Stress distribution and induced birefringence analysis for pressure vector sensing based on single mode fibers

We propose a theoretical approach to analyze the pressure stress distribution in single mode fibers (SMFs) and achieve the analytical expression of stress function, from which we obtain the stress components with their patterns in the core and compute their induced birefringence. Then we perform a pressure vector sensing based on approximately 2 km SMF. Using Mueller matrix method we measure the birefringence vectors which are employed to compute the pressure magnitudes and their orientation. When rotating the pressure around the fiber, the corresponding birefringence vector rotates around a circle with double speed. Statistics show the average deviation of calculated pressure-magnitude to practical value is approximately 0.17 N and it is approximately 0.85 degrees for orientation.

First Report of a Leaf Spot on Snow Lotus Caused by Alternaria carthami in China

Snow lotus (Saussurea involucrata Karel. & Kir. ex Sch. Bip.) is an economically important medicinal herb increasingly grown in China in recent years. In June of 2005, a leaf spot disease on commercially grown plants was found in the QiTai Region, south of the Tianshan Mountain area of Xinjiang, China at 2,100 m above sea level. Disease incidence was approximately 60 to 70% of the plants during the 2006 and 2007 growing seasons. Initial symptoms appeared on older leaves as irregularly shaped, minute, dark brown-to-black spots, with yellow borders on the edge of the leaflet blade by July. As the disease progressed, the lesions expanded, causing the leaflets to turn brown, shrivel, and die. A fungus was consistently isolated from the margins of these lesions on potato dextrose agar. Fifty-eight isolates were obtained that produced abundant conidia in the dark. Conidia were usually solitary, rarely in chains of two, ellipsoid to obclavate, with 6 to 11 transverse and one longitudinal or oblique septum. Conidia measured 60 to 80 × 20 to 30 μm, including a filamentous beak (13 to 47 × 3.5 to 6 μm). According to the morphology, and when compared with the standard reference strains, the causal organism of leaf spot of snow lotus was identified as Alternaria carthami (1,4). Pathogenicity of the strains was tested on snow lotus seedlings at the six-leaf stage. The lower leaves of 20 plants were sprayed until runoff with conidial suspensions of 1 × 10⁴ spores mL^-1, and five plants sprayed with sterile distilled water served as controls. All plants were covered with a polyethylene bag, incubated at 25°C for 2 days, and subsequently transferred to a growth chamber at 25°C with a 16-h photoperiod. Light brown lesions developed within 10 days on leaflet margins in all inoculated plants. The pathogen was reisolated from inoculated leaves, and isolates were deposited at the Key Oasis Eco-agriculture Laboratory of Xinjiang Production and Construction Group, Xinjiang and the Institute of Biotechnology, Zhejiang University. No reports of a spot disease caused by A. carthami on snow lotus leaves have been found, although this pathogen has been reported on safflower in western Canada (3), Australia (2), India (1), and China (4). To our knowledge, this is the first report of a leaf spot caused by A. carthami on snow lotus in China. References: (1) S. Chowdhury. J. Indian Bot. Soc. 23:59, 1944. (2) J. A. G. Irwin. Aust. J. Exp. Agric. Anim. Husb. 16:921, 1976. (3) G. A. Petrie. Can. Plant Dis. Surv. 54:155, 1974. (4) T. Y. Zhang. J. Yunnan Agric. Univ.17:320, 2002.

MRI-derived T2 relaxation times and cartilage morphometry of the tibio-femoral joint in subjects with and without osteoarthritis during a 1-year follow-up

OBJECTIVE

To assess differences in magnetic resonance imaging (MRI)-based compositional (T2) and morphometric (volume and thickness) parameters of the tibio-femoral joint cartilage in subjects with and without osteoarthritis (OA) and compare these with clinical assessment tools during a 1-year follow-up.

METHOD

Three Tesla MRI of the knee joint was performed in eight female patients (body mass index [BMI]>30) with early OA and 10 age-matched female controls (BMI<30) at baseline (BL) and after 3, 6 and 12 months. Cartilage T2 maps, volume and average thickness were calculated in five compartments (medial/lateral femoral condyle, medial/lateral tibia and trochlea). These data were correlated with changes in clinical parameters and joint space width determined in standardized knee radiographs using a mixed random effects model.

RESULTS

At BL, T2 was significantly higher (P<0.05) across the cartilage in patients (45.68+/-5.17ms) compared to controls (41.75+/-4.33ms). Patients had significantly (P<0.05) less cartilage volume and less average cartilage thickness in the tibia than controls (2.10+/-0.53cm(3) vs 2.91+/-0.49cm(3) and 1.59+/-0.24mm vs 1.90+/-0.29mm, respectively). A significant change in clinical parameters of OA, cartilage T2 values or a decrease of volume and average thickness could not be demonstrated within both groups.

CONCLUSION

Significant differences between the groups indicate that both T2 and morphometric parameters may be useful in quantifying early OA related changes. In a 12-month follow-up, however, no significant alterations of the studied parameters were found, which may be due to the length of the observation interval.

Predominant basal directional release of thromboxane, but not prostacyclin, by placental trophoblasts from normal and preeclamptic pregnancies

OBJECTIVE

To investigate apical and basal releases of thromboxane (TX) and prostacyclin (PGI2) by trophoblasts (TCs) from normal and preeclamptic (PE) placentas.

METHODS

TCs isolated from normal and PE placentas were incubated in cell culture inserts for 48h. Medium from the upper (apical) and the lower (basal) chambers were then collected separately and measured for TX and PGI2 by their stable metabolites of TXB2 and 6-keto PGF1alpha by ELISA. Apical and basal releases of TX and PGI were also examined with apical exposure of TCs to arachidonic acid (AA)+/-aspirin at different concentrations. Villous tissue expressions for PGI synthase, TX synthase and TX (TP) receptor were examined by immunohistochemistry.

RESULTS

(1) TXB2, but not 6-keto PGF1alpha, concentrations were significantly higher in the lower than in the upper chambers with both normal and PE TCs (p<0.01); (2) apical exposure of TCs to AA resulted in a significant increase in TX release towards both the upper and the lower chambers in normal TCs (p<0.01), but only a significant increase in the upper chamber in PE TCs (p<0.01); (3) aspirin could attenuate AA-induced TX release both in the upper and the lower chambers in normal, but not in PE, TCs (p<0.01), respectively; (4) there were no differences in 6-keto PGF1alpha productions both in normal and PE TCs treated with AA+/-aspirin; (5) intense staining of TX synthase and TP receptor was seen in syncytiotrophoblast layer, villous core vessels and stromal cells in preeclamptic placental tissue sections.

CONCLUSION

Predominant basal release of TX together with intense staining of TX synthase and TP receptor in trophoblasts, stromal cells and villous core vessels are found in placentas from PE. We speculate if predominant basal release of TX by TCs occurs in vivo as we found in our in vitro culture condition, basal released TX may play a significant role in increased placental vasoconstriction such as in PE.

Assignment of solute carrier family 2 (facilitated glucose transporter), members <i>SLC2A2</i>, <i>SLC2A3</i>, <i>SLC2A5</i>, <i>SLC2A8</i> and <i>SLC2A12</i> to porcine chromosomes by somatic cell and radiation hybrid panel mapping (Brief report)

Abstract. The transport of glucose plays an important role in cellular glucose homeostasis and metabolism [1]. Due to the hydrophilic character of glucose, the transport of glucose in and out of cells requires specific carrier proteins. The mammalian facilitative glucose transport family, which contains the energy-independent transporters (gene symbol SLC2A, protein symbol GLUT), catalyzes the entry of glucose into mammalian cells by facilitative diffusion down a concentration gradient. Thirteen members of mammalian GLUT family have been now characterized [1]. In swine, the chromosomal locations for the five genes (SLC2A2, SLC2A3, SLC2A5, SLC2A8 and SLC2A12) have not yet been determined. In this study, as the first step to better understand of the roles of these GLUTs in pigs which could subsequently be beneficial for pig production, we report the mapping of the five genes using both porcine somatic cell hybrid panel (INRA-SCHP) and radiation hybrid panel (IMpRH).

A novel nude mice model of human extranodal nasal type NK/T-cell lymphoma

A novel nude mice model of human extranodal nasal type NK/T-cell lymphoma was established by subcutaneously implanting the sample taken from the patient with secondary extranodal nasal type NK/T-cell lymphoma of the stomach into the right axillary region of a BALB/c (nu/nu) nude mouse. This model had been successfully transplanted in vivo for thirty-two generations with a stable growth cycle. The survival rates of both resuscitation and transplantation were 100%. Histologically, the tumor cells were medium to large size and arranged in sheets, with a little mesenchyma, and disseminated almost in all passages of the lymphoma-bearing nude mice. Immunologically, the tumor cells were positive for CD56, cytoplasmic CD3, granzyme B or TIA-1 and LMP1, sometimes for CD8 but negative for surface CD3, CD7, CD20 and CD1a. EBER1/2 was found. No T-cell receptor gamma gene rearrangement was detected in the transplanted tumors. Furthermore, both human sequencing-tagged sites SY14 and Y chromosome were detected by PCR or fluorescent in situ hybridization, respectively, in the transplanted tumor. The transplanted tumor in this novel nude mice model maintained the essential features of human extranodal nasal type NK/T-cell lymphoma, and it would be an ideal tool in vivo for further research of the tumor.

Characterization of multidrug resistant Salmonella recovered from diseased animals

Three hundred and eighty Salmonella isolates recovered from animal diagnostic samples obtained from four state veterinary diagnostic laboratories (AZ, NC, MO, and TN) between 2002 and 2003 were tested for antimicrobial susceptibilities and further characterized for bla(CMY) beta-lactamase genes, class 1 integrons and genetic relatedness using PFGE. Forty-seven serovars were identified, the most common being S. Typhimurium (26%), S. Heidelberg (9%), S, Dublin (8%), S. Newport (8%), S. Derby (7%), and S. Choleraesuis (7%). Three hundred and thirteen (82%) isolates were resistant to at least one antimicrobial, and 265 (70%) to three or more antimicrobials. Resistance was most often observed to tetracycline (78%), followed by streptomycin (73%), sulfamethoxazole (68%), and ampicillin (54%), and to a lesser extent chloramphenicol (37%), kanamycin (37%), amoxicillin-clavulanic acid (20%), and ceftiofur (17%). With regards to animal of origin, swine Salmonella isolates displayed the highest rate of resistance, being resistant to at least one antimicrobial (92%), followed by those recovered from turkey (91%), cattle (77%), chicken (68%), and equine (20%). Serovars commonly showing multidrug resistance (MDR) to > or =9 antimicrobials were S. Uganda (100%), S. Agona (79%), and S. Newport (62%), compared to S. Heidelberg (11%) and S. Typhimurium (7%). Class-1 integrons were detected in 43% of all isolates, and were found to contain aadA, aadB, dhfr, cmlA and sat1 gene cassettes alone or in various combinations. All ceftiofur resistant isolates (n=66) carried the bla(CMY) beta-lactamase gene. A total of 230 PFGE patterns were generated among the 380 isolates tested using XbaI, indicating extensive genetic diversity across recovered Salmonella serovars, however, several MDR clones were repeatedly recovered from different diseased animals.

Effect of heat shock protein 47 on collagen accumulation in keloid fibroblast cells

BACKGROUND

Keloid is characterized by excessive collagen accumulation, but the mechanism of keloid formation remains unknown, and none of the treatment modalities are consistently effective. Heat shock protein (HSP) 47, known as a collagen-specific molecular chaperone, plays a critical role in collagen biosynthesis. Our previous research has demonstrated that HSP47 is highly expressed in keloid compared with normal skin tissues, which indicates that there might be a close relationship between overexpression of HSP47 and excessive collagen accumulation in keloid formation.

OBJECTIVES

To further investigate whether overexpression of HSP47 might promote excessive collagen deposition in keloid formation, we examined the alteration of intracellular and extracellular collagen expression, following inhibition of HSP47 expression in keloid fibroblast cells by the RNA interference technique.

METHODS

Three constructed psiRNA-hH1neo plasmids, carrying three pairs of related HSP47-shRNA (small hairpin RNA), respectively, were transfected into keloid fibroblast cells and compared with three control groups. After transfection, the mRNA and protein expression of HSP47 and collagen type I were detected by quantitative real-time polymerase chain reaction and Western blot; the content of extracellular secreting collagen was assessed by hydroxyproline assay; and the MTT [3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide] method was adopted to examine the proliferation of keloid fibroblast cells.

RESULTS

Both the mRNA and protein levels of HSP47 in keloid fibroblast cells decreased dramatically 48 h after post-transfection of three related HSP47-shRNA plasmids, compared with control groups. Following the downregulation of HSP47, we found that the expression of intracellular and extracellular collagen was correspondingly reduced. On the other hand, the MTT assay showed that transfection of HSP47-shRNA plasmids did not influence the growth of keloid fibroblast cells.

CONCLUSIONS

Combined with our previous histological results, we propose that overexpression of HSP47 in keloid fibroblast cells could induce excessive collagen accumulation by enhancing synthesis and secretion of collagen, which not only presents a possible mechanism of keloid formation, but also offers a therapeutic potential of RNA interference to HSP47 for the treatment of keloid and other fibroproliferative disorders.

Occurrence of Rust Caused by Puccinia carthami on Snow Lotus in China

Snow lotus (Saussurea involucrata (Kar. & Kir.) Sch. Bip.) is an economically important medicinal herb increasingly grown in China in recent years. In August 2005, a rust disease on snow lotus plants commercially grown was found in the Tianshan mountain area of Xinjiang at 2,100 m above sea level. Disease incidence was approximately 15% of the plants observed in a commercial field in 2006. At the initial stage, tiny (1 to 2 mm long), orange brown pustules are formed on leaves. Later in the season, pustules turned chestnut brown to form bigger rust patches. Severely attacked leaves may die prematurely. During the growing season, rust pustules broke open to release reddish brown spores that cause secondary infection. The infected snow lotus plants were sampled, and the urediniospores and teliospores were observed for identification with a light microscope (4). Urediniospores were globose or broadly ellipsoid, 22 to 28 × 22 to 25 μm; teliospores were slightly or not constricted at the septum, 31.5 to 41.5 × 21.5 to 26.5 μm, wall was sienna to fulvous, occasionally chestnut colored, and pedicels were basal or oblique, verrucose, hyaline, and fragile. The pathogenicity test of the fungus was done by burying five leaves bearing telia around the roots of healthy safflower seedlings grown in a greenhouse under controlled conditions (25°C and 70% relative humidity) and healthy snow lotus seedlings grown under natural conditions with five replications. Symptoms were evaluated 60 days after inoculation. Similar rust symptoms were observed on both the snow lotus and safflower seedlings (1). The pycnidial and aecial stages of this autoecious rust were not observed in nature or the pathogenicity tests. The teliospores were reisolated and deposited at the Key Oasis Eco-Agriculture Laboratory of Xinjiang Production and Construction Group, Xinjiang and the Institute of Biotechnology, Zhejiang University. The causal organism of rust of snow lotus was identified as Puccinia carthami Corda on the basis of the morphology and pathogenicity test. To our knowledge, this is the first report of this rust on snow lotus (S. involucrata) (1-4). References: (1) W. L. Bruckart. Plant Dis. 83:181, 1999. (2) M. L. Deadman et al. Plant Dis. 89:208, 2005. (3) S. J. Kolte. Diseases of annual edible oilseeds crops. In: Rapeseed-Mustard and Sesame Diseases. Vol. II. CRC Press, Boca Raton, FL, 1985. (4) G. F. Laundon. N. Z. J. Bot. 8:310, 1970.

Hepatic lipogenesis in broiler chickens with different fat deposition during embryonic development

In order to identify the genes involved in the fatness variability, we studied the expression of several genes implicated in the hepatic lipid metabolism of broiler chickens with different fat deposition patterns during embryonic development. The mRNA expression of acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), malic enzyme (ME) and apolipoprotein B100 (apoB100) genes were determined using reverse transcriptase-polymerase chain reaction (RT-PCR). Samples of livers were collected from Arbor Acres (AA) and Sanhuang (SH) chickens on day 9, 14 and 19 of embryonic development as well as at hatching. This study showed that hepatic triglyceride (TG) level was found to increase suddenly during day 14 of embryonic development, to gradually increase thereafter, and to remain relatively constant at hatching. FAS gene expression in AA and SH broilers occurred prior to hatching and at hatching. The gene was expressed more in the former breed. ACC gene expression was observed beginning at the earlier development stage of days 9. No breed difference was observed in ME and apoB gene expression. This study indicated that the expression of lipogenic enzyme genes of the liver in broiler chickens exhibited scheduling during embryogenesis. The ACC gene started to express earlier than the FAS gene during embryonic development. This suggested that embryonic liver synthesized fatty acid, and breed difference was noticed prior to hatching.

A double tyrosine phosphorylation of P68 RNA helicase confers resistance to TRAIL-induced apoptosis

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising anticancer agent with the capability of inducing apoptosis specifically in tumor cells. However, cancer cells of many cancer types developed TRAIL resistance, limiting the applications of TRAIL in cancer therapies. We show here that p68 acquires a double tyrosine phosphorylation at Y593 and Y595 in TRAIL-resistant T98G glioblastoma cells. The double phosphorylations are induced by platelet-derived growth factor autocrine loop. The double phosphorylation mediates resistance to TRAIL-induced apoptosis. Our data suggest that the phosphorylated p68 protects the cells from programmed cell death by preventing procaspase-8 from proteolytic cleavage. The double-phosphorylated p68 may also confer apoptosis resistance by upregulation of X-chromosome-linked inhibitor apoptosis protein-associated factor 1. In addition, exogenous expression of p68 mutant that carries mutations at the phosphorylation sites (Y593/595F) dramatically sensitizes TRAIL-resistant cells to TRAIL-induced apoptosis, suggesting a potential therapeutic strategy to overcome TRAIL resistance.

Selective imaging of adherent targeted ultrasound contrast agents

The goal of ultrasonic molecular imaging is the detection of targeted contrast agents bound to receptors on endothelial cells. We propose imaging methods that can distinguish adherent microbubbles from tissue and from freely circulating microbubbles, each of which would otherwise obscure signal from molecularly targeted adherent agents. The methods are based on a harmonic signal model of the returned echoes over a train of pulses. The first method utilizes an 'image-push-image' pulse sequence where adhesion of contrast agents is rapidly promoted by acoustic radiation force and the presence of adherent agents is detected by the signal change due to targeted microbubble adhesion. The second method rejects tissue echoes using a spectral high-pass filter. Free agent signal is suppressed by a pulse-to-pulse low-pass filter in both methods. An overlay of the adherent and/or flowing contrast agents on B-mode images can be readily created for anatomical reference. Contrast-to-tissue ratios from adherent microbubbles exceeding 30 dB and 20 dB were achieved for the two methods proposed, respectively. The performance of these algorithms is compared, emphasizing the significance and potential applications in ultrasonic molecular imaging.

Genetics of antimicrobial resistance

Antimicrobial resistant strains of bacteria are an increasing threat to animal and human health. Resistance mechanisms to circumvent the toxic action of antimicrobials have been identified and described for all known antimicrobials currently available for clinical use in human and veterinary medicine. Acquired bacterial antibiotic resistance can result from the mutation of normal cellular genes, the acquisition of foreign resistance genes, or a combination of these two mechanisms. The most common resistance mechanisms employed by bacteria include enzymatic degradation or alteration of the antimicrobial, mutation in the antimicrobial target site, decreased cell wall permeability to antimicrobials, and active efflux of the antimicrobial across the cell membrane. The spread of mobile genetic elements such as plasmids, transposons, and integrons has greatly contributed to the rapid dissemination of antimicrobial resistance among several bacterial genera of human and veterinary importance. Antimicrobial resistance genes have been shown to accumulate on mobile elements, leading to a situation where multidrug resistance phenotypes can be transferred to a susceptible recipient via a single genetic event. The increasing prevalence of antimicrobial resistant bacterial pathogens has severe implications for the future treatment and prevention of infectious diseases in both animals and humans. The versatility with which bacteria adapt to their environment and exchange DNA between different genera highlights the need to implement effective antimicrobial stewardship and infection control programs in both human and veterinary medicine.

Statistical study of effective anisotropy field in ordered ferromagnetic nanowire arrays

Soft ferromagnetic nanowire arrays were obtained by electrodeposition of Co-Fe-P alloy into the pores of high quality home-made anodized aluminum oxide (AAO) templates. Bath acidity and current density were the two parameters used in order to tailor the orientation of local anisotropy axes in individual nanowires. In order to quantify the influence of the induced anisotropies on the magnetization processes in individual nanowires, the in-plane magnetization loops of the arrays are modeled as log-normal distributions of Stoner-Wohlfarth transverse magnetization processes. Using the lognormal mean parameter as an approximation for the saturation applied field of the array, we compute the effective anisotropy of the nanowires, which is found to increase with the pH of the electrodeposition bath.

Functional reconstruction of maxilla with pedicled buccal fat pad flap, prefabricated titanium mesh and autologous bone grafts

The aim of this study was to evaluate the use of pedicled buccal fat pad flap (PBFPF), prefabricated titanium mesh and autologous bone graft in maxillary reconstruction. Seventeen patients with a unilateral class I-III maxillary defect were involved. Preoperatively, a solid model was manufactured based on virtual maxillectomy and reconstruction of the abnormal maxilla. Intraoperatively, PBFPF was applied to repair the soft-tissue defect, serving as nasal lining and the receiving bed for bone grafts. Titanium mesh was prefabricated on the solid model and then, together with bone grafts from iliac crest, fixed to residual bones to reconstruct the hard-tissue defect. Postoperative aesthetic appearance and function were followed up. No exposure of titanium mesh, leakage or oronasal regurgitation occurred. Of the patients with a class I or II defect 91% (10/11) and of those with a class III defect 50% (3/6) gained a good appearance. Fifteen patients were articulate. Eleven patients received dental rehabilitation and had a normal diet. PBFPF with prefabricated titanium mesh and autologous bone grafts is a reliable option for reconstruction of unilateral maxillary defects of class I and II, but this method alone should be used cautiously in defects of class III and beyond.

Comparison of multilocus sequence typing, pulsed-field gel electrophoresis, and antimicrobial susceptibility typing for characterization of Salmonella enterica serotype Newport isolates

In the United States, multidrug-resistant phenotypes of Salmonella enterica serotype Newport (commonly referred to as MDR-AmpC) have emerged in animals and humans and have become a major public health problem. Although pulsed-field gel electrophoresis (PFGE) is the current "gold standard" typing method for Salmonella, multilocus sequence typing (MLST) may be more relevant to investigations exploring evolutionary and population biology relationships. In this study, 81 Salmonella enterica serotype Newport isolates from humans, food animals, and retail foods were examined for antimicrobial susceptibility and characterized using PFGE and MLST of seven genes, aroC, dnaN, hemD, hisD, purE, sucA, and thrA. Forty-nine percent of the isolates were resistant to nine or more of the tested antimicrobials. Salmonella isolates displayed resistance most often to sulfamethoxazole (57%), streptomycin (56%), tetracycline (56%), ampicillin (52%), and ceftiofur (49%) and, to a lesser extent, to kanamycin (19%), trimethoprim-sulfamethoxazole (17%), and gentamicin (11%). A total of 43 PFGE patterns were generated using XbaI, indicating a genetically diverse population. The largest PFGE cluster contained isolates from clinically ill swine, cattle, and humans. MLST resulted in 12 sequence types (STs), with one type encompassing 62% of the strains. Ten new sequence types and one novel allele type were identified. Furthermore, MLST typing showed that strains closely related by PFGE clustered in major STs, whereas more distantly related strains were separated into two clusters by PFGE. The results of this study demonstrated that the MLST scheme employed here clustered S. enterica serovar Newport isolates in distinct molecular populations, and strain discrimination was enhanced by combining PFGE, antimicrobial susceptibility, and MLST results.

Armored RNA as positive control and standard for quantitative reverse transcription-polymerase chain reaction assay for rubella virus

RV Armored RNA constructed in the laboratory was shown to be resistant to RNase and DNase digestion. It could remain stable at 4 degrees C for at least 60 days, and was much more stable than RV strain TR23 [corrected] in normal human plasma. Therefore it could be used as stable, well-characterized positive control and standard for quantitative RT-PCR assay.

Transcatheter closure of patent ductus arteriosus with severe pulmonary arterial hypertension in adults

BACKGROUND

Surgical closure of patent ductus arteriosus (PDA) with severe pulmonary arterial hypertension in adults carries higher risk than in children.

OBJECTIVES

To investigate the application of self-expandable occluders for transcatheter closure of PDA associated with severe pulmonary arterial hypertension in adults, and the assessment of immediate and short-term results.

METHODS

29 adult patients (6 men, 23 women) underwent attempted transcatheter closure of PDA at a mean (standard deviation (SD)) age of 31.1 (11.4) years (range 18-58 years) and a mean (SD) weight of 54.1 (7.1) kg (range 42-71 kg). On the basis of haemodynamic and clinical data obtained before and after trial occlusion, the final duct occlusion was determined and carried out. Radiographs of the chest, electrocardiograms and echocardiograms were used for follow-up evaluation of the treatment within 1 day, 1 month and 3-6 months after successful closure.

RESULTS

20 of the 29 patients had successful occlusion (group 1), and 9 patients failed (named group 2). In group 1, in which occlusion was successful, mean (SD) pulmonary arterial pressures decreased markedly after trial occlusion: 78 (19.3) mm Hg (range 50-125 mm Hg) before occlusion and 41 (13.8) mm Hg (range 23-77 mm Hg) after occlusion. Systemic arterial oxygen saturation was found to be >90% in 19 patients and <90% in the remaining patient before inhalation of oxygen, and >95% during inhalation of oxygen or after occlusion in all 20 patients. In group 2, the occlusion was not successful, because in two patients the device was not available; another two patients showed worsening of symptoms. The other five patients showed increased pulmonary arterial pressures after trial closure; their mean (SD) pulmonary arterial pressures increased by 10.3 (6) mm Hg (4-16 mm Hg) after trial occlusion, and systemic arterial oxygen saturation was 85.5% (2.6%) (range 82.6-88%) before inhalation of oxygen and 94.7% (1.7%) (range 90.7-99.1%) during inhalation of oxygen. In group 1, the dimensions of the left atrium, left ventricle and pulmonary artery increased considerably in 3-6-months of follow-up compared with those of preocclusion.

CONCLUSIONS

Transcatheter closure is an effective treatment for adults with PDA associated with reversible severe pulmonary arterial hypertension. Further research is needed for the evaluation of long-term results.

Nucleostemin mRNA is expressed in both normal and malignant renal tissues

Nucleostemin (NS), a p53-binding protein, has been shown essential for stem and cancer cell proliferation and implicated in oncogenesis. To explore potential contributions of NS to the development of clear cell renal cell carcinomas (ccRCCs), we determined NS expression in ccRCC cell lines, and in paired normal and malignant renal tissues from 31 patients with ccRCC. Nucleostemin mRNA and/or protein expression was observed in all four cell lines and 27 of 31 (87%) tumour specimens. Surprisingly, 16 of 31 (52%) adjacent normal renal samples also expressed NS mRNA and its levels in four of them were comparable with those in paired tumour tissues. Three of the patients had detectable NS mRNA in their normal renal tissues whereas lacked its expression in the matched tumours. Compared to the oncogene c-MYC expression in these same samples, NS expression showed a much less specificity for ccRCC. We further demonstrated that NS mRNA expression was closely associated with cellular proliferation in normal fibroblasts or T lymphocytes and renal cell carcinoma cell lines. Collectively, NS expression widely occurs in normal and malignant renal tissues, and is likely a proliferation marker rather than a unique regulator of cell proliferation and survival in stem and cancer cells.

Intelligent compensation of friction, ripple, and hysteresis via a regulated chatter

In this paper, a hybrid control scheme utilizing a PID feedback control with an additional regulated chatter signal is developed to compensate motion impeding influences such as the effects due to friction, force ripples, and hysteresis in linear piezoelectric motor. The regulated chatter signal is a pulse sequence superimposed on the PID control signal. It has a fixed amplitude, and a pulse width regulated via iterative learning control. As such, the scheme is expected to be useful for applications involving iterative motion sequences. An analysis of the closed-loop performance is presented in the paper. Simulation and experimental results are also furnished to demonstrate that the proposed control scheme can reduce tracking errors significantly.