Combination chemotherapy of intermediate-dose cytarabine, idarubicin, plus etoposide and subsequent mobilized donor leukocyte infusion for relapsed acute leukemia after allogeneic bone marrow transplantation

The efficacy and side effects of intermediate-dose cytarabine, idarubicin plus etoposide and subsequent donor leukocyte infusion (DLI) were investigated in patients with acute leukemia who relapsed after allogeneic bone marrow transplantation (BMT). Patients were given cytarabine continuous i.v. (1 g/m2 per day x 5), idarubicin i.v. (12 mg/m2 per day x 3), and etoposide i.v. infusion (150 mg/m2 per day x 3). Two days later, G-CSF mobilized donor leukocytes were infused for 2 days. No graft-versus-host disease (GVHD) prophylaxis was given. Between August 1997 and February 2000, 13 patients enrolled (eight acute myeloid leukemia (AML) and five acute lymphoblastic leukemia (ALL)). All patients finished chemotherapy and DLI. Eleven patients (85%) achieved complete remission (CR) at median 27 days after DLI. After median follow up of 10.9 months (2.5-33.3), five of 11 patients who achieved CR relapsed. Overall, six of 13 patients were surviving (6/8 AML and 0/5 ALL, P=0.059). Marrow recovery after chemotherapy and DLI was rapid (12 days for absolute neutrophil count (ANC) >500/microl). Side effects included fever with neutropenia (100%), pneumonia (46%), grade II-IV mucositis (69%), grade III-IV acute GVHD (45%), and extensive chronic GVHD (64%). One patient died from chronic GVHD. Chemotherapy containing intermediate-dose cytarabine and DLI produced a high CR rate in acute leukemia in relapse after allogeneic BMT. A fraction of patients are surviving long term. Side effects were substantial but manageable.

Toxicology of Kalopanax pictus extract and hematological effect of the isolated anti-rheumatoidal kalopanaxsaponin A on the Freunds complete adjuvant reagent-treated rat

We have reported that kalopanaxsaponin A (KPS-A) isolated from Kalopanax pictus have anti-rheumatoidal activity in the rat treated with Freunds complete adjuvant (FCA) reagent. In addition, it has been also reported that KPS-A is a potent antioxidant in the rheumatoidal rat. This research was undertaken to examine whether the saponins of KPS-A and -I could adjust the abnormal lipid metabolisms and hematological changes in immunological diseases. KPS-A significantly inhibited the increases in both triglycerides and total proteins in addition to the decrease in total cholesterol induced by FCA reagent treatment. KPS-A treatment decreased the number of leucocytes elevated by FCA reagent treatment. Excess dose of the methanol extract produced no severe toxicity on the body weight, wet organ weights and hepatic functions. Since LD50 value of K. pictus methanol extract was shown to be 4,033 mg/kg, it could be estimated to be a safe agent for anti-rheumatoidal herbal medicines.

Subacute toxicities and toxicokinetics of a new erectogenic, DA-8159, after single and 4-week repeated oral administration in dogs

The subacute toxicities and toxicokinetics of a new erectogenic, DA-8159, were evaluated after single (at the 1st day) and 4-week (at the 28th day) oral administration of the drug, in doses of 0 (to serve as a control), 12.5, 50 and 200 mg/kg/day, to male and female dogs (n=3 for male and female dogs for each dose). DA-8159 had an effect on the immune-related organs (or tissues), circulatory systems, liver, adrenal glands, ovaries and pancreas. The toxic dose was 200 mg/kg and no observed adverse effect level was less than 50 mg/kg for male and female dogs. There were no significant gender differences in the pharmacokinetic parameters of DA-8159 for each dose after both single and 4-week oral administration. The pharmacokinetic parameters of DA-8159 were dose-independent after single oral administration; the time to reach a peak plasma concentration (T(max)) and the dose-normalized area under the plasma concentration-time curve from time zero to 24 h in plasma (AUC(0-24 h)) were not significantly different among three doses. However, accumulation of DA-8159 after 4-week oral administration was considerable at toxic dose, 200 mg/kg/day. For example, after 4-week administration, the dose-normalized AUC(0-24 h) value at 200 mg/kg/day (4.71 and 15.3 microg h/ml) was significantly greater than that at 12.5 mg/kg/day. After 4-week oral administration, the dose-normalized C(max) and AUC(0-24 h) at 200 mg/kg/day were significantly higher and greater, respectively, than those after a single oral administration.

Clinical impacts of tumor cell contamination of hematopoietic stem cell products in metastatic breast cancer patients undergoing autologous peripheral blood stem cell transplantation: multicenter trial

To determine whether the tumor cell contamination of peripheral blood stem cells influences clinical impacts on high-dose chemotherapy in patients with metastatic breast cancer, we analyzed carcinoembryonic antigen (CEA) mRNA in the apheresis products by nested RT-PCR (reverse transcriptase-polymerase chain reaction). A total of 38 metastatic breast cancer patients and ten normal healthy subjects as a negative control were included. Twenty out of 38 (51.3%) apheresis products from patients with metastatic breast cancer were positive for CEA mRNA. CEA mRNA was noted in 54.8% (17/31) of patients mobilized with chemotherapy plus G-CSF and 42.8% (3/7) of patients with G-CSF alone. There was no significant difference in age, estrogen receptor, menopausal status, mobilization method, disease free interval, or number of metastasis sites (1 vs > or = 2) between positive and negative groups. The presence of CEA mRNA in apheresis products did not influence the time to progression and overall survival in both groups. However, both the univariate and the multivariate analysis disclosed that the number of metastasis was associated with survival significantly. We suggest that the tumor cell contamination does not predict poor treatment outcome in patients with metastatic breast cancer.

Clinical significance of enlarged perihepatic lymph nodes in chronic hepatitis B

GOALS

To evaluate the clinical significance of enlarged perihepatic lymph nodes in patients with chronic hepatitis B.

BACKGROUND

Enlargement of perihepatic lymph node is a common finding during ultrasonography in patients with chronic hepatitis. Its relation with liver histology and viremia was reported in chronic hepatitis C, but little has been known about its clinical significance in chronic hepatitis B.

STUDY

We evaluated the clinical significance of perihepatic lymphadenopathy in chronic hepatitis B. In 50 patients with biopsy-proven chronic hepatitis B and 15 healthy controls, the perihepatic lymph node volume was evaluated by ultrasonography and its possible correlation with biochemical tests, hepatitis activity index, and hepatitis B viremia was investigated.

RESULTS

Perihepatic lymph node was detected in 48 of 50 patients with chronic hepatitis B (volume = 3.4 +/- 2.4 mL) and in two of 15 controls (0.4 mL and 0.6 mL). In chronic hepatitis B, lymph node volume showed a significant correlation with serum aspartate transaminase (r = 0.66), alanine transaminase (r = 0.63), gamma-glutamyl-transpeptidase (r = 0.53), histologic activity index (r = 0.59), and necroinflammatory score (r = 0.59; p < 0.05 for all), but not with fibrosis score and serum hepatitis B viremia.

CONCLUSIONS

Enlarged perihepatic lymph nodes in chronic hepatitis B can be a good indicator for histologic and biochemical inflammatory activity of the liver, but not for viremia.

Oncocytoma of the spinal cord. Case report

The authors report a case of oncocytoma arising from the spinal cord in a 40-year-old woman who presented with the complaints of gradual difficulty in walking. The excised tumor was exclusively composed of polygonal cells with abundant homogeneous eosinophilic cytoplasms. Electron microscopy study showed densely packed swollen mitochondria and frequent desmosomes. The histological and ultrastructural findings were consistent with a diagnosis of oncocytoma. To the authors' knowledge, this represents the first reported case of oncocytoma of the spinal cord.

Circulating levels of interleukin-8 and vascular endothelial growth factor in patients with carotid stenosis

Interleukin (IL)-8 and vascular endothelial growth factor (VEGF) are important factors that induce the migration and proliferation of endothelial cells, increase the vascular permeability, and the modulate chemotaxis of monocytes. These molecules have been found in human atherosclerotic plaques. However, it is not clear whether the circulating levels of IL-8 and VEGF correlate with the extents of carotid stenosis. In this study, we investigated the relationship between circulating levels of IL-8 as well as VEGF and the extents of carotid stenosis. Sera from 41 patients with carotid stenosis were assessed for concentrations of IL-8 and VEGF by enzyme-linked immunosorbent assay. The degree of stenosis of extracranial carotid artery was calibrated by carotid B- mode ultrasonography. The serum concentration of IL-8 (r = -0.04733, p > 0.05) was not correlated with the degree of stenosis. However, the serum concentration of VEGF (r = 0.4974, p < 0.01) was significantly correlated with the degree of carotid stenosis. These findings suggest that increased serum level of VEGF might be a marker for higher degree of stenosis of extracranial carotid artery.

Immunostimulatory effects of anionic alkali mineral complex solution Barodon in porcine lymphocytes

The anionic alkali mineral complex solution, Barodon (Barodon-S.F. Corp., Korea), was evaluated for its effectiveness as a nonspecific immunostimulator in pigs. The effects of Barodon were determined by analysis of feed efficiency, growth rate, and phenotype of leukocyte subpopulations using monoclonal antibodies specific to porcine leukocyte differentiation antigens and flow cytometry (FC). The study was focused to investigate the change in proportion of the CD4+CD8+ double positive T lymphocyte subpopulation (dpp) which exists uniquely in pigs. In addition, the mitogen-stimulated lymphoproliferative response, tissue distribution in lymphoid organs and the adjuvant effect of Barodon on hog cholera vaccine efficiency were determined. The study has revealed the average daily gain rates and feed conversion rates were significantly (p<0.05) improved in either group of pigs fed with 0.05% Barodon-spray feed (Tx-1) or pigs fed with 3% Barodon-fermented feed (Tx-2) in comparison with group of pigs fed with feed containing no Barodon (control). The proportion of cells expressing CD4+ antigen in Barodon-treated group increased from 3 weeks posttreatment and was significantly higher (p<0.05) than that of control at 8 weeks posttreatment. Particularly, the significantly higher proportion was maintained from 8 weeks through 13 weeks posttreatment in Tx-1 group (p<0.05). The proportion of cells expressing CD8+ antigen was significantly higher at 3 weeks posttreatment in Tx-2 (p<0.01). Proportion of MHC class II-expressing cells was significantly higher in Tx-1 and Tx-2 group at 11 weeks and 8 weeks posttreatment (p<0.05), respectively. In addition, the proportion of Non T/Non B (N) cells was also significantly higher in Tx-2 at 3 weeks posttreatment (p<0.01) and maintained to 13 weeks posttreatment (p<0.1). Between Barodon-treated groups, the proportion of MHC class II-expressing cells was observed to be larger in Tx-2 than Tx-1 from 3 weeks to 8 weeks posttreatment (p<0.05). However, there were no significant difference in the proportions of CD2+ cells, B cells, monocytes and granulocytes between Barodon-treated and control group during the experiment. Dual-color FC analysis, study has revealed an increased proportion of dpp present in lymphocytes obtained from peripheral blood (PB) and mesenteric lymph node (MLN) of Barodon-treated group at 8 and 11 weeks posttreatment. The proportion of dpp in PB was 27.5% and 32.1% in Tx-1 and Tx-2, respectively, but only 2.2% in control group at 8 weeks posttreatment. In MLN, the proportion was 45.1% and 52.1% in Tx-1 and Tx-2, respectively, otherwise 16.5% in control group at 8 weeks posttreatment. The mitogen-stimulated activity was significantly higher in Tx-1 than in the control group at 11 weeks posttreatment when cells were stimulated with Con A and PHA, respectively (p<0.01). Also, Con A-, PHA and PWM-stimulated activity was significantly higher in Tx-2 than in the control group at the same time (p<0.05). The tissue distribution of CD4+, CD8+ and CD4+CD8+ dpp in MLN and spleen was significantly larger in Tx-1 and Tx-2 than in the control group (p<0.01). Also, a larger proportion of dpp was observed in Tx-2 than Tx-1 in spleen between Barodon-treated groups (p<0.01). In conclusion, the study has demonstrated that Barodon had an immunostimulatory effect on pigs through proliferation and activation of porcine immune cells, specially CD4+CD8+ dpp lymphocytes.

Influence of gestational age at exposure on the prenatal effects of gamma-radiation

The objective of this investigation was to evaluate the influence of gestational age at exposure on the prenatal effects of gamma-radiation. Pregnant ICR mice were exposed to a single dose of 2.0 Gy gamma-radiation at a gestational 2.5 to 15.5 days post-coitus (p.c.). The animals were sacrificed on day 18 of gestation and the fetuses were examined for mortality, growth retardation, change in head size and any other morphological abnormalities. The only demonstrable effect of irradiation during the preimplantation period was an increase in prenatal mortality. Resorptions were maximal on post-exposure day 2.5 after conception. The pre-implantation irradiated embryos which survived did not show any major fetal abnormalities. Small head, growth retardation, cleft palate, dilatation of the cerebral ventricle, dilatation of the renal pelvis and abnormalities of the extremities and tail were prominent after exposure during the organogenesis period, especially on day 11.5 of gestation. Our results indicate that the late period of organogenesis in the mouse is a particularly sensitive phase in terms of the development of the brain, skull and extremities.

Inhibiting expression of a tomato ripening-associated membrane protein increases organic acids and reduces sugar levels of fruit

Tomato (Lycopersicon esculentum Mill.) ripening-associated membrane protein (TRAMP) is a channel protein of the membrane intrinsic protein (MIP) class encoded by the cDNA clone pNY507 [R.G. Fray et al. (1994) Plant Mol Biol 24: 539-543]. It has been suggested that these proteins encode water channels or aquaporins. TRAMP mRNA accumulated in all tomato tissues tested and was elevated in fruit during post-anthesis development and again during ripening. Transgenic plants that constitutively expressed a TRAMP antisense RNA sequence were generated with a 94% reduction of endogenous TRAMP mRNA in fruit. They showed no obvious phenotype that could be associated with gross perturbation of water relations, but ripening fruit of these plants showed marked alterations in the normal pattern of accumulation of both organic acids and sugars. At the onset and during ripening, levels of the organic acids L-malate and citrate were significantly elevated while levels of D[+]-glucose and D[+]-fructose were reduced. Additional transgenic lines were generated with reduced TRAMP mRNA, and the phenotype of increased acids and reduced sugars during fruit maturation and ripening was shown to be reproducible and stably inherited. Fruit of plants that over-expressed TRAMP mRNA showed no significant alteration in the sugars or acids investigated. These results suggest a role for TRAMP in the movement of solutes between cell compartments.

Protective effects of acetylbergenin against carbon tetrachloride-induced hepatotoxicity in rats

The present study was undertaken to investigate whether or not the hepatoprotective activity of acetylbergenin was superior to bergenin in carbon tetrachloride (CCl4)-intoxicated rat. Acetylbergenin was synthesized by acetylating bergenin, which was isolated from Mallotus japonicus. The hepatoprotective effects of acetylbergenin were examined against CCl4-induced liver damage in rats by means of serum and liver biochemical indices. Acetylbergenin was administered orally once daily for 7 successive days, then a 0.5 ml/kg mixture of CCl4 in olive oil (1:1) was intraperitoneally injected at 12 h and 36 h after the final administration of acetylbergenin. Pretreatment with acetylbergenin reduced the elevated serum enzymatic activities of alanine/aspartate aminotransferase, sorbitol dehydrogenase and gamma-glutamyltransferase in a dose dependent fashion. Acetylbergenin also prevented the elevation of hepatic malondialdehyde formation and depletion of glutathione content dose dependently in CCl4-intoxicated rats. In addition, the decreased activities of glutathione S-transferase and glutathione reductase were restored to almost normal levels. The results of this study strongly suggest that acetylbergenin has potent hepatoprotective activity against CCl4-induced hepatic damage in rats by glutathione-mediated detoxification as well as having free radical scavenging activity. In addition, acetylbergenin doses of 50 mg/kg showed almost the same levels of hepatoprotective activity as 100 mg/kg of bergenin, indicating that lipophilic acetylbergenin is more active against the antihepatotoxic effects of CCl4 than those of the much less lipophilic bergenin.

Effects of cysteine on the pharmacokinetics and pharmacodynamics of intravenous and oral azosemide in rats with protein-calorie malnutrition

The effects of cysteine on the pharmacokinetics and pharmacodynamics of azosemide were investigated after intravenous (10 mg/kg) and oral (20 mg/kg) administration to male Sprague-Dawley rats fed on 23% protein diet (control rats), and 5% protein diet with (rats with PCMC) or without (rats with PCM) oral cysteine (250 mg/kg, twice daily for the fourth week) for 4 weeks. After intravenous administration to rats with PCMC, some pharmacokinetic parameters restored fully or more than the level of control rats; the time-averaged nonrenal clearance (2.70 versus 2.32 ml/min/kg) and apparent volume of distribution at steady state (160 versus 189 ml/kg) were comparable to those in control rats, however, the terminal half-life (34.7 versus 57.2 min) and mean residence time (73.3 versus 99.3 min) were significantly shorter, area under the plasma concentration-time curve from time zero to time infinity (AUC, 1930 versus 2680 microg min/ml) was significantly smaller, and time-averaged renal (2.24 versus 1.21 ml/min/kg) and total body (CL, 4.98 versus 3.65 ml/min/kg) clearances were significantly faster than those in control rats. This could be mainly due to significantly faster renal clearance and at least partly due to increased cytochrome P450 1A2 activity by cysteine supplementation. After intravenous administration to rats with PCMC, the total amount of 8-hr urinary excretion of unchanged azosemide was significantly greater (457 versus 305 microg/g body weight), however, the 8-hr urine output (15.3 versus 31.1 ml/g kidney) was not significantly different between control rats and rats with PCMC. This could be due to the fact that urine output seemed to reach an upper plateau from 10 mg/kg dose of azosemide in rats.

Effect of graded running on esophageal motility and gastroesophageal reflux in fed volunteers

The effects of different grades of running on esophageal motility and gastroesophageal reflux in the fed state were evaluated. We studied healthy volunteers (male: 12, age: 27 +/- 5 yr) using ambulatory esophageal manometry, pH catheter and portable digital data recorder. Each exercise was performed 30 min after meal, with 20 min of rest between exercises. Subjects exercised on a treadmill at 40% and 70% maximal heart rate. The number of gastroesophageal reflux episodes, the duration of esophageal acid exposure and percent time pH below 4 were significantly (p < 0.01) increased during exercise at 70% maximal heart rate. The frequency of contraction (contraction/min) (p < 0.05), frequency of repetition (p < 0.01), percent of simultaneous contraction (p < 0.01), percent of above 100 mmHg amplitude (p < 0.05), and frequency of 2-peak contraction (p < 0.01) were significantly increased during exercise at 70% maximal heart rate. However, median amplitude and median duration showed no significant changes between each exercise session. Postprandial running exercises induce gastroesophageal reflux, which correlates with exercise intensity. These effects are mediated by disorganized esophageal motility.

Quantitative mRNA expression analysis from formalin-fixed, paraffin-embedded tissues using 5' nuclease quantitative reverse transcription-polymerase chain reaction

Analysis of gene expression and correlation with clinical parameters has the potential to become an important factor in therapeutic decision making. The ability to analyze gene expression in archived tissues, for which clinical followup is already available, will greatly facilitate research in this area. A major obstacle to this approach, however, has been the uncertainty about whether gene expression analyses from routinely archived tissues accurately reflect expression before fixation. In the present study we have optimized the RNA isolation and reverse transcription steps for quantitative reverse transcription-polymerase chain reaction (RT-PCR) on archival material. Using tissue taken directly from the operating room, mRNAs with half-lives from 10 minutes to >8 hours were isolated and reverse transcribed. Subsequent real-time quantitative PCR methodology (TaqMan) on these cDNAs gives a measurement of gene expression in the fixed tissues comparable to that in the fresh tissue. In addition, we simulated routine pathology handling and demonstrate that this method of mRNA quantitation is insensitive to pre-fixation times (time from excision to fixation) of up to 12 hours. Therefore, it should be feasible to analyze gene expression in archived tissues where tissue collection procedures are largely unknown.

Differential display reveals downregulation of the phospholipid transfer protein (PLTP) at the mRNA level in brains of patients with Down syndrome

The phospholipid transfer protein (PLTP) shows a wide variety of functions including transfer of phospholipids and other lipid-like substances. Performing gene hunting in brain of patients with Down syndrome (DS) we detected the absence of a fragment identified as PLTP. Cerebellum of 4 controls, 7 patients with DS, 5 patients with Alzheimer's disease (AD) were used for differential display and for quantification of mRNA steady state levels of the isomer PLTP-1 by blotting methods. Differential display showed the absence of a cDNA fragment and cloning, sequencing and gene bank work revealed 100% homology with human PAC 337018 on chromosome 20q containing the PLTP gene. The PLTP gene in turn consists of at least three different PLTP-isomers. Based on these results, a 450 bp cDNA fragment of the PLTP-isomer I (PLTP I) was isolated and amplified by PCR, serving as probe for the PLTP-1 isomer and its expression level was found to be significantly reduced in cerebellum of patients with DS. Biologically, the downregulation of PLTP maybe involved in the pathology of DS as phospholipids not only are of importance for membrane biogenesis and structure but also in the regulation of cellular metabolism, signaling and growth. In the brain, phospholipids in addition are integral constituents of myelins and synaptosomes (Johnson etc) and deficient PLTP levels may account for the deteriorated functions described to occur in DS brain.

The asymmetric catalytic aldol reaction of allenolates with aldehydes using n-fluoroacyl oxazaborolidine as the catalyst

The asymmetric catalytic aldol reaction of silyl allenolates with aldehydes has been achieved by using N-C(3)F(7)CO oxazaborolidine as the catalyst. The fluoroacyl group of the catalyst was found to be crucial for control of enantioselectivity. The reaction provides the first enantioselective approach to beta-halo Baylis-Hillman-type adducts.

Mitochondrial dysfunction by gamma-irradiation accompanies the induction of cytochrome P450 2E1 (CYP2E1) in rat liver

Multiple biological effects are induced by ionizing radiation through dysfunction of cellular organelles, direct interaction with nucleic acids and production of free radical species. The expression of cytochrome P450s was assessed in the livers of 60Co gamma-irradiated rats. Three gray (G) of gamma-irradiation caused CYP2E1 induction with a 3.6-fold increase in the mRNA at 24 h, whereas the expression of CYP1A2 and CYP3A was not changed. Pharmacokinetics of chlorzoxazone, a specific substrate of CYP2E1, was studied in 3 G-irradiated rats. The area under the plasma concentration-time curve from time zero to infinity of 6-hydroxychlorzoxazone and the amount of 6-hydroxychlorzoxazone excreted in 8 h urine were both significantly greater than those in control rats. Hepatic CYP2E1 was not induced in rats exposed to 0.5-1 G of gamma-rays. Rats irradiated at 6-9 G accumulated doses of gamma-rays exhibited smaller increases in the mRNA due to liver injury than those irradiated at a single dose of 3 G gamma-rays. The plasma glucose and insulin levels were not altered in rats with 3 G of gamma-irradiation. As the exposure level of gamma-irradiation increased, the activity of hepatic aconitase, a key enzyme in energy metabolism in mitochondria, was 30-90% decreased. The amount of mitochondrial DNA per gram of wet liver was 50% decreased in rats exposed to 3 G of gamma-rays. These results demonstrated that gamma-ray irradiation at the exposure level inducing organelle dysfunction induced CYP2E1 in the liver, which might be associated with mitochondrial damage, but not with alterations in glucose or insulin levels.

Size analysis of automobile soot particles using field-flow fractionation

Soot particles emitted from various automobile engines are analyzed for size distributions using field-flow fractionation (FFF). Soot samples are prepared for FFF analysis using a three-step procedure, where a layer of soot particles is focused between the layers of n-hexane and water, followed by dispersing of particles in water containing 0.05% Triton X-100. The mean diameters determined by FFF show similar trends with those obtained from dynamic light scattering (DLS) and scanning electron microscopy (SEM). Data from FFF are also compared with those from an on-line scanning mobility particle sizer (SMPS). SMPS size distributions extend further to larger size than those of FFF distributions, which indicates the three-step sample preparation procedure effectively disaggregates the agglomerated particles. Although the amount of particulate matter (PM) emitted from a heavy-duty diesel engine is much higher than that from a light-duty diesel engine, the size distributions of soot particles show no significant difference between heavy- and light-duty diesel engines. The engine-operating mode (engine speed and load rate) does not seem to affect significantly the size distribution of soot particles. It was found that the PM from a turbocharged diesel engine contains a higher percentage of particles smaller than 100 nm than an engine with a naturally aspirated (NA) air-inhalation system. As for gasoline engines, the PM collected after the catalytic converter has a narrower size distribution than those collected before and has a higher percentage of particles smaller than 100 nm.

Long-term delivery of all-trans-retinoic acid using biodegradable PLLA/PEG-PLLA blended microspheres

All-trans-retinoic acid (atRA) has been proved to be effective against several malignancies in human clinical trials. However, in many patients who were treated with atRA, the cancer relapsed after a brief remission. One reason for such relapse is that atRA is metabolized by specific P450s that are induced in the liver during prolonged atRA treatments. In order to overcome such a drawback of atRA, we prepared biodegradable microspheres to provide continuous release of atRA for a long period of time. These biodegradable microspheres were prepared by poly(L-lactide) (PLLA) and polyethylene glycol (PEG)-PLLA diblock copolymers (PLE) in various blending ratios to control the release rate of atRA. As the PLE content in microsphere was increased, the density of the hydrophilic PEG block of PLE on microsphere surfaces increased and the microspheres were dispersed well in PBS without any surfactants. Various release patterns of atRA were obtained according to PLE and atRA contents in the microspheres. Especially, the pseudo-zero-order release profiles were observed for 5 weeks when the contents of PLE and atRA in the microspheres were above 4 wt.%.

Site-specific mutations in the mature form of human IL-18 with enhanced biological activity and decreased neutralization by IL-18 binding protein

IL-18 can be considered a proinflammatory cytokine mediating disease as well as an immunostimulatory cytokine that is important for host defense against infection and cancer. The high-affinity, constitutively expressed, and circulating IL-18 binding protein (IL-18BP), which competes with cell surface receptors for IL-18 and neutralizes IL-18 activity, may act as a natural antiinflammatory as well as immunosuppressive molecule. In the present studies, the IL-18 precursor caspase-1 cleavage site was changed to a factor Xa site, and, after expression in Escherichia coli, mature IL-18 was generated by factor Xa cleavage. Mature IL-18 generated by factor Xa cleavage was fully active. Single point mutations in the mature IL-18 peptide were made, and the biological activities of the wild-type (WT) IL-18 were compared with those of the mutants. Mutants E42A and K89A exhibited 2-fold increased activity compared with WT IL-18. A double mutant, E42A plus K89A, exhibited 4-fold greater activity. Unexpectedly, IL-18BP failed to neutralize the double mutant E42A plus K89A compared with WT IL-18. The K89A mutant was intermediate in being neutralized by IL-18BP, whereas neutralization of the E42A mutant was comparable to that in the WT IL-18. The identification of E42 and K89 in the mature IL-18 peptide is consistent with previous modeling studies of IL-18 binding to IL-18BP and explains the unusually high affinity of IL-18BP for IL-18.

Syntheses and evaluation of pyrido[2,3-dlpyrimidine-2,4-diones as PDE 4 inhibitors

The syntheses and in vitro evaluation of a new series of pyrido[2,3-d]pyrimidine-2,4-diones bearing substituents at C-3 and/or C-4 positions on the pyridine ring are described. Some of these compounds, especially 51 and 6f, were found to be potent phosphodiesterase 4 (PDE 4) inhibitors exhibiting improved ratio of PDE 4 inhibitory activity:rolipram binding assay (RBA).

Vascular endothelial growth factor expression of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin through nuclear factor-kappa B activation in endothelial cells

Vascular endothelial growth factor (VEGF) induces adhesion molecules on endothelial cells during inflammation. Here we examined the mechanisms underlying VEGF-stimulated expression of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin in human umbilical vein endothelial cells. VEGF (20 ng/ml) increased expression of ICAM-1, VCAM-1, and E-selectin mRNAs in a time-dependent manner. These effects were significantly suppressed by Flk-1/kinase-insert domain containing receptor (KDR) antagonist and by inhibitors of phospholipase C, nuclear factor (NF)-kappaB, sphingosine kinase, and protein kinase C, but they were not affected by inhibitors of mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) 1/2 or nitric-oxide synthase. Unexpectedly, the phosphatidylinositol (PI) 3'-kinase inhibitor wortmannin enhanced both basal and VEGF-stimulated adhesion molecule expression, whereas insulin, a PI 3'-kinase activator, suppressed both basal and VEGF-stimulated expression. Gel shift analysis revealed that VEGF stimulated NF-kappaB activity. This effect was inhibited by phospholipase C, NF-kappaB, or protein kinase C inhibitor. VEGF increased VCAM-1 and ICAM-1 protein levels and increased leukocyte adhesiveness in a NF-kappaB-dependent manner. These results suggest that VEGF-stimulated expression of ICAM-1, VCAM-1, and E-selectin mRNAs was mainly through NF-kappaB activation with PI 3'-kinase-mediated suppression, but was independent of nitric oxide and MEK. Thus, VEGF simultaneously activates two signal transduction pathways that have opposite functions in the induction of adhesion molecule expression. The existence of parallel inverse signaling implies that the induction of adhesion molecule expression by VEGF is very finely regulated.

First and second generation total synthesis of the teicoplanin aglycon

Full details of studies leading to the total synthesis of the teicoplanin aglycon are provided. Key elements of the first generation approach (26 steps from constituent amino acids, 1% overall) include the coupling of an EFG tripeptide precursor to the common vancomycin/teicoplanin ABCD ring system and sequential DE macrocyclization of the 16-membered ring with formation of the diaryl ether via a phenoxide nucleophilic aromatic substitution of an o-fluoronitroaromatic (80%, 3:1 atropisomer diastereoselection) followed by 14-membered FG ring closure by macrolactamization (66%). Subsequent studies have provided a second generation total synthesis which is shorter, more convergent, and highly diastereoselective (22 steps, 2% overall). This was accomplished by altering the order of ring closures such that FG macrolactamization (95%) preceded coupling of the EFG tripeptide to the ABCD ring system and subsequent DE ring closure. Notably, DE macrocyclization via diaryl ether formation on substrate 57, the key intermediate in the latter approach incorporating the intact FG ring system, occurred with exceptional diastereoselection for formation of the natural atropisomer (>10:1, 76%) without problematic C(2)(3) epimerization provided the basicity of the reaction is minimized.

Familial British dementia: expression and metabolism of BRI

Vidal et al. (1999. Nature 399: 776-778) discovered that the underlying genetic lesion in familial British dementia (FBD) is a T-A transversion at the termination codon of a membrane protein, termed BRI. The mutation creates an arginine codon; translational read-through generates a novel protein, termed BRI-L, that is extended by 11 amino acids at the carboxyl-terminus. BRI-L is the precursor of the ABri peptide, a component of amyloid deposits in FBD brain. We demonstrate that both BRI and its mutant counterpart are constitutively processed by furin, resulting in the secretion of carboxyl-terminal peptide derivatives that correspond to all, or part of, ABri. Notably, elevated levels of peptides are generated from the mutant BRI precursor, suggesting that subtle conformational alterations at the carboxyl-terminus may influence furin-mediated processing. We have examined BRI/BRI-L processing by other members of the prohormone convertase (PC) family (PACE4, LPC, PC 5/6) and found that these enzymes also process BRI, albeit inefficiently. Moreover, BRI-L processing by the other PC members is severely compromised. Finally, our electron microscopic studies reveal that synthetic ABri peptides assemble into insoluble beta-pleated fibrils. Collectively, our results support the view that enhanced furin-mediated processing of mutant BRI generates amyloidogenic peptides that initiate the pathogenesis of FBD.