Survey of dental fees charged by dentists in Singapore

A survey on dental fees was conducted among all private dental clinics registered with the Medical Audit and Accreditation Unit of the Ministry of Health in Singapore. Replies were received from 74 dental clinics. Analysis of results showed that there was a general increase in the median of fees charged in 1998 compared to the fees listed in the Minimum Fee Schedule issued by the Singapore Dental Association in 1994. 93% of the respondents indicated that there is a need to revise the Minimum Fee Schedule.

Effects of diets containing gossypol on reproductive capacity of rainbow trout (Oncorhynchus mykiss)

We evaluated five practical diets in which 0%, 25%, 50%, 75%, and 100% (dietary treatments 1-5) of fish meal protein was replaced by solvent-extracted cottonseed meal protein. Adult rainbow trout (initial average weight 247 +/- 8 g) were fed the diets over a period of 131 days during which a general 2-fold body weight increase occurred. The total diet gossypol concentration (free and protein-bound) showed a gradual increase with increased cottonseed meal substitution. Blood samples were collected on Days 0, 64, 112, and 131 for hematological and steroid hormone determination in plasma of males and females. Hemoglobin content was significantly reduced in fish from treatment 5 (7.9 +/- 0.3 g/dl) in comparison to treatments 1-3 (10.3-10.9 g/dl). After 112 and 131 days of feeding, testis weights, concentrations of testosterone, and 11-ketotestosterone were elevated in fish from dietary treatments 2 and 3 in comparison to control and diets 4 and 5. On Day 71, sperm were collected from 6 fish per dietary treatment to assess sperm quality. No significant differences in sperm concentrations (7.2-9.8 x 10(9)/ml), motility (78-89%), and standardized (300 x 10(5) sperm/egg) fertilizing ability (18.9-22.6% hatched embryos) were found. Total gossypol concentrations in blood plasma differed significantly among treatments, and the levels were among the highest ever recorded in animals fed cottonseed-supplemented diets (2.9 +/- 0.2, 11.7 +/- 4.1, 21.7 +/- 1.4, and 29.9 +/- 3.9 microg/ml, for treatments 2-5, respectively). The major portion of gossypol in blood plasma was protein-bound (81-93%). This was in contrast to minute amounts of gossypol present in seminal plasma, mostly in free form (0.02-0.18 microg/ml), which indicates the presence of a barrier between general circulation and the testis with respect to gossypol distribution in lower vertebrates. Thus, the reproductive parameters of male rainbow trout examined in this study were not significantly affected by feeding cottonseed meal for 131 days.

Soluble-polymer supported synthesis of a prostanoid library: identification of antiviral activity

[formula: see text] The prostaglandins are potent natural products taking part in many biological processes. The "convergent generation of diversity" from a "toolbox" of prostanoid components, augmented with additional polymer-supported transformations, can enable construction of valuable libraries. A parallel-pool strategy was used to assemble a small library of prostanoids. The inhibition of a herpes-family virus demonstrated the potential for new drug discovery.

Tc-99m MIBI SPECT is useful for noninvasively predicting the presence of MDR1 gene-encoded P-glycoprotein in patients with hepatocellular carcinoma

PURPOSE

Resistance to chemotherapeutic drugs continues to be one of the major unsolved problems in the treatment of cancer. Multidrug resistance is defined as the ability of cells exposed to a single drug to develop resistance to a broad range of structurally and functionally unrelated drugs as a result of enhanced outward transport of drugs mediated by P-glycoprotein that is encoded by multidrug resistance genes. Recent evidence has shown that Tc-99m MIBI is a suitable transport substrate for P-glycoprotein. A potential advantage of Tc-99m MIBI SPECT is its superiority to diagnose noninvasively the presence of P-glycoprotein overexpression in vivo. In this study, the authors determined the association of enhanced MIBI efflux in Tc-99m MIBI SPECT with overexpression of P-glycoprotein in hepatocellular carcinoma.

MATERIALS AND METHODS

Thirty-five patients with hepatocellular carcinoma were enrolled in the study. Tc-99m MIBI SPECT was performed 10 minutes after intravenous injection of 20 mCi Tc-99m MIBI. All patients had liver biopsy or surgery within 1 week of MIBI imaging. Immunohistochemical study of the biopsy or resected hepatocellular carcinoma specimens was performed using the avidin-biotin-peroxidase technique with monoclonal antibody JSB-1 directed against P-glycoprotein.

RESULTS

On Tc-99m MIBI SPECT, 30 of 35 (85.7%) patients with hepatocellular carcinoma had no Tc-99m MIBI uptake in tumor lesions, whereas five patients with hepatocellular carcinoma had Tc-99m MIBI uptake in tumor lesions. P-glycoprotein expression was observed in tumor tissues of all the patients without Tc-99m MIBI uptake, whereas among the five patients with Tc-99m MIBI uptake, no P-glycoprotein expression was seen in tumor lesions (P < 0.015).

CONCLUSION

Tc-99m MIBI SPECT is useful for noninvasively predicting the presence of MDR1 gene-encoded P-glycoprotein in patients with hepatocellular carcinoma.

Microcephaly-cardiomyopathy syndrome: confirmation of the phenotype

We report a 9 year old girl with microcephaly and self-limiting dilated cardiomyopathy. Additional features include mental retardation, delayed developmental milestones, and minor dysmorphic features. This is the second reported case of this phenotype, which is believed to be a new autosomal recessive syndrome.

Survey of the Korean population for 9 short tandem repeat loci

The short tandem repeats with repeat units ranging from two to several nucleotides became a powerful tool in the field of forensic identification and paternity determination as well as for research in human gene mapping. Allele and genotype frequencies for 9 short tandem repeats including HUMCSF1PO, HUMTH01, HUMPLA2A1, HUMF13A01, HUMCYAR04, HUMLIPOL, HUMHPRTB, HUMCD4, and HUMFABP were determined using PCR and subsequent analysis of the PCR products by denaturing polyacrylamide gel electrophoresis followed by silver-staining. DNA samples were obtained from about 100 Korean people and amplified in a thermocycler adopting glass capillaries rather than traditional tubes. We found that the bovine serum albumin was an essential additive for the capillary PCR, presumably to coat the inner surface of the capillary which may adsorb Taq DNA polymerase. The capillary thermocycler was very effective in reducing the cycling time such that most of the amplification reactions could be finished within 30 min albeit the PCR product was less than that for the tube systems. All loci except HUMHPRTB met the Hardy-Weinberg expectations according to the exact test. The cumulative power of discrimination (PD) was 0.9999998 and the power of exclusion (POE) for the paternity test was a little low, being 0.9873989.

Autoregulation of the Drosophila disconnected gene in the developing visual system

The Drosophila disconnected (disco) gene is required for the formation of appropriate connections between the larval optic nerve and its target cells in the brain. The disco gene encodes a nuclear protein with two zinc fingers, which suggests that the gene product is a transcription factor. Here, we present data supporting this notion. We find that disco expression in the optic lobe primordium, a group of cells contacted by the developing optic nerve, depends on an autoregulatory feedback loop. We show that wild-type disco function is required for maintenance of disco mRNA and protein expression in the developing optic lobe. In addition, we demonstrate that ubiquitous Disco activity supplied by a heat-inducible gene construct activates expression from the endogenous disco gene specifically in the optic lobe primordium. Consistent with a role of Disco as a transcriptional regulatory protein, we show that portions of the Disco protein are capable of activating the transcription of reporter constructs in a heterologous system. Moreover, we find that the zinc finger portion of Disco binds in vitro to sequences located near the disco transcription unit, suggesting that Disco autoregulates its transcription in the optic lobe primordium by direct binding to a regulatory element in its own promoter.

Amycolatopsis thermoflava sp. nov., a novel soil actinomycete from Hainan Island, China

A soil isolate, which had been assigned to the genus Nocardia, was shown to have properties consistent with its classification in the genus Amycolatopsis. An almost complete nucleotide sequence of the 16S rDNA of the strain was determined following cloning and sequencing of the amplified gene. The sequence was aligned with those available for members of the family Pseudonocardiaceae and related taxa and phylogenetic trees were inferred using three tree-making algorithms. The organism consistently formed a distinct monophyletic clade with the type strain of Amycolatopsis methanolica, but DNA-DNA relatedness data showed that the two strains belonged to distinct genomic species. The organism was also distinguished from the type strains of all validly described species of Amycolatopsis using a battery of phenotypic properties. The genotypic and phenotypic data show that the strain merits recognition as a new species of the genus Amycolatopsis. The name proposed for the new species is Amycolatopsis thermoflava sp. nov. The type strain is IFO 14333T.

Altered serum cytokine and immunoglobulin levels in the workers exposed to antimony

1 Antimony (Sb), an industrial and environmental toxicant, is known to cause dermatitis and pulmonary inflammations, but the immunomodulatory effects of environmental or occupational exposure to Sb have not been reported. To initiate investigation of Sb-induced alterations of the immune system, the concentrations of the IgG subclasses, IgE, interleukin-2, interferon-gamma, and interleukin-4 in sera obtained from workers exposed to Sb through antimony trioxide manufacture were determined and compared with those of control subjects. 2 The serum levels of IgG1, an immunoglobulin involved in host defense against many microbial infections, were significantly lower in the sera of Sb-exposed individuals than the controls. The serum concentrations of IgE, an immunoglobulin mediating allergic hypersensitivity, also were lower in the Sb-exposed workers than the controls. In addition, the levels of interleukin-2 and interferon-gamma, multifunctional cytokines for T-cell mediated immunity, were lowered in the factory workers. 3 A significant positive correlation between IgG4 and urine Sb levels was found among the Sb-exposed workers, indicating a possible role of IgG4 in Sb-mediated pulmonary or skin pathogenesis. 4 The present study provides the first report on immune alterations induced by occupational exposure to Sb and suggests that Sb exposure disturbs immunohomeostasis in humans observed as a function of aberrant serum cytokine and immunoglobulin levels, which could influence health.

A metal complex that binds alpha-amino acids with high and predictable stereospecificity

Molecular recognition is the key step in a wide range of controlled separation and chemical transformation processes, with enzymes performing this task with an unsurpassed degree of selectivity. Enzymes contain only 20 simple amino acids, yet it remains difficult to rationalize or even predict these stereospecific recognition events. Nonetheless, the rational design of receptors able to recognize amino acids stereospecifically is attracting considerable interest because therapeutic drugs, that may be developed from chiral amino acid intermediates, are increasingly required in enantiomerically pure form. Early work has stimulated the development of efficient receptors based on small molecules, but binding of amino acids with high and predictable stereospecificity remains difficult to achieve. Directed molecular evolution, on the other hand, does select for RNA sequences or antibodies that bind amino acids with high specificity, but typically without providing insights into the molecular recognition mechanisms involved. Here we show that a rationally designed metal complex formed from a trivalent cobalt ion and a tetradentate ligand binds natural amino acids, including the simple yet challenging amino acid alanine, with high and predictable regio- and stereospecificity. We expect that our approach will allow the binding as well as separation and stereospecific catalytic formation of its target amino acids.

Frequency of sister chromatid exchange in chrysotile-exposed workers

Chrysotile, which is an industrial carcinogen, has been shown to induce a dose-dependent increase in the frequency of sister chromatid exchange (SCE) in vitro. Authors designed this study to examine the increase of SCEs frequency in the workers occupationally exposed to chrysotile. Heparinized whole blood samples from 45 chrysotile-exposed and 45 control volunteers were cultured for 72 h. The significant difference of SCE frequency was found between chrysotile-exposed workers and control group. The highest SCEs frequency was found in chrysotile-exposed smokers, and the lowest in control non-smokers. The effect of chrysotile exposure on SCEs was marginally significant after controlling the effects of age and smoking by multiple regression analysis.

An incidental case of human Heterophyes nocens infection diagnosed by sectional morphology in a biopsy specimen of the small intestine

A case of human infection with Heterophyes nocens (Heterophyidae) was incidentally found in a biopsy specimen of the Meckel's diverticulum at the upper part of the small intestine. The patient was a 58-year-old man living in a rural area of Talsonggun, Kyongsangbuk-do. He had gastrointestinal symptoms such as epigastric pain, indigestion, and abdominal discomfort for 3 months, and severe diarrhea, abdominal pain, and vomiting for about 1 month before hospitalization. Endoscopy of the upper part of the small intestine revealed a Meckel's diverticulum, and it was excised and histopathologically examined. Three adult flukes were incidentally found sectioned in the mucosa, and they were identified as H. nocens. The patient had a history of eating raw mullets at a fish market in Pusan 6 months ago, and the mullets were presumed to be the source of infection. This case brings a considerable interest in that specific diagnosis of heterophyid infections could be done by sectional morphology of the worms.

Identification and characterization of human Fas associated factor 1, hFAF1

We have identified and characterized a cDNA encoding human Fas associated factor 1 (hFAF1) cDNA and a shorter form of hFAF1 cDNA [hFAF1(s)] with a 456 bp internal in-frame deletion from a human HeLa cDNA library. The nucleotide sequences of hFAF1 and hFAF1(s) were identical except for the deletion. GST-hFAF1 fusion protein bound to the in vitro translation product of Fas. The N-terminal region (amino acid 1 approximately 201) including the upstream ubiquitin homology domain of hFAF1 could bind with the death domain of Fas unlike that of qFAF1 whose binding region with Fas could not be determined. However hFAF1 did not bind to the death domain of Fas mutant, lpr(cg). hFAF1 was expressed abundantly in testis, skeletal muscle, and heart as 2.8 kb mRNA. Polyclonal antibody against hFAF1 detected 74 kD protein, a deduced protein size from the ORF and 40 kD protein in some cell lines.

Competitive binding of calmodulin isoforms to calmodulin-binding proteins: implication for the function of calmodulin isoforms in plants

In plants, multiple calmodulin (CaM) isoforms exist in an organism which vary in their primary structures in as much as 32 residues out of their 148 amino acids. These CaM isoforms show differences in their expression patterns and/or target enzyme activation ability. To further understand the biological significance of CaM isoforms, we examined whether CaM isoforms act on specific regulatory targets. In gel overlay assays on various soybean tissue extracts, surprisingly, two soybean CaM isoforms (SCaM-1 and SCaM-4) did not show significant differences in their target binding protein profiles, although they exhibited minor differences in their relative target binding affinities. In addition, both SCaM isoforms not only effectively bound five known plant CaMBPs, but also showed competitive binding to these proteins. Finally, immunolocalization experiments with the SCaM proteins in sections of various tissues using specific antibodies revealed similar distribution patterns for the SCaM isoforms except for root tissues, which indicates that the SCaM isoforms are concomitantly expressed in most plant tissues. These results suggest that CaM isoforms may compete for binding to CaMBPs in vivo. This competitive nature of CaM isoforms may allow modulation of Ca(2+)/CaM signaling pathways by virtue of relative abundance and differential target activation potency.

Molecular cloning and expression analysis of a mouse phospholipase C-delta1

We describe here the molecular cloning and expression analysis of mouse PLC-delta1 (mPLC-delta1), a key enzyme in cell signal transduction. A mouse brain cDNA library was screened in order to isolate the mPLC-delta1 cDNA. The mPLC-delta1 cDNA was 2660 bp in length. The predicted open reading frame encodes a protein of 756 amino acids with an estimated molecular mass of 85 kDa. The deduced amino acid sequence exhibits 96.9% and 92.7% identity with the sequence of rat and human PLC-delta1, respectively. The mPLC-delta1 mRNA was highly expressed in brain, heart, lung, and testis. We found that transcripts of mPLC-delta1 are present in almost all regions of mouse brain examined, implying that the enzyme may play a role in some fundamental cellular process in brain. In male reproductive tract, mPLC-delta1 mRNA was widely expressed in the epididymis as well as in the testis. In situ hybridization studies indicate that distribution of mPLC-delta1 mRNA in mouse testis is discrete and unique. The expression of mPLC-delta1 mRNA was defined in the periphery of each seminiferous tubule, especially in spermatogonia, which might imply that mPLC-delta1 plays a role in proliferation of spermatogonia. To the best our knowledge, this is the first report to demonstrate the high expression of mPLC-delta1 mRNA in spermatogonia of testis. Taken together, these results suggest that mPLC-delta1 may carry out fundamental roles in almost all of mouse tissues, especially in brain and specific roles in testis.

A case of methemoglobinemia after ingestion of an aphrodisiac, later proven as dapsone

Methemoglobin (MetHb) is an oxidation product of hemoglobin in which the sixth coordination position of ferric iron is bound to a water molecule or to a hydroxyl group. The most common cause of acquired MetHb-emia is accidental poisoning which usually is the result of ingestion of water containing nitrates or food containing nitrite, and sometimes the inhalation or ingestion of butyl or amyl nitrite used as an aphrodisiac. We herein report a case of MetHb-emia after ingestion of an aphrodisiac, later identified as dapsone by gas chromatograph/mass selective detector (GC/MSD). A 24-year old male was admitted due to cyanosis after ingestion of a drug purchased as an aphrodisiac. On arterial blood gas analysis, pH was 7.32, PaCO2 26.8 mmHg, PaO2 75.6 mmHg, and bicarbonate 13.9 mmol/L. Initial pulse oxymetry was 89%. With 3 liter of nasal oxygen supplement, oxygen saturation was increased to 90-92%, but cyanosis did not disappear. Despite continuous supplement of oxygen, cyanosis was not improved. On the fifth hospital day, MetHb was 24.9%. Methylene blue was administered (2 mg/kg intravenously) and the patient rapidly improved. We proved the composition of aphrodisiac as dapsone by the method of GC/MSD.

Clinical outcomes of acute myocarditis in childhood

OBJECTIVE

To describe clinical outcomes of a paediatric population with histologically confirmed lymphocytic myocarditis.

DESIGN

A retrospective review between November 1984 and February 1998.

SETTING

A major paediatric tertiary care hospital.

PATIENTS

36 patients with histologically confirmed lymphocytic myocarditis.

MAIN OUTCOME MEASURES

Survival, cardiac transplantation, recovery of ventricular function, and persistence of dysrhythmias.

RESULTS

Freedom from death or cardiac transplantation was 86% at one month and 79% after two years. Five deaths occurred within 72 hours of admission, and one late death at 1.9 years. Extracorporeal membrane oxygenation support was used in four patients, and three patients underwent heart replacement. 34 patients were treated with intravenous corticosteroids. In the survivor/non-cardiac transplantation group (n = 29), the median follow up was 19 months (range 1.2-131.6 months), and the median period for recovery of a left ventricular ejection fraction to > 55% was 2.8 months (range 0-28 months). The mean (SD) final left ventricular ejection and shortening fractions were 66 (9)% and 34 (8)%, respectively. Two patients had residual ventricular dysfunction. No patient required antiarrhythmic treatment. All survivors reported no cardiac symptoms or restrictions in physical activity.

CONCLUSIONS

Our experience documents good outcomes in paediatric patients presenting with acute heart failure secondary to acute lymphocytic myocarditis treated with immunosuppression. Excellent survival and recovery of ventricular function, with the absence of significant arrhythmias, continued cardiac medications, or restrictions in physical activity were the normal outcomes.

Generation of cerebellar granule neurons in vivo by transplantation of BMP-treated neural progenitor cells

Cerebellar granule neurons, the most abundant class of CNS neurons, have a critical role in cerebellar function. Granule neurons are generated at the dorsal border of the mesencephalon and metencephalon, the rhombic lip. In the mouse embryo, rhombic lip cells express a number of granule neuron markers, notably the bHLH transcription factor Math1. Dorsal midline cells adjacent to the rhombic lip express Bmp6, Bmp7 and Gdf7, three genes encoding peptide growth factors of the bone morphogenetic protein (BMP) family. These BMPs induced the expression of granule neuron markers in cultured neural tissue. Moreover, BMP-treated neural cells formed mature granule neurons after transplantation into the early postnatal cerebellum, suggesting that BMPs initiate the program of granule cell specification.

The specification of dorsal cell fates in the vertebrate central nervous system

The generation of distinct classes of neurons at defined positions within the developing vertebrate nervous system depends on inductive signals provided by local cell groups that act as organizing centers. Genetic and embryological studies have begun to elucidate the processes that control the pattern and identity of neuronal cell types. Here we discuss the cellular interactions and molecular mechanisms that direct neuronal cell fates in the dorsal half of the vertebrate central nervous system. The specification of dorsal neuronal cell fates appears to depend on a cascade of inductive signals initiated by cells of the epidermal ectoderm that flank the neural plate and propagated by roof plate cells within the neural tube. Members of the transforming growth factor-beta (TGF beta) family of secreted proteins have a prominent role in mediating these dorsalizing signals. Additional signals involving members of the Wnt and fibroblast growth factor (FGF) families may also contribute to the proliferation and differentiation of dorsal neuronal cell types.

Application of biological monitoring to the quantitative exposure assessment for neuropsychological effect by chronic exposure to organic solvents

OBJECTIVE

Quantitative exposure assessment became more common as a result of attempts to reduce nondifferential exposure misclassification and to observe a steeper exposure-response relationship. Several exposure variables were compared in a demonstration of the exposure-response relationship between neuropsychological abnormality and long-term exposure to organic solvents in workers at one shipyard.

METHOD

Environmental monitoring and biological monitoring were performed to evaluate the exposure of the workers to organic solvents. Cumulative exposure (CE) and lifetime-weighted average exposure variables were developed with both environmental and biological monitoring data. A neuropsychological questionnaire and a function test for confirmation of a disorder or dysfunction in attention, executive function, visuospatial, and constructional abilities, learning and memory, and psychomotor function were performed.

RESULTS

The abnormal rate in neuropsychological diagnosis was 9.3% in the exposed group, which was much higher than the 2.1% rate obtained in the nonexposed group (P<0.01). The neuropsychological abnormal rate showed a significant dose-response association with CE created with biological monitoring data. The results also suggest that biological monitoring can provide impressive and effective information for quantitative exposure assessment, even in epidemiology studies.

Involvement of specific calmodulin isoforms in salicylic acid-independent activation of plant disease resistance responses

The Ca2+ signal is essential for the activation of plant defense responses, but downstream components of the signaling pathway are still poorly defined. Here we demonstrate that specific calmodulin (CaM) isoforms are activated by infection or pathogen-derived elicitors and participate in Ca2+-mediated induction of plant disease resistance responses. Soybean CaM (SCaM)-4 and SCaM-5 genes, which encode for divergent CaM isoforms, were induced within 30 min by a fungal elicitor or pathogen, whereas other SCaM genes encoding highly conserved CaM isoforms did not show such response. This pathogen-triggered induction of these genes specifically depended on the increase of intracellular Ca2+ level. Constitutive expression of SCaM-4 and SCaM-5 in transgenic tobacco plants triggered spontaneous induction of lesions and induces an array of systemic acquired resistance (SAR)-associated genes. Surprisingly, these transgenic plants have normal levels of endogenous salicylic acid (SA). Furthermore, coexpression of nahG gene did not block the induction of SAR-associated genes in these transgenic plants, indicating that SA is not involved in the SAR gene induction mediated by SCaM-4 or SCaM-5. The transgenic plants exhibit enhanced resistance to a wide spectrum of virulent and avirulent pathogens, including bacteria, fungi, and virus. These results suggest that specific CaM isoforms are components of a SA-independent signal transduction chain leading to disease resistance.

Cardiac troponin I gene knockout: a mouse model of myocardial troponin I deficiency

Troponin I is a subunit of the thin filament-associated troponin-tropomyosin complex involved in calcium regulation of skeletal and cardiac muscle contraction. We deleted the cardiac isoform of troponin I by using gene targeting in murine embryonic stem cells to determine the developmental and physiological effects of the absence of this regulatory protein. Mice lacking cardiac troponin I were born healthy, with normal heart and body weight, because a fetal troponin I isoform (identical to slow skeletal troponin I) compensated for the absence of cardiac troponin I. Compensation was only temporary, however, as 15 days after birth slow skeletal troponin I expression began a steady decline, giving rise to a troponin I deficiency. Mice died of acute heart failure on day 18, demonstrating that some form of troponin I is required for normal cardiac function and survival. Ventricular myocytes isolated from these troponin I-depleted hearts displayed shortened sarcomeres and elevated resting tension measured under relaxing conditions and had a reduced myofilament Ca sensitivity under activating conditions. The results show that (1) developmental downregulation of slow skeletal troponin I occurs even in the absence of cardiac troponin I and (2) the resultant troponin I depletion alters specific mechanical properties of myocardium and can lead to a lethal form of acute heart failure.

Identification of a domain containing B-cell epitopes in hepatitis C virus E2 glycoprotein by using mouse monoclonal antibodies

Evidence from clinical and experimental studies of human and chimpanzees suggests that hepatitis C virus (HCV) envelope glycoprotein E2 is a key antigen for developing a vaccine against HCV infection. To identify B-cell epitopes in HCV E2, six murine monoclonal antibodies (MAbs), CET-1 to -6, specific for HCV E2 protein were generated by using recombinant proteins containing E2t (a C-terminally truncated domain of HCV E2 [amino acids 386 to 693] fused to human growth hormone and glycoprotein D). We tested whether HCV-infected sera were able to inhibit the binding of CET MAbs to the former fusion protein. Inhibitory activity was observed in most sera tested, which indicated that CET-1 to -6 were similar to anti-E2 antibodies in human sera with respect to the epitope specificity. The spacial relationship of epitopes on E2 recognized by CET MAbs was determined by surface plasmon resonance analysis and competitive enzyme-linked immunosorbent assay. The data indicated that three overlapping epitopes were recognized by CET-1 to -6. For mapping the epitopes recognized by CET MAbs, we analyzed the reactivities of CET MAbs to six truncated forms and two chimeric forms of recombinant E2 proteins. The data suggest that the epitopes recognized by CET-1 to -6 are located in a small domain of E2 spanning amino acid residues 528 to 546.

Characterization of a tobacco MADS-box gene homologous to AGL2

Flower development is regulated by a group of regulatory factors containing the MADS box domain. Recently, we isolated and characterized a tobacco MADS-box gene, NtMADS1, which is homologous to AGL2 in Arabidopsis. Sequence analysis revealed that NtMADS1 encodes a putative MADS-box protein homologous to the AGL2 with 68.4% identity and 82% similarity in amino acids. The NtMADS1 gene started to express at a very early stage of flower development, such as floral primodia, and the expression was maintained during the entire floral development. In the tobacco flower, the gene was expressed in all four floral organs, namely the sepal, petal, anther, and carpel, and was not detected in the vegetative organs such as the leaf and root. In situ hybridization was also performed to monitor the detailed expression pattern of NtMADS1 at the tissue level. These results indicate that NtMADS1 is the AGL2 homolog of tobacco and plays important roles in the floral development.

Automatic motion correction in dynamic radionuclide renography using image registration

Time-activity curves from dynamic renograms can be analysed to yield important quantitative parameters. However, accurate results are dependent on curves being free from artefacts caused by patient movement. We describe a method to correct for both translational and rotational motion during renography. The method is image-based and does not require markers. Sequential dynamic frames are registered using an affine transform from which rotational and translational components are extracted by singular-value decomposition. Computer simulations demonstrate correction to < 1 pixel and < 1 degree. The method is also fast, with renograms comprising 75 frames of 64 x 64 pixels taking under 1 min for correction on a Sun SPARC 5.

Actinorhodin and undecylprodigiosin production in wild-type and relA mutant strains of Streptomyces coelicolor A3(2) grown in continuous culture

The effects of growth rate and nutrient feed rate on the production of actinorhodin (Act) and undecylprodigiosin (Red) were determined in Streptomyces coelicolor A3(2) and in a congenic relA null-mutant known to be deficient in ppGpp synthesis and antibiotic production under conditions of nitrogen limitation. In the relA+ strain, Act production was inversely related to specific growth rate in continuous cultures limited by glucose, ammonium, or phosphate, while Red biosynthesis was optimal at 0.05 h-1 regardless of the specific nutrient limitation. Production of Act and Red in the relA mutant was lower than that of the parental strain, particularly under conditions of glucose- and ammonium-limitation, indicating an important and general role for ppGpp in determining the onset of the antibiotic biosynthesis under conditions of nutrient limitation. At constant growth rate, but with varying nutrient feed rates, the specific rate of Act production was adversely influenced by increasing levels of glucose, ammonium, and phosphate, with phosphate having the greatest inhibitory effect. Under the same conditions, the specific rate of Red production was stimulated by increasing glucose levels, but markedly decreased by increased levels of phosphate.

Neuronal patterning by BMPs: a requirement for GDF7 in the generation of a discrete class of commissural interneurons in the mouse spinal cord

Inductive factors are known to direct the regional differentiation of the vertebrate central nervous system (CNS) but their role in the specification of individual neuronal cell types is less clear. We have examined the function of GDF7, a BMP family member expressed selectively by roof plate cells, in the generation of neuronal cell types in the dorsal spinal cord. We find that GDF7 can promote the differentiation in vitro of two dorsal sensory interneuron classes, D1A and D1B neurons. In Gdf7-null mutant embryos, the generation of D1A neurons is eliminated but D1B neurons and other identified dorsal interneurons are unaffected. These findings show that GDF7 is an inductive signal from the roof plate required for the specification of neuronal identity in the dorsal spinal cord and that GDF7 and other BMP family members expressed by the roof plate have non-redundant functions in vivo. More generally, these results suggest that BMP signaling may have a prominent role in the assignment of neuronal identity within the mammalian CNS.

Prostaglandin E2 increases proenkephalin mRNA level in rat astrocyte-enriched culture

The effect of prostaglandin E2 (PGE2) on proenkephalin (proENK) mRNA expression in primary cultured rat astrocytes was studied. The proENK mRNA level was significantly increased about 3.3-fold 4 h after PGE2 (10 microM) treatment and this increase was potentiated by the pre-treatment with cycloheximide (CHX; 15 microM) about 1.7-fold as much as PGE2 alone treated cells. The pretreatment with staurosporine (1 microM) completely inhibited the increase of PGE2-induced proENK mRNA level, although only a partial inhibition of PGE2-induced proENK mRNA level (approximately 1.5-fold) by H89 (10 microM) was observed. The increase of PGE2-induced proENK mRNA level was not affected by the pretreatment with PD98059 (1, 5, and 10 microM), omega-conotoxin GIVA (1 microM), nimodipine (1 microM), calmidazolium (1 microM), or KN-62 (1 microM). In addition to the proENK mRNA level, PGE2 also increased c-Fos (approximately 4.3-fold), Fra-1 ( approximately 3.8 fold), and Fra-2 (approximately 8.2-fold) protein levels at 4 h after drug treatment. However, c-Jun, JunB, and JunD protein levels were not affected by PGE2. Indeed, PGE2 failed to up-regulate c-jun mRNA expression as well as its protein product. Surprisingly, although three Jun proteins were not induced by PGE2, AP-1 and ENKCRE-2 DNA binding activities were increased by PGE2, (approximately 5 and approximately 2.8-fold, respectively) and which were effectively reduced by CHX (approximately 2.5 and 2-fold, respectively). In western blot analyses, PGE2 enhanced the phosphorylation of CREB (approximately 2.6-fold at 1 h), and CHX showed a potentiative effect on PGE2-induced CREB phosphorylation ( approximately 1.7 fold at 1 h) which is similar to the action on proENK mRNA regulation. Our results suggest that PGE2 increases proENK mRNA expression via activating serine/threonine protein kinase such as PKA, but not calcium/calmodulin dependent protein kinase and MAPK. In addition, phosphorylation of CREB rather than the increase of AP-1 may have a possible role at least early stage in PGE2-induced proENK mRNA level and CHX-evoked potentiation.

Design of mechanism-based carboxypeptidase A inactivators on the basis of the X-ray crystal structure and catalytic reaction pathway

The X-ray crystal structure of the complex of carboxypeptidase A (CPA) and Gly-Tyr, has been documented. The crystal structure reveals that both the amide carbonyl oxygen and the terminal amino nitrogen of Gly-Tyr coordinate to the active site zinc ion of CPA in a bidentate fashion, whereby the zinc-bound water molecule is displaced by the amino group. As to the catalytic mechanism of CPA, it is generally believed that while in the cases of ester substrates the carboxylate of Glu-270 functions as the nucleophile which attacks the scissile carbonyl carbon (anhydride pathway), in the case of peptide substrates the zinc-bound water molecule attacks the scissile peptide bond (general base pathway). In light of the X-ray crystal structure and the proposed catalytic mechanism for the enzyme, it is envisioned that the ester bond of O-(hydroxyacetyl)-L-beta-phenyllactic acid (L-1) would be hydrolyzed by the attack of the carboxylate of Glu-270 to generate an anhydride intermediate. The latter intermediate would then undergo an intramolecular rearrangement initiated by the attack of the hydroxyl to result in to form an ester bond with the Glu-270 carboxylate. This ester formation impairs the catalytic activity of CPA. We have demonstrated using kinetic analysis that L-1 is indeed an inactivator for the enzyme having the Kinact/KI value of 0.057 M-1 s-1. We have also demonstrated that N-(hydroxyacetyl)-L-phenylalanine (L-2) inactivates the enzyme with the kinact/KI value of 0.071 M-1 s-1, suggesting that the carboxylate becomes to attack the peptide carbonyl carbon to generate the same anhydride intermediate as that formed in the inactivation of CPA by L-1. The formation of the anhydride intermediate rather than a tetrahedral transition state that is expected for peptide type substrates was envisioned to occur on the ground that the zinc-bound water molecule is displaced by the hydroxyl of L-2 upon binding to the enzyme.

Helicobacter pylori infection, oxidative DNA damage, gastric carcinogenesis, and reversibility by rebamipide

Several epidemiological studies have demonstrated a close association between Helicobacter pylori infection and carcinoma of the mid- or distal stomach. If this can be shown to be a causal association, eradication of the organism may prevent later development of cancer. Several mechanisms have been proposed by which H. pylori infection might lead to predisposition for gastric cancer. Although many potential pathogenic mechanisms, such as increased proliferative gastric epithelial response to H. pylori, lowered gastric ascorbic acid levels, and high occurrences of atrophic gastritis, have been proposed, there is little evidence as to which might be of direct importance to such H. pylori-related disease in vivo. H. pylori-associated inflammation may interact with other causal factors related to gastric carcinogenesis and can result in the intestinal type of gastric cancer and then DNA damage due to oxygen radicals induced by persistent inflammatory cell infiltrations in the gastric mucosa may lead to alterations of the gene and result in the development of diffuse-type carcinoma. In order to know the influence of H. pylori on changes of inflammation-related DNA damage, we measured the sequential changes of 8-hydroxydeoxyguanosine (8-OHdG) contents of DNA and the changes of two biomarkers inducible nitric oxide synthase (iNOS) and apoptosis from human gastric mucosa according to the status of H. pylori. The increased levels of oxidative DNA damage, increased occurrences of apoptosis, and increased expressions of iNOS seem to provide the mechanistic links between H. pylori infection and gastric carcinogenesis and rebamipide can abrogate the levels of these hazard factors.

Quantitative and qualitative usefulness of rebamipide in eradication regimen of Helicobacter pylori

The aim of the present study was to determine the efficacy of a new combination regimen including antioxidant, proton pump inhibitor, and antibiotics against Helicobacter pylori and to document the changes of oxidative stress and cytokines involved in H. pylori-associated gastritis. From each of 57 patients with endoscopically diagnosed gastric and/or duodenal ulcers associated with H. pylori infection, five gastric antral biopsy specimens were taken for the diagnosis of H. pylori and for experimental measures. The patients were then treated either with lansoprozole 30 mg + amoxicillin 1.5 g (LA group; 21 patients) or lansoprazole 30 mg + amoxicillin 1.5 g + rebamipide 300 mg (LAM group; 36 patients) for two weeks. Four weeks after the initiation of treatment, the patients were endoscoped again and biopsy specimens were obtained. Mucosal malondialdehyde (MDA) levels; myeloperoxidase (MPO) activities; superoxide dismutase; catalase; glutathione peroxidase; cytokines IL-1, IL-6, TNF-alpha; and chemokines IL-8, GRO-alpha, RANTES (regulated on activation normal T expressed and secreted) were measured. Using paraffin-embedded tissue sections, in situ terminal deoxyribonucleotide transferase (TdT) -mediated dUTP nick end labeling (TUNEL) for apoptosis and immunohistochemical staining for inducible nitric oxide synthase (iNOS) were performed. Two weeks of treatment with the LA regimen resulted in 57.4% eradication rates of H. pylori, whereas two weeks of treatment with the LAM regimen resulted in 75.0% eradication rates. Eradication rates between these two groups were statistically significantly different (P < 0.05). Mucosal MDA levels and MPO activities were significantly lower in the LAM group than the LA group. Mucosal levels of cytokines IL-1, IL-6, and TNF-alpha and of chemokines IL-8, GRO-alpha, and RANTES were all significantly decreased after the treatment of H. pylori, especially in the LAM-treated group. The apoptotic index and iNOS score were significantly reduced after the eradication of H. pylori. The addition of the antioxidative drug rebamipide to the eradication regimen against H. pylori has quantitative and qualitative advantages such as either augmenting the eradication rates of H. pylori or decreasing oxidative stress and cytokines levels generated by H. pylori infection.

Application of micellar electrokinetic capillary chromatography for the determination of benzoic acid and its esters in liquid formula medicines as preservatives

We described a method for the simultaneous determination of preservatives including benzoic acid, methyl-, ethyl- and propyl-benzoate by micellar electrokinetic capillary chromatography (MECC). The factors affecting the reproducibility in the quantitative analysis of pharmaceuticals by MECC were investigated by varying the running buffer and washing condition in-between runs. Preservatives in liquid formula medicines have been determined by optimum MECC condition using p-hydroxy benzoic acid as an internal standard. The reproducibility of this method was acceptable as a validate method for the quality control of pharmaceuticals (RSD < 2%). Routine quantitative analysis of pharmaceuticals using MECC could be possible with well characterized reproducible procedure.

Suppression of accelerated diabetic atherosclerosis by the soluble receptor for advanced glycation endproducts

Accelerated atherosclerosis in patients with diabetes is a major cause of their morbidity and mortality, and it is unresponsive to therapy aimed at restoring relative euglycemia. In hyperglycemia, nonenzymatic glycation and oxidation of proteins and lipids results in the accumulation of irreversibly formed advanced glycation endproducts. These advanced glycation endproducts engage their receptor in cells of the blood vessel wall, thereby activating mechanisms linked to the development of vascular lesions. We report here a model of accelerated and advanced atherosclerosis in diabetic mice deficient for apolipoprotein E. Treatment of these mice with the soluble extracellular domain of the receptor for advanced glycation endproducts completely suppressed diabetic atherosclerosis in a glycemia- and lipid-independent manner. These findings indicate interaction between the advanced glycation endproducts and their receptor is involved in the development of accelerated atherosclerosis in diabetes, and identify this receptor as a new therapeutic target in diabetic macrovascular disease.

Application of a wavelet adaptive filter to minimise distortion of the ST-segment

A wavelet adaptive filter (WAF) for the removal of baseline wandering in ECG signals is described. The WAF consists of two parts. The first part is a wavelet transform that decomposes the ECG signal into seven frequency bands using Vaidyanathan-Hoang wavelets. The second part is an adaptive filter that uses the signal of the seventh lowest-frequency band among the wavelet transformed signals as primary input and a constant as reference input. To evaluate the performance of the WAF, two baseline wandering elimination filters are used, a commercial standard filter with a cutoff frequency of 0.5 Hz and a general adaptive filter. The MIT/BIH database and the European ST-T database are used for the evaluation. The WAF performs better in the average power of eliminated noise than the standard filter and adaptive filter. Furthermore, it shows a lower ST-segment distortion than the standard filter and the adaptive filter.

Hepatitis C virus envelope DNA-based immunization elicits humoral and cellular immune responses

The vaccine development for hepatitis C virus (HCV) is highly urgent to prevent non A and non B hepatitis. It was recently shown that the HCV envelope proteins appeared to the key viral antigens to induce protective immunity. To generate immune responses to the HCV envelope proteins on the DNA-based immunization, various envelope gene-containing plasmids were constructed. For efficient expression and secretion of envelope proteins, the signal sequence of each envelope protein was replaced with either herpes simplex virus type-1 (HSV-1) gD or signal sequence of gD and truncated C-terminal hydrophobic regions of envelope proteins. The intramuscular injection of these plasmids generated a significant level of antibody titers to the E1 and E2 proteins, which maximally reached 850 and 25,000 respectively. The secreted form of each envelope protein and the fusion of the highly immunogenic gD proteins were shown to have no significant effect on generating immune responses to the envelope proteins. In addition, immunized rats appeared to generate antibodies directed to the homologous HVR-1 peptide. Splenic lymphocytes from immunized rats were shown to induce significant T-cell proliferative responses with the stimulation of recombinant E1 and E2 proteins. Our results demonstrated that the HCV envelope-DNA based immunization could elicit both humoral and cellular immune responses.

Molt-inhibiting hormone mRNA levels and ecdysteroid titer during a molt cycle of the blue crab, Callinectes sapidus

Synthesis of ecdysteroid molting hormones by crustacean Y-organs is believed to be regulated by a neuropeptide, molt-inhibiting hormone (MIH), produced in eyestalk neural ganglia. In the present study, steady-state MIH mRNA and hemolymph ecdysteroid levels were determined by Northern blot and radioimmunoassay, respectively, during the molt cycle of the blue crab, Callinectes sapidus. The level of MIH mRNA dropped steadily during premolt (D1-D4), reaching a minimum in D3/D4, then increased by 10-fold in postmolt (A/B) and remained elevated during intermolt (C4). These stage-specific changes in MIH mRNA levels were accompanied by significant fluctuations in the hemolymph ecdysteroid titer. The ecdysteroid titer increased steadily to a peak of 377.0 ng/ml in D3 of premolt, then dropped to 120.0 ng/ml in D4 (just prior to molting), and was low during postmolt (A/B, 4.4 ng/ml) and intermolt (C4, 3.3 ng/ml). The results represent the first report of developmental changes in MIH gene expression and are generally consistent with the hypothesis that MIH negatively regulates ecdysteroid synthesis in crustaceans.

Effects of sexual dimorphism on facial attractiveness

Testosterone-dependent secondary sexual characteristics in males may signal immunological competence and are sexually selected for in several species. In humans, oestrogen-dependent characteristics of the female body correlate with health and reproductive fitness and are found attractive. Enhancing the sexual dimorphism of human faces should raise attractiveness by enhancing sex-hormone-related cues to youth and fertility in females, and to dominance and immunocompetence in males. Here we report the results of asking subjects to choose the most attractive faces from continua that enhanced or diminished differences between the average shape of female and male faces. As predicted, subjects preferred feminized to average shapes of a female face. This preference applied across UK and Japanese populations but was stronger for within-population judgements, which indicates that attractiveness cues are learned. Subjects preferred feminized to average or masculinized shapes of a male face. Enhancing masculine facial characteristics increased both perceived dominance and negative attributions (for example, coldness or dishonesty) relevant to relationships and paternal investment. These results indicate a selection pressure that limits sexual dimorphism and encourages neoteny in humans.

Nocardia flavorosea sp. nov

An actinomycete strain, 'Nocardai flavorosea' JCM 3332, was found to have properties consistent with its classification in the genus Nocardia. An almost complete gene sequence of the 16S rDNA of the strain was determined following cloning and sequencing of the amplified gene. The sequence was aligned with those available for nocardiae and phylogenetic trees were inferred using four tree-making algorithms. The organisms consistently formed a distinct clade with the type strain of Nocardia carnea. However, DNA relatedness experiments showed that the strain and N. carnea DSM 43397T belonged to two distinct genomic species. The organism was also distinguished from representative of all of the validly described species of Nocardia using a combination of phenotypic properties. These genotypic and phenotypic data show that the strain merits recognition as a new species of the genus Nocardia. The name proposed for the new species of is Nocardia flavorosea sp. nov. The type strain is JCM 3332T.

A case of arteriovenous type cardiac hemangioma

Cardiac hemangiomas are rare primary tumors of the heart and constitute only 2.8% of primary cardiac tumors. They are classified into capillary, cavernous, epitheloid and arteriovenous type and the last one is the most uncommon type. We experienced a case of cardiac hemangioma which was diagnosed as arteriovenous type for the first time in Korea in the literature. The patient was a 54-year-old woman who presented with palpitation and anterior chest pain. The diagnosis was based upon coronary angiography which showed two tumor blushings located in the interatrial and interventricular septum with venous drainage to the coronary sinus and right atrium. Associated atrial fibrillation with rapid ventricular response was controlled with digitalis.

Characterization of the leupeptin-inactivating enzyme from Streptomyces exfoliatus SMF13 which produces leupeptin

Leupeptin-inactivating enzyme (LIE) was purified from Streptomyces exfoliatus SMF13 by ammonium sulphate fractionation of cell-free culture broth, ultrafiltration, anion-exchange chromatography on DEAE-Sephadex A-50 and gel filtration chromatography on Sephadex G-75. The molecular mass of the purified enzyme was measured as 34700 Da and the N-terminal amino acid sequence was APTPPDIPLANVPA. Acetyl-leucine, leucine and argininal were identified as the products of leupeptin inactivated by the LIE, indicating that leupeptin is inactivated by hydrolysis of peptide bond between leucine and leucine and between leucine and argininal of leupeptin (acetyl-leucine-leucine-argininal). Synthetic-peptide substrates specificity of LIE showed that LIE has absolute specificity for peptide bonds with leucine in the P1 position, suggesting that LIE is a leucine-specific protease. The optimum pH and temperature were pH 9.0 and 45 degrees C, respectively. LIE activity was inhibited by metalloprotease inhibitors such as EDTA, EGTA, o-phenanthroline and bestatin, but activated by Mg2+ and Ca2+, suggesting that the enzyme is a metalloprotease. Aerial-mycelium growth and aerial spore formation of S. exfoliatus SMF13 were inhibited by the addition of bestatin, an inhibitor of LIE. The inhibition of morphological differentiation was due to the inhibition of trypsin-like protease (TLP) activity, which is essential for aerial-mycelium formation and is inhibited specifically by remaining leupeptin that was not inactivated. These results show that LIEs play a role in controlling the amount of leupeptin during colony development. Therefore, it is suggested that the physiological function of LIE is to inactivate leupeptin when or where TLP activity is required for aerial-mycelium formation.

Synthesis and antibacterial activities of new carbapenems having a proline reverse amide moiety at the C-2 position

The synthesis of new 1 beta-methylcarbapenems (1a-l) having a proline reverse amide moiety at the C-2 position and their in vitro antibacterial activities are described. The compounds were evaluated by the Mueller-Hinton agar dilution method and compared with meropenem as control. Aliphatic amides (1a-h) are found to show greater antibacterial activity than aromatic amides (1i-l). Moreover, C-2 free amino compound (1m) reveals greater activity than any other amide compounds (1a-l).

Presentation-time measures of the effects of manipulations in colour space on discrimination of famous faces

Caricaturing the distinctive shape of famous faces can produce an advantage in reaction-time paradigms but the role of distinctive colour and intensity information in recognition of facial identity has not previously been explored. A presentation-time paradigm was developed by which stimuli could be presented for a range of brief display periods. Subjects were required to identify photo-realistic colour representations of famous faces which either were veridical, were caricatured in colour space, or had enhanced colour saturation and intensity contrast (as contrast controls). Recognition accuracy was greater when viewing the caricatured stimuli than either the veridical images or the contrast controls. The removal of colour information to produce grey-scale images also decreased accuracy of face recognition. Both results indicate that colour information aids differentiation of a class of natural stimuli with similar configurations. Thus it is demonstrated that caricaturing faces can be extended to the colour domain and, as with shape caricaturing, enhancement of distinctive information can produce a recognition advantage for famous faces.

Transactivation potential of the C-terminus of human Nm23-H1

The transactivation potential of Nm23-H1, a homolog of c-myc transcription factor Nm23-H2/PuF was assessed in yeast as a fusion protein with the DNA binding domains (DBDs) of GAL4 and LexA. The C-terminal half of Nm23-H1 exhibited strong transactivation of the reporter genes, LacZ and Leu2 carrying GAL4 and LexA upstream activating sequences (UASs), whereas the full-length Nm23-H1 and its N-terminal did not. Similar results were also obtained with Nm23-H2/PuF transactivating the reporter genes only by the C-terminus fused to GAL4 and LexA DBDs. Hence, our results suggested a possible regulatory role of the N-termini of Nm23 isotypes upon transactivation.

Inhibition of thermolysin with nitrone-bearing substrate analogs: a new type of thermolysin inhibitors

Nitrones are utilized as the active site zinc coordinating functionality in the design of inhibitors for thermolysin. This new type of thermolysin inhibitors are as potent as the existing inhibitors bearing a carboxylate or hydroxamate zinc ligating moiety.

Augmented eradication rates of Helicobacter pylori by new combination therapy with lansoprazole, amoxicillin, and rebamipide

The aim of the present study was to determine the efficacy of a new combination regimen including an antioxidant, a proton pump inhibitor, and antibiotics against Helicobacter pylori and to document the changes of oxidative stress and cytokines involved in H. pylori-associated gastric inflammation. From 57 patients with endoscopically diagnosed gastric and/or duodenal ulcers associated with H. pylori infection five gastric antral biopsy specimens were taken for the diagnosis of H. pylori and for the experimental measures. The patients were then treated either with lansoprazole 30 mg + amoxicillin 1.5 g (LA group; 21 patients) or lansoprazole 30 mg + amoxicillin 1.5 g + rebamipide 300 mg (LAM group; 36 patients) for two weeks. Four weeks after the initiation of treatment, the patients were endoscoped again and biopsy specimens were obtained. Mucosal malondialdehyde (MDA) levels; myeloperoxidase (MPO) activities; superoxide dismutase; catalase; glutathione peroxidase; cytokines IL-1, IL-6, TNF-alpha; and chemokines IL-8, GRO-alpha, RANTES (regulated on activation normal T expressed and secreted) were measured. Using paraffin-embedded tissue sections, in situ terminal deoxyribonucleotide transferase (TdT) mediated dUTP nick end labeling (TUNEL) for apoptosis and immunohistochemical staining for inducible nitric oxide synthase (iNOS) were performed. Two weeks of treatment with the LA regimen resulted in 57.4% eradication rates of H. pylori, whereas two weeks of treatment with the LAM regimen resulted in 75.0% eradication rates. Eradication rates between these two groups were statistically significantly different (P < 0.05). Mucosal MDA levels and MPO activities were significantly lower in the LAM group than the LA group. Mucosal levels of cytokines IL-1, IL-6, and TNF-alpha and of chemokines IL-8, GRO-alpha, and RANTES were all significantly decreased after the treatment of H. pylori, especially so in the LAM group. The apoptotic index and iNOS score were significantly reduced after the eradication of H. pylori. The addition of an antioxidative drug to the eradication regimen against H. pylori has advantages either in augmenting the eradication rates of H. pylori or in decreasing the oxidative stress and cytokines levels generated by H. pylori infection.

Chordin regulates primitive streak development and the stability of induced neural cells, but is not sufficient for neural induction in the chick embryo

We have investigated the role of Bone Morphogenetic Protein 4 (BMP-4) and a BMP antagonist, chordin, in primitive streak formation and neural induction in amniote embryos. We show that both BMP-4 and chordin are expressed before primitive streak formation, and that BMP-4 expression is downregulated as the streak starts to form. When BMP-4 is misexpressed in the posterior area pellucida, primitive streak formation is inhibited. Misexpression of BMP-4 also arrests further development of Hensen's node and axial structures. In contrast, misexpression of chordin in the anterior area pellucida generates an ectopic primitive streak that expresses mesoderm and organizer markers. We also provide evidence that chordin is not sufficient to induce neural tissue in the chick. Misexpression of chordin in regions outside the future neural plate does not induce the early neural markers L5, Sox-3 or Sox-2. Furthermore, neither BMP-4 nor BMP-7 interfere with neural induction when misexpressed in the presumptive neural plate before or after primitive streak formation. However, chordin can stabilise the expression of early neural markers in cells that have already received neural inducing signals. These results suggest that the regulation of BMP signalling by chordin plays a role in primitive streak formation and that chordin is not sufficient to induce neural tissue.

Thermotolerance inhibits various stress-induced apoptosis in NIH3T3 cells

When NIH3T3 cells were exposed to mild heat and recovered at 37 degrees C for various time intervals, they were thermotolerant and resistant to subsequent stresses including heat, oxidative stresses, and antitumor drug methotrexate which are apoptotic inducers. The induction kinetics of apoptosis by stresses were determined by DNA fragmentation and protein synthesis using [35S]methionine pulse labeling. We investigated the hypothesis that thermotolerant cells were resistant to apoptotic cell death compared to control cells when both cells were exposed to various stresses inducing apoptosis. The cellular changes in thermotolerant cells were examined to determine which components are involved in this resistance. At first, the degree of resistance correlates with the extent of heat shock protein synthesis which were varied depending on the heating times at 45 degrees C and recovery times at 37 degrees C after heat shock. Secondly, membrane permeability change was observed in thermotolerant cells. When cells prelabeled with [3H]thymidine were exposed to various amounts of heat and recovered at 37 degrees C for 1/2 to 24 h, the permeability of cytosolic [3H]thymidine in thermotolerant cells was 4 fold higher than that in control cells. Thirdly, the protein synthesis rates in thermotolerant and control cells were measured after exposing the cells to the same extent of stress. It turned out that thermotolerant cells were less damaged to same amount of stress than control cells, although the recovery rates are very similar to each other. These results demonstrate that an increase of heat shock proteins and membrane changes in thermotolerant cells may protect the cells from the stresses and increase the resistance to apoptotic cell death, even though the exact mechanism should be further studied.

Molecular cloning of a cDNA encoding molt-inhibiting hormone of the crab, Cancer magister

A neuropeptide molt-inhibiting hormone (MIH) negatively regulates crustacean molting glands (Y-organs). We report here the molecular cloning of a cDNA encoding putative MIH of the Dungeness crab, Cancer magister. A cDNA library was commercially prepared using poly (A+) RNA isolated from C. magister eyestalk neural ganglia. The library was screened using as probe a previously cloned portion of a cDNA encoding MIH of the blue crab, Callinectes sapidus. DNA sequence analysis of one positive clone revealed a 339 base pair open reading frame encoding a 78 amino acid putative MIH and a 35 amino acid signal peptide. The deduced amino acid sequence of C. magister MIH shows high sequence identity (80-98%) with MIH of three other brachyuran crabs, but lower identity (26-45%) with MIH and MIH-like peptides from astacurans and shrimp. Studies using reverse transcription-polymerase chain reaction (RT-PCR) indicate the MIH gene is expressed in eyestalk but not control (muscle, gill, gonad, hepatopancreas) tissue.