Treatment of atherosclerosis in apolipoprotein E-deficient mice with 4-(3-Bromobenzoyl)-6,7-dimethoxyquinazoline (WHI-P164), a potent inhibitor of triglyceride synthesis

We identified a novel organic compound, 4-(3'-bromobenzoyl)-6,7-dimethoxyquinazoline (compound WHI-P164), as a potent inhibitor of triglyceride (TG) synthesis. In an in vitro model of lipid synthesis, WHI-P164 (but not any one of the three structurally similar control dimethoxyquinazoline compounds) inhibited the accumulation of TG-rich intracellular lipid droplets in Caco-2 human intestinal cells in a concentration-dependent fashion. WHI-P164 caused no acute toxicity associated with morbidity or mortality in mice when administered at dose levels ranging from 0.5 to 80 mg/kg. In pharmacokinetic studies in mice, WHI-P164 was rapidly eliminated from plasma with a terminal elimination half-life of 26.1 +/- 1.3 min after intraperitoneal administration and 33.3 +/- 11.3 min after intravenous administration. Treatment with 40 mg/kg WHI-P164 (but not one of three structurally similar control dimethoxyquinazoline compounds) administered intraperitoneally once daily for 7 consecutive treatment days blocked the in vivo hepatic TG synthesis in both apoE-deficient and wild-type C57B1/6 mice. In apoE-deficient mice maintained on a high-fat/high-cholesterol Western diet, WHI-P164 substantially reduced the lipid accumulation in the liver after 7 days of treatment and the lipid accumulation in the aorta after 1 month of treatment. Our results in apoE-deficient mice show that lipid accumulation in hepatocytes and foam cells are related events, and inhibiting TG synthesis with WHI-P164 offers an effective means to treat atherosclerosis.

Loss of imprinting of the IGF-II and H19 genes in epithelial ovarian cancer

To establish a possible role of genomic imprinting in the carcinogenesis of epithelial ovarian cancer, we determined the imprinting status of both IGF-II and H19 genes in 43 ovarian cancers, 7 low malignant potential ovarian tumors, and their matched normal tissues. In ovarian cancer, loss of heterozygosity (LOH) of IGF-II, H19 RsaI, and H19 AluI was found in 4 of 24 (16.7%), 3 of 20 (15%), and 1 of 16 (6.3%) samples, respectively. All patients with tumor specimens exhibiting LOH are of advanced clinical stages. Loss of imprinting (LOI) was found in 5 of 20 (25%) for IGF-II and in 4 of 17 (23.5%) and 1 of 15 (6.7%) for the RsaI and AluI sites of H19 gene with no LOH. However, no LOH was found in low malignant potential tumors, and only one of them showed LOI in H19 AluI site. Overexpression of IGF-II was demonstrated in all five LOI samples with normal expression of H19. Three of the five tumor specimens exhibiting LOI were transcribed from P1 promoter, whereas the remaining two were from the P3 promoter. These results suggested that LOH of both IGF-II and H19 genes was associated with advanced ovarian cancer. LOI of IGF-II and H19 genes may be involved in the development of ovarian cancer. Transcription of IGF-II from the P1 promoter may account for the biallelic expression of the IGF-II gene.

Second primary epithelial malignancy of nasopharynx and nasal cavity after successful curative radiation therapy of nasopharyngeal carcinoma

Patients with head and neck cancer are at high risk of developing additional second primary tumors in the aerodigestive tract as a result of the field cancerization phenomenon. In this context, the appearance of a new neoplasm often poses a problem in differential diagnosis between recurrence and new primary tumor. Twelve patients with nasopharyngeal carcinoma (NPC) who received radiation therapy for the primary tumor and developed a second epithelial malignancy in the nasal cavity or nasopharynx during the follow-up period are presented in this report. The differentiation between the 2 entities based on the spatiotemporal relations, histological features, and the status of Epstein-Barr virus in tumor lesions are also presented. Our study showed that the epithelial malignancy after NPC having late-onset or prolonged interval (range, 5 to 18 years), different histological patterns (keratinizing squamous cell carcinoma, neuroendocrine carcinoma, or small cell carcinoma) distinct from the primary NPC (differentiated or undifferentiated nonkeratinizing carcinoma), and absence of Epstein-Barr virus, indicate a newly developed tumor rather than recurrent NPC. Our observations showed for the first time that second primary epithelial malignancy developed in the nasal cavity or nasopharynx years after curative therapy for NPC with a prevalence of 0.4% (12/2,794). Wild-type p53 protein was expressed more often in the original NPC (9 of 12) than in the second tumors (4 of 10), but the significance was not statistically significant (P = .2048). Genomic analysis for p53 mutation and in situ hybridization for human papillomavirus showed negative results, indicating that both important molecular events in NPC or head and neck cancer play a small role in this particular type of newly developed second malignant tumor. More studies are warranted for further clarification for the development of second epithelial malignancies in treated NPC patients.

Preliminary acute and subchronic toxicity studies of GLG-V-13, a novel class III antiarrhythmic agent, in mice

The acute and subchronic toxic effects of GLG-V-13 (3-[4-(1H-imidazol-1-yl)benzoyl]-7-isopropyl-3,7-diazabicyclo[3.3.1]nona ne dihydroperchlorate, CAS 155029-33-7), a novel class III with some class Ib antiarrhythmic activity, were investigated in mice. The estimated LD50 for GLG-V-13 given orally were 419 mg/kg for male mice and 383 mg/kg for female mice, respectively. The acute toxic signs appeared to be of the central nervous system in origin. Four groups of mice (15 per sex, group and dose) were fed daily with diets containing GLG-V-13 for 90 consecutive days. The equivalent daily doses were 0, 22, 50 and 121 mg/kg/day and 0, 27, 60 and 136 mg/kg/day for male and female mice, respectively. All of the mice survived. Food consumption was decreased. However, mean body weight and body weight gain were not significantly changed. Gross pathological changes, especially in the lungs and liver, were found in the middle and high dose groups. Consistent increased mean corpuscular hemoglobin concentration and decreased mean corpuscular hemoglobin were observed in all dose groups. Hepatocellular necrosis was found in both male and female mice treated with the drug and was dose-dependent. Marked vacuolation of the X zone in the adrenal gland with mild to moderate deposition of ceroid pigments (brown degeneration) was observed in female mice. Lesions in the kidneys and adrenal glands may be a possible reason for changes in serum sodium and potassium ions concentrations leading to an increase in water intake. A significant reduction in cholesterol in the high dose group may be a favorable pharmacological effect of GLG-V-13. The data from the 90-day subchronic toxicity studies indicate that GLG-V-13 appears to have limited systemic toxicity potential.

Activation of rat locus coeruleus neuron GABA(A) receptors by propofol and its potentiation by pentobarbital or alphaxalone

The action of propofol on the rat locus coeruleus was examined using intracellular recording from in vitro brain slice preparations. Concentrations of propofol between 3 and 300 microM were tested. At 100 microM, propofol completely inhibited the firing of all neurons tested (n=34); this was associated with a 5.7-mV hyperpolarization (range 0-16 mV, n=33) and a 35.6% reduction in input resistance (range 7.3-66.1%, n=33). The propofol-induced responses were not affected by 2-hydroxysaclofen (50 microM) or BaCl(2) (300 microM), but were completely blocked by bicuculline methiodide (100 microM) or picrotoxin (100 microM), indicating that propofol acts on GABA(A) receptors. As assessed by inhibition of the spontaneous firing rate, propofol was 5.6-fold more potent than GABA (gamma-aminobutyric acid). Potentiation of the propofol effect by other general anesthetics or other drugs was also investigated. When pentobarbital (100 microM) was tested alone on locus coeruleus cells, no change in membrane potential or input resistance was seen and there was only a 20.3+/-7.2% (n=8) inhibition of firing rate; however, in combination with 30 microM propofol, it caused a 6.1-fold greater increase in membrane hyperpolarization and a 9.7-fold greater reduction in input resistance than 30 microM propofol alone. A relatively low concentration of alphaxalone (10 microM), when tested alone, had little effect on the membrane potential or input resistance and only produced a 46.0+/-8.9% (n=8) inhibition of firing rate; however, in combination with 30 microM propofol, it caused a 9.3-fold greater hyperpolarization and an 8.6-fold greater reduction in input resistance compared with 30 microM propofol alone. In contrast, diazepam caused no potentiation of either propofol- or GABA-induced responses. Our data also indicate that locus coeruleus neuron GABA(A) receptors possess distinctive pharmacologic characteristics, such as blocking of the propofol effects by zinc and insensitivity to diazepam and the direct action of pentobarbital. On the basis of these pharmacologic properties, we suggest that locus coeruleus neuron GABA(A) receptors do not contain the gamma subunit.

Toxicity, biological activity, and pharmacokinetics of TXU (anti-CD7)-pokeweed antiviral protein in chimpanzees and adult patients infected with human immunodeficiency virus

The purpose of the present study was to evaluate the toxicity and pharmacokinetics of TXU (anti-CD7)-pokeweed antiviral protein (PAP) in human immunodeficiency virus (HIV)-infected chimpanzees and adult patients. At a total dose of 100 microg/kg, TXU-PAP did not cause severe (grade >/= 3) toxicity in any of the four HIV type 1 (HIV-1)-infected or two healthy chimpanzees. The only side effects were a transient elevation of the liver enzyme alanine aminotransferase between days 2 and 14 without a concomitant rise in total bilirubin levels and a decrease in the serum albumin levels between days 1 and 5 without any concomitant weight gain or peripheral edema. TXU-PAP showed favorable pharmacokinetics in chimpanzees with a plasma elimination half-life of 5.1 to 12.0 h and a systemic clearance of 5.8 to 15.1 ml/h/kg. At 2 months after initiation of the TXU-PAP infusions, the HIV-1 burden was reduced to below-detection levels in three of the four chimpanzees, and in the remaining chimpanzee, the HIV burden was <500 RNA copies/ml at 2 weeks but returned to the pretreatment levels by 2 months. TXU-PAP was well tolerated by HIV-1-infected adult patients who received a single 5 microg/kg i.v. infusion of TXU-PAP. TXU-PAP showed very favorable pharmacokinetics in these patients with a relatively long plasma elimination half-life of 12.4 +/- 1.4 h, a mean residence time of 17.9 +/- 2.0 h, and a slow systemic clearance of 2.7 +/- 0.7 ml/h/kg. Concentrations of TXU-PAP required for effective inhibition of HIV-1 replication in preclinical models were achieved in HIV-1-infected patients at the 5 microg/kg dose level without any adverse reactions, and the mean value for AUC was 3059 +/- 721 ng. h/ml. The 1-h postinfusion plasma samples from TXU-PAP-treated patients showed potent anti-HIV activity in vitro and inhibited the replication of HIV in normal peripheral blood mononuclear cells (PBMCs) even at a 1:100 dilution. Although treatment with TXU-PAP at the 5 microg/kg dose level does not provide sustained therapeutic levels, it was capable of reducing the viral burden in six of six patients evaluated. To our knowledge, this is the first report of a clinical pharmacokinetics study of a PAP immunoconjugate in HIV-infected patients. The favorable long plasma elimination half-life of TXU-PAP in combination with its low toxicity provides the basis for further investigation of TXU-PAP as a potential anti-HIV agent.

Anterior ankle-foot orthosis effects on postural stability in hemiplegic patients

OBJECTIVES

To evaluate the effects of an anterior ankle-foot orthosis (AFO) on static and dynamic postural stability in hemiplegic patients.

DESIGN

A cross-sectional assessment of hemiplegic subjects with and without an AFO.

SETTING

Outpatient department of a rehabilitation hospital.

PATIENTS

A convenience sample of 24 subjects who had been prescribed an anterior AFO.

OUTCOME MEASURES

Postural sway index and postural symmetry (body weight distribution through the affected leg) when standing were measured as static postural stability. Maximal balance range in anterior-posterior and lateral directions and the affected leg's weight bearing after weight shift to affected side were measured as dynamic postural stability.

RESULTS

When wearing the anterior AFO, there was no significant difference and small effect size (r<0.3) in postural sway index (p = .35), postural symmetry (p = .21), and maximal balance range in anterior-posterior direction (p = .46). There was a significant improvement and large effect size (r>0.5) in lateral weight shifting (p<.01) and weight bearing through the affected leg after weight shifted to the affected side (p<.01).

CONCLUSIONS

The significant effects of the anterior AFO in long-term hemiplegic patients were on lateral weight shifting and weight bearing through affected leg after weight shifted to the affected side. Postural sway, postural symmetry, and anterior-posterior weight shifting were not significantly affected.

Treatment of therapy-refractory B-lineage acute lymphoblastic leukemia with an apoptosis-inducing CD19-directed tyrosine kinase inhibitor

Seven children and eight adults with CD19+ B-lineage acute lymphoblastic leukemia, as well as one adult with chronic lymphocytic leukemia, were treated with the CD19 receptor-directed tyrosine kinase inhibitor B43-Genistein. All patients had failed previous chemotherapy regimens, and six patients had relapsed after bone marrow transplantation. B43-Genistein was administered as a 1-hour i.v. infusion at 0.1-0.32 mg/kg/day dose levels for 10 consecutive days or 3 consecutive days weekly for a total of nine doses. B43-Genistein was well tolerated by all patients with no life-threatening side effects. There were six episodes of grade 2-3 fever, two of which were clearly drug related, one episode each of grade 3 myalgia, grade 2 sinus tachycardia, and grade 2 vascular leak syndrome. There was one durable complete remission and two transient responses. Pharmacokinetic analyses in 12 patients revealed a plasma half-life of 20 +/- 5 h, mean residence time of 24 +/- 5 h, and a systemic clearance rate of 20 +/- 3 ml/h/kg. Moderate levels of human antimouse antibody (HAMA) ranging from 20-87 ng/ml were detected in the day 28 blood samples from three of nine cases examined. Treatment of these three HAMA-positive patients with a second course of B43-Genistein did not yield measurable immunoconjugate levels in the plasma, indicating that the administered B43-Genistein molecules were rapidly cleared from circulation due to the HAMA. On the basis of its acceptable toxicity profile and its ability to elicit objective responses at nontoxic dose levels, B43-Genistein may provide the basis for an effective treatment strategy for B-lineage acute lymphoblastic leukemia patients who have failed standard therapy.

Clinical pharmacokinetics of the CD19 receptor-directed tyrosine kinase inhibitor B43-Genistein in patients with B-lineage lymphoid malignancies

The authors examined the pharmacokinetics of the CD19 receptor-directed tyrosine kinase inhibitor B43-Genistein in 17 patients (4 children, 13 adults) with B-lineage lymphoid malignancies, including 12 patients with acute lymphoblastic leukemia (ALL) and 5 patients with non-Hodgkin's lymphoma (NHL). The immunoconjugate was administered intravenously as a 1-hour continuous infusion at a dose level of either 0.1 mg/kg (N = 12) or 0.18 mg/kg (N = 5), and the plasma concentration-time data were modeled by using the WinNonlin program to estimate the pharmacokinetic parameters. Pharmacokinetic analyses revealed a plasma half-life of 19 +/- 4 hours, mean residence time of 22 +/- 4 hours, and a systemic clearance of 18 +/- 2 mL/h/kg. The average (mean +/- SEM) values for the maximum plasma concentration Cmax, volume of distribution at steady state (Vss), and area under curve (AUC) were 1092 +/- 225 ng/ml, 291 +/- 37 mL/kg, and 9987 +/- 2021 micrograms x h/L, respectively. The AUC values were higher at the 0.18 mg/kg dose level than at the 0.1 mg/kg dose level (16,848 +/- 5118 micrograms x h/L vs. 7128 +/- 1156 micrograms x h/L, p = 0.009). Patients with ALL had a significantly larger volume of distribution at steady state (332 +/- 47 mL/kg vs. 191 +/- 12 mL/kg, p = 0.04), faster clearance (21 +/- 3 mL/h/kg vs. 11 +/- 2 mL/h/kg, p = 0.03), and lower dose-corrected AUC than patients with NHL (6010 +/- 836 micrograms x h/L vs. 12,044 +/- 2707 micrograms x h/L, p = 0.006). There was a trend toward faster clearance rates (23 +/- 4 mL/h/kg vs. 16 +/- 3 mL/h/kg, p = 0.1), shorter elimination half-lives (5.7 +/- 3.6 hours vs. 13 +/- 8.8 hours, p = 0.1), and shorter mean residence times (11 +/- 3 hours vs. 25 +/- 5 hours, p = 0.08) for non-Caucasian patients as compared to Caucasian patients. When compared to adult patients, pediatric patients showed a significantly larger volume of distribution at steady state (418 +/- 82 mL/kg vs. 252 +/- 34 mL/kg, p = 0.02) and a longer elimination half-lives (18.4 +/- 13.6 hours vs. 8.7 +/- 6.7 hours, p = 0.04). The pharmacokinetics of B43-Genistein was not affected by the gender of the patients or by bone marrow transplantation in past medical history. Overall, B43-Genistein showed favorable pharmacokinetics in this heavily pretreated leukemia/lymphoma patient population, which is reminiscent of its recently reported favorable pharmacokinetics in cynomolgus monkeys. To our knowledge, this is the first clinical pharmacokinetics study of a tyrosine kinase inhibitor containing immunoconjugate.

Safrole-like DNA adducts in oral tissue from oral cancer patients with a betel quid chewing history

Betel quid (BQ) chewing has been associated with an increased risk of oral squamous cell carcinoma (OSCC) and oral submucous fibrosis (OSF). Piper betel inflorescence, which contains 15 mg/g safrole, is a unique ingredient of BQ in Taiwan. Chewing such prepared BQ may contribute to safrole exposure in human beings (420 microM safrole in saliva). Safrole is a known rodent hepatocarcinogen, yet its carcinogenicity in human beings is largely undetermined. In this study, using a (32)P-post-labeling method, we have found a high frequency of safrole-like DNA adducts in BQ-associated OSCC (77%, 23/30) and non-cancerous matched tissue (NCMT) (97%, 29/30). This was in contrast to the absence (< 1/10(9) nucleotides) of such adducts in all of non-BQ-associated OSCC and their paired NCMT (P < 0.001). Six of seven OSF also exhibited the same safrole-like DNA adduct. The DNA adduct levels in OSF and NCMT were significantly higher than in OSCC (P < 0.05). Using co-chromatography and rechromatography techniques, we further demonstrated that these adducts were identical to synthetic safrole-dGMP adducts as well as DNA adducts from 1'-hydroxysafrole-treated HepG2 cells. These results suggest that safrole forms stable safrole-DNA adducts in human oral tissue following BQ chewing, which may contribute to oral carcinogenesis.

Age, gender, and local geographic variations of viral etiology of hepatocellular carcinoma in a hyperendemic area for hepatitis B virus infection

BACKGROUND

There are etiologic variations of hepatocellular carcinoma (HCC) in different geographic areas. Taiwan is a hyperendemic area for hepatitis B virus (HBV) infection. Hepatitis C virus (HCV) infection also plays an important role in HCC development in Taiwan. Identification of local HCV-endemic areas is important to keep HCV from spreading. This study investigated the etiologic variations of HCC in different geographic areas of Taiwan.

METHODS

The authors evaluated the hepatitis B surface antigen (HBsAg) and antibodies to HCV (anti-HCV) status of 284 patients (232 male, 52 female) with HCC. They also evaluated the gender ratio and mean age of these patients.

RESULTS

The mean age of HBsAg positive patients was significantly lower than the mean age of HBsAg negative patients (52.6 +/- 12.3 vs. 61.3 +/- 11.2 years) (P < 0.05). The male-to-female ratio was 4.5:1 for all HCC patients, 7:1 for HBsAg positive HCC patients, and 2.8:1 for anti-HCV positive HCC patients. In Chaiyi County in southern Taiwan, the prevalence of anti-HCV in male HCC patients was 52%, significantly greater than that of Taiwan as a whole (27.6%) (P = 0.07). However, the prevalence of anti-HCV in male HCC patients in Taipei County in northern Taiwan was 8.7%, significantly less than that of Taiwan as a whole (P = 0.043). Of a total of 65 Chiayi-based HCC patients, 55.4% were anti-HCV positive and 46.2% were HBsAg positive. In the Chiayi area, results of multiple logistic regression showed that the HCC patients who were age 60 years or older or who were living in the city area both had highly HCV-related disease.

CONCLUSIONS

The mean age of patients with HBV-related HCC was significantly lower than that of patients with non-HBV-related HCC. The male-to-female ratio for patients with HBV-related HCC was significantly higher than that of patients with HCV-related HCC. The authors identified an area of Taiwan in which HCV-related HCC was prevalent.

Age, gender, and local geographic variations of viral etiology of hepatocellular carcinoma in a hyperendemic area for hepatitis B virus infection

BACKGROUND

There are etiologic variations of hepatocellular carcinoma (HCC) in different geographic areas. Taiwan is a hyperendemic area for hepatitis B virus (HBV) infection. Hepatitis C virus (HCV) infection also plays an important role in HCC development in Taiwan. Identification of local HCV-endemic areas is important to keep HCV from spreading. This study investigated the etiologic variations of HCC in different geographic areas of Taiwan.

METHODS

The authors evaluated the hepatitis B surface antigen (HBsAg) and antibodies to HCV (anti-HCV) status of 284 patients (232 male, 52 female) with HCC. They also evaluated the gender ratio and mean age of these patients.

RESULTS

The mean age of HBsAg positive patients was significantly lower than the mean age of HBsAg negative patients (52.6 +/- 12.3 vs. 61.3 +/- 11.2 years) (P < 0.05). The male-to-female ratio was 4.5:1 for all HCC patients, 7:1 for HBsAg positive HCC patients, and 2.8:1 for anti-HCV positive HCC patients. In Chaiyi County in southern Taiwan, the prevalence of anti-HCV in male HCC patients was 52%, significantly greater than that of Taiwan as a whole (27.6%) (P = 0.07). However, the prevalence of anti-HCV in male HCC patients in Taipei County in northern Taiwan was 8.7%, significantly less than that of Taiwan as a whole (P = 0.043). Of a total of 65 Chiayi-based HCC patients, 55.4% were anti-HCV positive and 46.2% were HBsAg positive. In the Chiayi area, results of multiple logistic regression showed that the HCC patients who were age 60 years or older or who were living in the city area both had highly HCV-related disease.

CONCLUSIONS

The mean age of patients with HBV-related HCC was significantly lower than that of patients with non-HBV-related HCC. The male-to-female ratio for patients with HBV-related HCC was significantly higher than that of patients with HCV-related HCC. The authors identified an area of Taiwan in which HCV-related HCC was prevalent.

In vivo toxicity and pharmacokinetic features of the janus kinase 3 inhibitor WHI-P131 [4-(4'hydroxyphenyl)-amino-6,7- dimethoxyquinazoline

4-(4'Hydroxyphenyl)-amino-6,7-dimethoxyquinazoline (WHI-P131) is a potent and selective inhibitor of the Janus kinase 3, which triggers apoptosis in human acute lymphoblastic leukemia (ALL) cells. In this preclinical study, we evaluated the pharmacokinetics and toxicity of WHI-P131 in rats, mice, and cynomolgus monkeys. Following i.v. administration, the terminal elimination half-life of WHI-P131 was 73.2 min in rats, 103.4 min in mice, and 45.0 min in monkeys. The i.v. administered WHI-P131 showed a very wide tissue distribution in mice. Following i.p. administration, WHI-P131 was rapidly absorbed in both rats and mice, and the time to reach the maximum plasma concentration (tmax) was 24.8 min in rats and 10.0 min in mice. Subsequently, WHI-P131 was eliminated with a terminal elimination half-life of 51.8 min in rats and 123.6 min in mice. The estimated i.p. bioavailability was 95% for rats, as well as for mice. WHI-P131 was quickly absorbed after oral administration in mice with a tmax of 5.8 min, but its oral bioavailability was relatively low (29.6%). The elimination half-life of WHI-P131 after oral administration was 297.6 min. WHI-P131 was not acutely toxic to mice at single i.p. bolus doses ranging from 0.5-250 mg/kg. Two cynomolgus monkeys treated with 20 mg/kg WHI-P131 and one cynomolgus monkey treated with 100 mg/kg WHI-P131 experienced no side effects. Plasma samples from WHI-P131-treated monkeys exhibited potent antileukemic activity against human ALL cells in vitro. To our knowledge, this is the first preclinical toxicity and pharmacokinetic study of a Janus kinase 3 inhibitor. Further development of WHI-P131 may provide the basis for new and effective treatment programs for relapsed ALL in clinical settings.

Influence of genotypes at SAA1 and SAA2 loci on the development and the length of latent period of secondary AA-amyloidosis in patients with rheumatoid arthritis

To examine whether polymorphism at the SAA loci is associated with the development of amyloid protein A (AA)-amyloidosis, we determined the genotypes at the SAA1 and SAA2 loci in 43 AA-amyloidosis patients (amyloidosis population) and 77 patients with rheumatoid arthritis (RA) who had been ill for less than 5 years (early RA population). We also compared the frequencies of the genotypes at the SAA1 locus among 90 Korean, 95 Taiwanese, and 103 Japanese healthy subjects. The frequencies of the gamma/gamma genotype and gamma alleles at the SAA1 locus were significantly higher in the amyloidosis population than in the early RA population (34.9% versus 7.8%, and 58.1% versus 33.8%, chi2 test P=0.0001). The frequencies of the gamma allele at the SAA1 locus in Koreans, Taiwanese, and Japanese were 41.6%, 35.6%, and 37.4%, respectively. The length of the latent period of AA-amyloidosis was significantly longer in the patients with smaller numbers of the gamma allele at the SAA1 locus (Spearman's correlation coefficient: -0.42, P<0.05). On the other hand, the mean C-reactive protein (CRP) level during 2 years prior to the diagnosis of AA-amyloidosis was significantly higher in the patients with larger numbers of the gamma allele at the SAA1 locus (Spearman's correlation coefficient: 0.34, P<0.05). No significant association was found between amyloidosis and polymorphism at the SAA2 locus. We postulate that the allele SAA1gamma renders an RA patient susceptible to amyloidosis, possibly by affecting the severity of inflammation in RA.

The fas and fas ligand pathways in liver allograft tolerance

The Fas and Fas ligand (Fas/FasL) pathways may play a central role in cytotoxicity or immunoregulation in liver transplantation. Here, in an attempt to examine the role of Fas/FasL on drug-free tolerance, we measured mRNA levels of Fas/FasL in livers by reverse transcriptase-polymerase chain reaction (RT-PCR), and also protein levels of Fas/FasL in livers by immunohistochemistry and in serum by dot blot assay. PVG recipients bearing DA livers showed serious rejection between post-operative (POD) days 7 and 14, but this rejection was naturally overcome without any immunosuppression. Fas gene and protein products were expressed on almost every cell in livers taken from naive rats, and at any time point in both syngeneic and allogeneic orthotopic liver transplantation (OLT) rats. In contrast, FasL mRNA in DA livers was detectable at POD 2, peaked at POD 14, and declined at POD 63 in allogeneic OLT (DA-PVG). Although the FasL gene was detectable in isografts at POD 14, its expression was much lower than in allografts. The time course and localization of FasL expression indicated that the expression of FasL gradually switched from infiltrating cells to hepatocytes when the rejection was naturally overcome and tolerance was induced in this OLT model. Soluble Fas could constitutively be detected at any time point in the serum of the tolerogenic OLT (DA-PVG) rats and was not diminished during the rejection phase. Soluble FasL peaked at POD 14 in allogeneic OLT, while sFasL was significantly lower in the serum of normal and syngeneic OLT rats. These findings suggest that the Fas and FasL pathways, including soluble forms, may contribute to the control of the immune response in this drug-free tolerance OLT model.

11,12-Epoxyeicosatrienoic acid stimulates endogenous mono-ADP-ribosylation in bovine coronary arterial smooth muscle

The role of endogenous ADP-ribosylation in mediating the activation of the Ca(2+)-activated K(+) channels was determined in bovine coronary arteries. Endogenous ADP-ribosylation was examined by incubating coronary arterial homogenates or lysates of cultured coronary arterial smooth muscle cells with [adenylate-(32)P]NAD. Four (32)P-labeled proteins were observed at 51, 52, 80, and 124 kDa in the homogenates and lysates. This reaction was enhanced by the addition of 11,12-epoxyeicosatrienoic acid (11,12-EET), a cytochrome P450-derived eicosanoid, and GTP to the incubation. By Western blot analysis, 42- and 70-kDa proteins were recognized by specific antibodies against ADP-ribosyltransferase in the coronary arterial homogenates and smooth muscle cell lysate but not in the lysate of endothelial cells. The 52-kDa acceptor protein of endogenous ADP-ribosylation comigrated with a protein ADP-ribosylated by cholera toxin and was recognized and immunoprecipitated by an anti-G(S)alpha antibody. These results suggest that G(S)alpha is one of several acceptors of the ADP-ribose moiety. As shown by the patch-clamp technique, 11,12-EET stimulated the activation of the K(+) channels in the smooth muscle cells, and this activation was completely blocked by novobiocin, vitamin K(1), 3-aminobenzamide, and m-iodobenzylguanidine, inhibitors of endogenous mono-ADP-ribosyltransferases. We conclude that endogenous mono-ADP-ribosyltransferases are present in smooth muscle from bovine coronary arteries. These enzymes transfer ADP-ribose to the cellular proteins such as G(S)alpha and may mediate intracellular signal transduction in coronary vascular smooth muscle. In the coronary circulation, the ADP-ribosylation signaling pathway may play an important role in mediating the activation of the K(+) channels induced by 11,12-EET.

Functional and transcriptional analyses of a fengycin synthetase gene, fenC, from Bacillus subtilis

A 37-kb DNA fragment containing five fengycin synthetase genes, including fenC, fenD, fenE, fenA, and fenB, was cloned and sequenced. Among these genes, fenC encodes a fengycin synthetase 2,560 amino acids long with an estimated molecular mass of 287 kDa. This protein contains two amino acid activation modules, FenC1 and FenC2, which activate L-glutamic acid and L-ornithine, respectively. Primer extension, using mRNA isolated from the log-phase cells, identified a transcription start site located 86 nucleotides upstream from the initiation codon of fenC, implying that a promoter is located upstream from the start site. Primer extension using total RNA isolated from stationary-phase cells also identified a transcription start site located 61 nucleotides upstream from the initiation codon of fenC. Gene fusion studies demonstrated that in nHA medium, the cells transcribe the fengycin synthetase genes at two different stages of cell growth. The promoter is active during the log phase, and the activity reaches the highest level during the late log phase. The activity decreases sharply but is maintained at a low level for approximately 24 h after cells enter the early stationary phase. The results of this investigation also suggest that the transcription of fenC is positively regulated during the late log phase. Results presented herein provide further insight into fengycin synthesis by B. subtilis F29-3.

Evaluation of the pharmacokinetic features and tissue distribution of the potent nonnucleoside inhibitor of HIV-1 reverse transcriptase, N-[2-(2-fluorophenethyl)]-N'-[2-(5-bromopyridyl)]-thiourea (HI-240) with an analytical HPLC method

PURPOSE

The purpose of the present study was to examine the pharmacokinetic features and tissue distribution of N-[2-(2-fluorophenethyl)]-N'-[2-(5-bromopyridyl)]-thiourea (HI-240), a novel non-nucleoside inhibitor of HIV reverse transcriptase with potent anti-viral activity against AZT-sensitive as well as multidrug-resistant HIV-1 strains.

METHODS

A sensitive and accurate high performance liquid chromatography (HPLC)-based quantitative detection method was established to measure concentrations of HI-240 in pharmacokinetic studies. The plasma concentration-time data were modeled by using the WinNonlin program to estimate the pharmacokinetic parameter values.

RESULTS

HI-240 had an elimination half-life of 78.3 +/- 2.0 min after i.v. administration and 196.8 +/- 3.1 min after i.p. administration. The systemic clearance of HI-240 was 2194 +/- 61 ml/h/kg after i.v. administration and 9339 +/- 1160 ml/h/kg after i.p. administration. Following i.v. injection, HI-240 rapidly distributed to and accumulated in multiple tissues with particularly high accumulation in adipose tissue, adrenal gland, and uterus+ovary. The concentration of HI-240 in brain tissue was comparable to that in the plasma, indicating that HI-240 easily crosses the blood-brain-barrier. Following i.p. injection, HI-240 was rapidly absorbed with a t1/2ka and a tmax values of less than 10 min. Following oral administration, HI-240 was absorbed with a t1/2ka of 4.2 +/- 1.1 min and a tmax of 95.1 +/- 25.1 min. The intraperitoneal bioavailability was estimated at 23.5%, while the oral bioavailability was only 1%.

CONCLUSIONS

The HPLC-based accurate and precise analytical detection method and pilot pharmacokinetic studies described herein provide the basis for advanced preclinical pharmacodynamic studies of HI-240. The ability of HI-240 to distribute rapidly and extensively into extravascular compartments and easily cross the blood-brain barrier represent significant pharmacokinetic advantages over AZT.

Magnetic resonance of the hepatic veins with angular reconstruction: application in living-related liver transplantation

BACKGROUND

Preoperative mapping of the hepatic venous system of the partial liver graft is indispensable to the success of living-related liver transplantation. We assessed the accuracy of magnetic resonance (MR) venography with angular reconstruction in depicting the tributaries of the middle hepatic vein and left hepatic vein in the donors, which was essential in graft retrieval and venoplasty.

METHODS

Nineteen living-related liver transplantation donors underwent a pretransplantation survey, including sonography and MRI for hepatic venous evaluation. T1-weighted images were reconstructed manually, using the inferior vena cava as a fixed point for tilting to produce an oblique plane image where both the middle hepatic vein and left hepatic vein could be demonstrated draining into the inferior vena cava. The reconstructed images of the hepatic veins were compared with preoperative sonography, intraoperative sonography, and operative findings.

RESULTS

Preoperative sonography and MR findings correlated well with the operative findings in the major hepatic veins. The MR venography of the ramification of the hepatic veins has an accuracy of 93%, the sonography, 84%. Sonography is slightly inferior in the evaluation of the hepatic vein in segment 4 and the left superior hepatic vein, with an accuracy of 73% and 67%, respectively.

CONCLUSION

MR venography with angular reconstruction is accurate in depicting the complex distribution of the hepatic veins of the left liver, providing important information for decision making as to the cutting plane during graft retrieval and the method of venoplasty and anastomosis. Thus, unnecessary blood loss could be avoided and vascular complications could be prevented, as these conditions would be unacceptable for a healthy living donor. We propose that MR venography, a rapid and reliable technique, is an appropriate alternative examination or complementary modality to sonography in the pretransplantation evaluation of the living donor.

Pharmacokinetic features and metabolism of calphostin C, a naturally occurring perylenequinone with antileukemic activity

PURPOSE

To examine the pharmacokinetic features and metabolism of calphostin C, a naturally occurring perylenequinone with potent antileukemic activity.

METHODS

HPLC-based quantitative detection methods were used to measure calphostin C levels in lysates of leukemic cells and in plasma of mice treated with calphostin C. The plasma concentration-time data were analyzed using the WinNonlin program. In vitro esterases and a microsome P450 preparation in conjunction with a LC-MS(API-EI) system were used to study the metabolism of calphostin C.

RESULTS

An intracellular exposure level (AUC0-6h) of 257 microM x h was achieved after in vitro treatment of NALM-6 cells with calphostin C at a 5 microM final concentration in culture medium. After intraperitoneal (i.p.) injection of a 40 mg/kg nontoxic bolus dose of calphostin C, the estimated Cmax was 2.9 microM, which is higher than the effective in vitro concentration of calphostin C against leukemic cells. Drug absorption after i.p. administration was rapid with an absorption half-life of 24.2 min and the estimated t(max) was 63.0 min. Calphostin C was cleared with an elimination half-life of 91.3 min. An inactive and smaller metabolite (calphostin B) was detected in plasma of calphostin C-treated mice with a t(max) of 41.3 min. Esterase (but not P450) treatment of calphostin C in vitro yielded an inactive metabolite (calphostin B) of the same size and elution profile.

CONCLUSIONS

Target plasma calphostin C concentrations of potent antileukemic activity can be reached in mice at nontoxic dose levels. This pilot pharmacokinetic study of calphostin C combined with the availability of the described quantitative HPLC method for its detection in cells and plasma provide the basis for future preclinical evaluation of calphostin C and its potential as an anti-leukemic drug.

Safrole-induced oxidative damage in the liver of Sprague-Dawley rats

Safrole is a weak hepatocarcinogen, and its carcinogenic effect has been linked to the formation of stable safrole DNA adducts. In this study, we tested whether safrole also induces oxidative damages in Sprague-Dawley rats. By single i.p. injection, safrole dose-dependently induced the formation of hepatic lipid hydroperoxides (LHP) and 8-hydroxy-2'-deoxyguanosine (8-OH-dG). The safrole-induced LHP reached peak level on day 3 and gradually returned to the basal level on day 15. On the other hand, 8-OH-dG levels from the similarly treated rats peaked on day 5 and returned to basal level on day 15. Safrole also dose-dependently induced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. We also examined the protective effect of vitamin E, deferoxamine and N-acetylcysteine against the safrole-induced oxidative damage. N-Acetylcysteine, the precursor of glutathione, exerted the greatest protective effect among the three antioxidants tested. In contrast, buthionine sulfoximine, the glutathione synthesis inhibitor, enhanced the safrole-induced oxidative damage, as evidenced by the elevation of LHP and 8-OH-dG levels on day 3 (P<0.05). These findings demonstrate that safrole treatment induces oxidative damage in rat hepatic tissue, and glutathione plays an important protective role. This oxidative damage may be involved in the hepatocarcinogenic effect of safrole.

Expression of nm23 in the primary tumor and the metastatic regional lymph nodes of patients with gastric cardiac cancer

Tumor recurrence and distant metastasis are major causes of treatment failure in gastric cardiac cancer (GCC). Rapid growth of tumor cells and reduced expression of nm23, a metastatic suppressor gene, in tumor cells have been suggested as two important mechanisms for disease progression of GCC. Therefore, to determine the prognostic value of nm23 expression in GCC, we used immunohistochemistry to examine the expression of nm23 in the pathological sections of both gastric cancer and metastatic lymph nodes from 24 stage III patients. Twenty-two patients had total gastrectomy, and two patients had proximal subtotal gastrectomy with a D2 dissection. Postoperative adjuvant therapy was provided, and the clinical responses were followed routinely. Clinical correlation was evaluated by chi2 with Fisher's exact test and survival by log-rank test. Our results show that the reduced nm23 expression in the primary tumor and in the nodal metastasis is the most useful marker for the poor prognosis of GCC following surgery.

Characterization of residual lignin after SO(2)-catalyzed steam explosion and enzymatic hydrolysis of Eucalyptus viminalis wood chips

The lignin component found in both water insoluble (WI) and water and alkali insoluble (WIA) fractions derived from SO(2)-impregnated steam-exploded eucalyptus chips (SEE) was isolated and characterized. Dioxane lignins with a sugar content lower than 2% (w/w) were obtained after each material was treated with commercial cellulases. The C9 formulas of both SEE-WI and SEE-WIA dioxane lignins were C(9)H(6.83)N(0.04)O(2.24)(OCH(3))(1.21)(OH(aro))(0.56)(OH(ali))(0. 77) and C(9)H(8.65)N(0.29)O(1.97)(OCH(3))(0.90)(OH(aro))(0. 46)(OH(ali))(1.02), respectively. The weight-average molecular weight (M(w)) of the SEE-WI lignin corresponded to 3.85 kDa, whereas the SEE-WIA lignin had an M(w) of 3.66 kDa for the same polydispersity of 2.4. The SEE-WIA lignin was shown to be more thermally stable than the SEE-WI lignin, requiring temperatures in the range of 520 degrees C for complete degradation. FTIR and (1)H NMR analyses of both untreated and peracetylated lignin fractions showed that (a) the alkali insoluble lignin contained a relatively higher degree of substitution in aromatic rings per C9 unit and that (b) alkaline extraction removed lignin fragments containing appreciable amounts of phenolic hydroxyl groups.

Transhepatic artery chemoembolization for liver metastases of primary retroperitoneal endodermal sinus tumor. A case report

BACKGROUND

Primary retroperitoneal endodermal sinus tumors (EST) are extremely rare and highly malignant. Hepatic metastases from EST are often very difficult to manage and carry a dismal prognosis. Transhepatic artery chemoembolization has been widely applied in primary unresectable hepatoma and had been reported to have antitumor activity for some metastatic tumors. We report a case in which transhepatic artery chemo-embolization was employed to control hepatic metastases from EST.

CASE

A 35-year-old woman presented to our service with primary retroperitoneal EST associated with multiple hepatic metastases. The patient underwent aggressive debulking surgery followed by a combination chemotherapy regimen of cisplatin, vinblastine and bleomycin. Transhepatic artery chemoembolization with adriamycin, lipoidol and gelfoam was subsequently employed to treat hepatic metastases.

CONCLUSION

The combination of transhepatic artery chemoembolization and systemic chemotherapy after surgical resection of primary retroperitoneal EST was effective in controlling the hepatic disease in this case.

Structure-activity relationships of naturally occurring and synthetic opioid tetrapeptides acting on locus coeruleus neurons

Intracellular recording was used to study the effects of eight opioid tetrapeptides with similar amino acid sequences, namely endomorphin-1 (Tyr-Pro-Trp-Phe-NH2), endomorphin-2 (Tyr-Pro-Phe-Phe-NH2), morphiceptin (Tyr-Pro-Phe-Pro-NH2), hemorphin-4 (Tyr-Pro-Trp-Thr), Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2), Tyr-W-MIF-1 (Tyr-Pro-Trp-Gly-NH2), TAPS (Tyr-D-Arg-Phe-Sar) and DALDA (Tyr-D-Arg-Phe-Lys-NH2), on neurons of the rat locus coeruleus, using a submerged brain slice preparation. All the tetrapeptides inhibited the spontaneous firing of all neurons of the locus coeruleus tested. Higher concentrations also caused hyperpolarization of the neurons and a reduction in input resistance. These inhibitory effects were rapidly and completely reversed by CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2, a selective micro-opioid receptor antagonist). The IC50 of the opioid tetrapeptides, in terms of inhibition of spontaneous firing of locus coeruleus neurons, as compared to the concentrations which produced a 5-mV hyperpolarization (HC5 mV) were calculated, giving the same rank order of potency: TAPS (IC50 = 1.9 nM, HC5 mV = 3.4 nM) > endomorphin-1 (IC50 = 8.8 nM, HC5 mV = 22.1 nM) and endomorphin-2 (IC50 = 5.3 nM, HC5 mV = 16.1 nM)> DALDA (IC50 = 20 nM, HC5 mV = 143 nM) > morphiceptin (IC50 = 65 nM, HC5 mV = 335 nM) > Tyr-W-MIF-I (IC50 = 3.8 microM, HC5 mV = 6.7 microM) > hemorphin-4 (IC50 = 6.7 microM, HC5 mV = 36.9 microM) > Tyr-MIF-1 (IC50 = 37.5 microM, HC5 mV = 76.2 microM). Comparison of the ability of endomorphin-1 and endomorphin-2 to inhibit spontaneous firing based on single-cell recordings (n = 5) showed these two peptides to be equipotent. Based on these results, the structure-activity relationships of these opioid tetrapeptides are discussed herein.

WHI-05, a novel bromo-methoxy substituted phenyl phosphate derivative of zidovudine, is a dual-action spermicide with potent anti-HIV activity

Heterosexual transmission of HIV to women is the fastest-growing mode of transmission. In a systematic effort to develop a microbicide capable of preventing HIV transmission as well as providing fertility control, novel phenyl phosphate derivatives of 3'-azido-3'-deoxythymidine (zidovudine, ZDV) have been identified that exhibit potent anti-HIV and spermicidal activities. This study reports the synthesis, characterization, and preclinical formulation of compound WHI-05, 5-bromo-6-methoxy-5,6-dihydro-3'-azidothymidine-5'-(p-methoxyphenyl) methoxyalaninyl phosphate. The anti-HIV activities of WHI-05 and ZDV were compared by measuring p24 antigen production and reverse transcriptase activity as markers of viral replication using human peripheral blood mononuclear cells (PBMC) infected with both ZDV-sensitive and ZDV-resistant strains of HIV. The sperm immobilizing activity (SIA) of WHI-05 was compared with that of ZDV and nonoxynol-9 (N-9) by computer-assisted sperm analysis (CASA). The effect of WHI-05 on sperm membrane integrity was examined by high resolution, low voltage scanning electron microscopy (HR-LVSEM). The in vitro cytotoxicity profile of WHI-05 versus N-9 were compared using normal human vaginal, ectocervical, and endocervical epithelial cells. The in vivo vaginal tolerance, absorption, and toxicity of a 2% WHI-05 gel-microemulsion was tested in the rabbit. Whereas ZDV displayed potent anti-HIV activity but lacked SIA, WHI-05 elicited both potent anti-HIV activity and SIA. WHI-05 inhibited the replication of ZDV-sensitive as well as ZDV-resistant strains of HIV in PBMC. CASA combined with HR-LVSEM demonstrated that WHI-05-induced SIA was not associated with membrane damage. Unlike, N-9, the spermicidal activity of WHI-05 was not associated with cytotoxicity to reproductive tract epithelial cells. Repetitive intravaginal application of a 2% WHI-05 gel-microemulsion did not damage the vaginal epithelium or cause local inflammation in the rabbit model. As a potent anti-HIV agent that has spermicidal activity and is devoid of mucosal toxicity, WHI-05 shows a unique clinical potential to become the active ingredient for a vaginal contraceptive for women who are at high risk for acquiring HIV by heterosexual vaginal transmission.

Synthesis, characterization and preclinical formulation of a dual-action phenyl phosphate derivative of bromo-methoxy zidovudine (compound WHI-07) with potent anti-HIV and spermicidal activities

In a systematic effort to develop a microbicide contraceptive capable of preventing transmission of human immunodeficiency virus (HIV), as well as providing fertility control, we have previously identified novel phenyl phosphate derivatives of zidovudine (ZDV) with 5-halo 6-alkoxy substitutions in the thymine ring and halo substitution in the phenyl moiety respectively. Here, we describe the synthesis, characterization, and successful preclinical formulation of our lead compound, 5-bromo-6-methoxy-3'-azidothymidine-5'-(p-bromophenyl) methoxyalaninyl phosphate (WHI-07), which exhibits potent anti-HIV and sperm immobilizing activities. The anti-HIV activity of WHI-07 was tested by measuring viral p24 antigen production and reverse transcriptase activity as markers of viral replication in HIV-1 infected human peripheral blood mononuclear cells (PBMC). WHI-07 inhibited replication of HIV in a concentration-dependent fashion with nanomolar IC50 values. The effects of WHI-07 on human sperm motion kinematics were analysed by computer-assisted sperm analysis (CASA), and its effects on sperm membrane integrity were examined by confocal laser scanning microscopy (CLSM), and high-resolution low-voltage scanning electron microscopy (HR-LVSEM). WHI-07 caused cessation of sperm motility in a concentration- and time-dependent fashion. The in-vitro cytotoxicities of WHI-07 and nonoxynol-9 (N-9) were compared using normal human ectocervical and endocervical epithelial cells by the MTT cell viability assay. Unlike N-9, WHI-07 had no effect upon sperm plasma and acrosomal membrane integrity. N-9 was cytotoxic to normal human ectocervical and endocervical cells at spermicidal doses, whereas WHI-07 was selectively spermicidal. The in-vivo vaginal absorption and vaginal toxicity of 2% gel-microemulsion of WHI-07 was studied in the rabbit model. The sperm immobilizing activity of WHI-07 was 18-fold more potent than that of N-9. Over a 10 day period, there was no irritation or local toxicity to the vaginal epithelia or systemic absorption of WHI-07. Therefore, as a potent anti-HIV agent with spermicidal activity, and lack of mucosal toxicity, WHI-07 may have the clinical potential to become the active ingredient of a vaginal contraceptive for women who are at high risk for acquiring HIV by heterosexual vaginal transmission.

Quantitative high-performance liquid chromatographic method for pharmacokinetic studies of the potent mast cell inhibitor 4-(4'-hydroxyphenyl)amino-6,7-dimethoxyquinazoline (WHI-P131)

The novel quinazoline derivative 4-(4'-hydroxyphenyl)amino-6,7-dimethoxyquinazoline (WHI-P131) has recently been identified as a potent mast cell inhibitor capable of preventing IgE/antigen induced cutaneous as well as systemic fatal anaphylaxis in mice. Here we describe a sensitive high-performance liquid chromatography (HPLC)-based quantitative detection method for measurement of WHI-P131 levels in plasma as well as in target mast cells. The average extraction recovery for WHI-P131 was 88.4% for plasma and 75.7% for RBL-2H3 mast cell lysates. Good linearity (r>0.999) was observed throughout the concentration range of 0.1-20 microM in plasma and 0.01-5 nmol in 5 x 10(6) cells (0.5-238 microM per cell) for WHI-P131. Intra- and inter-assay variabilities were <7% and the lowest detection limit of WHI-P131 was 0.05 microM in plasma and 0.005 nmol in 5 million cells, respectively, at a signal-to-noise ratio of approximately 2. The practical utility of this new HPLC method was confirmed in a pilot pharmacokinetic study in BALB/c mice as well as in a cellular drug uptake and disposition study in RBL-2H3 mast cells. After intraperitoneal administration of a non-toxic 40 mg/kg bolus dose of WHI-P131, the estimated maximum plasma concentration was 92.7 microM, which is approximately 1-log higher than the effective in vitro mast cell inhibitory concentrations of WHI-P131. The drug absorption was rapid with an absorption half-life of only 2.9 min and the estimated time to reach the maximum plasma concentration was 8.3 min. WHI-P131 was cleared with an apparent systemic clearance rate of 2586 ml/h/kg and an elimination half-life of 1.8 h. An intracellular exposure level (AUC) of 55 microM x h was obtained after in vitro treatment of RBL-2H3 mast cells with WHI-P131 at a 33.6 microM final concentration in culture medium. The availability of the described quantitative HPLC detection method for WHI-P131 provides the basis for further development of WHI-P131 as an anti-allergic drug through detailed pharmacodynamic studies in preclinical animal models.

Differential serine phosphorylation regulates IkappaB-alpha inactivation

NF-kappaB is a ubiquitous transcription factor involved in the signal transduction mechanisms of the immune response, acute phase reactions, and viral infections. NF-kappaB proteins are retained in the cytoplasm by association with an inhibitor, termed IkappaB. Studies on the regulation of mammalian IkappaB-alpha have revealed that two amino-terminal conserved phosphoserines are the target sites of incoming signals. We report that the corresponding amino-terminal phosphoserines of avian IkappaB-alpha are phosphorylation targets leading to inactivation of IkappaB-alpha upon stimulation. In addition, we show differential roles for these two serines. Mutation of serine 40 to alanine blocks all stimuli tested (TNF-alpha, phorbol ester, and anti-CD3 and anti-CD28), leading to NF-kappaB activation, while mutation of serine 36 to alanine attenuates only certain transduced signals (PMA, TNF-alpha). These novel findings support the hypothesis that the amino-terminal phosphoserine residues of avian IkappaB-alpha differentially mediate NF-kappaB signal transduction pathways and activation by distinct signals, thereby resulting in the activation NF-kappaB.

Profile of cytokine expression in nasopharyngeal carcinomas: a distinct expression of interleukin 1 in tumor and CD4+ T cells

Nasopharyngeal carcinoma (NPC) is an epithelial cancer that is causally associated with Epstein-Barr virus (EBV) infection. NPC tumor biopsies are characterized histopathologically by an abundant infiltration of nonmalignant lymphocytes. We analyzed the expression of various cytokines in NPC tissues to investigate the interaction of the infiltrating lymphocytes and tumor cells. Analysis using reverse transcriptase-PCR revealed the expression of a panel of cytokines in the NPC biopsies: interleukin (IL)-1alpha, IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-10, IFN-gamma, tumor necrosis factor-alpha, transforming growth factor-beta, and IL-1 receptor types I and II. Elevated expression of IL-1alpha and IL-1beta was observed in primary tumors and NPC metastases compared to control tissues. Interestingly, this increased expression correlated with the EBV-encoded viral IL-10 transcript. To determine which cells were responsible for producing IL-1, we determined the cellular constituents of NPC biopsies by immunoflow cytometric analysis. On the basis of data from these analyses, the three major specific cell populations, epithelial cells, CD4+ T cells, and CD8+ T cells, were selected from five NPC tumors using specific, antibody-coated paramagnetic beads. Reverse transcriptase-PCR of RNA from these fractionated cells showed that transcripts of IL-1alpha and IL-1beta were present not only in the malignant epithelial cells but also in CD4+ T cells infiltrating the tumor, a finding confirmed by immunohistochemical staining. We hypothesize that the unusual synthesis of IL-1alpha and IL-1beta by EBV-positive epithelial cells as well as by CD4+ T cells might contribute to lymphocyte infiltration and/or tumor growth during NPC development.

Quantitative high-performance liquid chromatography-based detection method for calphostin C, a naturally occurring perylenequinone with potent antileukemic activity

Calphostin C is a potent inhibitor of protein kinase C and can induce Ca2+-dependent apoptosis in human ALL cells. Further development of calphostin C will require detailed pharmacodynamic studies in preclinical animal models. Therefore, we established a sensitive and accurate high-performance liquid chromatography (HPLC)-based quantitative detection method for the measurement of calphostin C levels in plasma. Extraction of calphostin C from plasma was performed by precipitation of plasma protein using acetonitrile and an aliquot of extracted supernatant was injected onto a Hewlett-Packard HPLC system constituting a 250x4 mm LiChrospher 100, RP-18 (5 microm) in conjunction with a 4x4 mm LiChrospher 100, RP-18 guard column (5 microm). The eluted compounds were detected by diode array detection set at a wavelength of 479 nm. Acetonitrile-water containing 0.1% trifluoroacetic acid and 0.1% triethylamine (70:30, v/v) was used as the mobile phase. The average extraction recovery from plasma was 97.3%. Good linearity (r>0.999) was observed throughout the concentration range of 0.05-40 microM for calphostin C in 50 microl of plasma. Intra- and inter-assay variabilities were less than 6% in plasma. The lowest detection limit of calphostin C in 50 microl plasma was 0.02 microM at a signal-to-noise ratio of approximately 3. The availability of this assay will now permit detailed pharmacodynamic and pharmacokinetic studies of calphostin C in vivo.

Maternal smoking and Down syndrome: the confounding effect of maternal age

Inconsistent results have been reported from studies evaluating the association of maternal smoking with birth of a Down syndrome child. Control of known risk factors, particularly maternal age, has also varied across studies. By using a population-based case-control design (775 Down syndrome cases and 7,750 normal controls) and Washington State birth record data for 1984-1994, the authors examined this hypothesized association and found a crude odds ratio of 0.80 (95% confidence interval 0.65-0.98). Controlling for broad categories of maternal age (<35 years, > or =35 years), as described in prior studies, resulted in a negative association (odds ratio = 0.87, 95% confidence interval 0.71-1.07). However, controlling for exact year of maternal age in conjunction with race and parity resulted in no association (odds ratio = 1.00, 95% confidence interval 0.82-1.24). In this study, the prevalence of Down syndrome births increased with increasing maternal age, whereas among controls the reported prevalence of smoking during pregnancy decreased with increasing maternal age. There is a substantial potential for residual confounding by maternal age in studies of maternal smoking and Down syndrome. After adequately controlling for maternal age in this study, the authors found no clear relation between maternal smoking and the risk of Down syndrome.

T cell receptor gene deletion circles identify recent thymic emigrants in the peripheral T cell pool

Progenitor cells undergo T cell receptor (TCR) gene rearrangements during their intrathymic differentiation to become T cells. Rearrangements of the variable (V), diversity (D), and joining (J) segments of the TCR genes result in deletion of the intervening chromosomal DNA and the formation of circular episomes as a byproduct. Detection of these extrachromosomal excision circles in T cells located in the peripheral lymphoid tissues has been viewed as evidence for the existence of extrathymic T cell generation. Because all of the T cells in chickens apparently are generated in the thymus, we have employed this avian model to determine the fate of the V(D)J deletion circles. In normal animals we identified TCR Vgamma-Jgamma and Vbeta-Dbeta deletion circles in the blood, spleen, and intestines, as well as in the thymus. Thymectomy resulted in the gradual loss of these DNA deletion circles in all of the peripheral lymphoid tissues. A quantitative PCR analysis of Vgamma1-Jgamma1 and Vbeta1-Dbeta deletion circles in splenic gamma delta and Vbeta1(+) alphabeta T cells indicated that their numbers progressively decline after thymectomy with a half-life of approximately 2 weeks. Although TCR deletion circles therefore cannot be regarded as reliable indicators of in situ V(D)J rearrangement, measuring their levels in peripheral T cell samples can provide a valuable index of newly generated T cells entering the T cell pool.

Immunization with a synthetic peptide conjugate derived from the N-terminal sequence of either the beta-chain of haemoglobin or the immunosuppressive protein (reOLT 4) reduces the litter size of pregnant rats

A synthetic peptide conjugate based on the N-terminal sequence of a 10 000 MW immunosuppressive serum protein (reOLT 4) was used to immunize female Lewis rats prior to mating, in order to determine whether blocking this protein had an effect on pregnancy. The N-terminal sequence of (reOLT 4) has close sequence homology to the beta-chain of rat haemoglobin so a peptide conjugate based on the N-terminal sequence of this protein was also used to immunize female Lewis rats. Controls included animals that were not immunized and animals that received the peptide carrier, diphtheria toxoid (DT). No statistical differences were found in gestation time or litter sizes in these groups. Differences were, however, evident between these groups and animals that received DT-(reOLT 4) (group 4) or the DT-beta-chain haemoglobin (group 5). There were no statistical differences in litter size or gestation time for group 4 when compared with group 5. Enzyme-linked immunosorbent assay and dot-blot analysis revealed that rats from both groups also had strong responses against DT, the peptide conjugate they were immunized with and the corresponding full-length protein. In both cases, animals from group 4 and group 5 had weak responses to the peptide that they did not receive, together with lower erythrocyte counts and haematocrits, and elevated heart to body weight ratios. Additionally, antibody purified on a (reOLT 4) immunoaffinity column was capable of binding to rat erythrocytes. A second investigation comparing anaemia prior to fertilization and maintained anaemia over the gestation period revealed that only the latter was capable of decreasing litter size to the same degree as obtained for groups 4 and 5. We conclude that for groups 4 and 5 it is the autoimmune effect of continual anaemia over the gestation period, mediated by autoantibodies, which results in the observed lower litter size.

Overexpression of p53 is not associated with drug resistance of gastric cancers to 5-fluorouracil-based systemic chemotherapy

BACKGROUND/AIMS

Recent in vitro evidence has strongly suggested that most anti-cancer drugs exert their cytotoxic effects via a p53-dependent apoptosis pathway. An intact p53 molecule appears to be a prerequisite for the cancer cells to be susceptible to these drugs. In this study, we specifically examined if overexpression of p53 may confer drug resistance on human gastric cancer.

METHODOLOGY

All patients were treated by an empirical HDFL regimen (weekly 24-hour infusion of 5-FU, 2,600 mg/m2 and leucovorin, 300 mg/m2) in a prospective phase II clinical trial. Among them, patients with adequate pre-chemotherapy gastric cancer tissues for immunohistochemical studies were selected for this study. A p53 DO7 monoclonal antibody was used to detect the overexpression of p53. The results were designated as "-" or "+" by the independent interpretation of two pathologists.

RESULTS

A total of 30 patients, 18 men and 12 women, with a median age of 61.5 years (range: 32-78 years), were studied. There were 15 responders and 15 non-responders to HDFL chemotherapy. The percentage of p53 overexpression with positive DO7 staining was 20.0% (6 out of 30). There were no significant differences in the pertinent clinicopathologic features between the patients with positive staining of p53 and the patients with negative staining of p53. Three out of 6 (50.0%) patients with positive staining of p53 and 12 out of 24 (50.0%) patients with negative staining of p53 responded to chemotherapy, respectively (p = 1.000 by Fisher's exact test).

CONCLUSIONS

Our data suggested that the overexpression of p53 does not predict drug resistance to 5-FU of human gastric cancer.

Inflammatory pseudotumor of the liver in Kostmann's disease

A case in which inflammatory pseudotumor of the liver (IPTL) seemed to complicate severe congenital neutropenia (Kostmann's disease) is reported. IPTL is a rare entity, especially in childhood. The exact etiology of this lesion is unknown, but it is generally regarded as a benign, reactive inflammatory condition. Based on 15 reported pediatric cases in the literature, the causes, diagnosis, and treatment of IPTL are discussed.

Synthesis of dual function (5R,6R)- and (5S,6S)-5-bromo-6-methoxy-5,6-dihydro-AZT-5'-(para-bromophenyl methoxyalaninyl phosphate) as novel spermicidal and anti-HIV agents

We synthesized a novel compound, 5-bromo-6-methoxy-5,6-dihydro-AZT-5'- (p-bromophenyl methoxyalaninyl phosphate), which had an EC50 value of 5 microM in sperm motility assays. This is > 1 log10 better than that of the detergent spermicide nonoxynol-9 (EC50 81 microM). The compound also displayed a potent anti-human immunodeficiency virus (HIV) activity with an IC50 value of 0.005 microM in HIV replication assays, which was virtually identical to that of AZT (IC50 0.006 microM) and > 2 log10 more potent than that of nonoxynol-9 (IC50 2.2 microM). The promising results reported herein recommend the further development of the dual function 5-halo-6-alkoxyl-5,6-dihydro-AZT derivatives as a new class of vaginal contraceptives capable of preventing the sexual transmission of HIV while providing fertility control for women who are at high risk of acquiring HIV by heterosexual transmission. These dual function 5-halo-6-alkoxyl-5,6-dihydro-AZT derivatives may also have utility in curbing domestic and wildlife animal retroviral transmissions.

Pharmacokinetics and biologic activity of the novel mast cell inhibitor, 4-(3-hydroxyphenyl)-amino-6,7-dimethoxyquinazoline in mice

PURPOSE

The purpose of the present study was to examine the pharmacodynamic and pharmacokinetic features of the novel mast cell inhibitor 4-(3'-Hydroxyphenyl)-amino-6,7-dimethoxyquinazoline (WHI-P180) in mice.

METHODS

A high performance liquid chromatography (HPLC)-based quantitative detection method was used to measure plasma WHI-P180 levels in mice. The plasma concentration-time data was fit to a single compartment pharmacokinetic model by using the WinNonlin program to calculate the pharmacokinetic parameters. A cutaneous anaphylaxis model was used to examine the pharmacodynamic effects of WHI-P180 on anaphylaxis-associated vascular hyperpermeability.

RESULTS

The elimination half-life of WHI-P180 in CD-1 mice (BALB/ c mice) following i.v., i.p., or p.o. administration was less than 10 min. Systemic clearance of WHI-P180 was 6742 mL/h/kg in CD-I mice and 8188 mL/h/kg in BALB/c mice. Notably, WHI-P180, when administered in two consecutive nontoxic i.p. bolus doses of 25 mg/kg, inhibited IgE/antigen-induced vascular hyperpermeability in a well-characterized murine model of passive cutaneous anaphylaxis.

CONCLUSIONS

WHI-P180 is an active inhibitor of IgE-mediated mast cell responses in vitro and in vivo. Further preclinical characterization of WHI-P180 may improve the efficacy of WHI-P180 in vivo and provide the basis for design of effective treatment and prevention programs for mast cell mediated allergic reactions.

A transient increase in endogeneous erythropoietin levels after paediatric liver transplantation

We investigated whether liver transplantation affects endogeneous erythropoietin (EPO) synthesis. Serum EPO levels were measured before transplantation and during the peri-transplant period in ten consecutive paediatric patients who had received a liver allograft without recombinant EPO therapy. All patients were anaemic on post-operative day 1 (POD 1); however, the haemoglobin levels of three patients gradually increased and required phlebotomy on POD 5-9. The serum levels of EPO in all patients were within the normal range before surgery, but six of the ten patients had a transient increased level of EPO at 1248 h after transplantation. A transient increase of endogeneous EPO following paediatric liver transplantation may be associated with extramedullary erythropoiesis in human liver grafts.

Enhancing effects of a mono-bromo substitution at the para position of the phenyl moiety on the metabolism and anti-HIV activity of d4T-phenyl methoxyalaninyl phosphate derivatives

d4T-5'-[p-Bromophenyl methoxyalaninyl phosphate] (d4T-pBPMAP), a novel phenyl phosphate derivative of 2',3'-didehydro-2',3'-dideoxythymidine (d4T) that has an enhanced ability to undergo hydrolysis due to the electron withdrawing properties of its single bromo substituent at the para-position of the phenyl moiety, was found to yield substantially more of the key metabolite alaninyl d4T monophosphate (A-d4T-MP) than the unsubstituted d4T-5'-phenyl methoxyalaninyl phosphate or para-methoxy substituted d4T-5'-phenyl methoxyalaninyl phosphate. d4T-pBPMAP was tested for its anti-HIV-1 activity in peripheral blood mononuclear cells (PBMNC) and thymidine kinase (TK)-deficient CEM T-cells. d4T-pBPMAP was 12.6-fold more potent than the parent compound d4T in inhibiting p24 production (IC50 values: 44 nM vs 556 nM) and 41.3-fold more potent than d4T in inhibiting the reverse transcriptase (RT) activity (IC50 values: 57 nM vs 2355 nM) in HIV-1-infected TK-deficient CEM cells. Similarly, d4T-pBPMAP was more potent than the unsubstituted or para-methoxy substituted phenyl methoxyalaninyl phosphate derivatives of d4T. d4T-pBPMAP did not exhibit any detectable cytotoxicity to PBMNC or CEM cells at concentrations as high as 10,000 nM. Notably, d4T-pBPMAP was capable of inhibiting the replication of a zidovudine (ZDV/AZT)-resistant HIV-1 strain as well as HIV-2 in PBMNC at nanomolar concentrations. To our knowledge, this is the first demonstration that the potency of the d4T-aryl-phosphate derivatives can be substantially enhanced by introducing a single para-bromo substituent in the aryl moiety.

Characterization of latex allergenic components by capillary zone electrophoresis and N-terminal sequence analysis

In a previous study, protein components purified from latex gloves that elicited allergenic reactions were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and yielded apparent molecular weights of 14, 22, 30, 34, 46, and 58 kD. These allergenic components were isolated for further characterization by capillary zone electrophoresis and N-terminal amino acid sequence analysis. These components all migrated at approximately 25 and 35 min on capillary zone electrophoresis. Diode array spectral analysis detected indistinguishable characteristics between these two protein peaks. In addition, complex formation of these components with patients' immunoglobulin was demonstrated by capillary zone electrophoresis. Analysis of components separated by SDS-PAGE on a polyvinylidene difluoride membrane showed that the first 13 residues were identical to the sequence of hevein. Based on the criteria of charge-to-mass ratio and N-terminal amino acid sequence, our results suggest that these components of latex proteins are similar in the primary structure.

Analysis of immunosuppressive proteins in serum of liver-transplanted rats by using an anti-LSF-1 affinity column

Liver suppressor factor one (LSF-1) is a 40-kDa immunosuppressive protein in the serum of rats 60 days after orthotopic liver transplantation (OLT) between the nonrejector combination of DA donors into PVG recipients. In the present study, the purification of proteins from rat OLT serum taken 60 days after transplantation was performed by affinity chromatography using the anti-LSF-1 polyclonal antibody (pAb). The assessment of column eluates using anti-LSF-1 and OLT serum was studied using rat heart and liver transplantation models. Rejection was not suppressed by the administration of OLT serum in heart or liver allografts. However, heart allografts treated with peak eluates (450 micrograms single shot im, dissolved in Intralipos) taken from the affinity OLT serum survived significantly longer than untreated rats (median = 36.5 days; n = 7 vs 6.5 days; n = 5, respectively, P = 0.011). The same treatment with anti-LSF-1 column eluates also prolonged liver allografts significantly (>200 days) than those in either the untreated group (median = 11 days; n = 7) or those which received only Intralipos (median = 10.5 days; n = 5, P = 0.019). Subsequent analysis of the N-terminal sequences of some of the proteins which were eluted from the affinity column revealed that the homology of a 30-kDa protein was identical to hemoglobin alpha-chain, a 59-kDa protein to granulocyte inhibitory factor, a 70-kDa and a 90-kDa to albumin and its precursor, respectively. Although the specific immunosuppressive component has not been isolated, our results suggested that the anti-LSF-1 column can extract immunosuppressive moiety of LSF-1 from OLT serum.