A proteomic analysis of secreted proteins from xylan-induced Bacillus sp. strain K-1

The expression level of extracellular proteins in an alkaliphilic bacterium, Bacillus sp. strain K-1, grown in a xylan-containing medium, is significantly increased when compared with that grown in the nonxylan culture medium. A proteomic approach has been efficiently applied to separate and characterize these differentially expressed secretory proteins. Eight prominent protein spots were identified and subjected to N-terminal amino acid sequencing. The results show that three spots share considerable similarity with the xylanolytic enzymes and that two spots share considerable similarity with the GltC regulatory protein and 3-dehydroquinate dehydratase, respectively. In addition, the three other proteins show little similarity with the known proteins in the database. In conclusion, our results demonstrate that the proteomic approach is a highly efficient method to rapidly study the differential expression of the secreted proteins by Bacillus sp. strain K-1 grown under xylan-induced condition.

Correlation between Helicobacter pylori infection and gastrointestinal symptoms in pregnancy

Nausea, vomiting, and other dyspeptic symptoms are common in pregnancy. This hospital-based, cross-sectional study was designed to determine the role of Helicobacter pylori infection in gastrointestinal (GI) symptoms during pregnancy. Standardized verbal scales were used to evaluate the frequency and severity of GI symptoms in 54 women whose pregnancies were in the first 16 gestational weeks. H. pylori infection was defined as a positive serum immunoglobulin G result on an immunochromatographic assay. The H. pylori seropositivity rate was higher in the pregnant women (69%) than in the general population (approximately 50%-55%), but seropositivity did not correlate with clinical symptoms. Moreover, no specific patterns of GI symptoms were uncovered in the H. pylori-infected patients. Maternal age, body weight, parity, gestational week, and educational level were not associated with H. pylori infection; neither were the prevalence and severity of GI symptoms.

Cytokine regulation of IL-12 receptor beta2 expression: differential effects on human T and NK cells

The biological activities of IL-12 are mediated through a specific, high-affinity receptor composed of IL-12 receptor(R)beta1 and IL-12Rbeta2 subunits that exist primarily on T and NK cells. Remarkably, the expression of IL-12Rbeta2 on CD4(+) T cells in mouse and humans appears to be differentially regulated by IFN-gamma and IFN-alpha, respectively. Using an antibody specific for the human IL-12Rbeta2 subunit, the effect of IFN-gamma, IFN-alpha, IL-12 and IL-2 on the regulation of IL-12R expression and IL-12 responsiveness of human T and NK cells was assessed. The presence of IFN-alpha or IFN-gamma in cultures enhanced IL-12Rbeta2 expression of CD4(+) and CD8(+) T cells. The enhancing effect of IFN-alpha and IFN-gamma was independent of endogenous IL-12. Furthermore, the clearest effects of IFN-alpha and IFN-gamma on IL-12Rbeta2 expression on T cells were seen by abrograting the inhibition induced by the presence of IL-4 in cultures. In contrast to T cells, IFN-alpha and IFN-gamma had little effect on regulating IL-12Rbeta2 expression on human NK cells. Taken together, these data show that there is differential regulation of IL-12Rbeta2 expression by IFN-alpha and IFN-gamma on human T and NK cells.

Repeat transthoracic endoscopic sympathectomy for palmar and axillary hyperhidrosis

BACKGROUND

Patients undergoing an unsuccessful sympathectomy experience dryness on one hand and excessive sweating on the other. This is embarrassing for the patients, and resolution of both a previous failed sympathectomy and recurrent hyperhidrosis is important.

METHODS

From September 1995 to January 1998, 24 patients (11 men and 13 women; mean age, 28.2 years) underwent repeat transthoracic sympathectomy (TES). The repeat TES was performed with patients under general anesthesia using either a standard single-lumen endotracheal tube (12 patients) or a double-lumen endotracheal tube (12 patients). Ablation of T2 and T3 ganglia and any Kuntz fiber was performed in treating patients with palmar hyperhidrosis, and a similar procedure was performed on T3 and T4 ganglia for patients with axillary hyperhidrosis.

RESULTS

The reasons for failure of the previous TES were pleural adhesion (14/24), intact T2 ganglion (5/24), aberrant venous arch drainage to the superior vena cava (2/24), incomplete interruption of sympathetic nerve (2/24), and possible reinnervation (1/24). The mean operation time was 28 min (range, 18-72 min). In all, 23 patients had a satisfactory result, without recurrence of palmar or axillary hyperhidrosis. The mean follow-up time was 22 months (range, 5-30 months). The average hospital stay was 1.8 days. There was no surgical mortality.

CONCLUSION

Repeat TES is a safe and effective method for treating both an unsuccessful sympathectomy and recurrent palmar or axillary hyperhidrosis.

Assessment of a new quantitative ultrasound calcaneus measurement: precision and discrimination of hip fractures in elderly women compared with dual X-ray absorptiometry

The incidence of osteoporotic hip fracture increases in postmenopausal women with low hip bone mineral density (BMD). Dual X-ray absorptiometry (DXA) is the most commonly used technique for the assessment of bone status and provides good measurement precision. However, DXA affords little information about bone architecture. Quantitative ultrasound (QUS) systems have been developed to evaluate bone status for assessment of fracture risk. Our study was designed to assess a new QUS system from Hologic, the Sahara; to compare it with a previous model, the Walker-Sonix UBA 575+; and to investigate whether it is able to discriminate between women with and without fracture. Using both ultrasound devices, the measurements were performed at the heels of 33 postmenopausal women who had recently sustained hip fracture. A control group of 35 age-matched postmenopausal women was recruited for comparison. The total, neck and trochanter femoral BMD values were assessed using DXA for both groups. QUS and DXA measurements were significantly lower in fractured patients (p < 0.005) than in the control group. The short-term, mid-term and standardized short-term precisions were used to evaluate the reproducibility of the two QUS systems. The Sahara showed a better standardized coefficient of variation for broadband ultrasound attenuation (BUA) than did the UBA 575+ (p < 0.001). The correlation of BUA and speed of sound (SOS) between the two QUS devices was highly significant, with an r value of 0.92 for BUA and 0.91 for SOS. However, the correlation between DXA and ultrasound parameters ranged from 0.28 to 0.44. We found that ultrasound measurements at the heel were significant discriminators of hip fractures with odds ratios (OR) ranging from 2.7 to 3.2. Even after adjusting the logistic regressions for total, neck or trochanter femoral BMD, QUS variables were still significant independent discriminators of hip fracture. The areas under the ROC curves of each ultrasound parameter ranged from 0.75 to 0.78, and compared very well with femoral neck BMD (p > 0.05). In conclusion, our study indicated that the calcaneal QUS variables, as measured by the Sahara system can discriminate hip fracture patients equally as well as hip DXA.

Comparison of six calcaneal quantitative ultrasound devices: precision and hip fracture discrimination

Quantitative ultrasound (QUS) is now accepted as a useful tool in the management of osteoporosis. There are a variety of QUS devices clinically available with a number of differences among them, including their coupling methods, parameter calculation algorithms and sites of measurement. This study evaluated the abilities of six calcaneal QUS devices to discriminate between normal and hip-fractured subjects compared with the established method of dual-energy X-ray absorptiometry (DXA). The short-term and mid-term precisions of these devices were also determined. Thirty-five women (mean age 74.5+/-7.9 years) who had sustained a hip fracture within the past 3 years, and 35 age-matched controls (75.8+/-5.6 years) were recruited. Ultrasound measurements were acquired using six ultrasound devices: three gel-coupled and three water-coupled devices. Bone mineral density was measured at the hip using DXA. Discrimination of fracture patients versus controls was assessed using logistic regression analysis (expressed as age- and BMI-adjusted odds ratios per standard deviation decrease with 95% confidence interval) and receiver operating characteristics (ROC) curve analysis. Measurement precision was standardized to the biological range (sCV). The sCV ranged from 3.14% to 5.5% for speed of sound (SOS) and from 2.45% to 6.01% for broadband ultrasound attenuation (BUA). The standardized medium-term precision ranged from 4.33% to 8.43% for SOS and from 2.77% to 6.91% for BUA. The pairwise Pearson correlation coefficients between different devices was highly significant (SOS, r = 0.79-0.93; BUA, r = 0.71-0.92). QUS variables correlated weakly, though significantly, with femoral BMD (SOS, r = 0.30-0.55; BUA, r = 0.35-0.61). The absolute BUA and SOS values varied among devices. The gel-coupled devices generally had a higher SOS than water-coupled devices. Bone mineral density (BMD) and BUA were weakly correlated with weight (r = 0.48-0.57 for BMD and r = 0.18-0.54 for BUA), whereas SOS was independent of weight. All the QUS devices gave similar, statistically significant hip fracture discrimination for both SOS and BUA measures. The odds ratios for SOS (2.1-2.8) and BUA (2.4-3.4) were comparable to those for femoral BMD (2.6-3.5), as were the area under the curve (SOS, 0.65-0.71; BUA, 0.62-0.71; BMD, 0.65-0.74) from ROC analysis. Within the limitation of the sample size all devices show similar diagnostic sensitivity.

Sub-Nanosecond Lifetime Measurement Using the Recoil-Distance Method

The electromagnetic properties of low-lying nuclear states are a sensitive probe of both collective and single-particle degrees of freedom in nuclear structure. The recoil-distance technique provides a very reliable, direct and precise method for measuring lifetimes of nuclear states with lifetimes ranging from less than one to several hundred picoseconds. This method complements the powerful, but complicated, heavy-ion induced Coulomb excitation technique for measuring electromagnetic properties. The recoil distance technique has been combined with heavy-ion induced Coulomb excitation to study a variety of problems. Examples discussed are: study of the two-phonon triplet in (110)Pd, coupling of the β and γ degrees of freedom in (182,184)W, highly deformed γ bands in (165)Ho, octupole collectivity in (96)Zr, and opposite parity states in (153)Eu. Consistency between the Coulomb excitation results and the lifetime measurements confirms the reliability of the complex analysis often encountered in heavy-ion induced Coulomb excitation work.

The preclinical pharmacologic study of dopamine transporter imaging agent [99mTc]TRODAT-1

The purpose of this study was to investigate the pharmacologic characteristics of TRODAT-1 (2beta-((N,N'-bis(2-mercaptoethyl)ethylene diamino)methyl), 3beta-(4-chlorophenyl)tropane) labeled with [99mTc] as an imaging agent for dopamine transporter (DAT). Radiochemical purity of [99mTc]TRODAT-1 was over 90%. The partition coefficients in octanol and buffer were 2.12 and 2.19 at pH 7.0 and 7.4, respectively. Animal studies have been performed in rats, rabbits, and normal and hemi-Parkinsonian model monkeys. Biodistribution displayed moderate uptake in rat brain (0.28 %ID/organ at 2 min) and the striatal uptake was 0.193, 0.142, and 0.136 %ID/g at 2, 60, and 120 min, respectively. The ratios of striatal/cerebellar (ST/CB) uptake were 2.4, 4.45, and 2.45 %ID/g at 60, 120, and 240 min, respectively. The major radioactivity was excreted by the hepatobiliary system. Blood clearance kinetics was performed in rabbits, and the initial half-life of 1.18 min and late half-life of 367.8 min were obtained. Brain single photon emission computed tomography imaging studies in normal monkeys showed the ratios of ST/CB uptake were 1.56-2.0 %ID/g and indicated that both uptake and retention in the striatal area were associated with the DAT. The imaging of hemi-Parkinsonian model monkeys also displayed the expected selectivity, the highest uptake being observed in the basal ganglia area of the normal side. Thereby, it is suggested that [99mTc]TRODAT-1 is a safe and useful imaging agent for localization of the presynaptic DAT in the brain.

Vertebral fractures in osteoporosis: a new method for clinical assessment

Vertebral fractures are the most common consequence of osteoporosis, and are an important risk factor for subsequent fractures. Patients with reduced bone mineral density (BMD) and vertebral fractures have significantly increased risk for future fractures, indicating great potential for the combined use of fracture assessment and BMD in risk evaluation. Despite the established importance of fractures, however, vertebral assessment is not typically performed in the clinical evaluation of patients at risk for osteoporosis. Radiographs are the accepted standard for assessment of fractures, but are rarely obtained in osteoporosis assessment for a variety of practical reasons, including cost, radiation dose, and the lack of office-based radiological facilities. Clinical assessment of fractures is difficult because most are asymptomatic. Consequently, this strong risk factor for osteoporotic fractures is often overlooked. High-resolution lateral spine images, obtained on advanced fan-beam dual X-ray absorptiometry (DXA) systems, provide a practical, low-radiation dose, point-of-care methodology for assessment of vertebral fractures, and have the potential to address this important clinical need. In this article, we review the importance of vertebral fractures and the methods of assessing them. We also review clinical data supporting the feasibility of visual evaluation of lateral spine images obtained using a fan-beam DXA system, and discuss the potential positive impact of this new methodology on clinical patient evaluation.

Clinicopathologic analysis of malignant melanoma in Taiwan

BACKGROUND

Malignant melanoma is the leading cause of death among skin cancers in western countries. However, the incidence, histologic subtypes, and tumor behaviors are quite different in Asians and people of color.

OBJECTIVE

Our purpose was to define the tumor behaviors and possible prognostic predictors of melanomas based on a Taiwanese patient population.

METHODS

From the 65 patients diagnosed with melanoma at Veterans General Hospital, Taichung, we analyzed mean age at onset, gender, histologic subtypes, tumor thickness, level of invasion, primary tumor locations, and metastatic sites. Univariate analysis and multivariate analyses for survival, according to clinical and histologic tumor behaviors, were performed by means of Cox proportional hazard model. Survival curves were plotted by Kaplan-Meier method.

RESULTS

Fifty-one cutaneous melanomas were identified and analyzed by both clinical behaviors and histology. Acral lentiginous melanoma was the most common type (54.9%), followed by nodular melanoma (29.4%), superficial spreading melanoma, and lentigo maligna melanoma. Univariate analysis for overall survival of melanoma revealed that age at onset older than 55 years, male gender, ulceration of tumor, and thicker tumor have the tendency to poorer prognosis, but without significant differences. The advanced stages (III and IV) and histologic subtypes other than acral lentiginous melanoma predicted a poorer survival with significant differences. Multivariate analysis demonstrated advanced stages, and histologic subtypes were the independent risk factors for poor prognosis.

CONCLUSION

We proposed that histologic subtypes other than acral lentiginous melanoma and advanced stages have a poorer prognosis with significant differences.

A novel chromosomal locus of enteropathogenic Escherichia coli (EPEC), which encodes a bfpT-regulated chaperone-like protein, TrcA, involved in microcolony formation by EPEC

The bfpTVW operon, also known as the per operon, of enteropathogenic Escherichia coli (EPEC) is required for the transcriptional activation of the bfp operon, which encodes the major subunit and assembly machinery of bundle-forming pili (BFP). An immobilized T7-tagged BfpT fusion protein that binds specifically to upstream promoter sequences of bfpA and eae was used to 'fish out' from a promoter library other EPEC chromosomal fragments that are bound by the BfpT protein. After screening for promoters exhibiting bfpTVW-dependent expression, one was identified that was positively regulated by bfpTVW and that is not present in the chromosomes of two non-virulent E. coli laboratory strains, DH5alpha and HB101. Further analysis of this positively regulated promoter in EPEC showed that it resided within a 4.9 kb sequence that is not present in E. coli K12. This locus, located downstream of the potB gene, was found to contain four open reading frames (ORFs): bfpTVW-activated promoter was localized upstream of ORF1. An ORF1 knockout mutant produced less of the BFP structural subunit (BfpA) and formed smaller than normal adherent microcolonies on cultured epithelial cells; however, this mutation did not affect bfp transcription. An ORF1-His6 fusion protein specifically bound the preprocessed and mature forms of the BfpA protein and thus appears to stabilize the former within the cytoplasmic compartment. ORF1 therefore is a newly isolated EPEC chromosomal gene that encodes a chaperone-like protein involved in the production of BFP. Hence, ORF1 was designated trcA (bfpT-regulated chaperone-like protein gene). The TrcA protein also specifically bound 39 kDa and 90 kDa proteins that are expressed by EPEC but not by E. coli K12. The 90 kDa protein was revealed to be intimin, a protein product of the eae gene, which is required for the EPEC attaching/effacing phenotype, suggesting a direct interaction of TrcA with intimin in the cytoplasmic compartment.

Suppression of tumorigenicity in cervical carcinoma HeLa cells by an episomal form of adeno-associated virus

To compare the oncosuppressive activity of integrated and episomal adeno-associated virus (AAV), two Epstein-Barr virus (EBV) derived episomal form vectors, p205 and p220, were used to generate plasmids containing episomal AAV. HeLa cells transfected with p205, p220, and the plasmids with forward (pA205-1, pA220-1) and reverse (pA205-1, pA220-2) orientation of inserted AAV DNA were designated H205, H220, HA205-1, HA220-1, HA205-1, and Ha220-2, respectively. The respective average copy numbers of pA205 and pA220 per cell are 4.9-6.9 and 4.3. The AAV-transfected HeLa cells displayed growth inhibition when compared to parental and the vector-transfected HeLa cells. Nude mice assay showed that the tumor size from HA205-1 and HA205-2 cells were 11.3 and 22.6%, and those from HA220-1 and HA220-2 cells were 54.8 and 57.3%, respectively, when compared to parental HeLa cells. HA205-1 cells containing forward AAV insert exerted more oncosuppressive effect than HA205-2 cells containing reverse AAV insert. Our data indicate that the episomal AAV can exert oncosuppressive activity as compared to the integrated AAV in HeLa cells.

A new picorna-like virus, PnPV, isolated from ficus transparent wing moth, Perina nuda (Fabricius)

Two viruses, Perina nuda nucleopolyhedrovirus and a new picorna-like virus, were previously isolated from P. nuda larvae with flacherie. In this study the new picorna-like virus was characterized using physical and biochemical methods. This small virus appears to belong to the family Picornaviridae and we propose the name PnPV. PnPV can be propagated in its homogenous cell line, NTU-PN-HH. PnPV purified from the cell line resembles PnPV isolated from insects: under electron microscopy, it exhibits icosahedral symmetry, measures 30 nm in diameter, and has no envelope and no distinct surface structure in negatively stained preparations. In addition, we show here that PnPV has a buoyant density of 1.381 g/ml in cesium chloride, the viral genome was composed of one single-stranded RNA molecule with a length of 10 kb, and poly(A) tract and polyacrylamide gel electrophoresis of purified viral particles revealed three major (31.5, 29.7, and 28.4 kDa) and three minor (27. 0, 24.5, and 4.0 kDa) structural proteins.

Effect of rehabilitation tasks on organization of movement after stroke

OBJECTIVE

The purpose of this study was to examine the effect of presence or absence of an object (goal-directed action vs. rote exercise) and the effect of functional specificity of the object on the organization of reaching movements of persons who have had a stroke.

METHOD

A repeated-measure counterbalanced design was used in each of two experiments. Eighteen persons who had been hospitalized after stroke were recruited from the roster of a rehabilitation hospital and through stroke clubs and volunteered to participate. Fourteen of these became the data-producing sample. In Experiment 1, the OPTO-TRAK/3020 motion analysis system was used to record movement when the participants reached for preferred food (goal-directed action) or to a spatial location (rote exercise). In Experiment 2, the system recorded movement when participants reached to pick up the receiver of an active telephone (natural context), a detached receiver (partial context), and a stick (simulated context). The organization of the reach movement was described kinematically as the number of zero crossings of the acceleration profile (smoothness), movement time (speed), displacement, peak velocity (an indication of force), and location of peak velocity in the velocity profile (planning strategy).

RESULTS

Goal-directed action produced significantly smoother, faster, more forceful, and more preplanned movement than did the rote exercise condition. Functional specificity of the context did not significantly affect organization of the reach.

CONCLUSION

Goal-directed reach enabled persons with stroke to display characteristics typical of reach to a target by persons who have not had a stroke better than reaching out in space. These findings support the occupational therapy practice of using objects in a functional context to improve coordinated movement. However, the nature of the objects to be used requires further study.

Microcalcifications of non-palpable breast lesions detected by ultrasonography: correlation with mammography and histopathology

OBJECTIVES

Microcalcifications are generally not demonstrated well on ultrasonography. In this study, we attempted to demonstrate the usefulness of high-resolution ultrasonography in the detection of microcalcifications associated with non-palpable breast cancers.

DESIGN

Fourteen patients with non-palpable breast lesions in whom microcalcifications were detected or suspected by ultrasonography and one patient in whom microcalcifications were detected on mammography only were included in the study. Mammography and analysis of biopsy specimens were performed in each patient and the findings were correlated with the ultrasonographic findings. Ultrasonography and mammography were performed independently by different physicians at different times.

RESULTS

In three patients < or = 30 years of age, who were not at high risk of breast cancer and who had no evidence of cancer on palpation, high-resolution ultrasonography clearly showed microcalcifications but no mass. Two of these patients had ductal carcinoma in situ and one had small invasive carcinoma with extensive comedocarcinoma. Among the other 12 patients with non-palpable breast lesions, ultrasonography detected microcalcifications accurately in six and suggested possible microcalcifications in a further four. Microcalcifications in all of these ten patients were confirmed by mammography thereafter. Four of these ten patients had ductal carcinoma in situ, with or without invasive carcinoma. Of the remaining two patients, one demonstrated false-positive findings and one false-negative findings on ultrasound. On high-resolution ultrasonography, microcalcifications produced the appearance of twinkling stars (bright dots in different planes) in a dark sky (contrasted against ill-defined hypoechoic patches), corresponding on histopathology to groups of expanded ducts with increased cell density with or without necrosis.

CONCLUSION

High-resolution ultrasonography may be used for detection of microcalcifications in non-palpable breast lesions. Ultrasonography is helpful in screening for early breast cancers, especially in young patients who are at risk for breast cancer and in whom mammography is not usually carried out.

Identification of cis-regulatory elements required for endosperm expression of the rice storage protein glutelin gene GluB-1

Rice storage protein glutelin genes are coordinately regulated during seed development. A previous 5' deletion analysis using transgenic tobacco revealed that the minimum 5' region necessary for endosperm specificity was within -245 bp of the transcription start site, and included the AACA and GCN4 motifs that are highly conserved in the 5'-flanking regions of all glutelin genes. In this paper, the sequence elements essential for endosperm-specific expression are characterized in stable transgenic tobacco plants by both loss-of-function and gain-of-function experiments using this minimum promoter. Base substitution analysis shows that the proximal AACA motif between -73 and -61, and the GCN4 motif between -165 and -158 act as critical elements. An ACGT motif between -81 and -75, and Skn-I-like elements between -173 and -169 also play important roles in controlling the seed-specific expression. When the distal region between -245 and -145 containing the AACA and the GCN4 motifs or the proximal region between -113 and -46 containing the ACGT and AACA motifs is fused to a truncated promoter (-90 to +9) of the CaMV 35S gene fused to the beta-glucuronidase (GUS) reporter gene, high levels of seed-specific expression are observed in these fusions, thereby indicating that either pair of motifs is sufficient to confer seed expression in these fusions. However, when substituted for by the CaMV 35S core promoter (-46 to +1), seed expression is abolished, suggesting that the sequence between -90 and -46 of the CaMV 35S promoter containing G-box-like motif (as-1 element) is required for such specific expression in addition to AACA and GCN4 motifs. Therefore, we conclude that at least three cis-regulatory elements, the AACA motif, GCN4 motif and ACGT motif, are necessary to mediate endosperm expression of the GluB-1 glutelin gene.

Pharmacology study of the neutral myocardial imaging agent technetium-99m-N(NOEt)2

OBJECTIVE

The biological properties of a new neutral myocardial imaging agent 99mTcN(NOEt)2 were evaluated.

METHODS

Blood clearance in rabbits, biodistribution in rats, and initial myocardial imaging in dogs were performed.

RESULTS

Radiochemical purity of 99mTcN(NOEt)2 was more than 90% and stable for 6 h at room temperature. Blood disappearance was analyzed with a biexponential model and T1/2(alpha) = 2.53 min, T1/2(beta) = 330 min and CI = 378 ml/h were obtained. Biodistribution studies demonstrated that 99mTcN(NOEt)2 localized selectively in the rat myocardium. Cardiac uptakes were 4.69, 4.20, 3.95 and 3.43% ID/g at 5, 30, 60 and 90 min postinjection, respectively. The mean heart-to-lung activity ratios were 1.69, 2.40 and 2.55 at 10 min, 30 min and 60 min postinjection, respectively.

CONCLUSION

Technetium-99m-N(NOEt)2 exhibited favorable stability and biological properties. Further study in humans is required.

Interaction between Helicobacter pylori and non-steroidal anti-inflammatory drugs in peptic ulcer bleeding

BACKGROUND

Helicobacter pylori and non-steroidal anti-inflammatory drugs (NSAIDs) are the two primary causes of peptic ulcer disease. How H. pylori and NSAIDs interact and influence the development of ulcer bleeding is still not clear.

METHODS

A hospital-based, age- and sex-matched case-control study was conducted. Multivariate and stratified analyses were performed for further evaluation of the interaction between H. pylori and NSAIDs.

RESULTS

Ninety-seven patients (52 gastric ulcers, 45 duodenal ulcers) and 97 non-ulcer controls were enrolled in the study. H. pylori and NSAIDs were both found to be independent risk factors for ulcer bleeding (H. pylori odds ratio, 2.22; 95% confidence interval (CI), 1.23-4.01; NSAIDs odds ratio, 4.57; 95% CI, 2.50-8.35). There was no synergistic effect. In contrast, a negative interaction was observed in the logistic regression and stratified analysis, although the difference was not significant (H. pylori adjusted odds ratio, 3.47; 95% CI, 1.73-6.95; NSAID adjusted odds ratio, 6.16; 95% CI, 3.14-12.09).

CONCLUSION

H. pylori increases the risk of peptic ulcer bleeding but may play a protective role in NSAID users.

Cholera toxin suppresses interleukin (IL)-12 production and IL-12 receptor beta1 and beta2 chain expression

Cholera toxin (CT) is a potent mucosal vaccine adjuvant, which has been shown to induce T helper cell type 2 (Th2) responses in systemic and mucosal tissues. We report that CT inhibits the production of interleukin (IL)-12, a major Th2 counterregulatory cytokine. IL-12 p70 production by stimulated human monocytes was inhibited by CT in a dose-dependent manner. This suppression occurred at the level of gene transcription, was maximal at low concentrations of CT, and was dependent on the A subunit of the toxin, since purified CT B subunit had minimal effect. CT also inhibited the production of IL-12 p70 by monocyte-derived dendritic cells, as well as the production of tumor necrosis factor alpha, but not IL-10, IL-6, or transforming growth factor (TGF)-beta1, by stimulated monocytes. The effects of CT were not due to autocrine production of IL-10, TGF-beta1, or prostaglandin E2. CT inhibited the production of IFN-gamma by anti-CD3-stimulated human peripheral blood mononuclear cell, due in part to suppression of IL-12 production, but also to the inhibition of expression of the beta1 and beta2 chains of the IL-12 receptor on T cells. In vivo, mice given CT before systemic challenge with lipopolysaccharide had markedly reduced serum levels of IL-12 p40 and interferon gamma. These data demonstrate two novel mechanisms by which CT can inhibit Th1 immune responses, and help explain the ability of mucosally administered CT to enhance Th2-dependent immune responses.

Differential requirement of IFN consensus sequence binding protein for the production of IL-12 and induction of Th1-type cells in response to IFN-gamma

IFN-gamma exerts multiple biological activities in the modulation of immune responses by the induction of transcription factors. One transcriptional factor of the IFN regulatory factor family found to be critical in regulating IL-12-dependent IFN-gamma production in vivo following infectious challenge has been designated IFN consensus sequence-binding protein (ICSBP). In this study, the role of ICSBP in regulating type 1 responses to T cell-specific stimulation in vitro was assessed. Total splenocytes from ICSBP-/- mice stimulated with soluble anti-CD3 were markedly impaired in the production of IFN-gamma compared with similarly stimulated cells from ICSBP+/+ mice. Consistent with the decrease in IFN-gamma production, splenocytes from ICSBP-/- mice stimulated with anti-CD3 in the presence or absence of IFN-gamma or a soluble CD40 ligand agonist failed to produce IL-12 p40 and IL-12 p70 protein; however, the deficient production of IFN-gamma from ICSBP-/- mice could be restored by the addition of anti-CD28 Ab in an IL-12-independent manner. In contrast to the previous data, production of IFN-gamma from naive CD4+/LECAM-1high cells of ICSBP-/- mice that had been primed in vitro with anti-CD3 was similar to or greater than that of ICSBP+/+ controls. In addition, the presence of IFN-gamma in priming cultures enhanced both priming for IFN-gamma and IL-12 responsiveness from ICSBP-/- CD4+ T cells. Overall, these results provide evidence that ICSBP is differentially required for the ability of IFN-gamma to regulate type 1 cytokine responses from APCs and CD4+ T cells.

CD40 ligand/trimer DNA enhances both humoral and cellular immune responses and induces protective immunity to infectious and tumor challenge

CD40/CD40 ligand interactions have a central role in the induction of both humoral and cellular immunity. In this study, we examined whether a plasmid expressing CD40 ligand/trimer (CD40LT) could enhance immune responses in vivo. BALB/c mice were injected with plasmid expressing beta-galactosidase DNA with or without CD40LT DNA or IL-12 DNA, and immune responses were assessed. Mice vaccinated with beta-gal DNA plus CD40LT DNA or IL-12 DNA had a striking increase in Ag-specific production of IFN-gamma, cytolytic T cell activity, and IgG2a Ab. The mechanism by which CD40LT DNA enhanced these responses was further assessed by treating vaccinated mice with anti-IL-12 mAb or CTLA-4 Ig (CTLA4Ig). Production of IFN-gamma and CTL activity was abrogated by these treatments, suggesting that CD40LT DNA was mediating its effects on IFN-gamma and CTL activity through induction of IL-12 and enhancement of B7 expression, respectively. Physiologic relevance for the ability of CD40LT DNA to enhance immune responses by the aforementioned pathways was shown in two in vivo models. First, with regard to CTL activity, mice vaccinated with CD40LT DNA did not develop metastatic tumor following challenge with lethal dose of tumor. Moreover, in a mouse model requiring IL-12-dependent production of IFN-gamma, mice vaccinated with soluble Leishmania Ag and CD40LT DNA were able to control infection with Leishmania major. These data suggest that CD40LT DNA could be a useful vaccine adjuvant for diseases requiring cellular and/or humoral immunity.

Intraluminal mucin pool in mucinous gastric adenocarcinoma: a case report

Mucinous gastric carcinoma is a rare pathologic subtype of gastric adenocarcinoma. Whether the mucin behaves aggressively as in mucinous colorectal carcinoma is still controversial. Most mucinous gastric carcinomas are diagnosed from surgical specimens. The mucinous gastric carcinoma in this case report was discovered preoperatively according to its characteristic presentation. An upper gastrointestinal endoscopic examination showed a round protruding tumor of greater than 4 cm in size on the mid-body of the stomach; it had an uneven, friable and shiny surface. The surface was coated with a sticky layer of mucin-like substance, which persisted even after the aspiration of the gastric juice. Endoscopic ultrasonography (EUS) revealed a large heterogeneous hyperechoic tumor mass, originating from the mucosal and submucosal layers, on the body of the stomach. The mass was covered with a thick layer of hypoechoic amorphous substance. Hence, a mucin-producing tumor was suspected. Subsequent surgical biopsy proved the mass to be a moderately differentiated mucinous adenocarcinoma. This case illustrates the first endoscopic ultrasonographic report of an intraluminal mucin pool as a hypoechoic substance, which is quite different from the hyperechoic presentation of intramural mucin lakes. In preoperative evaluation, EUS is not only important for determining the depth of tumor invasion, but it is also useful in differentiating mucinous gastric carcinoma from nonmucinous gastric carcinoma.

A clinicopathologic study of mucinous gastric carcinoma including multivariate analysis

BACKGROUND

Mucinous gastric carcinoma (MGC) is a rare subtype of gastric adenocarcinoma, and its clinical and pathologic features are still controversial. To clarify the significance of this subtype of carcinoma, the authors conducted a case-control study to investigate the clinicopathologic characteristics of MGC and determine whether this mucin-producing histologic type is associated with a worse prognosis than other gastric carcinomas.

METHODS

Twenty-two cases of MGC and 46 patients with nonmucinous gastric carcinoma (NGC) were included. Patients were evaluated on the basis of age, gender, tumor size, location, depth of tumor invasion, histologic differentiation, lymph node involvement, organ metastasis, stage at presentation, surgical curability, adjuvant chemotherapy and radiation therapy. To determine whether the MGC itself was an independent prognostic factor, a multivariate analysis was performed with the Cox proportional hazards model.

RESULTS

The MGC patients were found to have larger tumors (P < 0.001), tumors more often located in the upper stomach (P < 0.05), more serosal invasion (P < 0.05), more lymph node involvement (P < 0.05), greater frequency of advanced stage disease (P < 0.01), and lower 5-year survival rates (P < 0.05) than NGC patients. There was no significant correlation between the subtypes of differentiation of MGC and other data, including the prognosis. Multivariate analysis showed that clinically important predictive factors were serosal invasion and disease stage at diagnosis. The mucinous histologic type itself was not an independent factor for poor prognosis.

CONCLUSIONS

The overall survival rate for patients with MGC was worse than that for patients with NGC. The poor prognosis was correlated with more advanced stage at diagnosis and more frequent serosal invasion, not with the mucinous histologic type.

Prostaglandin E2 and dexamethasone inhibit IL-12 receptor expression and IL-12 responsiveness

Regulation of the factors governing IL-12R expression and IL-12 responsiveness has been shown to be important in the generation and stability of Th1- and Th2-type responses. In this regard, cytokines have been shown to have a prominent role in regulating IL-12R expression. In this study, the role that PGE2 and dexamethasone (DXM) have in regulating IL-12R expression was evaluated. Addition of PGE2 or DXM to human PBMCs stimulated with immobilized anti-CD3 plus IL-12 inhibited the production of IFN-gamma in a dose-responsive manner. Moreover, PBMCs stimulated with immobilized anti-CD3 in the presence of PGE2 or DXM for 3 days, washed extensively, and restimulated in the presence of IL-12 still did not produce IFN-gamma. This lack of IL-12 responsiveness from cells cultured in either PGE2 or DXM was correlated with diminished surface expression of IL-12Rbeta1, IL-12Rbeta2 mRNA expression, and IL-12 binding. Finally, the PGE2- and DXM-mediated inhibition of IL-12R expression was not affected significantly by addition of neutralizing Abs against either IL-4, IL-10, or TGF-beta. By contrast, addition of dibutyryl cAMP, 8-bromoadenosine 3:5 cAMP (8-Br-cAMP), or cholera toxin substantially reduced IL-12R expression, suggesting that PGE2 may be mediating its effects through enhancement of cAMP.

Molecular cloning and heterologous expression of a glutathione S-transferase involved in insecticide resistance from the diamondback moth, Plutella xylostella

Four glutathione S-transferase (GST, EC 2.5.1.18) isozymes have been characterized in the larvae of the diamondback moth (DBM), Plutella xylostella L., a cosmopolitan insect pest of crucifiers. This work aimed at cloning and heterologously expressing the cDNA of DBM GST-3, an isozyme involved in this insect resistance to some organophosphorus insecticides, and studying the molecular basis for its increased expression in the resistant strains. Reverse-transcription polymerase chain reaction (RT-PCR) using midgut mRNA from a methyl parathion resistant MPA strain and degenerate primers complimentary to the N-terminal and internal amino acid sequences of GST-3 generated a 128 bp DNA product. A clone of 809 bp, obtained by screening a midgut cDNA library of MPA strain using this PCR product as probe, encoded a protein of 216 amino acids (calculated Mr 24,083 and pI 8.50). This GST of DBM, PxGST3, shared the highest (46.3%) amino acid sequence identity, among insects, to MsGST1 of Manduca sexta. PxGST3 mRNA level was considerably higher in MPA than in susceptible strains, and Southern blots suggested that gene amplification was probably not involved in the increased expression of this GST isozyme. Enzymatically active PxGST3 expressed heterologously in E. coli exhibited similar biochemical and toxicological properties as GST-3 purified from DBM larvae. It is the first cloned GST with a well-defined role in insecticide resistance.

Chemical mechanism of the endogenous argininosuccinate lyase activity of duck lens delta2-crystallin

The endogenous argininosuccinate lyase activity of duck delta2-crystallin was specifically inactivated by the histidine-specific reagent, diethyl pyrocarbonate. The protein was protected by l-citrulline or l-arginine from the diethyl pyrocarbonate inactivation. To characterize further the chemical mechanism of the delta2-crystallin-catalysed reaction, deuterium-labelled argininosuccinate was enzymically synthesized from fumarate and l-arginine with delta2-crystallin in 2H2O. The argininosuccinate synthesized contained about 19% of the anhydride form; however, the deuterium was clearly demonstrated to be incorporated enantioselectively. Only the pro-HR atom at C-9 of the succinate moiety was labelled in the [2H]argininosuccinate-9-d synthesized, which indicates an anti-elimination mechanism for the endogenous argininosuccinate lyase activity of delta2-crystallin. The enzymic activity of duck lens delta2-crystallin in the pH range 5.5-8.5 was investigated using both protium- and deuterium-labelled argininosuccinate as the substrate. From the logkcat versus pH plot, two molecular pKa values of 6.18+/-0.02 and 8.75+/-0.03 were detected in the delta2-crystallin-argininosuccinate binary complex. The former must be dehydronated and the latter hydronated to achieve an optimum reaction rate. The logkcat/Km versus pH plot suggested two molecular pKa values of 5.96+/-0.09 and 8.29+/-0.10 for the free delta2-crystallin to be involved in the substrate binding. Small kinetic isotope effects of 1.17+/-0.02 and 1.05+/-0.09 were found for kcat and kcat/Km respectively. Combining results from labelling and kinetic analysis indicates that the endogenous argininosuccinate lyase activity of duck delta2-crystallin is compatible with a stepwise E1cB mechanism, the rate-limiting step probably at the C-N bond-cleavage step.

Type IV pili, transient bacterial aggregates, and virulence of enteropathogenic Escherichia coli

Type IV bundle-forming pili of enteropathogenic Escherichia coli are required for the localized adherence and autoaggregation phenotypes. Whether these pili are also required for virulence was tested in volunteers by inactivating bfpA or bfpT (perA) encoding, respectively, the pilus subunit and the bfp operon transcriptional activator. Both mutants caused significantly less diarrhea. Mutation of the bfpF nucleotide-binding domain caused increased piliation, enhanced localized adherence, and abolished the twitching motility-dispersal phase of the autoaggregation phenotype. The bfpF mutant colonized the human intestine but was about 200-fold less virulent. Thus, BfpF is required for dispersal from the bacterial aggregate and for full virulence.

The GCN4 motif in a rice glutelin gene is essential for endosperm-specific gene expression and is activated by Opaque-2 in transgenic rice plants

The GCN4 motif is conserved in a number of seed storage protein genes, and promoter fragments containing this motif have been shown to be involved in controlling seed-specific expression of the genes studied. All genes encoding the rice seed storage protein glutelin contain the GCN4 motif at similar sites in their 5' flanking regions. Using a stable homologous transgenic system, we have analysed the promoter of the rice glutelin gene GluB-1 and demonstrated that the GCN4 motif functions as an essential cis-element for endosperm-specific gene expression. Moreover, a 21 bp GluB-1 promoter fragment spanning the GCN4 motif, as a multimer, directed GUS gene expression in endosperm of transgenic rice plants, when fused directly to the core promoter (-46) of CaMV 35S. In transiently transfected rice protoplasts, over a hundred-fold transactivation was observed from the 21 bp sequence by the bZIP type transcriptional activator Opaque-2 (O2) co-expressed under a CaMV 35S promoter. The transactivation was also evident in transgenic plants containing both O2 and the 21 bp sequence/GUS fusion. The O2-mediated activation requires binding of O2 to an intact GCN4 motif. Our results suggest that a bZIP protein functionally similar to O2 may exist in rice and participate in controlling the endosperm-specific expression of GluB-1 through the GCN4 motif.

Rice MYB protein OSMYB5 specifically binds to the AACA motif conserved among promoters of genes for storage protein glutelin

Binding analyses revealed that the AAC--A sequence in glutelin gene promoters is the target site of OSMYB5 protein and that both the distal and proximal AACA motifs are recognized by this protein. These results suggest that the OSMYB5 protein functions as a trans-acting factor for glutelin gene expression.

Primary ethmoid sinus craniopharyngioma: a case report

A seven-year-old boy complained of intermittent epistaxis for several months. Computerized tomography (CT) scans showed increased soft tissue density over the left ethmoid sinus. Endoscopic sinus surgery was used to remove the mass completely. The pathological report was craniopharyngioma. No other focus of lesion was found, and he continues to do well.

Effects of task goal on movement kinematics and line bisection performance in adults without disabilities

OBJECTIVE

This study investigated (a) whether the kinematic profile of a reaching-for-an-object movement would differ depending on the goal of the reaching task and (b) the effect of task goal on attentional carryover.

METHOD

Twenty-four adults without disabilities performed a horizontal line bisection task under three conditions: (a) a natural condition (pressing the ringing lever of a desk bell), (b) an impoverished condition (touching the ringing lever of a desk bell), and (c) a control condition (bisecting a line only). Only the natural and impoverished conditions used the reaching task (i.e., pressing or touching the ringing lever of the desk bell). The kinematic profile of reaching for the bell was established with the OPTO-TRAK system, a quantitative kinematic analysis measure. The line bisection task was performed immediately after the reaching task, which was located adjacent to the left of the line to be bisected.

RESULTS

The natural condition elicited better quality of reaching movement than did the impoverished condition. It produced significantly shorter movement time and higher peak velocity. A less impressive effect was found for percentage of reach where peak velocity occurs. Bisection performance under the two experimental conditions was leftward biased relative to the control condition, and the magnitude of leftward bias in the natural condition was greater than that for the impoverished condition.

CONCLUSION

Results supported one core assumption of occupational therapy: goal-directed and functional tasks can be used to enhance human performance. If the results hold for clinical populations, manipulations of functional goals may enhance movement performance of persons with disabilities and remediate left neglect often seen in clients who have had a stroke.

Analysis of the multiple interactions between IL-12 and the high affinity IL-12 receptor complex

IL-12 is a heterodimeric cytokine, composed of a p40 and a p35 subunit, that exerts its biological effects by binding to specific cell surface receptors. Two IL-12R proteins, designated human IL-12 (huIL-12) receptor beta1 (huIL-12Rbeta1) and huIL-12Rbeta2, have been previously identified. These IL-12R individually bind huIL-12 with low affinity and in combination bind huIL-12 with high affinity and confer IL-12 responsiveness. In this study the interactions of hulL-12 with these two identified human IL-12R protein subunits are examined. The heterodimer-specific anti-huIL-12 mAb 20C2, which neutralizes huIL-12 bioactivity but does not block 125I-huIL-12 binding to huIL-12Rbeta1, blocked binding of huIL-12 to huIL-12Rbeta2. In contrast, anti-huIL-12Rbeta1 mAb 2B10 and mouse IL-12 p40 subunit homodimer (mo(p40)2) blocked 125I-huIL-12 binding to huIL-12Rbeta1, but not to huIL-12Rbeta2. Therefore, two classes of IL-12 inhibitors can be identified that differ in their ability to block huIL-12 interaction with either huIL-12Rbeta1 or huIL-12Rbeta2. Both mo(p40)2 and 20C2 blocked high affinity binding to huIL-12Rbeta1/beta2-cotransfected COS-7 cells, although, as previously reported, mo(p40)2 does not block high affinity binding to IL-12R on PHA-activated human lymphoblasts. Furthermore, these two classes of IL-12 inhibitors synergistically decreased hulL-12-stimulated proliferation and IFN-gamma production. Therefore, IL-12, in binding to the high affinity IL-12R, interacts with IL-12Rbeta1 primarily via regions on the IL-12 p40 subunit and with IL-12Rbeta2 via 20C2-reactive, heterodimer-specific regions of IL-12 to which the p35 and p40 subunits both contribute.

Control of toxic metal emissions from combustors using sorbents: a review

This paper constitutes a review of the control of toxic metal emissions using sorbents. The objective of sorbent-injection methods is to effectively capture the metal species (preferably transform it to an environmentally benign form) and to suppress the fraction in the submicrometer mode. The design of an effective sorbent-injection methodology thus requires an understanding of the fate of the metallic species and its transformation pathways (transfer to the gas phase, subsequent chemistry at high temperatures, and aerosol formation and growth dynamics) in the combustor. Several different sorbent methodologies used for metals capture are discussed, and a mechanistic description is provided. The need for further experimentation and pilot scale testing is also emphasized.

Vertebral fracture assessment using the lateral scoutview of computed tomography in comparison with radiographs

Semiquantitative vertebral fracture assessment was compared between lateral computed tomography (CT) scoutviews and conventional thoracolumbar spinal radiographs. Vertebral levels T4-L4 were assessed by both techniques in a group of 56 women (mean age 60 +/- 13 years). In order to compare inter- and intra-observer variabilities for the two techniques, the images were analyzed twice by two independent observers, and percentage agreement and kappa statistics were measured both between readings and between observers. Percentage agreement and kappa statistics were also used to quantify differences between techniques. In the CT scoutviews, noise and artifacts from overlying tissues in the thoracic spinal levels rendered 3.4% of the vertebrae unreadable for the first observer and 8.3% for the second observer. For the CT scoutviews the agreement between readings was 98.1%, 97.3% and 100% (kappa = 0.87, 0.83 and 1.0) on T4-L12, T4-12 and L1-4, respectively for the first observer, and 97.8%, 97.1% and 99.5% (kappa = 0.79, 0.73 and 0.92) for the second observer. For the lateral radiographs, the agreement between readings was 97.7%, 96.9% and 100% (kappa = 0.87, 0.85 and 1.0) on T4-L12, T4-12 and L1-4, respectively for the first observer, and 98.4%, 97.7% and 99.5% (kappa = 0.86, 0.82 and 0.95) for the second observer. The agreement between observers was 96.1%, 94.4% and 100% (kappa = 0.68, 0.58 and 1.0) on T4-L12, T4-12 and L1-4, respectively for the CT scoutviews and 96.8%, 95.9% and 99.0% (kappa = 0.79, 0.76 and 0.91) for the lateral radiographs. The inter-technique was 95.8%, 94.2% and 99.5% (kappa = 0.73, 0.68 and 0.95) on T4-L12, T4-12 and L1-4, respectively for the first observer and 95.6%, 94.2% and 99.0% (kappa = 0.64, 0.55 and 0.90) for the second observer, with the scoutview technique detecting, on average, 23% fewer fractures than the lateral radiographs. Although the vertebral fracture detection in lumbar spine is quite comparable to that of conventional radiographs, given its reduced sensitivity for vertebral fracture detection in thoracic spine, the lateral CT scoutview technique should not be substituted for conventional radiographs where diagnosis of all vertebral fractures is of primary importance.

Identification of the transcription start site for the spinach chloroplast serine tRNA gene

Deleting part of the 3' end of the spinach chloroplast serine tRNA coding region, which destroyed the proper folding of its RNA transcript and resulted in the inhibition of tRNA processing, allowed the detection of a serine tRNA primary transcript. The transcription start site for this primary transcript, synthesized from the internal promoter, was mapped to -12 upstream from the mature tRNA coding region. Transcription analysis with various 5' deletion mutants suggested that the AT-rich region between -31 and -11, immediately upstream of the serine tRNA transcription start site, affects the transcription efficiency, and possibly the selection of transcription start site. Identification of the transcription start site for the spinach chloroplast serine tRNA gene in this study represents the first example of 5' end mapping of a tRNA precursor transcribed from chloroplast tRNA genes containing an internal promoter.

Acute effects of nitric oxide blockade with L-NAME on arterial haemodynamics in the rat

1. We employed the technique of impedance spectral analysis to investigate the role of endogenous nitric oxide (NO) in the regulation of steady and pulsatile haemodynamics in Wistar Kyoto rat (WKY). 2. A total of 12 WKYs was anaesthetized with pentobarbitol sodium (40 mg kg-1, i.p.) and artificially ventilated with an animal respirator. The aortic pressure wave was monitored with a high fidelity Millar sensor, and aortic flow wave with an electromagnetic flow probe. The pressure and flow waves were subjected to Fourier transform for the analysis of impedance spectra. 3. The baseline cardiovascular parameters were mean arterial pressure (APm) 95 +/- 9 mmHg, heart rate (HR) 338 +/- 9 b.p.m., stroke volume (SV) 0.23 +/- 0.01 ml, cardiac output (CO) 77.8 +/- 1.6 ml min-1, total peripheral resistance (TPR) 98 +/- 11 (x10(3)) dyne s cm-5, characteristic impedance (Zc) 2046 +/- 141 dyne s cm-5, arterial compliance at mean AP (Cm) 3.78 +/- 0.22 microliters mmHg-1 and backward pulse wave (Pb) 12.9 +/- 0.6 mmHg. 4. An NO synthase inhibitor, NG-nitro-L-arginine monomethyl ester (L-NAME) was administered at graded intravenous doses. This agent caused dose-dependent increases in AP and TPR with decreases in HR. At an accumulative dose of 10 mg kg-1, APm was increased by 29 +/- 3 mmHg (+31%) and TPR by 49 +/- 6 (x10(3)) dyne s cm-5 (+50%), while HR was reduced by 37 +/- 5 b.p.m. (-11%) and CO by 10.4 +/- 0.8 ml min-1 (-14%). The pulsatile haemodynamics including Zc and Pb were slightly increased by 14-15%. Cm was decreased by 1.09 microliters mmHg-1 (-29%). L-NAME also did not significantly affect the ventricular work including the steady, oscillatory and total work. 5. Aminoguanidine, a specific inhibitor for inducible NO synthase (iNOS), in dose 10-60 mg kg-1 i.v. did not alter the AP, HR and other parameters. The result indicated that blockade of constitutive NOS, but not iNOS is involved in these changes. 6. Angiotensin II (Ang) in various infusion doses was used to produce a profile of AP increase similar to that caused by L-NAME. Ang remarkably increased Zc, while TPR was moderately elevated. The pattern of haemodynamic changes was different from that following L-NAME. 7. The results suggest that blockade of the endogenous NO affects predominantly the arterial pressure and peripheral resistance. The Windkessel functions such as arterial impedance and pulse wave reflection are slightly increased. Ventricular works are not significantly altered.

Kinetic studies of the inhibitory effects of propeptides subtilisin BPN' and Carlsberg to bacterial serine proteases

The propeptides of bacterial subtilisin BPN' and Carlsberg were synthesized to investigate their inhibitory function on the enzymes. Kinetically, pro-BPN' inhibits the proteolytic activities of subtilisin BPN' and Carlsberg separately in a slow binding mode. Pro-Carlsberg behaves as a typical rapid equilibrium competitive inhibitor for these two proteases. Functionally, pro-Carlsberg inhibits the subtilisins with moderate selectivity. The inhibition constant Ki of pro-BPN' to subtilisin BPN' is 5.0 nM, and 6.1 nM to subtilisin Carlsberg. The on-rate of pro-BPN' to subtilisin BPN' is 5.8 x 10(5) M(-1)s(-1), and the off-rate 2.9 x 10(-3) s(-1). Similarly, the on-rate of pro-BPN' to subtilisin Carlsberg is 2.2 x 10(5) M(-1)s(-1), and the off-rate 1.3 x 10(-3) s(-1). On the other hand, the Ki of pro-Carlsberg to subtilisin BPN' gives 1.3 x 10(2) nM, and 88 nM to subtilisin Carlsberg. Based on the key features of the interactions between pro-BPN' and subtilisin from X-ray crystallographic results (Gallagher et al., 1995), the correlation between the sequence of subtilisin propeptides and their inhibition abilities on the proteases are compared and discussed.

Cloning and expression of five myb-related genes from rice seed

Three elements in the promoter of rice glutelin genes are important for their endosperm specific expression. One of these, an AACA motif, has been shown to be a negative regulator in non-seed tissues and has a similarity to the barley gibberellin responsive element recognized by MYB-like DNA binding proteins. A cDNA library constructed from immature rice seed was screened using two types of myb gene probes to isolate cDNA clones representing genes encoding MYB-like DNA binding proteins that may recognize the AACA motif in rice glutelin gene promoter. We obtained four cDNA clones encoding MYB-related proteins, Oryza sativa MYB (OSMYB) 1-4, using the maize C1 probe. Another myb-like clone, Osmyb5, was obtained by screening a rice seed cDNA library with probes designed to recognize the AACA-like binding domain in GAMYB and PHMYB3. RT-PCR was used to analyze Osmyb expression during rice seed development and their presence in other rice tissues, as it was not possible to detect these mRNAs by conventional Northern analysis. RT-PCR analysis showed that Osmyb2, Osmyb3 and Osmyb5 genes were expressed in all tissues examined. In seed, the mRNA levels of Osmyb1 and Osmyb4 genes reached a maximum at 14 days after flowering (DAF), suggesting that these genes may play a role in seed maturation. As Osmyb5 exhibits a high similarity to the regions in both GAMYB and PHMYB3, which can bind to the AACA motif, there is a possibility that the OSMYB5 protein may bind to the AACA motif of glutelin genes.

The role of the N-terminal leucine residue in snake venom cardiotoxin II (Naja naja atra)

The N-terminal leucine residue of snake venom cardiotoxin II (CTX II) (Naja naja atra) was systematically replaced with D-leucine (CTXII-L1-D-L), glycine (CTXII-L1G) or deleted [CTXII-(2-60)] to study the role of leucine residue in CTX II molecule. CTX II, CTXL1-D-L, CTXL1G and CTX(2-60) were produced by chemical synthesis method and purified by high performance liquid chromatography. Owing to folding problem in CTXII-(2-60), only CTX II, CTXII-L1-D-L and CTXII-L1G were produced in a pure form and characterized by amino acid analysis, mass spectrometry and peptide mapping. In the structural aspect, changing the Leu-1 by D-Leu or Gly causes a drastic alteration in the whole CTX II structure as detected by circular dichroism, 1-anilino-naphthalene-8-sulfonate (ANS) fluorescence assay. In the functional aspect, both CTXII-L1-D-L and CTXII-L1G are still retained substantial biological activity of CTX II. Therefore, the results indicate that both the chirality and the side-chain of the N-terminal leucine residue of CTX II are important elements in maintaining the whole CTX II structure. In addition, this study is the first report in elucidating the reason why the first N-terminal residue of most CTXs (90.3%) is leucine residue.

Differential associations between the cytoplasmic regions of the interleukin-12 receptor subunits beta1 and beta2 and JAK kinases

The role of the cytoplasmic regions of interleukin-12 receptors (IL-12R) beta1 and beta2 in stimulating proliferation was examined. The transmembrane and cytoplasmic regions of IL-12Rbeta1 or IL-12Rbeta2 were fused to the extracellular domain of the epidermal growth factor (EGF) receptor, yielding chimeric receptors E12R1 and E12R2, respectively. These chimeras were stably transfected into BaF3 cells, a factor-dependent murine pro-B cell line. Only E12R2 or E12R1+E12R2 transfectants were capable of EGF-dependent proliferation. EGF-dependent phosphorylation of E12R2, JAK2, Tyk2, and STAT3 was observed. JAK2 was phosphorylated in E12R1-, E12R2-, and E12R1+E12R2-expressing cells. However, direct associations were detectable only between E12R2 and JAK2. Tyk2 phosphorylation was observed only in cells expressing E12R1 or E12R1+E12R2. In parallel with this activation pattern, direct interactions only between Tyk2 and E12R1 were demonstrable. Phosphorylation of STAT3 was observed in cells expressing E12R1, E12R2, and E12R1+E12R2. The expression levels of STAT4 protein in BaF3 cells are undetectable by the methods employed here; therefore, STAT4 phosphorylation was not observed. Taken together, the data indicate that differential interactions take place between the cytoplasmic regions of the two IL-12R subunits and JAK2/Tyk2 and that the cytoplasmic region of IL-12Rbeta2 alone is capable of delivering a proliferative signal.

A functional interleukin 12 receptor complex is composed of two beta-type cytokine receptor subunits

We have identified a cDNA from a human phytohemagglutinin-activated lymphoblast library encoding a protein that binds 125I-labeled human interleukin 12 (125I-huIL-12) with a Kd of about 5 nM when expressed in COS-7 cells. When coexpressed in COS-7 cells with the previously identified IL-12 beta receptor (IL-12R beta) protein, two classes of 125I-huIL-12 binding sites were measured with Kds of about 55 pM and 8 nM, corresponding to the high- and low-affinity binding sites seen on phytohemagglutinin-activated lymphoblasts. This newly identified huIL-12R subunit is a member of the cytokine receptor superfamily, with closest resemblance to the beta-type cytokine receptor gp130 and the receptors for leukemia inhibitory factor and granulocyte colony-stimulating factor. Consequently, we have reclassified the previously identified IL-12R beta subunit as huIL-12R beta 1 and designated the newly identified subunit as huIL-12R beta 2. huIL-12R beta 2 is an 862-amino acid type I transmembrane protein with a 595-amino-acid-long extracellular domain and a cytoplasmic tail of 216 amino acids that contains three tyrosine residues. A cDNA encoding the mouse homolog of the huIL12R beta 2 protein has also been isolated. Human and mouse IL-12R beta 2 proteins show a 68% amino acid sequence identity. When expressed in COS-7 cells, huIL-12R beta 2 exists as a disulfide-linked oligomer with an apparent monomeric molecular weight of 130 kDa. Coexpression of the two identified IL-12R subunits in Ba/F3 cells conferred IL-12 responsiveness, and clones of these cotransfected Ba/F3 cells that grew continuously in the presence of IL-12 were isolated and designated LJM-1 cells. LJM-1 cells exhibited dose-dependent proliferation in response to huIL-12, with an ED50 of about 1 pM huIL-12. Interestingly, Ba/F3 cells transfected with IL-12R beta 2 alone proliferated in response to huIL-12 with an ED50 of about 50 pM, although a role for endogenous mouse IL-12R beta 1 in IL-12 signal transduction in these transfectants cannot be ruled out. These results demonstrate that the functional high-affinity IL-12R is composed of at least two beta-type cytokine receptor subunits, each independently exhibiting a low affinity for IL-12.

IL-12-deficient mice are defective but not devoid of type 1 cytokine responses

Interleukin-12 (IL-12) has been described as a pivotal molecule in the immune response based in part on its ability to influence the differentiation of T helper (Th) cells into a type 1 (Th1) phenotype. This event is crucial in that appropriate differentiation of naive T cells can determine susceptibility or resistance to given pathogens by influencing the balance between cellular and humoral immunity. In order to further delineate the role of IL-12 in the immune response, we generated mice deficient for this cytokine. IL-12 knockout mice were viable, fully fertile, and displayed no obvious developmental abnormalities. Upon immunological analysis, these mice demonstrated an impaired ability to effect a Th1 response as well as an impaired ability to produce interferon-gamma in response to endotoxin in vivo. These data establish an essential role for IL-12 in the generation of optimal Th1 responses in vivo, but weak responses can occur independently of IL-12.

A pharmacokinetic study with the high-dose anticancer agent menadione in rabbits

The aim of this investigation was to assess the pharmacokinetic properties of high-dose menadione (VK3), as an anticancer agent, in plasma and red blood cells (RBCs) in rabbits. An extremely high dose of 75 mg menadiol sodium diphosphate (Synkayvite) was intravenously injected. HPLC analysis was applied to measure the major metabolite, menadione, VK3. The kinetic properties of VK3 in both plasma and red blood cells showed a short elimination half-life, high clearance, and large volume of distribution in plasma and RBCs. The mean elimination t1/2 values of menadione in plasma and in RBCs were 27.17 +/- 10.49 min and 35.22 +/- 11.82 min, respectively. The plasma clearance (CL/F) of VK3 was 0.822 +/- 0.254 L min-1. The systemic clearance in RBCs was 0.407 +/- 0.152 L min-1. The apparent volume of distribution (Vd/F) in plasma was 30.833 +/- 12.835 L and that in RBCs 20.488 +/- 9.401 L. The plasma AUC was 32.453 +/- 9.785 micrograms min mL-1 and that of RBCs 67.219 +/- 24.449 micrograms min mL-1. Menadiol was rapidly biotransformed to menadione in blood. The formation rate constant (kf) of menadione in plasma was 0.589 +/- 0.246 min-1, and that of RBCs 1.520 +/- 1.345 min-1. Through this study the estimated menadione dosage needed to maintain a plasma level of 1 microgram mL-1 for anticancer purposes was 19.7 mg kg-1 every hour.