Cellular immune response against tropomyosin isoform 5 in ulcerative colitis

We have reported an autoantibody response in ulcerative colitis (UC) against human tropomyosin isoform 5 (hTM5), the predominant colonic epithelial cell hTM isoform. In this report, we determined the number of IFN-gamma-secreting cells (spot-forming cells, SFC) against hTM5 by an enzyme-linked immunospot (ELISPOT) assay. Another cytoskeletal protein, caldesmon, CaD40, was used as a control antigen. Peripheral blood mononuclear cells were separated by a Ficoll density gradient from 28 patients with UC, 13 patients with Crohn's disease (CD), and 9 healthy subjects (HS). The mean (+/-SEM) SFC values against hTM5 in UC, CD, and HS were 48.8 +/- 8.1, 18.6 +/- 4.6, and 20.8 +/- 8.6, respectively. The value in UC was significantly higher than those in CD (P < 0.005) and HS (P < 0.025). SFC values in CD did not differ from those in HS. None of the 50 samples (except 1 UC) reacted to the CaD40 antigen. This study demonstrates, for the first time, a defined colon epithelial cell antigen, hTM5, that is capable of inducing a significant T cell response in UC but not in CD.

Memory effect on the dioxin emissions from municipal waste incinerator in Taiwan

Evaluation of the dioxin removal efficiency of the air pollution control device (APCD) at an existing municipal waste incinerator (MWI) located in Taiwan is conducted via stack sampling and analysis. The MWI investigated is equipped with cyclones, dry lime scrubbing systems and fabric filters as APCDs. Results indicate that the patterns of dioxin isomers at APCDs' inlet and stack are similar. During the first year of carbon injection, the concentrations of emitted dioxin decreased greatly. The dioxin removal efficiency increased from 26.9% to 96.6% after injecting 115 kg/day activated carbon (AC). At the second year, the dioxin removal efficiency reaches 98.7% after injecting the same rate of AC continuously. The lower efficiency achieved with activated carbon injection (ACI) during the first year can be attributed to the memory effect, i.e. the dioxin or precursor desorbs slowly to the flue gas and increases the dioxin concentration at stack, resulting in a lower dioxin removal efficiency than expected.

Genomic structure, chromosomal localization and expression profile of a novel melanoma differentiation associated (mda-7) gene with cancer specific growth suppressing and apoptosis inducing properties

Abnormalities in cellular differentiation are frequent occurrences in human cancers. Treatment of human melanoma cells with recombinant fibroblast interferon (IFN-beta) and the protein kinase C activator mezerein (MEZ) results in an irreversible loss in growth potential, suppression of tumorigenic properties and induction of terminal cell differentiation. Subtraction hybridization identified melanoma differentiation associated gene-7 (mda-7), as a gene induced during these physiological changes in human melanoma cells. Ectopic expression of mda-7 by means of a replication defective adenovirus results in growth suppression and induction of apoptosis in a broad spectrum of additional cancers, including melanoma, glioblastoma multiforme, osteosarcoma and carcinomas of the breast, cervix, colon, lung, nasopharynx and prostate. In contrast, no apparent harmful effects occur when mda-7 is expressed in normal epithelial or fibroblast cells. Human clones of mda-7 were isolated and its organization resolved in terms of intron/exon structure and chromosomal localization. Hu-mda-7 encompasses seven exons and six introns and encodes a protein with a predicted size of 23.8 kDa, consisting of 206 amino acids. Hu-mda-7 mRNA is stably expressed in the thymus, spleen and peripheral blood leukocytes. De novo mda-7 mRNA expression is also detected in human melanocytes and expression is inducible in cells of melanocyte/melanoma lineage and in certain normal and cancer cell types following treatment with a combination of IFN-beta plus MEZ. Mda-7 expression is also induced during megakaryocyte differentiation induced in human hematopoietic cells by treatment with TPA (12-O-tetradecanoyl phorbol-13-acetate). In contrast, de novo expression of mda-7 is not detected nor is it inducible by IFN-beta+MEZ in a spectrum of additional normal and cancer cells. No correlation was observed between induction of mda-7 mRNA expression and growth suppression following treatment with IFN-beta+MEZ and induction of endogenous mda-7 mRNA by combination treatment did not result in significant intracellular MDA-7 protein. Radiation hybrid mapping assigned the mda-7 gene to human chromosome 1q, at 1q 32.2 to 1q41, an area containing a cluster of genes associated with the IL-10 family of cytokines. Mda-7 represents a differentiation, growth and apoptosis associated gene with potential utility for the gene-based therapy of diverse human cancers.

Presentation of striatal hyperintensity on T1-weighted MRI in patients with hemiballism-hemichorea caused by non-ketotic hyperglycemia: report of seven new cases and a review of literature

Recent studies have shown unique clinicoradiologic characteristics in patients with hemiballism-hemichorea (HB-HC) caused by non-ketotic hyperglycemia; however, there is still a limited number of patients being reported. We report 7 patients (3 males and 4 females) with this type of dyskinesia, whose ages ranged from 60 to 84 years. Brain CT of these patients showed hyperdensity in the contralateral striatum, corresponding with MRI studies that showed an increased signal intensity on T1-weighted images and a decreased signal on T2-weighted images. After metabolic control had been achieved, the hyperkinetic state of these patients abruptly ceased. Follow-up neuroimaging studies in 2 patients documentied complete resolution of the striatal hyperintensity on brain CT and MRI after 3 months and 6 months, respectively. A review of patients with HB-HC caused by non-ketotic hyperglycemia reported formerly and in the present study shows that the dyskinesia tends to occur in aged diabetic patients. The age of patients with dyskinesia secondary to cerebral infarction is generelly much lower. We also found that 86% (30 out of 35 cases) patients reported with HB-HC caused by non-ketotic hyperglycemia were Asians. The prognosis of the dyskinesia was excellent, and the radiological abnormalities are completely reversible.

Three-dimensional quantitative structure-activity relationship for several bioactive peptides searched by a convex hull-comparative molecular field analysis approach

Three-dimensional (3D) convex hulls are computed for theoretically generated structures of a group of 18 bioactive tachykinin peptides. The number of peptides treated as a training set is 14, whereas that treated as a test set is four. The frequency of atoms of the same atomic type lying at the vertices of all the hulls computed for all the structures in a structural set is counted. Vertex atoms with non-zero frequency counted are collected together as a set of commonly exposed groups. These commonly exposed atoms are then treated as a set of correspondences for aligning all the other 13 structures in a structural set against a common template, which is the structure of the most potent peptide in the set using the FIT module of the SYBYL 6.6 program. Each aligned structural set is then analyzed by the comparative molecular field analysis (CoMFA) module using the C.3 probe having a charge of +1.0. The corresponding cross-validated r2 values range from -0.99 to 0.57 for a number of 73 structural sets studied. The comparative molecular similarity indices analysis (CoMSIA) module within the SYBYL 6.6 package is also used to analyze some of these aligned structural sets. Although the CoMSIA results are in accord with those of CoMFA, it is also found that the CoMFA results of several structural sets can be improved somewhat for conformations of the structures in the sets that are adjusted by constraint energy minimization and then constraint molecular dynamics simulation runs using distance constraints derived from some commonly exposed groups determined for them. This result further implies that the convex hull-CoMFA is a feasible approach to screen the bioactive conformations for molecules of this class.

Studies on anthracenes. 1. Human telomerase inhibition and lipid peroxidation of 9-acyloxy 1,5-dichloroanthracene derivatives

The synthetically useful approaches to 9-acyloxy 1,5-dichloroanthracene derivatives are reported. The system selectively reduces the carbonyl group flanked by the peri substituents of the anthracenediones to give the corresponding 1,5-dichloro-9(10H)-anthracenone. Simple regioselective acylation of anthracenone is applied with appropriate acyl chlorides in CH2Cl2 with catalytic amount of pyridine to give the novel 9-acyloxy 1,5-dichloroanthracene derivatives. Considerable interest has developed in the mechanism of how anthracenone achieves this desirable selectivity. In an attempt to understand the mechanism of this reaction, solid-state structures of anthracene derivatives have been obtained. In addition, the inhibition of lipid peroxidation in model membranes was determined as was their ability to inhibit the telomere-addition function of the human telomerase enzyme together with their inhibition of the Taq polymerase enzyme. In contrast to (+)-alpha-tocopherol, 3b, 3c, 3d, 3g, and 3i do not enhance lipid peroxidation in model membranes. Implications for 9-acyloxy 1,5-dichloroanthracene analogues as potential anticancer agents are discussed.

Specific binding of single-stranded telomeric DNA by Cdc13p of Saccharomyces cerevisiae

Cdc13p is a single strand telomere-binding protein of Saccharomyces cerevisiae; its telomere-binding region is within amino acids 451-693, Cdc13(451-693)p. In this study, we used purified Cdc13p and Cdc13(451-693)p to characterize their telomere binding activity. We found that the binding specificity of single-stranded TG(1-3) DNA by these two proteins is similar. However, the affinity of Cdc13(451-693)p to DNA was slightly lower than that of Cdc13p. The binding of telomeric DNA by these two proteins was disrupted at NaCl concentrations higher than 0.3 m, indicating that electrostatic interaction contributed significantly to the binding process. Because both proteins bound to strand TG(1-3) DNA positioned at the 3' end, the 5' end, or in the middle of the oligonucleotide substrates, our results indicated that the location of TG(1-3) in single-stranded DNA does not appear to be important for Cdc13p binding. Moreover, using DNase I footprint analysis, the structure of the telomeric DNA complexes of Cdc13p and Cdc13(451-693)p was analyzed. The DNase I footprints of these two proteins to three different telomeric DNA substrates were virtually identical, indicating that the telomere contact region of Cdc13p is within Cdc13(451-693)p. Together, the binding properties of Cdc13p and its binding domain support the theory that the specific binding of Cdc13p to telomeres is an important feature of telomeres that regulate telomerase access and/or differentiate natural telomeres from broken ends.

Renaturation and stabilization of the telomere-binding activity of Saccharomyces Cdc13(451-693)p by L-arginine

Production of recombinant proteins can be valuable in studying their biological functions. However, recombinant proteins expressed in Escherichia coli sometimes form undesirable insoluble aggregates. Solubilization and renaturation of these aggregates becomes a problem that one needs to solve. Here we used recombinant Cdc13(451-693)p as example to show the presence of l-arginine during renaturation greatly enhanced the renaturation efficiency. Cdc13p is the single-stranded telomere-binding protein of yeast Saccharomyces cerevisiae. The telomere-binding domain has been mapped within amino acids 451-693 of Cdc13p, Cdc13(451-693)p. Recombinant Cdc13(451-693)p was expressed in E. coli as insoluble protein aggregates. Purification of insoluble Cdc13(451-693)p was achieved by denaturing the protein with 6 M guanidine-HCl and followed by Ni-nitrilotriacetic acid agarose column chromatography. Renaturation of Cdc13(451-693)p to the active form was achieved by dialyzing denatured protein in the presence of l-arginine. Moreover, the presence of l-arginine was also helped in maintaining the telomere-binding activity of Cdc13(451-693)p. Taking together, l-arginine might have a general application in renaturation of insoluble aggregates.

Giant Hall effect in nonmagnetic granular metal films

Nearly 3 orders of magnitude enhancement in the Hall coefficient is observed in Cu(x)-(SiO(2))(1--x) granular films. This large enhancement of the Hall coefficient not only is significantly larger than the prediction of the classical percolation theory, but also occurs at a metal concentration identified to be the quantum percolation threshold. Measurements of the electron dephasing length and magnetoresistance, plus the TEM characterization of microstructures, yield a physical picture consistent with the mechanism of the local quantum interference effect.

Lithopedion

Lithopedion is a rare obstetrical outcome of an undiagnosed and untreated advanced abdominal pregnancy, mostly found incidentally. We present a case of lithopedion. In a 76 year-old female suffering from cervical neoplasm, total abdominal hysterectomy was performed for the lesion and the lithopedion was found incidentally. The patient's history was unremarkable, and laboratory tests were normal. The patient recalled having experienced a severe abdominal pain about 50 years before. Her physician had felt "a benign tumor" in her pelvis at that time, indicating that the stone child had retained in the maternal peritoneal cavity for 50 years.

Comparative studies on the expression patterns of three troponin T genes during mouse development

In vertebrates, three troponin T (TnT) genes, cardiac TnT (cTnT), skeletal muscle fast-twitch TnT (fTnT), and slow-twitch TnT (sTnT), have evolved for the regulation of striated muscle contraction. To understand the mechanism for muscle fiber-specific expression of the TnT genes, we compared their expression patterns during mouse development. Our data revealed that the TnT expression in the developing embryo was not as restricted as that in the adult. In addition to a strong expression in the developing heart beginning at day 7.5 p.c (postcoitum), the cTnT transcript was detected at later stages in some skeletal muscles, where beginning at day 11.75 p.c. the fTnT and sTnT genes were also expressed. Only sTnT but not fTnT was found transiently in the developing heart. At day 13.5 p.c., expressions of all three genes were detected in the developing tongue and this co-expression continued to day 16.5 p.c. with the fTnT isoform being predominant. At this stage, overlapping and distinct expression patterns of both sTnT and fTnT genes were also evident in many developing skeletal muscles. These data suggest that different muscles during development undergo a complex change in TnT isoforms resulting in different contractile properties. Unexpectedly, the cTnT transcript was persistently found in the developing bladder, where presumably smooth muscle is present. In transgenic mice, expression of a LacZ gene driven by a rat cTnT promoter (-497 to +192 bp) was very similar to that of the endogenous cTnT gene, suggesting that this promoter contained regulatory elements sufficient for the control of tissue-specific cTnT expression during development.

Treatment of intractable generalized dystonia by bilateral posteroventral pallidotomy--one-year results

BACKGROUND

Recent study has revealed that bilateral posteroventral pallidotomy (PVP) significantly improve dystonic movements and improve motor function of those patients with generalized dystonia (GD). However, there is only a limited number of patients who have been reported so far.

METHODS

This study was conducted to evaluate the clinical efficacy of surgical treatment with bilateral PVP on patients with intractable GD. All the studied patients were regularly rated with standardized scales (Burke-Fahn-Marsden Evaluation Scale for Dystonia) for dystonic movement and living disability before and after surgery.

RESULTS

There were 18 patients, 8 males and 10 females with an average age of 24.8 years, included in the study. Postoperatively, there were slow, partial, but steady improvements of the dystonic movement and daily living function. Maximal effects were noted at the sixth month and the clinical benefits were sustained one year after the surgical treatment when there were statistically significant improvements in 13% of total dystonia movement score and 9% of the total disability score (p < 0.05). Upon further analysis, improvements of dystonic movements were statistically significant in the regions of mouth (50%), speech/swallowing (19%) and neck (43%), and daily living functions in speech (14%) and eating/swallowing (29%).

CONCLUSIONS

Bilateral posteroventral pallidotomy was only partially effective for the treatment of GD, and it produced clinical improvement in the dystonic movement limited to the craniocervical region. We therefore suggest that patients with GD should be carefully selected for the treatment of bilateral posteroventral pallidotomy, despite the surgery having a partially beneficial effect on this kind of movement.

Effects of isomalto-oligosaccharides on bowel functions and indicators of nutritional status in constipated elderly men

OBJECTIVES

To evaluate effects of isomalto-oligosaccharides (IO) on the bowel function and nutritional status of elderly men.

METHODS

Seven older male subjects participated in this study that consisted of a 30-day control low fiber period followed by a 30-day IO-supplemented (10 g active components) experimental period. Bowel functions such as defecation, enema use and bloating were monitored daily. Fecal characteristics such as wet and dry stool weights, stool moisture, pH and short-chain fatty acid contents were determined on five-day fecal composites collected in each period. Feces were further fractionated into plant, bacterial and soluble fractions to determine the bases for the increase in stool weight. Nutritional status of subjects was assessed with anthropometric parameters, nutrient intake and biochemical measurements.

RESULTS

Incorporation of IO significantly increased the defecation frequency, wet stool output and dry stool weight by twofold, 70% and 55%, respectively. Fecal acetate and propionate concentrations significantly increased by nearly two and a half fold with IO supplement. The increase in stool bulk was mainly attributed by increased bacterial mass. Mean serum sodium concentration decreased in the experimental period while other blood characteristics did not change significantly. Anthropometric parameters and nutrient intake remained constant throughout the study.

CONCLUSIONS

Consumption of IO effectively improved bowel movement, stool output and microbial fermentation in the colon without any adverse effect observed in this study. Therefore, supplementation of IO into ordinary low fiber diets may be practical in relieving constipation in the elderly population.

A crossed molecular beam study of the O(1D) + C(3)H(8) reaction: multiple reaction pathways

The O((1)D) + C(3)H(8) reaction has been reinvestigated using the universal crossed molecular beam method. Three reaction channels, CH(3) + C(2)H(4)OH, C(2)H(5) + CH(2)OH, and OH + C(3)H(7), have been observed. All three channels are significant in the title reaction with the C(2)H(5) formation process to be the most important, while the CH(3) formation and the OH formation channels are about equal. Product kinetic energy distributions and angular distributions have been determined for the three reaction channels observed. The oxygen-containing radicals in the CH(3) and C(2)H(5) formation pathways show forward-backward symmetric angular distribution relative to the O atom beam, while the OH product shows a clearly forward angular distribution. These results indicate that the OH formation channel seems to exhibit different dynamics from the CH(3) and C(2)H(5) channels.

State-to-state dynamics for O(1D)+D2-->OD+D: evidence for a collinear abstraction mechanism

The O(1D)+D2-->OD+D reaction at two different collisional energies, 2.0 and 3.2 kcal/mol, is investigated by using the H(D) Rydberg "tagging" time-of-flight technique. Experimental results in this study indicate that the OD product is clearly more backward scattered relative to the O(1D) beam direction at the collisional energy of 3.2 kcal/mol. The extra backward scattered OD products are mostly in the highly vibrationally excited states (upsilon = 4,5,6), which is typical of a collinear abstraction mechanism. The experimental results in this work also provide a good testing bed for quantitative theoretical investigations of this benchmark system.

Characteristics of heavy metals on particles with different sizes from municipal solid waste incineration

Information on the concentration and size distribution of particles in the flue gas streams is essential for selecting and designing particle removal systems. Two municipal solid waste incinerators (MWIs) were selected for conducting flue gas sampling to determine the particulate distribution and heavy metals concentration on particles with different sizes by US EPA Method 5 sampling train and a cascade impactor. In addition, the characteristics of heavy metals contained on particles were investigated via isokinetic sampling of flue gas stream of air pollution control devices (APCDs). The experimental results indicated that average particulate matter (PM) concentrations at APCDs inlet were 2288.2+/-825.9 and 3069.2+/-810. 0mg/Nm(3), while the concentrations of PM at stack were 1.51+/-0.20 and 14.81+/-4.52mg/Nm(3) in MWI-A and MWI-B, respectively. The differential mass size distribution of PM and differential elemental size distribution of Zn, Pb, and Cu in front of APCDs were of bimodal forms. Results indicate that Zn>Pb>Cu in order of mass concentration in each stage. The fine particles represent approximately 70% and the coarse particles account for the rest 30% of total particulate matters collected on eight stages for both incinerators. Zn, Pb and Cu on fine particles account for approximately 80% and those on the coarse particles are less than 20% of the total heavy metals collected on eight stages of the cascade impactor for both incinerators.

Telomere-binding and Stn1p-interacting activities are required for the essential function of Saccharomyces cerevisiae Cdc13p

Yeast Saccharomyces cerevisiae Cdc13p is the telomere-binding protein that protects telomeres and regulates telomere length. It is documented that Cdc13p binds specifically to single-stranded TG(1-3) telomeric DNA sequences and interacts with Stn1p. To localize the region for single-stranded TG(1-3) DNA binding, Cdc13p mutants were constructed by deletion mutagenesis and assayed for their binding activity. Based on in vitro electrophoretic mobility shift assay, a 243-amino-acid fragment of Cdc13p (amino acids 451-693) was sufficient to bind single-stranded TG(1-3) with specificity similar to that of the native protein. Consistent with the in vitro observation, in vivo one-hybrid analysis also indicated that this region of Cdc13p was sufficient to localize itself to telomeres. However, the telomere-binding region of Cdc13p (amino acids 451-693) was not capable of complementing the growth defects of cdc13 mutants. Instead, a region comprising the Stn1p-interacting and telomere-binding region of Cdc13p (amino acids 252-924) complemented the growth defects of cdc13 mutants. These results suggest that binding to telomeres by Cdc13p is not sufficient to account for the cell viability, interaction with Stn1p is also required. Taken together, we have defined the telomere-binding domain of Cdc13p and showed that both binding to telomeres and Stn1p by Cdc13p are required to maintain cell growth.

Lack of association between angiotensin I-converting enzyme gene deletion polymorphism and cerebrovascular disease in Taiwanese

BACKGROUND AND PURPOSE

Angiotensin I-converting enzyme (ACE) gene deletion polymorphism (D) has recently been suggested as a significant risk factor for cerebrovascular disease in studies involving Japanese and white populations. We investigated the role of ACE D polymorphism in the pathogenesis of cerebrovascular disease in Taiwanese.

METHODS

To examine the association of ACE genotype and allele frequency with cerebrovascular disease, we conducted a study of 306 stroke patients and 300 control subjects matched by age and sex.

RESULTS

Although the frequencies of both the homozygous deletion (DD) genotype and the D allele were greater in stroke patients than in control subjects, these differences were not significant. Further comparison of the frequencies of the DD genotype and the D allele in the three stroke subgroups (intracerebral hemorrhage, probable large-vessel disease, and probable small-vessel lacunar infarction) with the control group revealed no significant associations. Moreover, ACE gene polymorphism was not significantly associated with age of onset of stroke. Stepwise logistic regression analysis of the presence of the D allele and data on risk factors confirmed the lack of significant association between ACE deletion polymorphism and cerebrovascular disease. Moreover, no association was identified between ACE genotypes and any of the relative risk factors for cerebral infarction or severity of carotid atherosclerosis.

CONCLUSIONS

Our results suggest that deletion polymorphism of the ACE gene is not associated with the pathogenesis of cerebrovascular disease in Taiwanese.

Sorting of tropomyosin isoforms in synchronised NIH 3T3 fibroblasts: evidence for distinct microfilament populations

The nonmuscle actin cytoskeleton consists of multiple networks of actin microfilaments. Many of these filament systems are bound by the actin-binding protein tropomyosin (Tm). We investigated whether Tm isoforms could be cell cycle regulated during G0 and G1 phases of the cell cycle in synchronised NIH 3T3 fibroblasts. Using Tm isoform-specific antibodies, we investigated protein expression levels of specific Tms in G0 and G1 phases and whether co-expressed isoforms could be sorted into different compartments. Protein levels of Tms 1, 2, 5a, 6, from the alpha Tm(fast) and beta-Tm genes increased approximately 2-fold during mid-late G1. Tm 3 levels did not change appreciably during G1 progression. In contrast, Tm 5NM gene isoform levels (Tm 5NM-1-11) increased 2-fold at 5 h into G1 and this increase was maintained for the following 3 h. However, Tm 5NM-1 and -2 levels decreased by a factor of three during this time. Comparison of the staining of the antibodies CG3 (detects all Tm 5NM gene products), WS5/9d (detects only two Tms from the Tm 5NM gene, Tm 5NM-1 and -2) and alpha(f)9d (detects specific Tms from the alpha Tm(fast) and beta-Tm genes) antibodies revealed 3 spatially distinct microfilament systems. Tm isoforms detected by alpha(f)9d were dramatically sorted from isoforms from the Tm 5NM gene detected by CG3. Tm 5NM-1 and Tm 5NM-2 were not incorporated into stress fibres, unlike other Tm 5NM isoforms, and marked a discrete, punctate, and highly polarised compartment in NIH 3T3 fibroblasts. All microfilament systems, excluding that detected by the WS5/9d antibody, were observed to coalign into parallel stress fibres at 8 h into G1. However, Tms detected by the CG3 and alpha(f)9d antibodies were incorporated into filaments at different times indicating distinct temporal control mechanisms. Microfilaments in NIH 3T3 cells containing Tm 5NM isoforms were more resistant to cytochalasin D-mediated actin depolymerisation than filaments containing isoforms from the alpha Tm(fast) and beta-Tm genes. This suggests that Tm 5NM isoforms may be in different microfilaments to alpha Tm(fast) and beta-Tm isoforms even when present in the same stress fibre. Staining of primary mouse fibroblasts showed identical Tm sorting patterns to those seen in cultured NIH 3T3 cells. Furthermore, we demonstrate that sorting of Tms is not restricted to cultured cells and can be observed in human columnar epithelial cells in vivo. We conclude that the expression and localisation of Tm isoforms are differentially regulated in G0 and G1 phase of the cell cycle. Tms mark multiple microfilament compartments with restricted tropomyosin composition. The creation of distinct microfilament compartments by differential sorting of Tm isoforms is observable in primary fibroblasts, cultured 3T3 cells and epithelial cells in vivo.

A Quantum State-Resolved Insertion Reaction: O((1)D) + H(2)(J = 0) --> OH((2) product operator product operator product operator, v, N) + H((2)S)

The O((1)D) + H(2) --> OH + H reaction, which proceeds mainly as an insertion reaction at a collisional energy of 1.3 kilocalories per mole, has been investigated with the high-resolution H atom Rydberg "tagging" time-of-flight technique and the quasiclassical trajectory (QCT) method. Quantum state-resolved differential cross sections were measured for this prototype reaction. Different rotationally-vibrationally excited OH products have markedly different angular distributions, whereas the total reaction products are roughly forward and backward symmetric. Theoretical results obtained from QCT calculations indicate that this reaction is dominated by the insertion mechanism, with a small contribution from the collinear abstraction mechanism through quantum tunneling.

Autoimmunity in ulcerative colitis (UC): a predominant colonic mucosal B cell response against human tropomyosin isoform 5

We set out to examine if the IgG-producing cells in the colonic mucosa in UC are committed to tropomyosin isoform 5 (hTM5), a putative autoantigen in UC. Lamina propria mononuclear cells (LPMC) were isolated from colonoscopic biopsy specimens from recto-sigmoid and proximal colon. Twenty-three patients with UC, eight with Crohn's colitis (CC), and 10 non-inflammatory bowel disease (non-IBD) controls were included. The ELISPOT assays were used to quantify lamina propria B cells producing total immunoglobulin (IgA, IgG, IgM), IgG, IgA, as well as IgG against hTM5 isoform. The median value of percentage of total IgG-producing lymphocytes was similar in UC (12%) and CC (11%), but was significantly (P < 0.0002) higher than non-IBD controls (6%). However, in UC, but not in CC and non-IBD, a large number of lamina propria B cells produced IgG against hTM5 (median values: UC 42%, CC 2.5%, non-IBD 0%). This difference in UC when compared with CC and non-IBD was highly significant (P < 0.00001). Twenty-one of 23 (91%) patients with UC had percentage of anti-hTM5 IgG-producing immunocytes more than 2 s. d. above the mean for non-UC patients. In UC but not in CC and non-IBD controls, the increased number of IgG-producing cells are largely committed to produce IgG against hTM5-related epitope(s).

Parkinsonism as an initial manifestation of brain tumor

Parkinsonism secondary to neoplasm is uncommon. We report two patients with bilaterally symmetric parkinsonism as the initial presentation of their brain tumors. The first patient was a 71-year-old woman who presented with a gradual onset of bilateral resting tremor, bradykinesia and rigidity. Computerized tomography (CT) of the brain revealed a large parasagittal tumor in the left frontal lobe. The patient completely recovered from the parkinsonian symptoms after removal of the brain tumor. The second patient, a 74-year-old man with a history of renal cell carcinoma of the right kidney suffered from an insidious onset of bilateral bradykinesia, rigidity and gait difficulty. Cerebral metastasis was noted on the brain CT scan. Early recognition of intracranial tumor as the cause of parkinsonism is important for the management of this type of movement disorder. Moreover, brain CT scanning plays an important role in the differential diagnosis of patients with parkinsonian symptoms.

Overexpression of microfilament-stabilizing human caldesmon fragment, CaD39, affects cell attachment, spreading, and cytokinesis

Previous studies have demonstrated that overexpression of the carboxyl-terminal fragment, CaD39, of human fibroblast caldesmon in Chinese hamster ovary cells protected endogenous tropomyosin from turnover and stabilized actin microfilament bundles [Warren et al., 1994: J. Cell Biol. 125:359-368]. To assess the consequences of having CaD39-stabilized microfilaments in living cell, we characterized the motile behaviors of stable CaD39-expressing lines. We here found that CaD39-expressing cells adhered faster to plastic, glass, fibronectin-coated glass, and collagen-coated glass than control cells. Moreover, the CaD39-expressing cells also exhibited enhanced spreading immediately after attachment. Despite these differences, overexpression of CaD39 had little effect on the velocity of intracellular granule movement, or the velocity and persistence of cellular translocation. However, CaD39-expressing cells were more elongate and encompassed less area than non-expressing cells during migration in a wound-healing assay. In interphase cells, the expressed CaD39 fragments were found associated with tropomyosin-enriched microfilaments. Like endogenous caldesmon, the CaD39 fragment was also modified at mitosis. Although a significant portion of CaD39 underwent only partial modification, the majority of the CaD39 was released from the microfilaments during mitosis. This is consistent with the finding that the CaD39-induced advantage for attachment and spreading was lost during mitosis. In CaD39-expressing cells, an incomplete release of the CaD39 from microfilaments at mitosis was found which may be responsible for the increase in the frequency of multinuclear cells in CaD39-expressing lines.

Tropomodulin-binding site mapped to residues 7-14 at the N-terminal heptad repeats of tropomyosin isoform 5

Tropomodulin is a globular protein that caps the pointed end of actin filaments by complexing with the N-terminus of a tropomyosin (TM) molecule. TM consists of coiled coils except for the N-terminus, which may be globular. Here we report that human TM isoform 5 (hTM5) lacking the N-terminal 18 residues lost its binding activity toward tropomodulin. We further characterized the tropomodulin-binding site by creating a series of deletion and missense mutations within this region, followed by a solid-phase binding assay. I7, V10, and I14, hydrophobic residues located at the a and d positions of N-terminal heptad repeats involving intertwine, are essential for tropomodulin binding. R12, a positively charged residue at the f position, is also involved in recognition. In contrast, A2R and G3Y mutations, each creating a bulky N-terminus, did not alter the binding. In addition, rat TM5b, which differs from hTM5 in residues 4-6, exhibits a similar binding affinity. The tropomodulin-binding site, therefore, is mapped to residues 7-14 at the beginning of the long heptad repeats. Column chromatography revealed that hTM5 mutants remained capable of dimerization. Results also suggest tropomodulin has a groove-type, rather than a cavity-type, binding site for hTM5. We also mapped the epitope of monoclonal antibody LC1 to residues 4-10 of hTM5 and showed the competition between mAb LC1 and tropomodulin in hTM5 binding. Since the N-terminal residues need to overlap with the C-terminus of TM in their head-to-tail association, this investigation elucidates the mechanisms by which the tropomodulin-hTM5 complex is formed and functions in regulating the actin filaments.

Stability of human serum albumin during bioprocessing: denaturation and aggregation during processing of albumin paste

PURPOSE

To assess the impact of various bioprocessing steps on the stability of freshly precipitated human serum albumin (HSA) obtained from pooled human plasma.

METHODS

After initial precipitation of HSA from plasma, the resultant paste is either (a) lyophilized or (b) washed with acetone and then air-dried in order to obtain a dry powder. The structure of HSA was examined using Fourier transform infrared (IR) spectroscopy. The extent of aggregation of redissolved HSA was measured using both dynamic light scattering and SDS-polyacrylamide gel electrophoresis (SDS-PAGE).

RESULTS

Both lyophilization and air-drying perturb the secondary structural composition of HSA, as detected by infrared (IR) spectroscopy. Upon dissolution of dried paste, most of the protein refolds to a native-like conformation. However, a small fraction of the protein molecules form soluble aggregates that can be detected by both dynamic light scattering and SDS-PAGE. The level of aggregation is so low that it could not be detected in the bulk by either circular dichroism or IR spectroscopy. The lyophilized protein, which appears to be more unfolded in the solid state than the acetone washed/air-dried material, exhibits a higher level of aggregation upon dissolution.

CONCLUSIONS

There is a direct correlation between the extent of unfolding in the solid state and the amount of soluble aggregate present after dissolution. Moreover, the presence of the aggregates persists throughout the remainder of the purification process, which includes dissolution, chromatography, sterile filtration and viral inactivation steps. Analytical methods used to monitor the stability of biopharmaceuticals in the final product can be used to assess damage inflicted during processing of protein pharmaceuticals.

Mechanisms of suppression of inducible nitric oxide synthase (iNOS) expression in RAW 264.7 cells by andrographolide

Andrographolide, an active component found in leaves of Andrographis paniculata, has been reported to exhibit nitric oxide (NO) inhibitory property in endotoxin-stimulated macrophages, however, the detailed mechanisms remain unclear. In the present study we investigated the effect of andrographolide on the expression of inducible NO synthase (iNOS) mRNA, protein, and enzyme activity in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS) plus interferon-gamma (IFN-gamma). RAW 264.7 cells stimulated with LPS/IFN-gamma activated NO production; in this condition andrographolide (1-100 microM) inhibited NO production in a dose-dependent manner with an IC(50) value of 17.4+/-1.1 microM. Andrographolide also reduces the expression of iNOS protein level but without a significant effect on iNOS mRNA. The reduction of iNOS activity is thought to be caused by decreased expression of iNOS protein. In a protein stability assay, andrographolide moderately but significantly reduced the amount of iNOS protein as suggested by accelerating degradation. Furthermore, andrographolide also inhibited total protein de novo synthesis as demonstrated by [(35)S]-methionine incorporation. As a whole, these data suggest that andrographolide inhibits NO synthesis in RAW 264.7 cells by reducing the expression of iNOS protein and the reduction could occur through two additional mechanisms: prevention of the de novo protein synthesis and decreasing the protein stability via a post-transcriptional mechanism. It is also possible that inhibition of iNOS protein expression and NO production under immune stimulation and/or bacteria infection may explain, in part, the beneficial effects of andrographolide as an anti-inflammatory agent.

Identification of cis elements in the cardiac troponin T gene conferring specific expression in cardiac muscle of transgenic mice

To investigate the underlying mechanism regulating cardiac gene expression, transgenic mice carrying the rat cardiac troponin T proximal promoter (-497 bp from the transcriptional start site) fused to a LacZ or chloramphenicol acetyltransferase (CAT) reporter gene were analyzed. The LacZ expression pattern throughout development was very similar to that of the endogenous cardiac troponin T gene. Within this promoter, a high degree of sequence homology was found at 2 sites, modules D (-335 to -289 bp) and F (-249 to -209 bp). Both regions contain at least a TCTG(G/C) direct repeat and an A/T-rich site, whereas only the F module has a muscle enhancer factor 2 (MEF2)-like motif. No significant decrease in CAT transgene expression was observed when only the MEF2 core sequence was mutated. However, when the MEF2 core sequence and its flanking TCTGG site were mutated (Mut5), CAT transgene expression was significantly decreased in the heart, and ectopic expression of the transgene was also observed. When mutations were introduced into this promoter to destroy all upstream TCTG(G/C) direct repeats in the D module (MutD), CAT expression remained cardiac specific, but the expression level was dramatically decreased. Relaxation of cardiac-specific transgene expression became even more severe in transgenic mice carrying double mutations (Mut[D+5]). In addition, CAT activity in the heart was nearly abolished. These results suggest that D and F modules have an additive function in determining the level of expression in the heart and only the F module confers cardiac-specific expression.

Tropomyosin isoform 5b is expressed in human erythrocytes: implications of tropomodulin-TM5 or tropomodulin-TM5b complexes in the protofilament and hexagonal organization of membrane skeletons

The human erythrocyte membrane skeleton consists of hexagonal lattices with junctional complexes containing F-actin protofilaments of approximately 33-37 nm in length. We hypothesize that complexes formed by tropomodulin, a globular capping protein at the pointed end of actin filaments, and tropomyosin (TM), a rod-like molecule of approximately 33-35 nm, may contribute to the formation of protofilaments. We have previously cloned the human tropomodulin complementary DNA and identified human TM isoform 5 (hTM5), a product of the gamma-TM gene, as one of the major TM isoforms in erythrocytes. We now identify TM5b, a product of the alpha-TM gene, to be the second major TM isoform. TM5a, the alternatively spliced isoform of the alpha-TM gene, which differs by 1 exon and has a weaker actin-binding affinity, however, is not present. TM4, encoded by the delta-TM gene, is not present either. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, hTM5 comigrated with the slower TM major species in erythrocyte membranes, and hTM5b comigrated with the faster TM major species. TM5b, like TM5, binds strongly to tropomodulin, more so than other TM isoforms. The 2 major TM isoforms, therefore, share several common features: They have 248 residues, are approximately 33-35 nm long, and have high affinities toward F-actin and tropomodulin. These common features may be the key to the mechanism by which protofilaments are formed. Tropomodulin-TM5 or tropomodulin-TM5b complexes may stabilize F-actin in segments of approximately 33-37 nm during erythroid terminal differentiation and may, therefore, function as a molecular ruler. TM5 and TM5b further define the hexagonal geometry of the skeletal network and allow actin-regulatory functions of TMs to be modulated by tropomodulin. (Blood. 2000;95:1473-1480)

Detection of plant genes using a rapid, nonorganic DNA purification method

We have developed a simple procedure for the preparation of plant genomic DNA using FTA paper. Plant leaves were crushed against FTA paper, and the genomic DNA was purified using simple, nonorganic reagents. The 18S rRNA gene and the gene encoding the ribulose-1, 5-bisphosphate carboxylase/oxygenase large subunit (rbcL) from the chloroplast genome were detected by PCR amplification of DNA on FTA paper. DNA amplification was successful using extracts from 16 dicot and monocot plants. Studies of specific plant extracts revealed that extracts of leaf samples could be collected and stored at room temperature on FTA paper without a decrease in the DNA amplification success rate for more than a month. Both the 18S RNA gene and the rbcL gene were detected in the genomic DNA isolated from various soybean cultivars stored in this manner. Furthermore, by modestly increasing the number of cycles of DNA amplification, we were able to detect the uidA gene in transgenic tobacco and rice leaves as well as a single copy gene linked to the resistance gene of cyst nematode race 3 using genomic DNA isolated on FTA paper. These results demonstrate that genomic DNA isolated using FTA paper can be used for the detection of plant genes, from a wide range of plants with either high or low gene copy number and of either nuclear or cytoplasmic origin.

Forced expression of a dominant-negative chimeric tropomyosin causes abnormal motile behavior during cell division

Forced expression of the chimeric human fibroblast tropomyosin 5/3 (hTM5/3) in CHO cell was previously shown to affect cytokinesis [Warren et al., 1995: J. Cell Biol. 129:697-708]. To further investigate the phenotypic consequences of misexpression, we have compared mitotic spindle organization and dynamic 2D and 3D shape changes during mitosis in normal cells and in a hTM5/3 misexpressing (mutant) cell line. Immunofluorescence microscopy of wild type and mutant cells stained with monoclonal anti-tubulin antibody revealed that the overall structures of mitotic spindles were not significantly different. However, the axis of the mitotic spindle in mutant cells was more frequently misaligned with the long axis of the cell than that of wild type cells. To assess behavioral differences during mitosis, wild type and mutant cells were reconstructed in 2D and 3D and motion analyzed with the computer-assisted 2D and 3D Dynamic Image Analysis Systems (2D-DIAS, 3D-DIAS). Mutant cells abnormally formed large numbers of blebs during the later stages of mitosis and took longer to proceed from the start of anaphase to the start of cytokinesis. Furthermore, each mutant cell undergoing mitosis exhibited greater shape complexity than wild type cells, and in every case lifted one of the two evolving daughter cells off the substratum and abnormally twisted. These results demonstrate that misexpression of hTM5/3 in CHO cells leads to morphological instability during mitosis. Misexpression of hTM5/3 interferes with normal tropomyosin function, suggesting in turn that tropomyosin plays a role through its interaction with actin microfilaments in the regulation of the contractile ring, in the localized suppression of blebbing, in the maintenance of polarity and spatial symmetry during cytokinesis, and in cell spreading after cytokinesis is complete.

Absence of G209A and G88C mutations in the alpha-synuclein gene of Parkinson's disease in a Chinese population

A G209A mutation in the alpha-synuclein gene was recently discovered in a large Italian kindred and three unrelated Greek kindreds with autosomal dominant Parkinson's disease (PD). Subsequently, another mutation in the gene (G88C) was also identified in a German family with autosomal PD. These results indicate that the alpha-synuclein gene may have an important role in the pathogenesis of PD. This study was designed to screen the existence of both mutations of the alpha-synuclein gene among 100 Chinese patients with PD, including 80 with sporadic and 20 with familial PD. Results showed that none of our patients, both sporadic and familial PD, had either of the two mutations of this gene. We therefore conclude that although of great interest, these two mutations are not relevant for the pathogenesis of PD in a Han Chinese population.

Lack of association between deletion polymorphism of the ACE gene and ischemic vascular diseases in a Chinese population in Taiwan

BACKGROUND

The association between deletion/insertion polymorphism of the angiotensin I-converting enzyme (ACE) gene and ischemic vascular diseases (IVDs) is still unclear. This study was designed to evaluate the role of ACE gene polymorphism in the pathogenesis of IVDs in a Chinese population living in Taiwan.

METHODS

A case-control study was carried out to examine the association of the ACE gene genotype and the allele frequency in 400 IVD patients, including 214 patients with ischemic cerebrovascular disease (ICVD) and 186 patients with ischemic heart disease (IHD), compared with 200 control individuals.

RESULTS

Although the patients with ICVD and IHD were found to have higher frequencies of the D/D genotype (22% and 43%) and the D allele (20% and 42%) than the controls (16% and 39%), the statistical differences were not significant, as shown by chi 2 analysis (p > 0.05). Upon further comparison of the frequencies of the D allele among the two sexes and different age subgroups, there was still no significant association.

CONCLUSIONS

Deletion polymorphism of the ACE gene was not associated with IVD in a Chinese population in Taiwan. The unique or synergistic effect of other genes that might contribute to the pathogenesis of IVDs needs further investigation.

Externalization of tropomyosin isoform 5 in colon epithelial cells

Ulcerative colitis (UC) is associated with autoantibody response to a cytoskeletal protein, human tropomyosin (hTM) isoform-5 (hTM5). Because hTM5 is an intracellular protein, it may remain inaccessible to the autoantibodies. Therefore, we have investigated the possibility of externalization of hTM5 in colon epithelial cells. Freshly isolated colonic and small intestinal epithelial cells and LS-180 colon cancer cell line were examined for surface expression of hTM5 by flow cytometric analysis using hTM isoform-specific MoAbs. The extracellular release of hTM5 was determined by Western blot and radioimmunoprecipitation analyses. Physical association of hTM5 with a membrane-associated colon epithelial protein (CEP) was examined by co-immunoprecipitation of hTM5 with anti-CEP MoAb, and CEP with anti-hTM5 MoAb. Cell surface expression of hTM5 was observed in colonic epithelial and LS-180 cells but not in small intestinal epithelial cells. LS-180 cells spontaneously released hTM5 as well as CEP into the culture medium that was significantly stimulated by a calcium ionophore, A23187, but inhibited by phorbol-12-myristate-13-acetate, monensin and methylamine. Co-immunoprecipitation experiments revealed that hTM5 forms a complex with CEP. We conclude that hTM5 is externalized in colon but not in small intestinal epithelial cells. The physical association of hTM5 with CEP suggests a possible chaperone function of CEP in the transport of hTM5, a putative target autoantigen in UC.

Expression of the Mf1 gene in developing mouse hearts: implication in the development of human congenital heart defects

The transcription factor FKHL7 gene has recently been associated with the anterior segment dysgenesis disorder of the eye known as Axenfeld-Rieger anomaly (ARA). A growing body of evidence indicates that mutations in FKHL7 cause not only defects in the anterior segment of the eye but defects in the heart valves and septa as well. In order to evaluate its contribution to normal heart septation and valve formation, expression of the mouse homologue Mf1 in embryonic hearts was analyzed by in situ hybridization. A weak but significant level of Mf1 expression could be detected in the endocardium of mouse embryos as early as day 8.5 post-conception (p.c.). Mf1 expression was undetectable in the hearts of day 9.5 p.c. embryos, but by day 10.5-11 p.c., Mf1 transcripts could be found again in the endocardium of both the atrium and ventricle and a relatively strong signal was observed in the dorsal portion of the septum primum, in what appeared to be the spinal vestibule. At day 13 p.c. when aortic and pulmonary trunks are separated, relatively more Mf1 transcripts were detected in the leaflets of aortic, pulmonary, and venous valves, the ventral portion of the septum primum, as well as in the single layer of cells on the edges of the atrioventricular cushion tissues. Surprisingly, there was no signal detected in the developing interventricular septum. At day 15 p.c., overall Mf1 signals were greatly decreased. However, significant levels of expression could still be observed in the atrial septum, the tricuspid valve, the mitral valve, and in the venous valve but not in the interventricular septum. The temporal and spatial expression patterns of the Mf1 gene in developing mouse hearts suggest that Mf1 may play a critical role in the formation of valves and septa with the exception of the interventricular septum. This is further supported by our studies showing that mutations in the FKHL7 gene were associated with defects in the anterior segment of the eye as well as atrial septal defects or mitral valve defects. Dev Dyn 1999;216:16-27.

Chemical "Double Slits": dynamical interference of photodissociation pathways in water

Photodissociation of water at a wavelength of 121.6 nanometers has been investigated by using the H-atom Rydberg tagging technique. A striking even-odd intensity oscillation was observed in the OH(X) product rotational distribution. Model calculations attribute this oscillation to an unusual dynamical interference brought about by two dissociation pathways that pass through dissimilar conical intersections of potential energy surfaces, but result in the same products. The interference pattern and the OH product rotational distribution are sensitive to the positions and energies of the conical intersections, one with the atoms collinear as H-OH and the other as H-HO. An accurate simulation of the observations would provide a detailed test of global H(2)O potential energy surfaces for the three (&Xtilde;/A/&Btilde;) contributing states. The interference observed from the two conical intersection pathways provides a chemical analog of Young's well-known double-slit experiment.

Benefit of bilateral pallidotomy in the treatment of generalized dystonia. Case report

This 29-year-old man with cerebral palsy complicated by generalized dystonia was treated by simultaneous bilateral posteroventral pallidotomy. Postoperatively, there was slow, but steady, improvement in the patient's dystonia and disability. However, the improvement in abnormal movements was only prominent for cervical dystonia and oromandibular dyskinesia. The patient's Burke-Fahn-Marsden dystonia scores were 51 preoperatively and 37, 33.5 and 33.5, at 3, 6, and 12 months postoperatively, respectively, demonstrating a maximum improvement of 34%. These results suggest that pallidotomy can be an alternative therapy for those patients suffering from intractable generalized dystonia.

Requirement of a novel gene, Xin, in cardiac morphogenesis

A novel gene, Xin, from chick (cXin) and mouse (mXin) embryonic hearts, may be required for cardiac morphogenesis and looping. Both cloned cDNAs have a single open reading frame, encoding proteins with 2,562 and 1,677 amino acids for cXin and mXin, respectively. The derived amino acid sequences share 46% similarity. The overall domain structures of the predicted cXin and mXin proteins, including proline-rich regions, 16 amino acid repeats, DNA-binding domains, SH3-binding motifs and nuclear localization signals, are highly conserved. Northern blot analyses detect a single message of 8.9 and 5.8 kilo base (kb) from both cardiac and skeletal muscle of chick and mouse, respectively. In situ hybridization reveals that the cXin gene is specifically expressed in cardiac progenitor cells of chick embryos as early as stage 8, prior to heart tube formation. cXin continues to be expressed in the myocardium of developing hearts. By stage 15, cXin expression is also detected in the myotomes of developing somites. Immunofluorescence microscopy reveals that the mXin protein is colocalized with N-cadherin and connexin-43 in the intercalated discs of adult mouse hearts. Incubation of stage 6 chick embryos with cXin antisense oligonucleotides results in abnormal cardiac morphogenesis and an alteration of cardiac looping. The myocardium of the affected hearts becomes thickened and tends to form multiple invaginations into the heart cavity. This abnormal cellular process may account in part for the abnormal looping. cXin expression can be induced by bone morphogenetic protein (BMP) in explants of anterior medial mesoendoderm from stage 6 chick embryos, a tissue that is normally non-cardiogenic. This induction occurs following the BMP-mediated induction of two cardiac-restricted transcription factors, Nkx2.5 and MEF2C. Furthermore, either MEF2C or Nkx2.5 can transactivate a luciferase reporter driven by the mXin promoter in mouse fibroblasts. These results suggest that Xin may participate in a BMP-Nkx2.5-MEF2C pathway to control cardiac morphogenesis and looping.

Chemiluminescent detection of AFLP markers

Nonradioactive amplified fragment-length polymorphism (AFLP) marker detection, a PCR-based, DNA-fingerprinting technique, was achieved by blotting AFLP products after electrophoresis onto a nylon membrane and subsequently hybridizing the blot with an alkaline phosphatase-labeled AFLP probe. Similar AFLP profiles were obtained by both a nonradioactive, chemiluminescent detection technique and by conventional AFLP marker detection using 32P-labeled AFLP primers. The suitability of the method using different gel systems combined with subsequent chemiluminescent detection of AFLP markers is validated by similar dendrograms that were generated using the unweighted pair group method with arithmetic averages (UPGMA). Moreover, chemiluminescent detection of AFLP markers using a universal AFLP nonradioactive probe has been successfully applied on prokaryotes such as Agrobacterium and eukaryotic genomes such as soybean and fungi.

Disinfection of denture base acrylic resin

STATEMENT OF PROBLEM

During repair or adjustments of acrylic resin removable complete and partial dentures, particles of the acrylic resin from the interior of the prosthesis may expose dental personnel to microbial health hazards if the prosthesis has not been thoroughly disinfected.

PURPOSE

This study investigates the efficacy of a commercially prepared microbial disinfectant (Alcide) on the external and internal surfaces of acrylic resins.

MATERIAL AND METHODS

Four groups of acrylic resin were incubated in an experimental model to simulate the oral environment over time. Specimens were treated in 2 groups, disinfected and not disinfected, and then further grouped by breaking and not breaking. Analysis was performed with microbial colony counts, SEM, and statistical analyses.

RESULTS

Viable microorganisms still remain on the internal and external surfaces of treated resins.

CONCLUSION

Chlorine dioxide reduces, but does not eliminate, viable microorganisms on these dental prostheses.

A comparative molecular field analysis study on several bioactive peptides using the alignment rules derived from identification of commonly exposed groups

A 3D convex hull computation algorithm designed by us previously is used as a tool to align a series of structures randomly generated for eleven bioactive tachykinin peptides. There are 10 random structures generated for each peptide. A random structure is selected for each peptide to form a structural set of eleven structures. The total number of structural sets generated is 100. The convex hull computation algorithm is applied to each peptide structure generated. We count the frequency of atoms lying on the vertices of each hull computed. Vertices of the same atom type are gathered together as a set of commonly exposed atoms for a structural set generated. Structures are then aligned by treating the set of commonly exposed atoms as a set of correspondences using the FIT option of the SYBYL 6.4 program. All the structure sets are also aligned by using the coordinates of the backbone C alpha atoms as a set of correspondences through the same program. It is found that while a smaller degree of structural similarity for structures aligned by the convex hull alignment rule is detected, the overall SYBYL comparative molecular field analysis (CoMFA) statistics computed for the aligned structures using the alignment rule is better than that computed for the aligned structures using the C alpha atoms alignment rule. A similar conclusion is drawn for a subset of structures selected and probed by a different type of atoms using the SYBYL CoMFA program. These results indicate that computation of 3D convex hulls is a feasible way that one can use to align structures generated for highly flexible molecules of this kind.

Immunodetection of Xenopus bone morphogenetic protein-1 in adult and embryonic cells

In order to analyze biochemical properties of Xenopus bone morphogenetic protein-1 (XBMP-1), rabbit antiserum (alpha-B1) was raised against a synthetic peptide (P1) corresponding to a hydrophilic N-terminal region. XBMP-1B (Xtld) synthesized in the reticulocyte lysate was successfully immunoprecipitated by this antiserum. This precipitation was completely blocked when P1 was added to the reaction, indicating that alpha-B1 recognized XBMP-1B specifically. In Western blot analysis, two distinct sizes of protein (107 and 34 kD) were detected in hind limbs in metamorphosing animals. Both proteins were detected in various adult tissues such as lung, liver, kidney, heart, muscle, intestine, brain, and testis. The mixing of the liver and muscle extracts, and the following detection of immunoreactive proteins suggested that the 34 kD band was a proteolytic product of the 107 kD protein. In the embryonic extracts from the unfertilized egg (stage 0) to swimming tadpoles (stage 40), a 63 kD protein was detected in addition to the 107 kD protein. We also showed that the 107 kD protein was much more expressed in the animal half of the unfertilized eggs than in the vegetal half, but that it was ubiquitously expressed in the gastrula embryos. We suggest that the 63 and 107 kD proteins correspond to full-length proteins encoded by XBMP-1A and XBMP-1B genes, and these proteins are expressed in embryo and in various adult tissues.

The cancer growth suppressor gene mda-7 selectively induces apoptosis in human breast cancer cells and inhibits tumor growth in nude mice

A differentiation induction subtraction hybridization strategy is being used to identify and clone genes involved in growth control and terminal differentiation in human cancer cells. This scheme identified melanoma differentiation associated gene-7 (mda-7), whose expression is up-regulated as a consequence of terminal differentiation in human melanoma cells. Forced expression of mda-7 is growth inhibitory toward diverse human tumor cells. The present studies elucidate the mechanism by which mda-7 selectively suppresses the growth of human breast cancer cells and the consequence of ectopic expression of mda-7 on human breast tumor formation in vivo in nude mice. Infection of wild-type, mutant, and null p53 human breast cancer cells with a recombinant type 5 adenovirus expressing mda-7, Ad.mda-7 S, inhibited growth and induced programmed cell death (apoptosis). Induction of apoptosis correlated with an increase in BAX protein, an established inducer of programmed cell death, and an increase in the ratio of BAX to BCL-2, an established inhibitor of apoptosis. Infection of breast carcinoma cells with Ad.mda-7 S before injection into nude mice inhibited tumor development. In contrast, ectopic expression of mda-7 did not significantly alter cell cycle kinetics, growth rate, or survival in normal human mammary epithelial cells. These data suggest that mda-7 induces its selective anticancer properties in human breast carcinoma cells by promoting apoptosis that occurs independent of p53 status. On the basis of its selective anticancer inhibitory activity and its direct antitumor effects, mda-7 may represent a new class of cancer suppressor genes that could prove useful for the targeted therapy of human cancer.

Peritoneal loss of insulin-like growth factor-I and binding proteins in end-stage renal disease

The kinetics of peritoneal transport of insulin-like growth factor (IGF) system-related proteins during dialysis is not well characterized. We studied temporal changes in dialysate and serum concentrations of IGF-I and IGF-II as well as IGF binding protein (BP)-1, -2, and -3 in ten children with end-stage renal disease (ESRD) undergoing continuous cycling peritoneal dialysis (CCPD) during a 4-h peritoneal equilibration test (PET). Dialysate concentrations of IGF-I, IGF-II, and all three IGFBPs demonstrated a time-dependent increase during PET. Despite their transport, the serum concentrations of these proteins did not change significantly during the PET. Dialysate/serum ratios for IGF-I, IGF-II, and IGFBP-1, -2, and -3 were significantly increased at 2 h and increased further at 4 h, at which time values averaged 1.3+/-0.2%, 3.1+/-0.5%, 6.2+/-1.0%, 2.4+/-0.2%, and 1.3+/-0.2% of serum levels, respectively. The transperitoneal clearance (microl/min per 1.73 m2) of the three IGFBPs was inversely related to both their molecular weight and plasma concentration. However, peritoneal clearance of IGF-I and -II was similar to that of the larger and more-abundant IGFBP-3. Mass transfer rates (microg/h per 1.73 m2) for the IGFs and their binding proteins were directly proportional to their prevailing plasma concentration. Based on estimates of mass transfer, only a small molar excess of IGFBPs was removed from the circulation relative to the combined molar concentration of IGF-I and IGF-II. Hence, it seems unlikely that any beneficial effect of CCPD on growth in children with ESRD is mediated via a preferential loss of IGFBPs into the dialysate fluid.

Andrographolide suppresses the expression of inducible nitric oxide synthase in macrophage and restores the vasoconstriction in rat aorta treated with lipopolysaccharide

1. We investigated whether andrographolide, a diterpenoid lactone found at Andrographis paniculata, influences the induction of the inducible nitric oxide synthase (iNOS) in RAW264.7 cells activated by bacterial endotoxin (LPS), as well as in the rats with endotoxic shock and in aortic rings treated with LPS. 2. Incubation of RAW264.7 cells with andrographolide (1 to 50 microM) inhibited the LPS (1 microg ml(-1))-induced nitrite accumulation in concentration- and time-dependent manners. Maximum inhibition was observed when andrographolide was added together with LPS and decreased progressively as the interval between andrographolide and LPS was increased to 20 h. 3. Western blot analysis demonstrated that iNOS expression was markedly attenuated in the presence of andrographolide for 6-24 h, suggesting that andrographolide inhibited iNOS protein induction. 4. Thoracic aorta incubation with LPS (300 ng ml(-1)) for 5 h in vitro exhibited a significant decrease in the maximal contractile response to phenylephrine (10(-9)-10(-5) M). Andrographolide (30 microM) restored the contractile response to control level. 5. In anaesthetized rats, LPS (10 mg kg(-1), i.v.) caused a fall in mean arterial blood pressure (MAP) from 116+/-4 to 77+/-5mmHg. The pressor effect of phenylephrine (10 microg ml(-1), i.v.) was also significantly reduced at 30, 60, 120 and 180 min after LPS injection. In contrast, animals pretreated with andrographolide (1 mg kg(-1), i.v., 20 min prior to LPS) maintained a significantly higher MAP when compared to LPS-rats given with vehicle. Administration of andrographolide 60 min after LPS caused a increase in MAP and significantly reversed the reduction of the pressor response to phenylephrine. 6. Our results indicated that andrographolide inhibits nitrite synthesis by suppressing expression of iNOS protein in vitro. And, this inhibition of iNOS synthesis may contribute to the beneficial haemodynamic effects of andrographolide in endotoxic shock.

Insulin-like growth factor-I restores microvascular autoregulation in experimental chronic renal failure

Impairment of autoregulation (AR) is associated with accelerated progression of chronic renal failure (CRF). As the bioavailability of insulin-like growth factor-I (IGF-I) is low in CRF, we investigated the effects of acute luminal application of 10 nM recombinant human IGF-I on AR in juxtamedullary (JM) afferent arterioles (AA) perfused in vitro with a blood solution [(approximately 30% hematocrit (HCT)]. Studies were conducted in AA from adult male rats three to four weeks after five-sixths nephrectomy (Nx) by either surgical excision (N = 7) or infarction (N = 5) of two thirds of the remnant kidney; controls (N = 6) had sham surgery. AA from both Nx groups exhibited marked hypertrophy and impaired AR responses (60 to 140 mm Hg perfusion pressure), features more pronounced in the infarction group. Responses to abluminal acetylcholine (10 microM) were similar in sham and excision groups but were significantly blunted in the infarction group. All groups vasodilated significantly after Ca-channel blockade (10 mM MnCl2). IGF-I restored AR in AA from both Nx groups (P < 0.05, analysis of variance) while it vasodilated AA from controls. These results suggest that IGF-I may protect the glomerulus from injury by maintaining autoregulatory control of renal blood flow, thereby slowing the progression of CRF.

Tropomyosin isoforms in intestinal mucosa: production of autoantibodies to tropomyosin isoforms in ulcerative colitis

BACKGROUND & AIMS

Autoantibodies against tropomyosins (TMs) have been reported in ulcerative colitis (UC). In this study the hTM isoforms (hTM1-5) present in intestinal epithelial cells and in smooth muscle were investigated, and the immunoreactivity against hTMs by immunoglobulin G (IgG) produced in vitro by colonic mucosal lymphocytes (LPMCs) from patients with UC, Crohn's disease (CD), and controls was examined.

METHODS

TMs were extracted from colonic and jejunal epithelial cells and smooth muscle, and hTM isoforms were identified using isoform-specific monoclonal antibodies by enzyme-linked immunosorbent assay and transblot analysis. The immunoreactivity of IgG produced by colonic LPMCs was analyzed against the recombinant hTM isoforms.

RESULTS

The major hTM isoforms present in colonic and jejunal epithelial cells are hTM5 and hTM4, whereas intestinal smooth muscle contains the hTM1-3 isoforms. The IgG synthesized in vitro by LPMCs from UC (n = 19) recognized hTM5 and hTM1, more significantly (P < 0.04 to <0.001) when compared with CD (n = 12) and controls (n = 17). However, IgG produced by LPMCs from CD did not show such anti-hTM reactivity. Mucosal anti-hTM IgG mainly belonged to the IgG1 subclass.

CONCLUSIONS

Intestinal epithelial cells and smooth muscle have distinct hTM isoforms. Patients with UC, and not CD, show mucosal autoantibody response against hTM isoforms, particularly hTM5 and hTM1.

Diagnosis of cerebral toxoplasmosis by a nested polymerase chain reaction: a case report

A 24-year-old man infected with human immunodeficiency virus type I rapidly progressed to acquired immune deficiency syndrome. His clinical picture was compatible with a presumptive diagnosis of cerebral toxoplasmosis. Application of a nested polymerase chain reaction (PCR) succeeded in detecting Toxoplasma gondii DNA in both the venous blood and cerebrospinal fluid specimens. This result indicates that PCR is a convenient tool for making a rapid and accurate diagnosis of cerebral toxoplasmosis, especially in developing countries.