[Relationship between UGT1A1 gene polymorphisms and irinotecan-induced severe adverse events]

Objective: To investigate the relationship between UGT1A1*6, UGT1A1*28, UGT1A1*60 and UGT1A1*93 polymorphisms and irinotecan-induced severe adverse reactions(grade 3-4 delayed diarrhea and neutropenia) in Chinese cancer patients. Methods: A total of 141 cancer patients treated with irinotecan were enrolled in this study. Peripheral venous blood was collected and genomic DNA was extracted. The genetic polymorphisms of UGT1A1*6, UGT1A1*28, UGT1A1*60 and UGT1A1*93 were analyzed by PCR and direct sequencing. The adverse reactions during chemotherapy were observed and recorded. The incidence of severe adverse reactions was compared among patients with different genotypes. Results: Among 141 patients, the cases with UGT1A1*6 GG, GA and AA genotypes were 71, 54 and 16, while those with UGT1A1*28 TA6/6, TA6/7 and TA7/7 genotypes were 105, 33 and 3, respectively. The cases with UGT1A1*60 AA, AC and CC genotypes were 52, 80 and 9, while those with UGT1A1*93 GG, GA and AA genotypes were 105, 32 and 4, respectively. The patients with grade 3-4 delayed diarrhea and neutropenia were 23 and 56, respectively. Multivariate logistic regression analysis showed that UGT1A1*6 and UGT1A1*60 genetic polymorphisms were independent factors influencing the occurrence of grade 3-4 delayed diarrhea. The risk of grade 3-4 delayed diarrhea in homozygous AA carriers of UGT1A1*6 increased 3.79 times compared with that in wild-type GG carriers (95%CI: 1.35-10.67). Moreover, the risk of grade 3-4 delayed diarrhea in homozygous CC carriers of UGT1A1*60 was 20.42 times compared with that in wild-type AA carriers (95%CI: 3.52-118.33). In addition, UGT1A1*28 genetic polymorphism was an independent factor of the occurrence of grade 3-4 neutropenia. The patients with homozygous TA7/7 carriers of UGT1A1*28 had an 1.61 times higher risk of grade 3-4 neutropenia compared with those with wild-type TA6/6 carriers (95%CI: 1.44-12.65). There was no correlation between UGT1A1*93 genetic polymorphism and severe adverse reactions caused by irinotecan. Conclusion: The cancer patients who carried UGT1A1*6, UGT1A1*28 and UGT1A1*60 gene polymorphisms have high risk of severe adverse events caused by irinotecan-based chemotherapy.

Association between polymorphisms of ethanol-metabolizing enzymes and susceptibility to alcoholic cirrhosis in a Korean male population

Alcohol is oxidized to acetaldehyde by alcohol dehydrogenase (ADH) and cytochrome P-4502E1 (CYP2E1), and then to acetate by aldehyde dehydrogenase (ALDH). Polymorphisms of these ethanol-metabolizing enzymes may be associated with inter-individual difference in alcohol metabolism and susceptibility to alcoholic liver disease. We determined genotype and allele frequencies of ALDH2, CYP2E1, ADH2, and ADH3 in male Korean patients with alcoholic cirrhosis (n=56), alcoholics without evidence of liver disease (n=52), and nondrinkers (n=64) by using PCR or PCR-directed mutagenesis followed by restriction enzyme digestion. The prevalences of heterozygous ALDH2*1/*2 plus homozygous ALDH2*2/*2 in patients with alcoholic cirrhosis (7.1%) and alcoholics without evidence of liver disease (3.8%) were significantly lower than that in nondrinkers (45.3%). The c2 allele frequencies of the CYP2E1 in alcoholic cirrhosis, alcoholics without evidence of liver disease, and nondrinkers were 0.21, 0.20, and 0.20, respectively. Allele frequencies of ADH2*2 in the three groups were 0.78, 0.74, and 0.77 and those of ADH3*1 were 0.94, 0.98, and 0.95. Therefore, we confirmed the observation that the ALDH2*2 gene protects against the development of alcoholism. However, the development of cirrhosis in Korean alcoholic patients was not associated with polymorphisms of ethanol-metabolizing enzymes.

Reactive oxygen species activity, mucosal lipoperoxidation and glutathione in Helicobacter pylori-infected gastric mucosa

BACKGROUND AND AIM

Helicobacter pylori is considered as the major pathogen in Helicobacter pylori-associated gastroduodenal disease, but the mechanism of its action has not been fully explained. This study was performed to assess the reactive oxygen species activity and the damage in Helicobacter pylori-infected gastric mucosa.

METHODS

Gastric biopsy specimens were obtained from 308 patients undergoing endoscopy. Gastric mucosal damage was assessed by using luminol enhanced chemiluminescence, thiobarbituric acid-reactive substance, and mucosal glutathione.

RESULTS

The chemiluminescence and thiobarbituric acid-reactive substance-equivalent levels in the mucosa of patients with Helicobacter pylori-positive gastric mucosa (43.8 +/- 134.9 c.p.m./microg tissue, 157.0 +/- 96.2 nmol/g tissue, respectively) were significantly higher than in those with Helicobacter pylori-negative mucosa (6.8 +/- 20.3 c.p.m./microg tissue, 110.0 +/- 51.6 nmol/g tissue, respectively; P=0.000, P=0.016, respectively). The glutathione levels in the mucosa of patients with Helicobacter pylori-positive gastric mucosa (159.3 +/- 76.6 nmol/microg tissue) were significantly lower than in those with Helicobacter pylori-negative gastric mucosa (212.3 +/- 134.3 nmol/microg tissue; P=0.008). After the data were divided according to the presence of Helicobacter pylori, there were no significant differences in chemiluminescence, thiobarbituric acid-reactive substance, and glutathione among the different macroscopic findings within Helicobacter pylori-positive and -negative gastric mucosa.

CONCLUSIONS

Helicobacter pylori infection plays a pathological role in many gastrointestinal diseases through excessive mucosal-reactive oxygen species production, pronounced membrane damage, and the depletion of gastric anti-oxidants.

A single-stranded telomere binding protein in the nematode Caenorhabditis elegans

We identified and characterized a protein (STB-1) from the nuclear extract of Caenorhabditis elegans that specifically binds single-stranded telomere DNA sequences, but not the corresponding RNA sequences. STB-1 binding activity is specific to the nematode telomere, but not to the human or plant telomere. STB-1 requires the core nucleotides of GCTTAGG and three spacer nucleotides in front of them for binding. While any single nucleotide change in the core sequence abolishes binding, the spacer nucleotides tolerate substitution. STB-1 was determined to be a basic protein of 45 kDa by Southwestern analyses. STB-1 forms a stable complex with DNA once bound to the telomere.

Ethnic differences and relationships in the oral pharmacokinetics of nifedipine and erythromycin

OBJECTIVE

Our objective was to investigate ethnic differences in the oral pharmacokinetics of nifedipine and erythromycin, both typical cytochrome P4503A (CYP3A) substrates, in Koreans and Caucasians and to identify the nature of any correlations between the pharmacokinetic parameters of the two drugs.

METHODS

Twenty healthy male volunteers (10 Koreans and 10 Caucasians) received single oral doses of nifedipine (10 mg) or erythromycin (500 mg) in a randomized 2-way crossover study. Pharmacokinetic evaluations were performed, and parameters were compared for the two ethnic groups. During the nifedipine study period, hemodynamic measurements were conducted to determine the pharmacodynamic relevance of the pharmacokinetic differences.

RESULTS

Koreans showed area under the concentration-time curves (AUCs) for both drugs that were 1.6 to 1.7 times higher than those of Caucasians. This difference decreased to 1.3 when normalized for body weight. Significant correlation between the AUCs of the two drugs was not evident. Hemodynamic changes after nifedipine administration paralleled those of the pharmacokinetic differences, with significantly greater decreases in blood pressure and total peripheral resistance noted in Koreans.

CONCLUSIONS

Koreans showed significantly lower oral clearances of nifedipine and erythromycin, probably because of genetic differences attributed to the CYP3A enzymes.

Microcytic adenoma coexistent with low-grade malignant islet cell tumor of the pancreas

We report a case of microcystic (glycogen-rich) adenoma of the whole pancreas with coexistent pancreatic low-grade malignant islet cell tumor in a 29-year-old woman. She complained of nausea, vomiting, and growing abdominal mass. Abdominal computed tomography showed multiple cysts in the whole pancreas and a calcified solid mass in the pancreatic head. A Whipple's operation and total pancreatectomy with splenectomy was performed to treat pancreatic cystic neoplasm. The pancreas was entirely replaced by variable-sized, multilocular cysts, which were lined by a flattened-to-cuboidal glycogen-rich epithelium. Furthermore, in the head of the pancreas, a focal yellowish solid mass showed a positive reaction for chromogranin A and neuron-specific enolase. Careful examination of the pancreas is warranted in cases of microcystic adenoma to rule out a possible coexistent pancreatic malignancy.

Effect of omeprazole on the pharmacokinetics of moclobemide according to the genetic polymorphism of CYP2C19

BACKGROUND

Moclobemide, an antidepressant with selective monoamine oxidase-A inhibitory action, is known to be metabolized by CYP2C19 and is also reported to be an inhibitor of CYP2C19, CYP2D6, and CYP1A2. To confirm the involvement of CYP2C19, we performed a pharmacokinetic interaction study.

METHODS

The effect of omeprazole on the pharmacokinetics of moclobemide was studied in 16 healthy volunteers. The volunteer group comprised 8 extensive metabolizers and 8 poor metabolizers of CYP2C19, which was confirmed by genotyping. Subjects were randomly allocated into two sequence groups, and a single-blind, placebo-controlled, two-period crossover study was performed. In study I, a placebo was orally administered for 7 days. On the eighth morning, 300 mg of moclobemide and 40 mg of placebo were coadministered with 200 mL of water, and a pharmacokinetic study was performed. During study II, 40 mg of omeprazole was given each morning instead of placebo, and pharmacokinetic studies were performed on the first and eighth day with 300 mg of moclobemide coadministration.

RESULTS

The inhibition of moclobemide metabolism was significant in extensive metabolizers even after a single dose of omeprazole. After daily administration of omeprazole for 1 week, the pharmacokinetic parameters of moclobemide and its metabolites in extensive metabolizers changed to values similar to those in poor metabolizers. In poor metabolizers, no remarkable changes in the pharmacokinetic parameters were observed.

CONCLUSION

Our results show that CYP2C19 is an important enzyme in the elimination of moclobemide and that it is extensively inhibited by omeprazole in extensive metabolizers, but not in poor metabolizers.

Pharmacokinetic/pharmacodynamic evaluation of a novel potassium channel opener, SKP-450, in healthy volunteers

To evaluate the pharmacokinetic/pharmacodynamic characteristics of SKP-450, a novel K+ channel opener, a single blind, randomized, placebo-controlled, dose-rising, parallel-group study was conducted in 28 healthy volunteers. The volunteers were randomly allocated to dosage groups of 50 micrograms, 100 micrograms, 200 micrograms, and 300 micrograms. Single doses of SKP-450 were administered orally, after overnight fasting, and serial blood sampling and pharmacodynamic measurements were performed up to 48 hours after the drug was administered. The 200 micrograms group was further studied for food interactions in a crossover fashion. Drug concentrations in plasma were determined by HPLC. Hemodynamic changes after drug administration were evaluated by serial measurements of blood pressure (BP), pulse rate (PR), cardiac index (CI), and total peripheral resistance (TPR), using computerized impedance cardiography. Changes in plasma renin activity (PRA) and aldosterone concentrations (PAC) were determined 4 and 24 hours after drug administration. Both SKP-450 and SKP-818, an active metabolite, showed linear pharmacokinetic characteristics, and food intake did not significantly affect the pharmacokinetic characteristics of either compound. Dose-related pharmacological effects were obvious for both the 200 micrograms and 300 micrograms groups. Hemodynamic parameters related to vasodilation and reflex tachycardia, such as maximum changes in diastolic BP, PR, CI, and TPR, showed significant dose-dependent changes. The area under the time-effect curve (AUEC) of the parameters also showed a similar dose-dependent pattern. The PRA and PAC exhibited significant changes 4 hours after drug administration in the 300 micrograms group. Adverse effects, such as headaches, were more frequently observed at the higher dose levels. SKP-450 was generally well tolerated by these normotensive subjects. The antihypertensive efficacy of SKP-450 needs to be evaluated in hypertensive patients after multiple dosing.

Recurrence of biliary symptoms after endoscopic sphincterotomy for choledocholithiasis in patients with gall bladder stones

BACKGROUND

There are a few reports regarding the long-term results of endoscopic sphincterotomy (EST). However, little data is available on the recurrence of biliary symptoms after EST for choledocholithiasis, in patients with gall bladder stones.

METHODS

All patients had gall bladder and common bile duct stones (n = 60; age 32-84 years, median age 55 years), and had received an EST. One group of these patients had a laparoscopic or open cholecystectomy (n = 39; group A), while the other group did not (n = 21; group B). The follow-up- period ranged from 5 to 54 months (average 22 months).

RESULTS

Complications included the recurrence of common bile duct stones, recurrent acute cholecystitis, postoperative bile leakage and papillary stenosis. Nine patients (15%) had a recurrence of biliary symptoms. Two significant prognostic factors for the recurrence of biliary symptoms were identified by multivariate analysis; namely an intact gall bladder and a dilated common bile duct. The recurrence rate of biliary symptoms in group B was 20.4%, while in group A it was 10.3% (P< 0.01). Patients with a larger than average common bile duct diameter (mean diameter 14 mm) were more prone to the recurrence of symptoms than those with a smaller common bile duct diameter (mean diameter 10 mm, P< 0.016). The hospital stay period was 8.9 +/- 3.1 days in group A and 2.8 +/- 1.9 days in group B (P< 0.01).

CONCLUSIONS

Biliary symptom recurrence occurred in a considerable proportion of patients after EST for the treatment of choledocholithiasis, in patients with gall bladder stones. The prognostic factors associated with the recurrence of biliary symptoms were an intact gall bladder and a dilated common bile duct diameter. Regardless of their short stay in hospital, non-cholecystectomy patients had a higher rate of recurrent biliary symptoms than cholecystectomy patients.

Detection of transforming growth factor-alpha in the serum of gastric carcinoma patients

Transforming growth factor-alpha (TGF-alpha) is a ligand for epidermal growth factor receptor (EGFR) and it is overexpressed in various malignancies including lung, esophageal, colorectal, ovarian and gastric carcinomas. In patients with gastric carcinoma, its overexpression may be associated with advanced stage or poor prognosis. We have recently demonstrated that the mean serum level for EGFR in gastric carcinoma patients was significantly elevated compared with that of healthy controls. Using the enzyme-linked immunosorbent assay, the levels of TGF-alpha were determined in serum from 40 patients with gastric carcinoma (5 patients with stage I, 2 stage II, 4 stage III, and 29 stage IV patients) and 33 healthy controls. The mean serum level for TGF-alpha in the gastric carcinoma patients was significantly elevated as compared with that of healthy controls (104 +/- 235 vs. 22 +/- 16 pg/ml; p = 0.03). Eleven patients with gastric carcinoma (27.5%) showed elevated serum TGF-alpha levels above the cutoff value of 54 pg/ml (defined as 2 standard deviations above the mean of the control group). No significant association was noted between the positivity of TGF-alpha and clinicopathologic characteristics including gender, age and stage. However, poorly differentiated adenocarcinoma showed a higher positivity of serum TGF-alpha (43.8%) compared with other histologic types, which was marginally significant (p = 0.06). These results suggest that serum TGF-alpha could be useful as a tumor marker of gastric carcinoma for predicting prognosis and follow-up after surgery in patients whose initial serum TGF-alpha levels are elevated.

Protective effect of chlormethiazole, a sedative, against acetaminophen-induced liver injury in mice

OBJECTIVES

The hepatotoxicity of acetaminophen is not a result of the parent compound but is mediated by its reactive metabolite N-acetyl-p-benzoquinone imine. Cytochrome P4502E1 (CYP2E1) is the principal enzyme of this biotransformation, which accounts for approximately 52% of the bioactivation in human microsomes. Recently, chlormethiazole a sedative drug, is reported to be an efficient inhibitor of CYP2E1 activity in human beings. In this study we wished to evaluate whether chlormethiazole, an inhibitor of CYP2E1, could prevent acetaminophen-induced liver injury in mice.

METHODS

Acetaminophen, at doses ranging from 200 to 600 mg/kg, was injected into the peritoneum of female C57BL/6 inbred mice fasted for four hours. Chlormethiazole (60 mg/kg) or 5% dextrose water was given 30 min before or 2 h after acetaminophen. Serum aminotransferase activities, histologic index score, survival rate and hepatic malondialdehyde levels were compared.

RESULTS

Pretreatment with chlormethiazole 30 min before 400 mg/kg of acetaminophen completely inhibited acetaminophen-induced liver injury (median 118.5 U/L, range 75 to 142 vs. 14,070 U/L, range 5980 to 27,680 for AST; 49 U/L, range 41 to 64 vs. 15,330 U/L, range 13,920 to 15,940 for ALT). In mice receiving chlormethiazole 2 h after acetaminophen, the mean AST and ALT levels were also less elevated, reaching only 20% of the value of acetaminophen-only group. These protective effects were confirmed histologically. Whereas more than 50% of mice died at 500 mg/kg of acetaminophen, all the mice pretreated with chlormethiazole survived at the same dose.

CONCLUSION

Chlormethiazole effectively reduces acetaminophen-induced liver injury in mice. Further studies are needed to assess its role in humans.

Molecular cloning of a catalase cDNA from Nicotiana glutinosa L. and its repression by tobacco mosaic virus infection

Recent reports revealed that catalase has a role in the plant defense mechanism against a broad range of pathogens through being inhibited by salicylic acid (SA). During an effort to clone disease resistance-responsive genes, a cDNA encoding catalase (Ngcat1; Nicotiana glutinosa cat1) was isolated from a tobacco cDNA library. In N. glutinosa, catalase is encoded by a small gene family. The deduced amino acid sequence of the Ngcat1 cDNA has 98% homology with the cat1 gene of N. plumbaginifolia. The Ngcat1 expression is controlled by the circadian clock, and its mRNA level is the most abundant in leaves. Both the expression of Ngcat1 mRNA and its enzyme activity in the tobacco plant undergoing a hypersensitive response (HR) to TMV infection were repressed. The repression of the mRNA level was also observed following treatment with SA. These results imply that SA may act as an inhibitor of catalase transcription during the HR of tobacco. Cloning and expression of the Ngcat1 in tobacco following pathogen infection and SA treatment are presented.

Somatostatin potentiates voltage-dependent K+ and Ca2+ channel expression induced by nerve growth factor in PC12 cells

It has been proposed that neurotransmitters and neuromodulators may function as neurotrophic factors during the development of the nervous system. Somatostatin (SS) was known to increase neurite outgrowth in PC12 cells, rat pheochromocytoma cell line, and cerebellar granule cells as well as Helisoma neuron. To further investigate a neurotrophic role of SS, voltage-dependent K+ and Ca2+ channel expression was studied using whole-cell patch-clamp in PC12 cells and the effect of SS was compared to that of nerve growth factor (NGF). Cyclic AMP (cAMP) level and mitogen-activated protein (MAP) kinase phosphorylation were also studied following the treatment with SS and/or NGF. Whereas NGF (50 ng/ml) increased continually the current density of the voltage-dependent K+ channel throughout 8 days treatment, SS (1 microM) increased the K+ current density on day 2 to the peak. K+ current density was decreased thereafter and was not different on day 6 from that of undifferentiated cells. Although SS did not increase voltage-dependent Ca2+ current density, it potentiated NGF-induced increase of voltage-dependent Ca2+ channel current density as well as the K+ current density. cAMP level was decreased by NGF and/or SS treatment. An increased phosphorylation of MAP kinase induced by NGF was not changed by SS treatment. These results support functionally that SS may function as a neurotrophic factor in developing nervous system.

Molecular cloning and characterization of a new basic peroxidase cDNA from soybean hypocotyls infected with Phytophthora sojae f.sp. glycines

Differential display techniques were used to isolate cDNA clones corresponding to genes which were expressed in soybean hypocotyls by Phytophthora sojae f.sp. glycines infection. With a partial cDNA clone C20CI4 from the differential display PCR as a probe, a new basic peroxidase cDNA clone, designated GMIPER1, was isolated from a cDNA library of soybean hypocotyls infected with P. sojae f.sp. glycines. Sequence analysis revealed that the peroxidase clone encodes a mature protein of 35,813 Da with a putative signal peptide of 27 amino acids in its N-terminus. The amino acid sequence of the soybean peroxidase GMIPER1 is between 54-75% identical to other plant peroxidases including a soybean seed coat peroxidase. Southern blot analysis indicated that multiple copies of sequences related to GMIPER1 exist in the soybean genome. The mRNAs corresponding to the GMIPER1 cDNA accumulated predominantly in the soybean hypocotyls infected with the incompatible race of P. sojae f.sp. glycines, but were expressed at low levels in the compatible interaction. Soybean GMIPER1 mRNAs were not expressed in hypocotyls, leaves, stems, and roots of soybean seedlings. However, treatments with ethephon, salicylic acid or methyl jasmonate induced the accumulation of the GMIPER1 mRNAs in the different organs of soybean. These results suggest that the GMIPER1 gene encoding a putative pathogen-induced peroxidase may play an important role in induced resistance of soybean to P. sojae f.sp. glycines and in response to various external stresses.

A glycine-rich RNA-binding protein gene is differentially expressed during acute hypersensitive response following Tobacco Mosaic Virus infection in tobacco

During efforts for cloning disease resistance-responsive genes, a cDNA encoding a putative Nicotiana glutinosa glycine-rich RNA binding protein (ngRBP) was isolated from TMV induced cDNA library. Northern blot hybridization revealed that ngRBP gene is negatively regulated during early hours of TMV induced acute hypersensitive response (HR). Under greenhouse conditions induced expression of ngRBP gene was observed after 24 h following TMV infection. Salicylic acid and copper also induced ngRBP mRNA expression. Our findings are suggestive of some possible role for ngRBP in plant-pathogen interaction.

Increased serum levels of transforming growth factor-alpha in patients with colorectal cancer

PURPOSE

This study was conducted to investigate the serum levels of transforming growth factor-alpha in patients with colorectal cancer and to investigate the clinical significance of these levels in association with tumor stage and histologic differentiation. Also, serum levels of transforming growth factor-alpha were measured after curative surgical resection.

METHODS

Serum levels of transforming growth factor-alpha were measured in 42 consecutive patients with colorectal cancer before surgery, in 21 patients after surgical resection (part of the 42 preoperative patients), and in 20 healthy volunteers. We used TGF-alpha Assay.

RESULTS

Serum levels of transforming growth factor-alpha in patients with colorectal cancer were significantly higher than in the healthy control group (P = 0.001). Significant elevations in serum levels of transforming growth factor-alpha were found in 50 percent (21/42) of patients with colorectal cancer when the mean + 2 standard deviations (80.4 pg/ml) of the control group were used as the upper limit of the normal range. Serum levels of transforming growth factor-alpha tended to decrease with increasing tumor size (n = 31; r = -0.52; P = 0.002). Serum levels of transforming growth factor-alpha before surgery (89.7 +/- 44.4 pg/ml; n = 21) significantly decreased to 60.3 +/- 19.8 pg/ml after surgical resections of tumors (P = 0.017). Serum levels of transforming growth factor-alpha completely decreased to the same serum levels of the control group after surgical resections in all patients who had serum levels of transforming growth factor-alpha greater than mean + 2 standard deviations (80.4 pg/ml) of the control group preoperatively (n = 11; P = 0.002).

CONCLUSIONS

Levels of preoperative transforming growth factor-alpha in patients with colorectal cancer appeared to be higher than levels measured in control subjects. Serum levels of transforming growth factor-alpha before surgery significantly decreased after surgical resections of tumors. Additional studies are warranted to determine if serum levels of transforming growth factor-alpha may be useful as a potential biomarker in the management of patients with colorectal cancer.

Binding mode of porphyrins to poly[d(A-T)2] and poly[d(G-C)2]

We examined the binding geometry of Co-meso-tetrakis (N-methyl pyridinium-4-yl)porphyrin, Co-meso-tetrakis (N-n-butyl pyridinium-4-yl)porphyrin and their metal-free ligands to poly[d(A-T)(2)] and poly[d(G-C)(2)] by optical spectroscopic methods including absorption, circular and linear dichroism spectroscopy, and fluorescence energy transfer technique. Signs of an induced CD spectrum in the Soret band depend only on the nature of the DNA sequence; all porphyrins exhibit negative CD when bound to poly[d(G-C)(2)] and positive when bound to poly[d(A-T)(2)]. Close analysis of the linear dichroism result reveals that all porphyrins exhibit outside binding when complexed with poly[d(A-T)(2)], regardless of the existence of a central metal and side chain. However, in the case of poly[d(G-C)(2)], we observed intercalative binding mode for two nonmetalloporphyrins and an outside binding mode for metalloporphyrins. The nature of the outside binding modes of the porphyrins, when complexed with poly[d(A-T)(2)] and poly[d(G-C)(2)], are quite different. We also demonstrate that an energy transfer from the excited nucleo-bases to porphyrins can occur for metalloporphyrins.

Purification and antifungal activity of a basic 34 kDa beta-1,3-glucanase from soybean hypocotyls inoculated with Phytophthora sojae f. sp. glycines

Inoculation of soybean (Glycine max L. cv. Jangyup) hypocotyls with Phytophthora sojae f. sp. glycines results in a marked accumulation of some pathogenesis-related (PR) proteins. A basic beta-1,3-glucanase (34 kDa) was purified from soybean hypocotyls infected by an incompatible race of P. sojae f. sp. glycines using CM-cellulose cation exchange chromatography and Bio-gel P-60 gel filtration. The purified soybean beta-1,3-glucanase cross-reacted with polyclonal antibody raised against a tomato beta-1,3-glucanase. The activity of beta-1,3-glucanase was much higher in the infected soybean hypocotyls than the healthy ones. The beta-1, 3-glucanase purified from soybean inhibited spore germination and hyphal growth of the chitin-negative fungus P. sojae f. sp. glycines, but did not show any antifungal activity against the chitin-containing fungi Alternaria mali, Colletotrichum gloeosporioides, and Magnaporthe grisea.

Detection of epidermal growth factor receptor in the serum of gastric carcinoma patients

BACKGROUND

Epidermal growth factor receptor (EGFR) is overexpressed in various malignancies including carcinoma of the breast, lung, esophagus, cervix, and stomach. In patients with gastric carcinoma, its overexpression may be associated with advanced stage and poor prognosis.

METHODS

The levels of EGFR extracellular domain were determined in serum from 40 gastric carcinoma patients using enzyme-linked immunosorbent assay. Serum EGFR levels were measured in 5 Stage I, 2 Stage II, 6 Stage III, and 27 Stage IV patients, and 29 healthy controls.

RESULTS

The mean serum level for EGFR in the gastric carcinoma patients was significantly elevated compared with that of healthy controls (681 +/- 226 fmol/mL vs. 440 +/- 46 fmol/mL; P < 0.0001). Thirty-one patients with gastric carcinoma (77.5%) showed elevated EGFR levels above a cutoff value of 532 fmol/mL (defined as 2 standard deviations above the mean of the controls). No significant association was noted between positivity of EGFR and gender, age, stage, and tumor differentiation.

CONCLUSIONS

The authors believe that serum EGFR could be useful as a tumor marker of gastric carcinoma for diagnosis, prognosis, follow-up after surgery, and monitoring patient response to chemotherapy.

Anti-angiogenic activity of triterpene acids

Ursolic acid (UA) and oleanolic acid (OA) were examined for anti-angiogenic activities by using the chick embryo chorioallantoic membrane (CAM) assay. The presence of UA or OA inhibited angiogenesis in a dose-dependent manner; the doses required for half-maximal inhibition (ID50) were 5 micrograms and 40 micrograms per CAM, respectively. UA was a more potent angiogenic inhibitor than OA. We also tested for inhibitory effect on the proliferation of bovine aortic endothelial cell. They effectively inhibited the proliferation of bovine aortic endothelial cell in a concentration-dependent manner. The IC50 values of anti-proliferative effects were determined to be 5 microM for UA and 20 microM for OA. Based on these results, we speculated that the inhibitory effects on bovine aortic endothelial cell proliferation of UA and OA might be important for anti-angiogenesis.

[Changes in and significance of atrial natriuretic peptide, angiotensin II after experimental brain injury]

We used the method of RIA determined the contents of atrial natriuretic peptide (ANP), angiotensin II (ANG II) in plasma and brain tissues after brain injury in 70 rats. The results showed that the ANP was significantly decreased in brain tissues on 6, 72 hours after brain injury. At the same time, the plasma and brain tissues ANG II, brain water contents were significantly increased. The results suggested that the unbalance of ANP and ANG II may be related to the pathophysiological process of brain edema.

Experimental evaluation of blood-brain barrier permeability using colloidal gold particles as tracers in early-stage brain injury

We used 46 rabbits for the study of blood-brain barrier (BBB) permeability quantitatively in early-stage brain injury by a dropping weight method. The animals were divided into two groups: control group and brain injury group. Both Evans' blue and colloidal gold (CG) particles were utilized for evaluation of BBB permeability alteration. Three different sizes of CG 5, 10 and 15 nm in diameter were employed as tracers for a quantitative investigation of BBB changes by light and electron microscopes respectively. In addition, the brain water contents were determined. The preliminary data indicated that an increase of BBB permeability began 30 minutes after the injury with a few of 5 or 10 nm CG particles present in the endocytic pits and endothelial microvilli, and the augmentation of BBB permeability reached its peak 6 hours after the injury. More CG tracers penetrated into the precapillary arterioles, venules or capillaries through the opening of tight junctions of BBB and by vesicular transportation. The variation of the brain water contents was closely correlated to the above-mentioned BBB changes. It is suggested that the vasogenic cerebral edema was mainly caused by the augmentation of BBB permeability.