Anti-stress and anti-fatigue effects of fermented rice bran

The anti-stress and anti-fatigue effects on rats and mice of a hot water extract of rice bran fermented with Saccharomyces cerevisae IFO 2346 were investigated. Oral administration (1 g/kg/day) of the hot water extract of fermented rice bran (FRB) inhibited major changes in the weight of the adrenal, thymus, spleen and thyroid, showing an anti-stress effect. The hot water extract of FRB also inhibited increases in the GPT and LDH activity, cholesterol and glucose in the serum. The administration (1 g/kg/day) for 2 weeks significantly prolonged the swimming time, resulting in an increase in the anti-fatigue effect. It is considered from these results that FRB had anti-stress and anti-fatigue effects.

Phase I/II trial of docetaxel and vinorelbine in patients with non-small cell lung cancer previously treated with platinum-based chemotherapy

We conducted a phase I/II trial of the combination of docetaxel and weekly vinorelbine in patients with stage IIIB or IV non-small cell lung cancer (NSCLC) who were refractory or resistant to platinum-based regimens. The objectives of the study were (1) to determine the maximum tolerated doses of docetaxel and weekly vinorelbine when given in combination and (2) to evaluate the response to and quantitative and qualitative toxicity of this combination of agents. Patients were required to have an ECOG performance status of 0 or 1, evaluable lesions, and no prior treatment with docetaxel or vinorelbine. A total of 30 patients were treated on this phase I/II study. Eight patients were treated at various doses on the phase I portion of the study. Twenty-two patients (11 males, 11 females, median age 64.5 years) were treated at the phase II dose of vinorelbine 15 mg/m(2) weekly with docetaxel 60 mg/m(2) on day 1 of a 21 day cycle. Twenty of these 22 patients enrolled at the phase II dose required dose modification or delay. Sixteen patients experienced absolute neutrophil count (ANC) <500/mm(3), and eight patients had neutropenic fever. Four patients experienced partial response (18%), nine patients had stable disease (41%), and nine patients had progressive disease (41%). With a median follow-up of 11 months, median survival for these 22 patients was 15.9 months (95% CI 8.1, 23.6 months). Median time to disease progression was 3.2 months with a 95% CI of (1.4, 4.1) months. Thus, the combination of docetaxel 60 mg/m(2) every 3 weeks and vinorelbine 15 mg/m(2) weekly appears to be active as a second line regimen in NSCLC, although it is a highly myelosuppressive regimen requiring dose modification in 91% of patients.

Effect of sodium chloride on the gelation temperature, gel strength and bioadhesive force of poloxamer gels containing diclofenac sodium

Liquid suppository systems composed of poloxamers and bioadhesive polymers were easy to administer to the anus and mucoadhesive to the rectal tissues without leakage after the dose. However, a liquid suppository system containing diclofenac sodium could not be developed using bioadhesive polymers, since the drug was precipitated in this preparation. To develop a liquid suppository system using sodium chloride instead of bioadhesive polymers, the physicochemical properties such as gelation temperature, gel strength and bioadhesive force of various formulations composed of diclofenac sodium, poloxamers and sodium chloride were investigated. The mixtures of P 407 (15%) and P 188 (15-20%) existed as a liquid at room temperature, but gelled at physiological temperature. Diclofenac sodium significantly increased the gelation temperature and weakened the gel strength and bioadhesive force, while sodium chloride did the opposite. Furthermore, the poloxamer gels with less than 1.0% of sodium chloride, in which the drug was not precipitated, were inserted into the rectum of rabbits without difficulty and leakage, and retained in the rectum of rats for at least 6 h. Our results suggested that a thermosensitive liquid suppository system with sodium chloride and poloxamers was a more physically stable and convenient rectal dosage form for diclofenac sodium.

Graphical search for two-stage designs for phase II clinical trials

In a typical two-stage design employed in a phase II cancer clinical trial for efficacy screening, a fixed number of patients are initially enrolled. The trial may be terminated for lack of clinical efficacy of treatment if the observed number of treatment successes after the first stage is too small. Otherwise, an additional fixed number of patients are enrolled to accumulate additional information on efficacy. Simon's optimal design and minimax design have often been applied to designing phase II clinical trials. Other designs have largely been ignored. In this paper, we introduce a graphical method to search for a good design that is a compromise between the optimal and the minimax designs.

Devising an objective nasal vibration test for nasal resonatory disorders

The present study investigates the clinical applicability of a new device, which objectively measured nasal resonating vibration via piezoelectric vibratory sensor in 10 normal volunteers, 10 patients with definite hypernasality, and 10 nasal polyposis patients. For the assessment of the hypernasality, the ratio of /ng/ to /a/ as well as the ratio of /mama/ to /papa/ passages were used. For the evaluation of hyponasality, the ratio of nasal vibration postinduced to preinduced cul-de-sac resonation was calculated. The control group showed the ratio of /ng/ to /a/ and /mama/ to /papa/ passages to be larger than 8, whereas the ratio was markedly lower in the hypernasality group. The vibratory signals of /a/ and /ng/ increased markedly in the control and the hypernasality groups after inducing cul-de-sac resonation, but the change was minimal in the hyponasality group. This new device could detect nasal resonatory disorders and readily differentiate between hypernasality and hyponasality.

Induction of human promyelocytic leukemia HL-60 cell differentiation into monocytes by silibinin: involvement of protein kinase C 1 1Abbreviations: 1,25-(OH)2D3, 1α,25-dihydroxyvitamin D3; ERK, extracellular signal-regulated kinase; mAb, monoclonal antibody; MAPK, mitogen-activated protein kinase; NBT, nitroblue tetrazolium; and PKC, protein kinase C

The effect of silibinin, an active component of Silybum marianum, on cellular differentiation was investigated in the human promyelocytic leukemia HL-60 cell culture system. Treatment of HL-60 cells with silibinin inhibited cellular proliferation and induced cellular differentiation in a dose-dependent manner. Cytofluorometric analysis and morphologic studies indicated that silibinin induced differentiation of HL-60 cells predominantly into monocytes. Importantly, strongly synergistic induction of differentiation into monocytes was observed when silibinin was combined with 5 nM 1alpha,25-dihydroxyvitamin D(3) [1,25-(OH)(2)D(3)], a well-known differentiation inducer of HL-60 cells into the monocytic lineage. Silibinin enhanced protein kinase C (PKC) activity and increased protein levels of both PKCalpha and PKCbeta in 1,25-(OH)(2)D(3)-treated HL-60 cells. PKC and extracellular signal-regulated kinase (ERK) inhibitors significantly inhibited HL-60 cell differentiation induced by silibinin alone or in combination with 1,25-(OH)(2)D(3), indicating that PKC and ERK may be involved in silibinin-induced HL-60 cell differentiation.

Post-translational modification of the N-terminal His tag interferes with the crystallization of the wild-type and mutant SH3 domains from chicken src tyrosine kinase

Structural studies of the wild type and mutants of the src SH3 domain were initiated to elucidate the correlation of the native-state topology with protein thermostability and folding kinetics. An extra mass of 178 Da arising from the post-translational modification at the N-terminal His tag was observed. The spontaneous alpha-N-6 gluconoylation at the amino group of the His-tagged SH3 domain contributed to the observed extra mass. The partial modification of the N-terminal His-tag produced heterogeneity, both in size and in charge, in the Escherichia coli expressed SH3 domain. The removal of the His tag from the SH3 domain was essential for the crystallization of both wild-type and mutant src SH3. Both the wild type and the W43I mutant were crystallized by hanging-drop vapor diffusion and are in the hexagonal space group P6(5)22 with one molecule in the asymmetric unit. Data sets were collected to 1.8 and 1.95 A resolution for the the wild type and the W43I mutant, respectively.

Design of a PC-based multimedia telemedicine system for brain function teleconsultation

During time-critical brain surgery, the detection of developing cerebral ischemia is particularly important because early therapeutic intervention may reduce the mortality of the patient. The purpose of this system is to provide an efficient means of remote teleconsultation for the early detection of ischemia, particularly when subspecialists are unavailable. The hardware and software design architecture for the multimedia brain function teleconsultation system including the dedicated brain function monitoring system is described. In order to comprehensively support remote teleconsultation, multi-media resources needed for ischemia interpretation were included: EEG signals, CSA, CD-CSA, radiological images, surgical microscope video images and video conferencing. PC-based system integration with standard interfaces and the operability over the Ethernet meet the cost-effectiveness while the modular software was customized with a diverse range of data manipulations and control functions necessary for shared workspace and standard interfaces.

Cloning and characterization of a hydroxycinnamoyl-CoA:tyramine N-(hydroxycinnamoyl)transferase induced in response to UV-C and wounding from Capsicum annuum

Hydroxycinnamoyl-CoA : tyramine N-(hydroxycinnamoyl) transferase (THT) is a pivotal enzyme in the synthesis of N-(hydroxycinnamoyl)-amines, which are associated with cell wall fortification in plants. The cDNA encoding THT was cloned from the leaves of UV-C treated Capsicum annuum (hot pepper) using a differential screening strategy. The predicted protein encoded by the THT cDNA is 250 amino acids in length and has a relative molecular mass of 28,221. The protein sequence derived from the cDNA shares 76% and 67% identity with the potato and tobacco THT protein sequences, respectively. The recombinant pepper THT enzyme was purified using a bacterial overexpression system. The purified enzyme has a broad substrate specificity including acyl donors such as cinnamoyl-, sinapoyl-, feruloyl-, caffeoyl-, and 4-coumaroyl-CoA and acceptors such as tyramine and octopamine. In UV-C treated plants, the THT mRNA was strongly induced in leaves, and the elevated level of expression was stable for up to 36 h. THT mRNA also increased in leaves that were detached from the plant but not treated with UV-C. THT expression was measured in different plant tissues, and was constitutive at a similar level in leaf, root, stem, flower and fruit. Induction of THT mRNA was correlated with an increase in THT protein.

Dimensional changes of dental impression materials by thermal changes

Dental impression materials for prosthodontic treatment must be easy to use, precisely replicate of oral tissue, be dimensionally stable, and be compatible with gypsum materials. The dimensional accuracy of all materials is affected by thermal changes; impression materials shrink during cooling from mouth temperature (37 degrees C) to room temperature (23 degrees C). Five kinds of light body addition-reaction silicone impression materials [Contrast (CT), Voco Co., Germany; Examix (EM), GC Co., Japan; Extrude (EX), Kerr Co., USA; Imprint II (IM), 3M Co., USA; Perfect (PF), Handae Chemical, Korea] were tested by making cylindrical specimens (6 mm diameter and 12 mm height). The thermal expansion of the impression materials was measured with a thermomechanical analyzer (TMA 2940, TA Instruments, USA) between 23-37 degrees C. Data were analyzed via the Mann-Whitney Usage Test. To simulate actual dental impressions, tooth and tray shapes were modeled to measure the linear shrinkage of impression materials at anterior and posterior locations. The thermal expansion of impression materials tested decreased as follows: CT >or= PF >or= EM >or= EX >or= IM (p < 0.05). The anterior region changed more than the posterior region for the same impression materials. The dimensional changes averaged more than 40 microm in the anterior region, but less than 40 microm in the posterior region for all materials. Thermal expansion coefficients of some impression materials were significantly different from each other (p < 0.05), and the anterior region had more dimensional change than the posterior region for the same impression materials.

Biophysical characterization of recombinant human Bcl-2 and its interactions with an inhibitory ligand, antimycin A

Apoptosis is an essential physiological process, regulated by the family of Bcl-2-related proteins. However, the molecular mechanism by which Bcl-2 regulates apoptosis still remains elusive. Here we report the functional studies of recombinant human Bcl-2 with the deletion of 22 residues at the C-terminal membrane-anchoring region (rhBcl-2Delta22). Characterization of rhBcl-2Delta22 showed that the recombinant protein is homogeneous and monodisperse in nondenaturing solutions, stable at room temperature in the presence of a metal chelator, and an alpha-helical protein with unfolding of secondary structure at a T(m) of 62.8 degrees C. Optimal membrane pore formation by rhBcl-2Delta22 required negatively charged phospholipids. The existence of a hydrophobic groove in rhBcl-2Delta22 was demonstrated by the fluorescence enhancement of the hydrophobic ANS probe with which a pro-apoptotic Bak BH3 peptide competed. The respiratory inhibitor antimycin A also bound to the hydrophobic groove of rhBcl-2Delta22 with a K(d) of 0.82 microM. The optimal binding conformation of antimycin A was predicted from molecular docking of antimycin A with the hBcl-2 model created by homology modeling. Antimycin A selectively induces apoptosis in cells overexpressing Bcl-2, suggesting that hydrophobic groove-binding compounds may act as selective apoptotic triggers in tumor cells.

Sphingosine 1-phosphate protects human umbilical vein endothelial cells from serum-deprived apoptosis by nitric oxide production

Sphingosine 1-phosphate (S1P) can prevent endothelial cell apoptosis. We investigated the molecular mechanisms and signaling pathways by which S1P protects endothelial cells from serum deprivation-induced apoptosis. We show here that human umbilical vein endothelial cells (HUVECs) undergo apoptosis associated with increased DEVDase activity, caspase-3 activation, cytochrome c release, and DNA fragmentation after 24 h of serum deprivation. These apoptotic markers were suppressed by the addition of S1P, the NO donor S-nitroso-N-acetylpenicillamine (100 micrometer), or caspase-3 inhibitor z-VAD-fmk. The protective effects of S1P were reversed by the nitric-oxide synthase (NOS) inhibitor N-monomethyl-l-arginine, but not by the soluble guanylyl cyclase inhibitor 1H-(1,2,4)oxadiazolo[4,3-a]-quanoxaline-1-one, suggesting that NO, but not cGMP, is responsible for S1P protection from apoptosis. Furthermore, S1P increased NO production by enhancing Ca(2+)-sensitive NOS activity without changes in the eNOS protein level. S1P-mediated cell survival and NO production were suppressed significantly by pretreatment with antisense oligonucleotide of EDG-1 and partially by EDG-3 antisense. S1P-mediated NO production was suppressed by the addition of pertussis toxin, an inhibitor of G(i) proteins, the specific inhibitor of phospholipase C (PLC), and the Ca(2+) chelator BAPTA-AM. These findings indicate that S1P protects HUVECs from apoptosis through the activation of eNOS activity mainly through an EDG-1 and -3/G(i)/PLC/Ca(2+) signaling pathway.

Cephalic spreading levels after volumetric caudal epidural injections in chronic low back pain

The volumetric caudal epidural steroid injection has been advocated to facilitate the delivery of medications to the lesion site. This study was aimed to examine the actual spreading patterns of this technique, using epidurogram. A total of 32 patients with chronic low back pain accompanied by radiculopathy of various causes (degenerative spondylosis, herniated nucleus pulposus, spondylolisthesis, and spinal stenosis) were included. The volumetric caudal epidural injection of the 10 mL mixture of contrast medium 5 mL, 0.5% bupivacaine 1 mL, triamcinolone 1.5 mL (60 mg) and normal saline 25 mL was performed. Immediately after the cessation of the first spread, the subsequent solution of another 10 mL of contrast medium 5 mL, 0.5% bupivacaine 1 mL and normal saline 4 mL was injected. This procedure was repeated serially until the total volume to be 50 mL. Continuous fluoroscopic imaging was obtained after each injection. Average time taken to complete the study was 37 sec per every 10 mL. The spreading levels of the mixture were distributed mainly at mid to lower lumbar area in the majority of the patients. During the subsequent injections, the levels were not changed significantly. This was thought to be due to the minimal resistance in cephalad direction, anatomic variations and Starling effect of epidural space.

Functional interaction between monoamine plasma membrane transporters and the synaptic PDZ domain-containing protein PICK1

PDZ domain-containing proteins play an important role in the targeting and localization of synaptic membrane proteins. Here, we report an interaction between the PDZ domain-containing protein PICK1 and monoamine neurotransmitter transporters in vitro and in vivo. In dopaminergic neurons, PICK1 colocalizes with the dopamine transporter (DAT) and forms a stable protein complex. Coexpression of PICK1 with DAT in mammalian cells and neurons in culture results in colocalization of the two proteins in a cluster pattern and an enhancement of DAT uptake activity through an increase in the number of plasma membrane DAT. Deletion of the PDZ binding site at the carboxyl terminus of DAT abolishes its association with PICK1 and impairs the localization of the transporter in neurons. These findings indicate a role for PDZ-mediated protein interactions in the localization, expression, and function of monoamine transporters.

Differential regulation of NO availability from macrophages and endothelial cells by the garlic component S-allyl cysteine

Garlic has been used as a traditional medicine for prevention and treatment of cardiovascular diseases. However, the molecular mechanism of garlic's pharmacological action has not been clearly elucidated. We examined here the effect of garlic extract and its major component, S-allyl cysteine (SAC), on nitric oxide (NO) production by macrophages and endothelial cells. The present study demonstrates that these reagents inhibited NO production through the suppression of iNOS mRNA and protein expression in the murine macrophage cell line RAW264.7, which had been stimulated with LPS and IFNgamma. The garlic extract also inhibited NO production in peritoneal macrophages, rat hepatocytes, and rat aortic smooth muscle cells stimulated with LPS plus cytokines, but it did not inhibit NO production in iNOS-transfected AKN-1 cells or iNOS enzyme activity. These reagents suppressed NF-kappaB activation and murine iNOS promoter activity in LPS and IFNgamma-stimulated RAW264.7 cells. In contrast, these reagents significantly increased cGMP production by eNOS in HUVEC without changes in activity, protein levels, and cellular distribution of eNOS. Finally, garlic extract and SAC both suppressed the production of hydroxyl radical, confirming their antioxidant activity. These data demonstrate that garlic extract and SAC, due to their antioxidant activity, differentially regulate NO production by inhibiting iNOS expression in macrophages while increasing NO in endothelial cells. Thus, this selective regulation may contribute to the anti-inflammatory effect and prevention of atherosclerosis by these reagents.

Cellular mechanism of calcification and its prevention in glutaraldehyde treated vascular tissue

OBJECTIVES

Prevention of calcification in glutaraldehyde (GA) treated porcine aortic valve fibroblasts and rat aorta with Ca2+ channel blockers (Ca(2+)-CBs).

BACKGROUND

GA causes a massive increase in [Ca2+]i and a many fold increase in [Pi]i followed by calcification of porcine aortic valve fibroblasts. The influx of extracellular Ca2+ into [Pi]i rich cells apparently underlies the mechanism of calcification. Inhibition of Ca2+ influx is likely to prevent calcification in GA-treated cells.

METHODS

[Ca2+]i in GA-treated cells was measured by fluorescence image analysis. [Ca2+]i increase in fibroblasts treated with various Ca(2+)-CBs was compared with the untreated control. To study the role of Ca2+ influx in calcification and to find out the portals of Ca2+ entry, porcine aortic valve fibroblasts and freshly removed rat aorta were treated with verapamil + ryanodine, or verapamil + econazole, fixed with GA and incubated in Hank's balanced salt solution with 2.5 mmol/L calcium. The progress of calcification was monitored by the rate of Ca and Pi depletions from the supernatant. Calcified cells and tissues were identified by calcein fluorescence.

RESULTS

Verapamil + ryanodine or econazole inhibited the GA-induced Ca2+ influx and prevented calcification of the cells and rat aorta. The effect of verapamil was additive to that of ryanodine and econazole.

CONCLUSIONS

Findings further support the influx theory of calcification. Ca2+ enters GA-treated cells mainly through the store operated and the L-type Ca2+ channels. Ca(2+)-CBs may be useful for prevention of calcification in GA-treated vascular bioprostheses. Cell culture serves as a convenient model for screening drug effects on calcification.

Cnidicin, a coumarin, from the root of Angelica koreana, inhibits the degranulation of mast cell and the NO generation in RAW 264.7 cells

Cnidicin (1) and five related coumarins were isolated from the root extract of Angelica koreana (Umbelliferae) as active principles responsible for the inhibitory effect on the degranulation process of cultured mast cells. Cnidicin (1) demonstrated a significant inhibition upon the release of beta-hexosaminidase from the cultured RBL-2H3 cells in a dose dependent manner (IC50 value, 25 microM) and upon the nitric oxide production from the activated RAW264.7 cells (IC50 value, 7.5 microM). In agreement with this, cnidicin inhibited the expression of nitric oxide synthase in RAW264.7 cells.

Eyebrow incision using tattoo for anterior fossa lesions: technical case reports

Some Korean women draw tattoo in their eyebrow to cover the scant hair. If a patient has a tattoo in her eyebrow, lesions of anterior cranial fossa can be easily managed with this small eyebrow skin incision through a small unilateral supraorbital craniotomy. By this technique, 7 cases of anterior cranial fossa lesions were successfully treated without any major complications. This leads to less facial scar, less operation time and an earlier return to social adaptation.

Intraoperative thermal regulation in patients undergoing laparoscopic vs open surgical procedures

BACKGROUND

Although perioperative hypothermia is a well-known consequence of general anesthesia, it has been hypothesized that laparoscopic surgery exacerbates hypothermia to a greater extent than open surgery. The aim of this study was to demonstrate that laparoscopic surgery does not represent an increased risk for hypothermia.

METHODS

A case-controlled retrospective study was conducted on 45 patients, 25 undergoing laparoscopic cholecystectomy and 20 undergoing parathyroid surgery under endotracheal general anesthesia. Data were collected regarding age, sex, weight, height, American Society of Anesthesiologists (ASA) status, length of surgery, and anesthesia. In addition, we analyzed the type of intraoperative intravenous fluids, anesthetics and perioperative drugs, and temperature, blood pressure, and heart rate recordings during anesthesia.

RESULTS

There was no significant difference between the two groups with respect to age, sex, body mass index (BMI), ASA status, type or amount of intravenous fluids infused, length of anesthesia or surgery, changes in mean blood pressure, or heart rate. Core body temperatures in both groups decreased significantly over time (p 0.05). There was no difference between the groups in terms of maximum drop in temperature (lowest temperature recorded vs baseline temperature) (1.1 +/- 0.7 vs 1.0 +/- 0.7 degrees C, p > 0.05).

CONCLUSION

This study demonstrates that patients who undergo laparoscopic and open procedures of similar duration under endotracheal general anesthesia have similar profiles in terms of perioperative hypothermia.

Quantitative trait loci mapping associated with plant regeneration ability from seed derived calli in rice (Oryza sativa L.)

Quantitative trait loci (QTLs), which are associated with the ability of plant regeneration from seed derived calli, were detected using a recombinant inbred (RI) population from a cross between 'Milyang 23 (toingil)' and 'Gihobyeo (japonica)' in rice (Oryza sativa L.). A tongil type cultivar, 'Milyang 23', has a lower frequency of callus induction and plant regeneration than those of japonica 'Gihobyeo'. Transgressive segregations were observed for the callus induction rate and plant regeneration ability from seed derived calli of the RI population. An interval mapping analysis was used to identify the QTL controlling the plant regeneration ability. Two QTLs for the callus induction rate were detected on chromosomes 1 and 2, explaining the 10.9% total phenotypic variation. Four QTLs that are associated with the plant regeneration ability were located on chromosomes 2, 3, and 11, accounting for 25.7% of the total phenotypic variation.

Antimycin A mimics a cell-death-inducing Bcl-2 homology domain 3

The Bcl-2-related survival proteins confer cellular resistance to a wide range of agents. Bcl-xL-expressing hepatocyte cell lines are resistant to tumour necrosis factor and anti-cancer drugs, but are more sensitive than isogenic control cells to antimycin A, an inhibitor of mitochondrial electron transfer. Computational molecular docking analysis predicted that antimycin A interacts with the Bcl-2 homology domain 3 (BH3)-binding hydrophobic groove of Bcl-xL. We demonstrate that antimycin A and a Bak BH3 peptide bind competitively to recombinant Bcl-2. Antimycin A and BH3 peptide both induce mitochondrial swelling and loss of DeltaPsim on addition to mitochondria expressing Bcl-xL. The 2-methoxy derivative of antimycin A3 is inactive as an inhibitor of cellular respiration but still retains toxicity for Bcl-xL+ cells and mitochondria. Finally, antimycin A inhibits the pore-forming activity of Bcl-x L in synthetic liposomes, demonstrating that a small non-peptide ligand can directly inhibit the function of Bcl-2-related proteins.

Somatic mutations of TRAIL-receptor 1 and TRAIL-receptor 2 genes in non-Hodgkin's lymphoma

Tumor necrosis factor-related apoptosis-inducing ligand-receptor 1 (TRAIL-R1) and tumor necrosis factor-related apoptosis-inducing ligand-receptor 2 (TRAIL-R2) are cell-surface receptors involved in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cell-death signaling. TRAIL-R1 and TRAIL-R2 genes have recently been mapped to chromosome 8p21-22, which is a frequent site of allelic deletions in many types of human tumors, including non-Hodgkin's lymphoma (NHL). Because TRAIL/TRAIL receptor system plays an important role in lymphocyte homeostasis, we hypothesized that the mutations of TRAIL-R1 and TRAIL-R2 may be involved in the development of NHL and that such mutations may be responsible for the allelic losses of 8p21-22 in NHL. In this study, we analysed the entire coding region of TRAIL-R2 gene and the death domain region of TRAIL-R1 gene for the detection of the somatic mutations in a series of 117 human NHLs using polymerase chain reaction (PCR)-based single strand conformation polymorphism (SSCP) analysis. Overall, eight tumors (6.8%) were found to have two TRAIL-R1 gene mutations or six TRAIL-R2 gene mutations. Interestingly, of the eight mutations, six missense mutations (two TRAIL-R1 and four TRAIL-R2) were detected in the death domains and one nonsense mutation of TRAIL-R2 was detected just before the death domain. Our data suggest that somatic mutations of TRAIL-R1 and TRAIL-R2 genes may play a role in the pathogenesis of some NHLs and that TRAIL-R1 and TRAIL-R2 genes might be the relevant genes to the frequent loss of chromosome 8p21-22 in human NHL.

Evidence for two modes of allelic loss: multifocal analysis on both early and advanced gastric carcinomas

To assess the extent and the timing of allelic loss required for the progression of gastric carcinoma, the intratumoral distribution of loss of heterozygosity (LOH) was compared in early and advanced tumors: early loss is uniformly observed in all tumor areas and late loss is localized in parts of tumor tissue. Tumor sites (167 sites) obtained from 42 gastric carcinoma tissues (26 advanced cancers and 16 early cancers) were examined for LOH on chromosomes 5q, 9p, 13q, 17p, and 18q. By using two or three microsatellite markers for each chromosome arm, it was shown that of 29 tumors showing LOH in at least one tumor site, 15 (51.7%, 12 advanced and three early cancers) harbored multiple losses on three or more chromosome arms, and 89.4% (84 of 94) of these losses was uniformly found in all tumor sites tested. In the remaining 14 tumors (48.3%, eight advanced and six early tumors) with sporadic losses on one or two chromosome arms, 44% (11 of 25) of the losses were commonly shared among the sites tested. Such marked difference (P<0.001, Fisher's exact test) in the intratumoral distribution of multiple and sporadic LOH patterns proposes two distinct LOH subtypes: multiple losses (high LOH), occurring at an early stage with a few additional losses, and sporadic losses (low LOH), taking place relatively late during tumor progression. The multifocal LOH findings imply that, rather than being gradual, the allelic losses take place in two manners that are already determined at an early stage.

Fas-mediated apoptosis and expression of related genes in human malignant hematopoietic cells

Fas transduces apoptotic signals upon cross-linking with the Fas ligand (FasL), which is experimentally replaced by agonistic anti-Fas monoclonal antibodies (mAb). Of eight human malignant hematopoietic cell lines (HL-60, KG-1, THP-1, K562, U937, Jurkat, IM-9, RPMI-8226) examined by flow cytometric analysis, all, except K562, were found to be positive for surface Fas antigen. However, despite surface Fas expression, the agonistic anti-Fas mAb (7C11) induced apoptosis in only three of seven Fas-expressing cell lines (KG-1, Jurkat and IM-9). This Fas-resistance did not correlated with high levels of mRNA either for DcR3, a decoy receptor for FasL, or for FAP-1, a Fas-associated phosphatase that can block the apoptotic function of Fas. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis did not show consistent differences in the expression of Bcl-2 and Bax between Fas-sensitive and Fas-resistant cell lines examined. These findings indicated that the presence or absence of mRNA expression of DcR3, FAP-1, Bcl-2 and Bax did not always correlate with relative sensitivity to Fas-mediated apoptosis. Treatment of cells with cycloheximide converted the phenotype of resistant cell lines from Fas-resistant to Fas-sensitive, and enhanced the sensitivity of Fas-sensitive cell lines. These results suggest that the Fas-resistance is dependent on the presence of labile proteins that determine resistance to Fas-mediated apoptosis and the apoptotic machinery is already in place in Fas-resistant cell lines.