Comparison of the prevalence of knee osteoarthritis between the elderly Chinese population in Beijing and whites in the United States: The Beijing Osteoarthritis Study

OBJECTIVE

To estimate the prevalence of radiographic and symptomatic knee osteoarthritis (OA) in a population-based sample of elderly subjects in Beijing, China and compare it with that reported in the Framingham (Massachusetts) OA Study.

METHODS

We recruited a sample of persons age > or = 60, using door-to-door enumeration in randomly selected neighborhoods in Beijing. Subjects completed a home interview including questions on knee symptoms and a hospital examination including knee radiographs obtained during weight bearing. The protocol was identical to that used in the Framingham OA Study. A reader read intermingled Beijing and Framingham Study films to ensure high reliability. We defined a subject as having radiographic knee OA when the Kellgren/Lawrence grade was > or = 2 in at least 1 knee. Symptomatic knee OA was recorded as present when knee pain was reported and the symptomatic knee had radiographic OA. We estimated the prevalence of these entities in elderly subjects in Beijing and compared it with OA prevalence in Framingham, using an age-standardized prevalence ratio.

RESULTS

Of 2,180 age-eligible Beijing subjects contacted, knee radiographs were obtained in 1,787 (82.0%). The prevalence of radiographic knee OA was 42.8% in women and 21.5% in men. Symptomatic knee OA occurred in 15.0% of women and 5.6% of men. Compared with women of the same age in Framingham, women in Beijing had a higher prevalence of radiographic knee OA (prevalence ratio 1.45, 95% confidence interval 1.31-1.60) and of symptomatic knee OA (prevalence ratio 1.43, 95% confidence interval 1.16-1.75). The prevalence of knee OA in Chinese men was similar to that in their white US counterparts (for radiographic OA, prevalence ratio 0.90; for symptomatic OA, prevalence ratio 1.02).

CONCLUSION

Using identical methods and definitions to evaluate the prevalence of OA across populations, we found, surprisingly, that older Chinese women have a higher prevalence of knee OA than women in Framingham, Massachusetts. The prevalence in men was comparable. Possible explanations for these differences range from genetic differences to heavy physical activity among Chinese.

Cre recombinase-mediated site-specific recombination between plant chromosomes

We report the use of the bacteriophage P1 Cre-lox system for generating conservative site-specific recombination between tobacco chromosomes. Two constructs, one containing a promoterless hygromycin-resistance gene preceded by a lox site (lox-hpt) and the other containing a cauliflower mosaic virus 35S promoter linked to a lox sequence and the cre coding region (35S-lox-cre), were introduced separately into tobacco plants. Crosses between plants harboring either construct produced plants with the two constructs situated on different chromosomes. Plants with recombination events were identified by selecting for hygromycin resistance, a phenotype expressed upon recombination. Molecular analysis showed that these recombination events occurred specifically at the lox sites and resulted in the reciprocal exchange of flanking host DNA. Progenies of these plants showed 67-100% cotransmission of the new transgenes, 35S-lox-hpt and lox-cre, consistent with the preferential cosegregation of translocated chromosomes. These results illustrate that site-specific recombination systems can be useful tools for the large-scale manipulation of eukaryotic chromosomes in vivo.

Improving social skills in children with ASD using a long-term, in-home social robot

Social robots can offer tremendous possibilities for autism spectrum disorder (ASD) interventions. To date, most studies with this population have used short, isolated encounters in controlled laboratory settings. Our study focused on a 1-month, home-based intervention for increasing social communication skills of 12 children with ASD between 6 and 12 years old using an autonomous social robot. The children engaged in a triadic interaction with a caregiver and the robot for 30 min every day to complete activities on emotional storytelling, perspective-taking, and sequencing. The robot encouraged engagement, adapted the difficulty of the activities to the child's past performance, and modeled positive social skills. The system maintained engagement over the 1-month deployment, and children showed improvement on joint attention skills with adults when not in the presence of the robot. These results were also consistent with caregiver questionnaires. Caregivers reported less prompting over time and overall increased communication.

poc1: an Arabidopsis mutant perturbed in phytochrome signaling because of a T DNA insertion in the promoter of PIF3, a gene encoding a phytochrome-interacting bHLH protein

The phytochrome family of informational photoreceptors has a central role in regulating light-responsive gene expression, but the mechanism of intracellular signal transduction has remained elusive. In a genetic screen for T DNA-tagged Arabidopsis mutants affected in early signaling intermediates, we identified poc1 (photocurrent 1), which exhibits enhanced responsiveness to red light. This phenotype is absent in a phyB (phytochrome B) null mutant background, indicating that the poc1 mutation enhances phyB signal transduction. The T DNA insertion in poc1 was found to be located in the promoter region of PIF3, a gene encoding a basic helix-loop-helix protein. The mutant phenotype seems to result from insertion-induced overexpression of this gene in red-light-grown seedlings, consistent with PIF3 functioning as a positively acting signaling intermediate. These findings, combined with data from a separate yeast two-hybrid screen that identified PIF3 as a phytochrome-interacting factor necessary for normal signaling, provide evidence that phytochrome signal transduction may include a direct pathway to photoresponsive nuclear genes via physical interaction of the photoreceptor molecules with the potential transcriptional regulator PIF3.

Intra-chromosomal rearrangements generated by Cre-lox site-specific recombination

Chromosomal rearrangements are useful genetic and breeding tools but are often difficult to detect and characterize. To more easily identify and define chromosome deletions and inversions, we have used the bacteriophage P1 Cre-lox site-specific recombination system to generate these events in plants. This involves three steps: (i) the introduction of two lox sites into one locus in a plant genome, including one site within a modified Ds transposon; (ii) Ac transposase-mediated transposition of the Ds-lox element to a new locus on the same chromosome; (iii) Cre-mediated site-specific recombination between the two lox sites that bracket a chromosome segment. We report the production of a deletion and three inversion events in tobacco. The utility of chromosomal segments bracketed by lox sites for targeted manipulation and cloning is discussed.

Effects of chronic immobilization stress on anxiety-like behavior and basolateral amygdala morphology in Fmr1 knockout mice

Several lines of clinical evidence support the idea that fragile X syndrome (FXS) may involve a dysregulation of hypothalamic-pituitary-adrenal axis function [Wisbeck et al. (2000) J Dev Behav Pediatr 21:278-282; Hessl et al. (2002) Psychoneuroendocrinology 27:855-872]. We had tested this idea in a mouse model of FXS (Fmr1 KO) and found that the hormonal response to acute stress was similar to that of wild-type (WT) mice [Qin and Smith (2008) Psychoneuroendocrinology 33:883-889]. We report here responses to chronic stress (CS) in Fmr1 KO mice. Following restraint for 120 min/d, 10 consecutive days, we assessed dendrite and spine morphology in basolateral amygdala (BLA). We also monitored behavior in an elevated plus maze (EPM) and the hormonal response to this novel spatial environment. After CS, mice of both genotypes underwent adrenal hypertrophy, but effects were greater in WT mice. Behavior in the EPM indicated that only WT mice had the expected increase in anxiety following CS. Serum corticosterone and adrenocorticotropic hormone (ACTH) levels were both increased following the spatial novelty of EPM, and there were no differences between genotypes in the hormonal responses. BLA dendritic branching increased proximal to the soma in WT, but in Fmr1 KO mice branching was unaffected close to the soma and slightly decreased at one point distal to the soma. Similarly, spine density on apical and basal dendrites increased in WT but decreased in Fmr1 KO mice. Spine length on apical and basal dendrites increased in WT but was unaffected in Fmr1 KO mice. These differences in behavioral response and effects on neuron morphology in BLA suggest a diminished adaptive response of Fmr1 KO mice.

A null mutation for Fmr1 in female mice: effects on regional cerebral metabolic rate for glucose and relationship to behavior

As a measure of functional activity we determined regional cerebral metabolic rate for glucose (rCMR(glc)) in adult, female wild type and fragile X (Fmr1 null) mice homozygous and heterozygous for the null mutation. To ascertain if the sexes differ with respect to the severity of the effects of the mutation we compared our results with results of our previous study on male Fmr1 null mice [Qin M, Kang J, Smith CB (2002) Increased rates of cerebral glucose metabolism in a mouse model of fragile X mental retardation. Proc Natl Acad Sci U S A 99:15758-15763.]. In contrast to the male Fmr1 null mouse, rCMR(glc) was unchanged in the homozygous female except in the dorsal raphe where rCMR(glc) was increased by 36%. There were no differences in rCMR(glc) between heterozygous and wild type female mice. We compared male and female mice for effects of the null mutation on behavior. We found that the female Fmr1 null mouse is similar to the male with deficits in performance on a passive avoidance task, general hyperactivity, and increased susceptibility to audiogenic seizures. Both homozygous and heterozygous female mice exhibited hyperactivity and increased susceptibility to seizures, whereas only the homozygous mice had a deficit on the passive avoidance test. Male Fmr1 null mice had a tendency for lower anxiety-like behavior in an open field, whereas this was not evident in females. Compared with male wild type, male Fmr1 null mice also had a diminished acoustic startle response at higher stimulus intensities, whereas all three female genotypes had responses similar to those of male Fmr1 null mice. Whether estrogen affords female Fmr1 null mice some protection from the effects of the mutation remains to be determined.

Expression of variants of the major surface glycoprotein of Pneumocystis carinii

Previously, we have shown that a multicopy family of related but unique genes encodes the major surface glycoprotein (MSG) of Pneumocystis carinii. To examine whether different members of this gene family are expressed by P. carinii, antisera were prepared against peptides whose sequences were determined from the deduced amino acid sequences of variants of rat-derived MSG. Immunohistochemical staining of serial sections of rat lungs of infected animals showed that at least three variants of MSG were expressed in an individual lobe, that there was a focal expression of these variants within the lung, and that the relative numbers of these foci were different. Indirect immunofluorescent staining of purified P. carinii organisms using these antisera revealed that at least three variants of MSG were present in organisms isolated from an individual rat and that both cysts and trophozoites reacted with each antiserum. A substantial difference in the fraction of organisms reacting with a specific antipeptide antiserum was seen when comparing organisms isolated from rats raised in a single colony over a period of two years as well as organisms isolated at one time point from rats raised in different colonies. This demonstration of antigenic variation in P. carinii supports the hypothesis that P. carinii utilizes such variation for evading host defense mechanisms.

The upregulation of osteoblast marker genes in mesenchymal stem cells prove the osteoinductivity of hydroxyapatite/tricalcium phosphate biomaterial

BACKGROUND

Calcium phosphate (Ca-P), mainly concerning hydroxyapatite (HA), is the main inorganic component of the body's hard tissue. It is acknowledged that Ca-P biomaterial not only has osteoconduction but also can form bone bonding to host bone, making an ideal tissue-engineering scaffold. However, whether Ca-P biomaterial possesses osteoinductivity is still debated. The present study was performed to explore the expression level of osteoblast maker genes in human mesenchymal stem cells (hMSCs) grown on a Ca-P biomaterial.

MATERIALS AND METHODS

hMSCs were cultured on the HA/tricalcium phosphate-(TCP) double-phase ceramic. After coculture for 5, 10, 15, or 20 days, the cells were digested for isolation of total RNA. Fluorescence quantitative polymerase chain reaction was used to detect the relative mRNA levels of Runx2, collagen type I, osteopontin, and osteocalcin, all of which are the marker genes for osteoblasts. The mg63 cell was recruited as the reference and un-cocultured hMSCs as the negative controls. Alkaline phosphatase (ALP) activity in the cells was also examined after culture for 10 or 20 days.

RESULTS

Our results showed that the expression levels of all four genes continued to rise during the first 10 days. Then, both collagen type I and Runx2 decreased. In contrast, osteocalcin mRNA reached its maximum at day 15 and osteopontin mRNA kept increasing throughout the whole experimental period. Additionally, ALP activity increased in a time-dependent manner.

CONCLUSION

The up-regulation of all four osteoblast marker genes in hMSCs grown on Ca-P biomaterial suggested that HA/TCP biomaterials possess osteoinductivity on hMSCs, cells a mechanism that requires further investigation.

Normal changes in spinal bone mineral density in a Chinese population: assessment by quantitative computed tomography and dual-energy X-ray absorptiometry

This study was designed to determine age- and gender-based normative values for spinal bone mineral density (BMD) in a Chinese population. In addition, we compared our data with those of other countries and populations. Four hundred and forty-three healthy Chinese subjects, aged 10-79 years (189 males, mean age 46.9 years; 254 females, mean age 45.7 years) were recruited for BMD assessment. BMD was measured by quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA), including posteroanterior DXA (PA-DXA), lateral DXA (L-DXA) and midlateral DXA (mL-DXA). For both genders, BMD values peaked in the 10-19 year age group when measured by QCT, and in the 30-39 year age group when measured by PA-DXA. BMD values decreased with age after reaching peak bone density in males and females for all measurements, except for PA-DXA in males. Male BMD values by DXA tended to increase beginning with the 60-69 age group through the 70-79 age group whether by PA-DXA, or L-DXA and mL-DXA. However, male QCT data showed stable BMD values among these two older groups. Comparative results showed female QCT data were higher in the 20-39 age group and lower after the 40-49 age group compared with American females. The peak BMD value by PA-DXA in Chinese females was reached in the same age group as American and European females and was similar in magnitude (p > 0.05). However, the peak BMD value for Chinese females was reached earlier and was significantly higher than that observed in Japanese females (p < 0.001). We conclude that the age group in which the peak BMD values are reached is different depending on the technique used, as is the calculated age-related rate of bone loss. It can be speculated that such differences reflect different timing for bone maturation in cancellous and cortical bone.

Characterization of an in situ IFN-gamma ELISA assay which is able to detect specific peptide responses from freshly isolated splenocytes induced by DNA minigene immunization

An in situ IFN-gamma ELISA assay has been developed and optimized for both freshly isolated and peptide-restimulated splenocytes. This assay is based on the ELISPOT assay, but utilizes a soluble chromagen, making it readily adaptable to high-throughput analysis. We show that in both the primary and restimulation assays this technique is more sensitive than either a traditional supernatant ELISA or the 51Cr-release assay, in that responses are observed in the in situ ELISA that are not detectable in these other assays. On a per-cell basis, the sensitivity of the in situ ELISA is approximately one IFN-gamma secreting cell/10(4) plated cells. The in situ IFN-gamma ELISA was utilized to describe the kinetics of the IFN-gamma response to DNA vaccination with pMin.1. For freshly isolated splenocytes, the peak response for all the peptides tested was observed from 10 to 12 days after immunization, with responses seen to some peptides as early as 7 days. When a 6-day in vitro peptide restimulation step was added, responses were seen for all the peptides tested after 7 days of in vivo immunization. This data demonstrates that a single intramuscular administration of a DNA vaccine can induce T-cell responses that can be detected in freshly isolated splenocytes.

Analysis of the replication region of a mycobacterial plasmid, pMSC262

We determined the nucleotide sequence of a DNA fragment which contains the replication region of pMSC262, a Mycobacterium scrofulaceum plasmid used to construct the Mycobacterium-Escherichia coli shuttle vector. The complete sequence of the fragment contained 2,504 bp with an overall G+C content of 69.8%. By deletion analysis, we found that the minimum length required for plasmid replication in M. bovis BCG was about 1.6 kb. Within this region, several open reading frames (ORFs) and a putative replication origin (ori) were identified by computer analysis. One of the ORFs, ORF2, which encodes a putative 28.9-kDa basic protein with characteristics of DNA-binding proteins, appeared to be involved in replication of the plasmid in BCG. By separation of ORF2 and the putative ori region, it was revealed that the relative locations of ORF2 and the putative ori region are likely important for replication in BCG. No DNA or amino acid homologies were found between this replication region and that of pAL5000, another mycobacterial plasmid used for vector plasmid construction. In addition, we found that this replicon did not lead to replication in E. coli and was compatible in BCG with pAL5000-derived vector plasmid pYUB75 (R. G. Barletta, D. D. Kim, S. B. Snapper, B. R. Bloom, and W. R. Jacobs, J., J. Gen. Microbiol. 138:23-30, 1992).

Sodium valproate inhibits MDA-MB-231 breast cancer cell migration by upregulating NM23H1 expression

Breast cancer is a common cancer in women, with a highly variable course, from inoffensive to lethal. To find a more effective strategy for its treatment, sodium valproate has been tested as an anti-cancer drug; it is the only clinically available histone deacetylase inhibitor. However, data about the effects of sodium valproate on breast cancer are insufficient in both animals and humans; studies have yielded conflicting conclusions. In particular, little is known about the association between expression of the metastasis suppressor Nm23H1 gene and breast cancer. We hypothesized that sodium valproate regulates NM23H1 expression, and affects migration and/or invasion. We found that sodium valproate at concentrations of 0.8-3.2 mM inhibits migration and modulates Nm23H1 gene expression in a concentration-dependent manner. Confluent MDA-MB-231 cells were scratched by a micropipette tip after VPA treatment for 24 h; 24 h later, the scratch was almostly closed in the 0 mM VPA-treated cells, while the 3.2 mM VPA-treated cells migrated the slowest. The cell migration ratio exposed to 0.8, 1.6 and 3.2 mM VPA was about 66.67, 30.67 and 26.67% (P < 0.05). We also found evidence that sodium valproate upregulates NM23H1 expression, which is a clue to its anti-cancer mode of action. The NM23H1 gene expression was relative fold increased determined by Western blotting at 3.2 mM VPA. Collectively, these observations indicate that sodium valproate has potential for use in breast cancer treatment.

Site-specific cleavage of chromosomes in vitro through Cre-lox recombination

Site-specific recombination systems are useful tools for chromosome engineering in vivo and site-specific DNA cleavage methods have applications in genome analysis and gene isolation. Here, we report a new method to fragment chromosomes in vitro using the Cre-lox site-specific recombination system. Two lox sites were targeted into the 5.7 Mb chromosomes I of Schizosaccharomyces pombe. In vitro recombination between chromosomal lox sites and exogenously provided lox oligonucleotides 'cleaved' the chromosome at the defined lox sequences. Site-specific cleavage of lox sites in the tobacco genome was also demonstrated. This recombination-based cleavage method provides a novel approach for structural and functional analyses of eukaryotic chromosomes as it allows direct isolation of chromosome regions that correspond to phenotypes revealed through Cre-lox mediated chromosome rearrangements in vivo. Moreover, recombination with end-labeled lox oligonucleotides would permit the specific end-labeling of chromosome segments to facilitate the long range mapping of chromosomes.

Randomized clinical trial of laparoscopic anterior 180° partial versus 360° Nissen fundoplication: 5-year results

Anterior partial fundoplication (AF) has been popularized by a lower risk of mechanical side effects. The question then emerges whether anterior partial wrap has a similar antireflux effect with Nissen fundoplication (NF). We therefore conducted a randomized study to compare the long-term outcome of anterior fundoplication with NF. One hundred patients who enrolled in the trial from May 2003 to March 2005 were randomized to laparoscopic AF or laparoscopic NF. Endoscopy, pH monitoring, manometry, a detailed questionnaire, and a visual analog symptom score were completed preoperative at 6, 12, 24, and 60 months after surgical procedures. The postoperative adverse effects such as dysphagia and flatulence were compared between the two groups. Revision surgery or maintenance proton pump inhibitor therapy was defined as failure. Fifty procedures were performed in each group. The outcome at 5 years follow-up was determined for 96 patients (96%; 49 patients in the AF group and 47 in the NF group). Three patients (3%) died of unrelated causes during follow-up, and one patient changed address. Both fundoplications were found to provide good control of reflux-related symptoms in most of the patients. For 96 patients followed up more than 5 years, gastroesophageal reflux symptoms were well controlled in 81 patients (84.38%); the mean DeMeester scores in the AF group decreased from 106.89 ± 14.12 to 12.67 ± 3.14 and in the NF group from 109.51 ± 17.98 to 10.81 ± 2.65, and the esophagitis was ameliorated visibly. Moreover, there were significantly fewer patients in the AF group who complained of flatulence. Compared with NF, anterior 180° partial fundoplication is an effective treatment of gastroesophageal reflux and associates with fewer postoperative adverse effects.

Tumour-infiltrating FoxP3+ and IL-17-producing T cells affect the progression and prognosis of gallbladder carcinoma after surgery

Tumour-infiltrating lymphocytes (TILs) have been found to play crucial roles in a series of cancers. However, the impact of these cells on gallbladder carcinoma (GBC) remains poorly understood. In this study, we examined infiltrating FoxP3+, IL-17+, CD4+ and CD8+ cells by immunohistochemistry in specimens of 104 patients with GBC and evaluated the association of these cells with clinicopathological features and prognosis. The number of FoxP3+ cells was increased in a stepwise manner from CC to GA and GBC (GA versus CC, P = 0.036; early GBC versus GA, P = 0.032; advanced versus early GBC, P = 0.025). Both intratumoral FoxP3+ and IL-17+ cells correlated with nodal metastasis and TNM stage. Additionally, there were more infiltrating FoxP3+ cells in specimens with distant metastasis (P = 0.014). The group with high FoxP3+ cells showed poor overall survival (OS, P < 0.001) and disease-free survival (DFS, P < 0.001), and high infiltration of IL-17-producing cells was also a predictor of poor OS (P = 0.024). Multivariate analysis revealed that the presence of intratumoral FoxP3+ cells was an independent prognostic indicator for poor DFS (P < 0.01). In summary, these findings indicate that FoxP3+ and IL-17+ cells cooperatively facilitate pathogenesis and progression of GBC and show prognostic significance for OS or DFS.

Overexpressed phytochrome C has similar photosensory specificity to phytochrome B but a distinctive capacity to enhance primary leaf expansion

Phytochrome C (phyC) is a low-abundance member of the five-membered phytochrome family of photoreceptors in Arabidopsis. Towards developing an understanding of the photosensory and physiological functions of phyC, transgenic Arabidopsis plants were generated that over-express cDNA-encoded phyC and seedling responses to continuous white, red, or far-red light (Wc, Rc or FRc, respectively) were examined. Transgenic seedlings over-expressing phyC displayed enhanced inhibition of hypocotyl elongation in Rc, but were unchanged in responsiveness to FRc relative to wild-type. These data indicate that phyC has photosensory specificity that is similar to that of phyB and thus distinct from that of phyA. phyC overexpressors with levels only 3 to 4 times the level of endogenous phyC exhibited enhanced primary leaf expansion in Wc. This is in contrast to phyA or phyB overexpressors which respectively have levels that are 500- and 100-fold that of overexpressed phyC but showed no enhancement of primary leaf expansion. Therefore, phyC may have some physiological roles that are different to those of phyA and phyB in the control of seedling responses to light signals.

A novel acrosomal protein, IQCF1, involved in sperm capacitation and the acrosome reaction

On the basis of the unknown tags in the mature human sperm serial analysis of gene expression library constructed by our laboratory, some transcripts were cloned, including Iqcf1 (IQ motif containing F1). To investigate the function of sperm-retained Iqcf1 in spermatogenesis and fertilization of mice, we investigated the spatial and temporal expression of IQCF1. By using the (transcription activator-like effector nuclease) strategy, Iqcf1-knockout mice were produced, and the phenotypes of the Iqcf1(-/-) mice were analyzed. The results showed that IQCF1 was localized in the acrosome of spermatozoa and spermatids; the expression of IQCF1 in testes was associated with spermatogenic capacity. The Iqcf1(-/-) mice were significantly less fertile than the wild-type mice (p = 0.0057) because of reduced sperm motility (p = 0.0094) and the acrosome reaction (AR) (p = 0.0093). In spermatozoa, IQCF1 interacted with calmodulin (CaM) and possibly participated in the tyrosine phosphorylation of sperm proteins during capacitation. In conclusion, a newly identified acrosomal protein, IQCF1, is closely related to sperm capacitation and AR; in particular, it is involved in tyrosine phosphorylation of sperm proteins through interaction with CaM. Research into the function of IQCF1 during fertilization could facilitate the investigation of the molecular mechanism of capacitation, which is unclear.

Isolation and characterization of recombinant Escherichia coli clones secreting a 24-kilodalton antigen of Treponema pallidum

Escherichia coli clones containing Treponema pallidum DNA in the pUC8 vector and secreting a 24-kilodalton antigen of T. pallidum have been isolated. Both syphilitic human and syphilis-immune rabbit sera reacted with the recombinant p24 antigen, indicating that an equivalent protein in T. pallidum is capable of eliciting antibody responses during natural infections. The p24 antigen of T. pallidum was identified by using two-dimensional gel electrophoresis and immunoblotting with monospecific anti-p24 serum. We tentatively concluded that this cloned antigen is a secreted protein or a labile or minor component of T. pallidum because (i) p24 was secreted by the recombinant E. coli cells; (ii) recombinant p24 in E. coli cells was processed into several smaller species with molecular masses ranging from 12 to 20 kilodaltons, which correlate well with the masses of secreted antigens described by others; and (iii) p24 protein appeared to be highly antigenic during natural infections, but only a very small amount of this antigen was associated with or retained by the purified organisms. The possible role of the p24 protein in determining the growth characteristics of T. pallidum is suggested by the ability of recombinant p24 to induce growth changes in E. coli cells. All E. coli colonies expressing the p24 polypeptide exhibited a flat and rough colony morphology and a filamentous growth pattern that were different from those of other E. coli cells. The DNA sequence coding for the p24 polypeptide is located on a 1.7-kilobase-pair BamHI fragment of the T. pallidum genomic DNA and is absent in the nonpathogenic Treponema phagedenis DNA. However, any possible relationship between the p24 antigen and the virulence of T. pallidum remains to be determined. In preliminary studies, rabbits immunized with the purified p24 were not protected from the infection with live T. pallidum organisms.

Regionally selective decreases in cerebral glucose metabolism in a mouse model of phenylketonuria

Impairment of cognitive function is characteristic of untreated phenylketonuria in humans and in the pah(enu2) mouse model of phenylketonuria. We measured regional cerebral metabolic rate for glucose in the adult male pah(enu2) mouse to determine the effect of PKU on functional activity in brain and to discern what, if any, brain areas are affected. Our results demonstrate selective decreases (17-21%) in regions thought to be involved in executive function. Regions most significantly affected include prelimbic, anterior cingulate, orbital frontal and perirhinal cortex. Sensory and motor areas of cortex and hippocampus were remarkably unaffected.

SRL1: a new locus specific to the phyB-signaling pathway in Arabidopsis

As part of an effort to isolate new Arabidopsis mutants specifically defective in responsiveness to red light, we identified srl1 (short hypocotyl in red light) by screening an EMS-mutagenized M2 population derived from a phytochrome B (phyB)-overexpressor line (ABO). The srl1 mutant shows enhanced responsiveness to continuous red but not far-red light, in both wild-type and ABO backgrounds, consistent with involvement in the phyB-signaling pathway but not that of phyA. The hypersensitive phenotype of srl1 is not due to overexpression of endogenous phyA or phyB, and the locus maps to the center of chromosome 2, distinct from any other known photomorphogenic mutants. srl1 seedlings display enhancement of several phyB-mediated responses, including shorter hypocotyls, more expanded cotyledons, shorter petioles and modestly higher levels of CAB gene expression under red light than the wild type. Double mutant analyses show that the hypersensitive phenotype of srl1 is completely phyB-dependent. The data suggest, therefore, that SRL1 may encode a negatively acting component specific to the phyB-signaling pathway.

Does alpha 1-acid glycoprotein act as a non-functional receptor for alpha 1-adrenergic antagonists?

The ability of a variety of alpha 1-acid glycoproteins (AAG) to affect the intrinsic activity of the alpha 1-adrenergic antagonist prazosin was studied in rabbit aortic strip preparations. From these studies, the activity of AAG appears to be linked to their ability to bind the antagonist. However, a capability to bind prazosin was not the only requirement for this effect. The removal of sialic acid and partial removal of the galactose and mannose residues by periodate oxidation of human AAG all but eliminated the ability of AAG to affect the intrinsic pharmacologic activity of prazosin, although the binding of prazosin was not significantly affected. The presence of bovine AAG, a protein that has a low ability to bind prazosin, reduced the effect of human AAG on prazosin activity. Based upon these results, we propose that AAG is able to bind in the vicinity of the alpha 1-adrenoceptors, therefore extending the binding region for antagonists in such a way as to decrease the ability of the antagonist to interact with the receptor. The carbohydrate side-chains are important for the binding of AAG in the region of the adrenoceptor.

A novel accurate rapid ELISA for detection of urinary connective tissue growth factor, a biomarker of chronic allograft nephropathy

BACKGROUND

Chronic allograft nephropathy (CAN) is a leading cause of kidney graft failure. The latest evidence suggests that connective tissue growth factor (CTGF) may be a biomarker of CAN. Detection of urinary CTGF levels is a potential noninvasive strategy to predict the early onset of CAN. Compared to the traditional "sandwich" enzyme-linked immunosorbent assay (ELISA), we established a novel, accurate, faster, one-step competitive indirect ELISA (Ci-ELISA) to estimate the urinary CTGF concentrations in humans, rats, and mice.

MATERIALS AND METHODS

We used recombinant human CTGF, which is an 11.2 kDa protein of 98 amino acid residues containing the C-terminal portion of the full-length CTGF protein having 96% and 94% homology with rats and mice, as the coating antigen and standard competitor. We then applied polyclonal antibody against the CTGF C-terminal portion, secondary antibody conjugated with horseradish peroxidase (HRP), and urine samples to establish one-step Ci-ELISA. Rat kidney allograft recipients were sacrificed at 4, 8, or 12 weeks posttransplantation. We harvested serum, urine, and transplanted kidneys. Hematoxylin-eosin (H&E), periodic acid-Schiff (PAS), and Masson trichrome stains were used to estimate the histopathologic changes according to the Banff schema. Serum creatinine (SCr) levels were measured to represent renal function. CTGF in kidney was detected by immunohistochemistry. Urinary CTGF concentrations were measured using the one-step Ci-ELISA.

RESULTS

The whole one-step Ci-ELISA test can be accomplished within 2 hours. The detection limit of the assay was 0.16 ng/mL CTGF. The time-dependent elevated recipient concentration of urinary CTGF was positively correlated with SCr, histologic changes, and CTGF in the kidney after transplantation. The 95% confidence intervals of urinary CTGF concentrations in control rats were 24.4 to 35.2 ng/mL; at 4, 8, and 12 weeks posttransplantation they were 139.4 to 395.6, 826.7 to 1429.5, and 3206.0 to 4448.2 ng/mL, respectively.

CONCLUSIONS

A rapid one-step Ci-ELISA was successfully established to detect the CTGF levels in urine. These results further indicated that detection of urinary CTGF is a potential noninvasive strategy to predict the early onset of CAN.