot express RhoB-GG due to homozygous deletion of the rhoB gene. Nullizygous (-/-) cells were susceptible to cotransformation by adenovirus E1A plus activated H-Ras but defective in their FTI response, despite complete inhibition of H-Ras prenylation. Actin cytoskeletal and phenotypic events were disrupted in -/- cells, implicating RhoB-GG in these effects. Interestingly, -/- cells were resistant to FTI-induced growth inhibition under anchorage-dependent but not anchorage-independent conditions, indicating that, while RhoB-GG is sufficient, it is not necessary for growth inhibition under all conditions. In contrast, -/- cells were resistant to FTI-induced apoptosis in vitro and in vivo. Significantly, the apoptotic defect of -/- cells compromised the antitumor efficacy of FTI in xenograft assays. This study offers genetic proof of the hypothesis that RhoB-GG is a crucial mediator of the antineoplastic effects of FTIs.

Weekly 1-hour infusion of paclitaxel. Clinical feasibility and efficacy in patients with hormone-refractory prostate carcinoma

BACKGROUND

Preclinically, paclitaxel given according to an intense bolus schedule has significant antitumor activity against human prostate carcinoma cell lines in SCID mice. The authors evaluated the feasibility and efficacy of weekly 1-hour infusion of paclitaxel in patients with metastatic hormone-refractory prostate carcinoma (HRPC).

METHODS

A total of 18 patients with progressive metastatic HRPC were enrolled. Patients had to have no prior chemotherapy. Paclitaxel was infused weekly at a dose of 150 mg/m(2) over 1 hour for 6 weeks every 8 weeks.

RESULTS

Eighteen patients with a median age of 68.5 years and a median prostate specific antigen (PSA) level of 82 ng/mL (range, 2.17-3196 ng/mL) were enrolled. The median number of prior hormone treatments was 2, and 12 patients on antiandrogens completed antiandrogen withdrawal. Ten of eighteen patients had bone-only metastasis and eight had metastasis to bone with lymph node and/or visceral metastasis. Seventeen patients received a total of 31 cycles (157 courses) and 1 patient refused chemotherapy. All patients were included in response evaluation. Of the 8 [corrected] patients with measurable disease, 4 achieved a major response, with 1 complete response (in the lung) and 3 partial responses (1 in the liver and 2 in the lymph nodes). Seven of eighteen patients (39%) had a PSA decline of >/=50%. The major high grade toxicity was peripheral neuropathy, with 6 patients (35%) developing Grade 3 toxicity.

CONCLUSIONS

Weekly 1-hour paclitaxel has activity in patients with HRPC. The major toxicity is peripheral neuropathy. The minimal myelosuppressive effects make a modified schedule (lower doses on the same schedule or a shorter schedule of the same dose) attractive for future combination chemotherapy trials.

Overlapping roles for the histone acetyltransferase activities of SAGA and elongator in vivo

Elp3 and Gcn5 are histone acetyltransferases (HATs) that function in transcription as subunits of Elongator and SAGA/ADA, respectively. Here we show that mutations that impair the in vitro HAT activity of Elp3 confer typical elp phenotypes such as temperature sensitivity. Combining an elp3Delta mutation with histone H3 or H4 tail mutations confers lethality or sickness, supporting a role for Elongator in chromatin remodelling in vivo. gcn5Deltaelp3Delta double mutants display a number of severe phenotypes, and similar phenotypes result from combining the elp mutation with mutation in a gene encoding a SAGA-specific, but not an ADA-specific subunit, indicating that Elongator functionally overlaps with SAGA. Because concomitant active site alterations in Elp3 and Gcn5 are sufficient to confer severe phenotypes, the redundancy must be specifically related to the HAT activity of these complexes. In support of this conclusion, gcn5Deltaelp3Delta phenotypes are suppressed by concomitant mutation of the HDA1 and HOS2 histone deacetylases. Our results demonstrate functional redundancy among transcription-associated HAT and deacetylase activities, and indicate the importance of a fine-tuned acetylation-deacetylation balance during transcription in vivo.

Associative learning is enhanced by selective neuronal nitric oxide synthase inhibitors and retarded by a nitric oxide donor in the rabbit

RATIONALE

Previous studies had reported that the nitric oxide (NO) donor, sodium nitroprusside (SNP), retarded and the non-specific NO synthase (NOS) inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME), enhanced acquisition of classically conditioned responses (CRs). These effects of IV SNP and IP L-NAME on CR acquisition occurred in the absence of any effect on non-associative processes or performance variables and at a time when there were no alterations in blood pressure or heart rate.

OBJECTIVES

In this study, we examined whether the changes in associative learning produced by L-NAME and SNP were due to their central effects on NO content of brain. To this end, we examined the effects of the selective neuronal NOS inhibitors 7-nitroindazole (7-NI) and AR-R 17477 and the effects of central (ICV) administration of the NO donor SNP on learning.

METHODS

Effects of drugs on CR acquisition were determined during classical conditioning of the rabbit's nictitating membrane (NM) response. Explicitly unpaired presentations of conditioned stimuli (CSs) and unconditioned stimuli (USs) were employed to measure non-associative levels of responding and unconditioned response (UR) topography.

RESULTS

The SC injection of 7-NI and AR-R 17477 significantly enhanced associative learning while ICV administration of SNP significantly retarded learning.

CONCLUSION

Production of NO within the brain by neuronal NOS normally acts to retard associative learning presumably by decreasing excitability within neuronal circuits involved in the acquisition of the classically conditioned NM reflex.

Cardiac sequelae of doxorubicin and paclitaxel as induction chemotherapy prior to high-dose chemotherapy and peripheral blood progenitor cell transplantation in women with high-risk primary or metastatic breast cancer

Doxorubicin plus paclitaxel has been shown to be an active regimen for metastatic breast cancer and is now frequently used as adjuvant therapy for high-risk primary breast cancer. Initial studies reported a higher than expected rate of cardiac toxicity with this regimen. We studied 105 patients with either high-risk primary breast cancer or metastatic breast cancer who were treated with doxorubicin (60 mg/m2) and 3-h infusions of paclitaxel (175 mg/m2) cycled every 3 weeks. Patients received three cycles of chemotherapy for high-risk primary or four cycles for metastatic disease. Patients then proceeded to high-dose chemotherapy (HDC) (STAMP I cyclophosphamide, cisplatin and carmustine) and peripheral blood progenitor cell transplantation (PBPCT). Patients underwent radionuclide multi-gated angiograms (MUGA) before and following induction chemotherapy and following HDC. During induction chemotherapy 40 (38%) of the patients had a reduction in left ventricular ejection fraction (LVEF). Fourteen had a decrease of 20% or greater and two were mildly symptomatic from CHF. There was additional reduction in the LVEF after HDC with a median value for LVEF of 59% (range, 20-78%). During HDC 10 patients developed clinical signs of congestive heart failure (CHF). Five patients responded to diuretic therapy and did not require any additional treatment. Four patients responded to vasodilation and/or digoxin with improvement in cardiac function. A clinically significant decrease in cardiac function was found in a small number of patients after induction chemotherapy and HDC with PBPCT. The majority of the patients tolerated this regimen without problems. Although there was a decline in LVEF as measured by radionuclide MUGA this did not prevent the majority of patients from proceeding with HDC. Bone Marrow Transplantation (2000).

Expression of fibronectin receptor, integrin alpha 5 beta 1 of hepatic stellate cells in rat liver fibrosis

OBJECTIVE

To investigate the role of fibronectin (FN) receptor alpha 5 beta 1 in liver fibrosis.

METHODS

Northern blot analysis and immunohistochemical techniques were used to observe changes in the expression of FN and FN receptor alpha 5 beta 1 on hepatic stellate cells (HSCs) in vivo and in vitro of rat liver fibrosis induced by CCl4.

RESULTS

(1) alpha 5 beta 1 was mainly detected in the endothelia and some of the desmin(DM) positive cells of the sinusoids in normal rat liver. The expression of alpha 5 beta 1 of DM positive cells detected by immunohistochemistry reached its peak at the 10th week of the experiment. The changes in FN expression were similar to that of alpha 5 beta 1. (2) The expression of FN, alpha 5 and beta 1 mRNAs in the experimental group was remarkably increased especially at the 6th week, compared to that of normal liver specimens. The expression of the three mRNAs of HSCs in vitro isolated from the experimental group (6 weeks) was higher than those from normal liver. (3) The expression of FN, alpha 5 and beta 1 mRNAs increased in normal rat HSCs after treatment with transforming growth factor-beta 1 (TGF-beta 1) for 2 hours. After 4 hours of treatment, the expression of the three mRNAs fell to levels similar to the control group. Immunocytochemistry revealed that the expression of alpha 5 beta 1 of HSCs reached its peak after 4 hours of treatment with TGF-beta 1 and dropped to normal 2 hours later.

CONCLUSION

These data suggest that HSCs normally express FN receptor alpha 5 beta 1. The activation of HSCs during liver fibrogenesis leads to an increase of FN, alpha 5 and beta 1 mRNA expression. The expression of FN and alpha 5 beta 1 of HSCs in vitro is up-regulated by TFG-alpha 5 beta 1. The detection of gene transcription of FN and its receptor by Northern blot analysis suggests the activation and proliferation of HSCs and thereby provides a sensitive signal of liver fibrosis.

[Determination of O6-methylguanine by high performance capillary zone electrophoresis]

In this paper, a method to determine O6-methylguanine in urine by high performance capillary zone electrophoresis has been established. O6-methylguanine was directly introduced into the capillary employing sodium borate at pH 9.0 as buffer. The capillary used was 75 microns i.d. x 57 cm. The calibration curve showed good linearity, r = 0.9987, CVs were 1.51% for intra-day and 1.93% for inter-day. The average recovery was 98.2%. In conclusion, this method is a simple, rapid, precise and reliable technique for O6-methylguanine measurement in urine.

[Antibody to human herpesvirus type-8 in the general populations of Xinjiang Autonomous Region(A.R.)]

OBJECTIVE

Kaposi 's sarcoma (KS) does not rarely occur in Xinjiang A. R. Much of the evidence show that human herpes virus-8 (HHV-8) is associated with KS, and the different incidence of classic KS among different countries reflects the different prevalence in general populations. The aim of this study was to know whether the prevalence of HHV-8 is higher in general populations of Xinjiang than the other places of the country.

METHODS

We used BCBL-1 cell line as antigen and collected 1071 serum sample of different nationalities (Uighur, Khalkhas, Kazak and Han nationality) from south and north regions of Xinjiang A. R. for detection of HHV-8 IgG antibody by IFA.

RESULTS

The results showed that HHV-8 IgG antibody positive rate in Khalkhas was 48% (96/200), Uighur 30.4%(62/204), Kazak 12.5% (25/200) and Han 16.9% (79/467). While sera were diluted in 1:20, the positive rate in Khalkhas still was as high as 30.5% (61/200). In addition, the positive rate of HHV-8 IgG antibody in minorities in the same native area all were higher than Han except Kazak nationality.

CONCLUSIONS

These data illustrated that the prevalence of HHV-8 IgG antibody in general populations of different nationality was different, Khalkhas and Uighur were higher than Kazak and Han. Most of the KS cases were reported from Uighur nationality, but no case was reported from Khalkhas thought a highest HHV-8 IgG antibody detection rate (48%) there was demonstrated. The reason for it would be further studied.

Assessment of carotid artery invasion in patients with head and neck cancer

PURPOSE

Define radiological and histological features in which patients with head and neck cancer would benefit from a carotid artery resection. Resection of the carotid artery has been advocated for local control of advanced squamous cell carcinoma of the head and neck. To provide appropriate preoperative counseling and optimize the utilization of resources, the criteria for patient selection has to be defined.

METHODS

Thirty-four patients underwent carotid artery resection based on the clinical impression of tumor fixation. Eighteen and 28 patients were evaluated using computed tomography (CT) and histological analysis, respectively. The distance between the tumor cells and external elastic lamina was measured. CT scans were examined to determine the circumference of tumor attachment around the carotid artery.

RESULTS

Clinical assessment predicted tumor within 1.8 mm of the carotid artery in 68% of cases. The overall survival for patients with tumor greater than 1.8 mm (N = 9) was better than that of patients with less (N = 19) than 1.8 mm (33.3% vs. 5.3%; median 24 versus 9 mo, P = .0899). Three of six patients (50%) with less than 180 degrees circumference tumor attachment had tumor within 1.8 mm from the external elastic lamina. Eight of twelve patients (67%) with tumors encompassing more than 180 degrees of the artery wall had tumor within 1.8 mm from the external elastic lamina. The overall survival rates for patients with tumor attachment greater and less than 180 degrees were 8.3% and 33%, respectively.

DISCUSSION

Tumor invasion into the carotid artery was the strongest predictor of outcome. Clinical assessment was as predictive as CT for tumor invasion. If tumor involvement of the carotid artery is less than 180 degrees, peeling the tumor is an alternative to carotid artery resection.

beta-Lactamase epidemiology and the utility of established and novel beta-lactamase inhibitors

beta-Lactamase inhibitor:beta-lactam combinations remain one of the most successful strategies for the treatment of bacterial infections. Over the last 20 years the number and diversity of serine and metallo active site beta-lactamases has increased dramatically. This review highlights some of the new additions to the beta-lactamase arena and discusses how the commercially available beta-lactamase inhibitors are keeping pace with the changing epidemiology of beta-lactamases. In addition, we survey the progress with the design of novel inhibitors of serine and metallo-beta-lactamases. Focus is given to the recent advances in the design of metallo-beta-lactamase inhibitors as these enzymes pose a serious emerging threat to the use of all beta-lactam based therapies.

[Determination of kalium in husked seed food by suspension sampling-flame atomic emission spectrometry]

Suspension sampling technique was applied to flame atomic emission spectrometry and Kalium in husked rice, millet and husked Kaoliang successfully determined. A new method for rapid determination of kalium was developed. The samples were grinded and then made into agar suspension. NaCl solution was added to an appropriate amount of suspension for eliminating ionijation interference, and test solution prepared. The test solution was injected into air-acetylene flame. The working curve method was used for the determination. Results were consistent with those obtained by ashing method. RSD < 3.0%. Relative error of the two methods was less than +/- 1.8%. The t-test showed that no difference was found. This method is convenient, rapid and accurate.

Suppression of the rbf null mutants by a de2f1 allele that lacks transactivation domain

In mammals, a large number of proteins including E2F transcription factors have been shown to interact with the tumor suppressor gene product pRB, but it is not clear to what extend the function of pRB is mediated by E2F. In addition, E2F was shown to mediate both transcription activation and repression; it remains to be tested which function of E2F is critical for normal development. Drosophila homologs of the RB and E2F family of proteins RBF and dE2F1 have been identified. The genetic interactions between rbf and de2f1 were analyzed during Drosophila development, and the results presented here showed that RBF is required at multiple stages of development. Unexpectedly, rbf null mutants can develop until late pupae stage when the activity of dE2F1 is reduced, and can develop into viable adults with normal adult appendages in the presence of a de2f1 mutation that retains the DNA binding domain but lacks the transactivation domain. These results indicate that most, if not all, of the function of RBF during development is mediated through E2F. In turn, the genetic interactions shown here also suggest that dE2F1 functions primarily as a transcription activator rather than a co-repressor of RBF during Drosophila development. Analysis of the expression of an E2F target gene PCNA in eye discs showed that the expression of PCNA is activated by dE2F1 in the second mitotic wave and repressed in the morphogenetic furrow and posterior to the second mitotic wave by RBF. Interestingly, reducing the level of RBF restored the normal pattern of cell proliferation in de2f1 mutant eye discs but not the expression of E2F target genes, suggesting that the coordinated transcription of E2F target genes does not significantly affect the pattern of cell proliferation.

Simulation modeling of nuclear steam generator water level process--a case study

Simulation modeling of the nuclear steam generator (SG) water level process in Qinshan Nuclear Power Plant (QNPP) is described in this paper. A practical methodology was adopted so that the model is both simple and accurate for control engineering implementation. The structure of the model is in the form of a transfer function, which was determined based on first-principles analysis and expert experience. The parameters of the model were obtained by taking advantage of the recorded historical response curves under the existing closed-loop control system. The results of process dimensional data verification and experimental tests demonstrate that the simulation model depicts the main dynamic characteristics of the SG water level process and is in accordance with the field recorded response curves. The model has been successfully applied to the design and test of an advanced digital feedwater control system in QNPP.

Characterization of Streptococcus pneumoniae 5-enolpyruvylshikimate 3-phosphate synthase and its activation by univalent cations

The aroA gene (Escherichia coli nomenclature) encoding 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase from the gram-positive pathogen Streptococcus pneumoniae has been identified, cloned and overexpressed in E. coli, and the enzyme purified to homogeneity. It was shown to catalyze a reversible conversion of shikimate 3-phosphate (S3P) and phosphoenolpyruvate (PEP) to EPSP and inorganic phosphate. Activation by univalent cations was observed in the forward reaction, with NH+4, Rb+ and K+ exerting the greatest effects. Km(PEP) was lowered by increasing [NH+4] and [K+], whereas Km(S3P) rose with increasing [K+], but fell with increasing [NH+4]. Increasing [NH+4] and [K+] resulted in an overall increase in kcat. Glyphosate (GLP) was found to be a competitive inhibitor with PEP, but the potency of inhibition was profoundly affected by [NH+4] and [K+]. For example, increasing [NH+4] and [K+] reduced Ki(GLP versus PEP) up to 600-fold. In the reverse reaction, the enzyme catalysis was less sensitive to univalent cations. Our analysis included univalent cation concentrations comparable with those found in bacterial cells. Therefore, the observed effects of these metal ions are more likely to reflect the physiological behavior of EPSP synthase and also add to our understanding of how to inhibit this enzyme in the host organism. As there is a much evidence to suggest that EPSP synthase is essential for bacterial survival, its discovery in the serious gram-positive pathogen S. pneumoniae and its inhibition by GLP indicate its potential as a broad-spectrum antibacterial target.

The kinetic mechanism of 5-enolpyruvylshikimate-3-phosphate synthase from a gram-positive pathogen Streptococcus pneumoniae

The Streptococcus pneumoniae 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase is a potential novel antibacterial target. The enzyme catalyzes a reversible transfer of an enolpyruvyl group from phospho(enol)pyruvate (PEP) to shikimate 3-phosphate (S3P) to give EPSP with the release of inorganic phosphate (Pi). Understanding the kinetic mechanism of this enzyme is crucial to the design of novel inhibitors of this enzyme that may have potential as antibacterial agents. Steady-state kinetic studies of product inhibition and inhibition by glyphosate (GLP) have demonstrated diverse inhibition patterns of the enzyme. In the forward reaction, GLP is a competitive inhibitor with respect to PEP, but an uncompetitive inhibitor relative to S3P. Product inhibition shows that EPSP is a competitive inhibitor versus both PEP and S3P, suggesting that the forward reaction follows a random sequential mechanism. In the reverse reaction, GLP is an uncompetitive inhibitor versus EPSP, but a noncompetitive inhibitor versus Pi. This indicates that a non-productive quaternary complex might be formed between the enzyme, EPSP, GLP and Pi. Product inhibition in the reverse reaction has also been investigated. The inhibition patterns of the S. pneumoniae EPSP synthase are not entirely consistent with those of EPSP synthases from other species, indicating that EPSP synthases from different organisms may adopt unique mechanisms to catalyze the same reactions.

Paclitaxel, cisplatin, and 5-fluorouracil for patients with advanced or recurrent squamous cell carcinoma of the head and neck

BACKGROUND

The combination of cisplatin and 5-fluorouracil (5-FU) is considered standard therapy for patients with recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN). Paclitaxel has exhibited single-agent activity in patients with this disease. The authors conducted this study to evaluate the feasibility and efficacy of combining paclitaxel with cisplatin and 5-FU for patients with advanced or recurrent SCCHN.

METHODS

Patients with recurrent, metastatic, or locally advanced SCCHN who had measurable or evaluable disease and no prior chemotherapy were eligible. The starting dose level consisted of paclitaxel 135 mg/m(2) on Day 1, cisplatin 75 mg/m(2) on Day 2, and 5-FU 1 gm/m(2)/day on Days 2-6. Due to Grade 4 mucositis, dose level 1 of 5-FU was reduced to 800 mg/m(2)/day on Days 2-6 (for 7 patients), and subsequently the 5-FU dose was adjusted to 1 gm/m(2)/day on Days 2-5 (for 17 patients).

RESULTS

Twenty-five patients were enrolled, with a median age of 60 years and a median Southwest Oncology Group performance status of 1. Of the 25 patients, 16 had recurrent disease, 3 had metastatic disease at diagnosis, and 6 had untreated locally advanced SCCHN. Ninety-nine courses of therapy were administered, with a median of 5 courses. Major toxicities were neutropenia and mucositis. Significant neurotoxicity or nephrotoxicity were not observed. There were two treatment-related deaths (one each due to mucositis and neutropenic pneumonia), and these precluded further dose escalation. Fifteen of the 25 patients (60%) achieved a major response. Of significance is the response rate of 58% (11 of 19 patients) in those with recurrent or metastatic disease who had a duration of response ranging from 3 to 19+ months. Two of these 19 patients continue to be in remission of 19+ and 15+ months' duration, respectively. The median survival for patients with recurrent or metastatic disease was 6 months (range, 1-26 months), with a 1-year survival rate of 37%.

CONCLUSIONS

The dose and schedule for the combination of paclitaxel, 5-FU, and cisplatin as determined in this study are feasible, with encouraging outcomes and activity in patients with recurrent or metastatic SCCHN. The results of this trial warrant larger-scale evaluation to determine the role of this combination in the management of patients with this disease.

Geranylgeranylated RhoB mediates suppression of human tumor cell growth by farnesyltransferase inhibitors

Farnesyltransferase inhibitors (FTIs) are in clinical trials, but their mechanism of action is not fully understood. We have shown that FTI treatment rapidly elevates the level of geranylgeranylated RhoB in cells and that this event is sufficient to inhibit cell cycle transit and reverse malignant transformation without affecting normal cells. However, because these observations were made in rodent fibroblast models in which transformation was driven by defined genetic alterations, it remained to be established whether RhoB-GG was relevant to the antineoplastic effects of FTIs in human epithelial tumor cells with diverse genetic backgrounds. In this study, we show that elevated levels of RhoB-GG are sufficient to block the proliferation of FTI-sensitive but not FTI-resistant human carcinoma cells. RhoB-GG induced the cell cycle kinase inhibitor p21(WAF1) in a p53-dependent manner, similar to FTI treatment, but this event was dispensable because RhoB-GG could still inhibit the growth of p53-null cells that lacked p21WAF1 activation. Consistent with actions beyond G1-phase arrest, certain cell lines exhibited accumulation in G2-M phase or an increased apoptotic index in response to RhoB-GG. We concluded that RhoB-GG suppressed human tumor cell proliferation by more than one mechanism and that it promoted apoptosis as well as inhibited cell cycle transit in malignant epithelial cells. These findings suggest how FTIs suppress the growth of human tumor cells that lack Ras mutations.

Multidrug resistance phenotype in high grade soft tissue sarcoma: correlation of P-glycoprotein immunohistochemistry with pathologic response to chemotherapy

BACKGROUND

P-glycoprotein-mediated drug efflux has been implicated as an important mechanism of multidrug resistance (MDR) in cancer. Its role in chemotherapy resistance in soft tissue sarcoma is unclear.

METHODS

Tumor specimens prior to and following neoadjuvant chemotherapy from 29 cases of high grade soft tissue sarcoma were analyzed with 2 monoclonal antibodies (C494 and JSB-1) that recognize different epitopes of P-glycoprotein. Staining intensity was graded 0 = negative, 1 = equivocal, 2 = moderate, 3 = strong. Only cases with Grade 2 or 3 staining intensity with both antibodies were considered MDR positive. The resection specimens were evaluated for tumor necrosis postchemotherapy. Pathologic response was graded as good for <15%, moderate for 15-50%, or poor for >50% posttreatment tumor viability.

RESULTS

Of the 29 pretreatment specimens, 10 (34%) were MDR positive and 19 (66%) were MDR negative. Pathologic response to treatment was characterized as good in 6, moderate in 7, and poor in 16 patients. Of the MDR positive biopsies, 9 (90%) had poor response, compared with 7 (36%) in the MDR negative biopsy group (P = 0.0078). None of the cases with MDR positive biopsies had a good response, compared with 6 cases in which biopsies were MDR negative (32%) (P = 0.057). Only one MDR negative case became MDR positive posttreatment.

CONCLUSIONS

Expression of MDR phenotype is found in approximately one-third of high grade soft tissue sarcomas. These preliminary data show a significant correlation between MDR phenotype and poor pathologic response to chemotherapy, and suggest that MDR induction by chemotherapy in soft tissue sarcoma is an uncommon event.

VEGF and VEGF type C play an important role in angiogenesis and lymphangiogenesis in human malignant mesothelioma tumours

The vascular endothelial growth factor (VEGF) family is a novel regulator of endothelial cell proliferation. We assessed the mRNA expression of VEGF, VEGF type C (VEGF-C) and their receptors together with the microvessel density (VD) and microlymphatic vessel density (LVD) in pursuit of their connection and prognostic value in malignant pleural mesothelioma (MPM). We used four human MPM cell lines, 54 MPM tumours and five normal pleural tissues. Expression levels for receptors and ligands were assessed by semiquantitative reverse transcriptase polymerase chain reaction analysis. Microvessels were highlighted by immunohistochemical staining for factor VIII. The discrimination of lymphatics was performed by enzyme-histochemistry for 5'-nucleotidase after adequate inhibition of non-specific activity. The expression levels of VEGF, VEGF-C and VEGFRs were high in all MPM cell lines. The percentages of tumours with higher expression compared to the mean values of normal pleural tissues were 31.5% (17/54) for VEGF, 66.7% (36/54) for VEGF-C, 20.4% (11/54) for fms-like tyrosine kinase (flt)-1, 42.6% (23/54) for kinase insert domain-containing recepter (KDR) and 59.3% (32/54) for flt-4. Significant positive correlations were found between VEGF-C and flt-4, VEGF and KDR, VEGF and flt-1 in tumour tissues. The association between LVD and VEGF-C expression level was especially strong (P< 0.0001, r= 0.63). There were also significant correlations between LVD and flt-4, and VD and VEGF. No correlation, however, was found between LVD and nodal metastasis. VD was a negative prognostic indicator in this study. The associations between VEGFNEGF-C and vessel density suggest that these factors play an important role in angiogenesis and lymphangiogenesis in this tumour, and assessment of vascularity may be a useful prognostic indicator for MPM patients.

Activation of the PI3'K-AKT pathway masks the proapoptotic effects of farnesyltransferase inhibitors

Farnesyltransferase inhibitors (FTIs) usually cause growth inhibition, but in certain preclinical settings they have been shown to induce apoptosis, a clinically desirable response. In this study, we show that the proapoptotic effects of FTIs in Ras-transformed cells are masked by activation of phosphatidylinositol 3'-kinase (PI3'K) or AKT, which are controlled by cytokines and integrins. The results implied that FTIs disrupt a signal that is crucial for survival of malignant cells, but not normal cells, if the PI3'K-AKT pathway is inactivated. Our findings have implications for clinical applications of FTIs where apoptotic responses would be preferred.

Mechanism for elimination of a tumor suppressor: aberrant splicing of a brain-specific exon causes loss of function of Bin1 in melanoma

Loss of tumor suppressors that restrain important oncoproteins such as c-Myc may contribute to malignant progression. Bin1 is an adapter protein with features of a tumor suppressor that was identified through its interaction with and inhibition of the oncogenic properties of c-Myc. In this study, we analyzed the patterns of Bin1 expression in normal melanocytes and melanoma cells at different stages of tumor progression. Evidence is provided that Bin1 function is abrogated in melanoma cells by a mechanism based on aberrant splicing of a tissue-specific exon. Specifically, most melanoma cells inappropriately expressed exon 12A, which is spliced alternately into Bin1 isoforms found in brain but not into isoforms found in melanocytes and many other nonneuronal cells. Exon 12A sequences abolished the ability of Bin1 to inhibit malignant transformation by c-Myc or adenovirus E1A. Similarly, these sequences abolished the ability of Bin1 to induce programmed cell death in melanoma cells that endogenously expressed exon 12A. Our findings suggest that aberrant splicing of Bin1 may contribute to melanoma progression, and they define a mechanism by which the activity of a tumor suppressor can be eliminated in cells.

Effects of prenatal cocaine exposure on amphetamine-induced dopamine release in the caudate nucleus of the adult rabbit

Acute amphetamine (AMPH) challenge has been used to probe the neurochemical and behavioral integrity of dopaminergic neurons under various conditions including prenatal cocaine exposure. In this study, we employed in vivo microdialysis to examine the effects of prenatal cocaine exposure on AMPH-induced dopamine (DA) release in the caudate nucleus of the awake adult rabbit. Pregnant rabbits were given intravenous injections of either saline or cocaine (4 mg/kg) twice a day from gestational day 8 (G8) through G29. Microdialysis was performed in adult saline and cocaine progeny at approximately postnatal day 70 (P70). There were no significant differences between cocaine and saline progeny in their basal concentrations of DA or its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA). AMPH (5 mg/kg, i.v.) significantly increased extracellular DA in the caudate of both groups. However, AMPH-induced DA release was 2 to 3-fold greater in cocaine progeny than in the saline controls. Although, DOPAC decreased in both groups following AMPH injection, there was no significant group effect. In addition, there were no significant changes in concentrations of HVA. AMPH is known to release DA by a mechanism of exchange diffusion via the presynaptic DA transporter (DAT). Therefore, we examined the binding of [(3)H]WIN 35,428 to membrane fractions prepared from fresh caudate tissue to determine whether prenatal exposure to cocaine had altered the density (B(max)) or affinity (K(d)) of the DAT. While the B(max) for [(3)H]WIN 35,428 binding increased 3-fold between P3 and P120, there were no significant differences between saline and cocaine progeny at any age examined. The K(d) for [(3)H]WIN 35,428 binding did not change with postnatal age and did not differ between cocaine and saline progeny. These findings suggest that prenatal exposure to cocaine produces a long-term increase in the size of the presynaptic, AMPH releasable, cytoplasmic pool of DA.

Bin1 functionally interacts with Myc and inhibits cell proliferation via multiple mechanisms

The tumor suppressor Bin1 was identified through its interaction with the N-terminal region of Myc which harbors its transcriptional activation domain. Here we show that Bin1 and Myc physically and functionally associate in cells and that Bin1 inhibits cell proliferation through both Myc-dependent and Myc-independent mechanisms. Bin1 specifically inhibited transactivation by Myc as assayed from artificial promoters or from the Myc target genes ornithine decarboxylase (ODC) and alpha prothymosin (pT). Inhibition of ODC but not pT required the presence of the Myc binding domain (MBD) of Bin1 suggesting two mechanisms of action. Consistent with this possibility, a non-MBD region of Bin1 was sufficient to recruit a repression function to DNA that was unrelated to histone deacetylase. Regions outside the MBD required for growth inhibition were mapped in Ras cotransformation or HepG2 hepatoma cell growth assays. Bin1 required the N-terminal BAR domain to suppress focus formation by Myc whereas the C-terminal U1 and SH3 domains were required to inhibit adenovirus E1A or mutant p53, respectively. All three domains contributed to Bin1 suppression of tumor cell growth but BAR-C was most crucial. These findings supported functional interaction between Myc and Bin1 in cells and indicated that Bin1 could inhibit malignant cell growth through multiple mechanisms.

[The relationship between IgA nephropathy and HBV infection]

OBJECTIVE

To clarify the correlation between hepatitis B virus (HBV) infection and the pathogenesis of IgA nephropathy.

METHODS

Ninety-one cases of primary IgA nephropathy were investigated by using in situ hybridization(HBV DNA), immunohistochemistry (HBAg) and HBV DNA-HBAg double staining techniques. In some of the cases, Southern blot analysis and serologic HBV infectious markers were detected also.

RESULTS

The positive rate of HBAg in renal tissue detected by immunohistochemistry was 69% (63/91) and that of the HBV DNA detected by in situ hybridization was 43% (39/91). Eighteen of 27 cases showed HBV DNA positive in Southern blot analysis, and all of the positive cases were identified to be the integrated form. Among them, 17 cases were HBAg detectable in renal tissue by immunohistochemistry and 16 cases were HBV DNA detectable by in situ hybridization simultaneously. The positive rate of the expression of HBcAg [77% (30/39)] and HBsAg [72% (28/39)] of the tubular epithelial cells with HBV DNA signals in nuclears by in situ hybridization was significantly higher than that of the cells without HBV DNA signals(10%, 21%). The double staining showed that most of the HBV DNA positive tubular epithelial cells coexpressed HBsAg and(or) HBcAg.

CONCLUSION

The renal tissue of some of IgA nephropathy infected with HBV directly and express HBAg in situ.

Elevation of alpha2(I) collagen, a suppressor of Ras transformation, is required for stable phenotypic reversion by farnesyltransferase inhibitors

Farnesyltransferase inhibitors (FTIs) are a novel class of anticancer drugs that can reverse Ras transformation. One of the intriguing aspects of FTI biology is that continuous drug exposure is not necessary to maintain phenotypic reversion. For example, after a single exposure to FTIs, Ha-Ras-transformed fibroblasts revert to a flat and anchorage-dependent phenotype that persists for many days after processed Ras has returned to pretreatment levels. In this study, we show that persistence of the reverted state is mediated by elevated expression of the collagen isoform alpha2(I), a suppressor of Ras transformation the transcription of which is repressed by activated Ras and derepressed by FTI treatment. To our knowledge, this is the first report identifying an FTI-regulated gene which is linked to phenotypic reversion. The finding that extracellular matrix alterations can influence the kinetics of reversion supports our assertion that Rho-regulated cell adhesion parameters are a crucial determinant of the cellular response to FTIs.

Prognostic significance of p53 gene mutations in laryngeal cancer

OBJECTIVE/HYPOTHESIS

We examined whether p53 gene mutations were predictive of clinical behavior in laryngeal cancer.

STUDY DESIGN

Retrospective study of 45 patients with laryngeal cancer from 1985 to 1997.

METHODS

DNA was extracted from tumor tissue and subject to polymerase chain reaction single-strand conformational polymorphism (PCR-SSCP) as well as DNA sequencing. The clinical outcome was correlated to the presence or absence of a p53 mutation.

RESULTS

The p53 gene was analyzed by direct DNA sequencing and was found to be mutated in 33% (15/45) of patients. The presence of a p53 mutation was associated with a significant improvement in overall survival (80% vs. 43%, P < .03) and a trend toward improved disease-free survival (87% vs. 60%, P = .08). When other prognostic factors were adjusted, multivariate analysis revealed a trend toward improvement in overall survival as well as disease-free survival.

CONCLUSION

Depending on the location of a p53 mutation, the suppressive functions or clinical outcome may or may not be affected. Fifty-three percent of mutations were detected in nonconserved regions as opposed to 17% as reported in colon cancer. In colon cancer, mutations in conserved regions of the p53 gene predicted a poorer survival, whereas nonconserved gene mutations were not predictive. In our group of patients. p53 mutations predicted a better prognosis, which may be due to a large proportion of mutations that lie within nonconserved areas. The predictive power of p53 gene mutations may depend on functional loss and inactivation of highly conserved areas and must be tested in a prospective trial.

Cell growth inhibition by farnesyltransferase inhibitors is mediated by gain of geranylgeranylated RhoB

Recent results have shown that the ability of farnesyltransferase inhibitors (FTIs) to inhibit malignant cell transformation and Ras prenylation can be separated. We proposed previously that farnesylated Rho proteins are important targets for alternation by FTIs, based on studies of RhoB (the FTI-Rho hypothesis). Cells treated with FTIs exhibit a loss of farnesylated RhoB but a gain of geranylgeranylated RhoB (RhoB-GG), which is associated with loss of growth-promoting activity. In this study, we tested whether the gain of RhoB-GG elicited by FTI treatment was sufficient to mediate FTI-induced cell growth inhibition. In support of this hypothesis, when expressed in Ras-transformed cells RhoB-GG induced phenotypic reversion, cell growth inhibition, and activation of the cell cycle kinase inhibitor p21WAF1. RhoB-GG did not affect the phenotype or growth of normal cells. These effects were similar to FTI treatment insofar as they were all induced in transformed cells but not in normal cells. RhoB-GG did not promote anoikis of Ras-transformed cells, implying that this response to FTIs involves loss-of-function effects. Our findings corroborate the FTI-Rho hypothesis and demonstrate that gain-of-function effects on Rho are part of the drug mechanism. Gain of RhoB-GG may explain how FTIs inhibit the growth of human tumor cells that lack Ras mutations.

The role of RBF in the introduction of G1 regulation during Drosophila embryogenesis

The first appearance of G1 during Drosophila embryogenesis, at cell cycle 17, is accompanied by the down-regulation of E2F-dependent transcription. Mutant alleles of rbf were generated and analyzed to determine the role of RBF in this process. Embryos lacking both maternal and zygotic RBF products show constitutive expression of PCNA and RNR2, two E2F-regulated genes, indicating that RBF is required for their transcriptional repression. Despite the ubiquitous expression of E2F target genes, most epidermal cells enter G1 normally. Rather than pausing in G1 until the appropriate time for cell cycle progression, many of these cells enter an ectopic S-phase. These results indicate that the repression of E2F target genes by RBF is necessary for the maintenance but not the initiation of a G1 phase. The phenotype of RBF-deficient embryos suggests that rbf has a function that is complementary to the roles of dacapo and fizzy-related in the introduction of G1 during Drosophila embryogenesis.

Accrual to breast cancer clinical trials at a university-affiliated hospital in metropolitan Detroit

Despite the large number of available studies, most women with breast cancer do not participate in clinical trials, and this is especially true among lower income and minority women. In this study the authors surveyed the practice patterns of four medical oncologists who comprised the clinical breast service at a large urban university hospital to develop a better understanding of the clinical trials enrollment process for women with breast cancer. Of 136 new female breast cancer patients seen by the four physicians over a 7-month period, there were 47 women (34%) offered participation in a clinical trial, and 16 women (12%) were eventually enrolled. Women who were offered participation were more likely to be younger (p = 0.068) and to have earlier stage disease then were women not offered participation (p = 0.008). Women enrolled into a trial were also more likely to be younger, although this difference was not statistically significant (p = 0.114). Patient race was not associated with the accrual or enrollment process. Over half of the women were not offered participation in clinical trials because of the lack of available studies. Further work evaluating the process of patient enrollment and physician and patient barriers is necessary to develop effective strategies for recruitment into breast cancer clinical trials.

Green fluorescent protein as a reporter to monitor gene expression and food colonization by Aspergillus flavus

Transformants of Aspergillus flavus containing the Aequorea victoria gfp gene fused to a viral promoter or the promoter region and 483 bp of the coding region of A. flavus aflR expressed green fluorescence detectable without a microscope or filters. Expression of green fluorescent protein fluorescence was correlated with resistance to aflatoxin accumulation in five corn genotypes inoculated with these transformants.

Antiproliferative effect of elevated glucose in human microvascular endothelial cells

Diabetic microangiopathy has been implicated as a fundamental feature of the pathological complications of diabetes including retinopathy, neuropathy, and diabetic foot ulceration. However, previous studies devoted to examining the deleterious effects of elevated glucose on the endothelium have been performed largely in primary cultured cells of macrovessel origin. Difficulty in the harvesting and maintenance of microvascular endothelial cells in culture have hindered the study of this relevant population. Therefore, the objective of this study was to characterize the effect of elevated glucose on the proliferation and involved signaling pathways of an immortalized human dermal microvascular endothelial cell line (HMEC-1) that possess similar characteristics to their in vivo counterparts. Human dermal microvascular endothelial cells (HMEC-1) were grown in the presence of normal (5 mM) or high D-glucose (20 mM) for 14 days. The proliferative response of HMEC-1 was compared under these conditions as well as the cAMP and PKC pathways by in vitro assays. Elevated glucose significantly inhibited (P < 0.05) HMEC-1 proliferation after 7, 10, and 14 days. This effect was not mimicked by 20 mM mannitol. The antiproliferative effect was more pronounced with longer exposure (1-14 days) to elevated glucose and was irreversible 4 days after a 10-day exposure. The antiproliferative effect was partially reversed in the presence of a PKA inhibitor, Rp-cAMP (10-50 microM), and/or a PKC inhibitor, Calphostin C (10 nM). HMEC-1 exposed to elevated glucose (20 mM) for 14 days caused an increase in cyclic AMP accumulation, PKA, and PKC activity but was not associated with the activation of downstream events such as CRE and AP-1 binding activity. These data support the hypothesis that HMEC-1 is a suitable model to study the deleterious effects of elevated glucose on microvascular endothelial cells. Continued studies with HMEC-1 may prove advantageous in delineation of the molecular pathophysiology associated with diabetic microangiopathy.

Phase II study of hyperfractionated radiotherapy and concurrent weekly alternating chemotherapy in limited-stage small cell lung cancer

Despite recent advances in combined modality therapy, long-term survival remains elusive in most patients with limited-stage small cell lung cancer (SCLC). The present study was designed to evaluate the activity and toxicity of concurrent hyperfractionated radiotherapy and weekly, alternating-regimen chemotherapy. Twelve patients with limited-stage SCLC and performance status 0-1 were treated with cyclophosphamide 250 mg/m2, etoposide 100 mg/m2, and cisplatin 50 mg/m2 on day 1 every other week, and vincristine 1 mg/m2 on day 8, and ifosfamide 1.2 mg/m2 on days 8 and 9 every other week. Hyperfractionated thoracic radiotherapy, consisting of three daily doses of 1.1 Gy for 20 days to a total dose of 66 Gy, was started on day 1 of chemotherapy. Ten patients (83%) exhibited an objective response (9 CRs and 1 PR) with a median duration of response of 8.6 months. Two complete responders died at 50 and 53 months without evidence of progression and two remain alive and free of SCLC at 73 and 87 months. Median survival was 19.8 months with 2- and 5-year survival rates of 50 and 17%, respectively. Severe toxicity, including grade 3-4 esophagitis (67%) and granulocytopenia (83%), as well as debilitating fatigue and pneumonitis, prompted early termination of the trial. Hyperfractionated radiotherapy and concurrent weekly alternating-regimen chemotherapy resulted in promising response and survival rates, but induced excessive toxicity, in patients with limited-stage SCLC.

Induction of interleukin (IL)-1 alpha and beta gene expression in human keratinocytes exposed to repetitive strain: their role in strain-induced keratinocyte proliferation and morphological change

Recent studies in our laboratory have demonstrated that mechanical strain alters many facets of keratinocyte biology including proliferation, protein synthesis, and morphology. IL-1 is known to play an important role in the autocrine regulation of these basic cellular properties under basal and stimulated conditions. However, it is not known whether IL-1 plays a role in strain-induced alteration of keratinocyte biology. Thus, the objective of this study was to test the hypothesis that cyclic strain stimulates IL-1 expression and that strain-induced changes in keratinocyte function is regulated by IL-1. To test this hypothesis, we examined the effect of cyclic strain (10% average deformation) on keratinocyte IL-1 gene expression and the effect of neutralizing antibodies of IL-1 alpha and IL-1 beta on strain-induced changes in keratinocyte proliferation, morphology, and orientation. Northern blot analyses demonstrated that steady state levels of IL-1 alpha and beta mRNA were elevated by 4 h, peaked at 1 2 h of cyclic strain (IL-1 alpha, 304+/-14.2%; IL-1 beta, 212+/-5.6% increase vs. static controls) and decreased gradually by 24 h. IL-1 antibodies (IL-1 alpha, 0.01 microg/ml; IL-1 beta, 0.01 microg/ml) significantly blocked strain-induced keratinocyte proliferation as well as the basal rate of proliferation. In contrast, IL-1 antibodies (IL-1 alpha, 0.01 microg/ml; IL-1 beta, 0.1 microg/ml) had no effect on strain-induced morphological changes such as elongation and alignment. We conclude that mechanical strain induces IL-1 mRNA expression in keratinocytes. The role of IL-1 in mediating strain-induced changes in keratinocyte biology remains to be determined but appears to be independent of morphological changes.

Successful allogeneic bone marrow transplantation in selected patients over 50 years of age--a single institution's experience

As allogeneic bone marrow transplantation (BMT) is a procedure with a higher risk of morbidity and mortality in older patients, many institutions place a limit of 50 to 55 years for allogeneic BMT. Consequently, older patients may not be offered potentially curative treatment for otherwise poor prognosis diseases such as AML or myelodysplastic syndrome. We compared the outcome of 59 patients aged over 50, 124 aged 40-50, and 253 aged 18-39 years who underwent allogeneic BMT in our institution between August 1987 and April 1996. Our results show little influence of age on outcome when comparing patients over 50 years with patients 40-50 years. Apart from an initial higher transplant mortality rate, overall survival was not significantly different between the three age groups. The 1-year and 2-year overall survival rates were 57% and 48%, 57% and 48%, and 62% and 58% for the >50 years, 40-50 years, and <40 years patients, respectively. The incidence of GVHD was also comparable. We conclude that allogeneic BMT can be performed in selected patients over the age of 50 years with acceptable morbidity and mortality and that older patients should not be denied this treatment based on age alone.

Phase II trial of paclitaxel and carboplatin in the treatment of advanced urothelial carcinoma

PURPOSE

Both paclitaxel and carboplatin have single-agent activity against carcinoma of the urothelium. We evaluated the combination of paclitaxel and carboplatin in the treatment of advanced cancers of the urothelium.

PATIENTS AND METHODS

Patients with cancers of the urothelium who had no prior chemotherapy (prior adjuvant chemotherapy > 6 months allowed) were eligible for treatment. Eligibility requirements were performance status of 2 or less, creatinine level less than 2.0 mg/dL, granulocyte count (AGC) 1,500/microL or greater, platelet count 100,000/microL or greater, and total bilirubin level less than 1.5 mg/dL. Paclitaxel 200 mg/m2 followed by carboplatin (area under the curve [AUC] 5, Calvert formula) were administered every 21 days. Patients were evaluated for toxicity weekly and assessed for response every 6 weeks.

RESULTS

Thirty-six patients were entered onto the study and 35 patients were assessable for response. A total of 184 cycles were administered (median, six cycles per patient). Nine patients required one dose reduction, and seven patients required two dose reductions for a nadir AGC less than 500/microL, with only one episode of febrile neutropenia and sepsis. Myalgias and arthralgias of grades 1 to 2 occurred in 16 patients and usually lasted 2 to 3 days after treatment. There were no treatment delays because of toxicity. There were 18 responses; seven complete responses (CRs) and 11 partial responses (PRs) (response rate 51.5%; 95% confidence interval, 35 to 68). Median response durations for CR and PR were 6 and 4 months, respectively. Overall median survival was 9.5 months.

CONCLUSION

The combination of paclitaxel and carboplatin is an active and well-tolerated regimen for the treatment of advanced urothelial carcinoma. Because of the modest toxicity of this combination, paclitaxel and carboplatin should be considered for addition to other agents with activity in urothelial carcinomas.