Genetic diversity and relationships among Chinese Eucommia ulmoides cultivars revealed by sequence-related amplified polymorphism, amplified fragment length polymorphism, and inter-simple sequence repeat markers

Sequence-related amplified polymorphism (SRAP), amplified fragment length polymorphism (AFLP), and inter-simple sequence repeat (ISSR) markers were used to estimate the genetic diversity and relationships among Eucommia ulmoides cultivars in China. A total of 240, 192, and 150 DNA fragments were detected by 10 SRAP primer combinations, 10 AFLP primer combinations, and 10 ISSR primers, among which 89.2, 65.1, and 88.0% of the fragments were polymorphic, respectively. Cluster analysis revealed that Qinzhong No. 3, Xiaoyeci, Qinzhong No. 1, and Qinzhong No. 2 formed independent clusters. The other 15 cultivars exhibited two clusters. The results of this study will help in the selection of parents for both genome mapping and crossbreeding purposes.

Relationship between progeny growth performance and molecular marker-based genetic distances in Eucommia ulmoides parental genotypes

Progeny performances, variations and combining abilities for growth traits were evaluated in a factorial mating design of Eucommia ulmoides. Three marker systems, sequence-related amplified polymorphism, amplified fragment length polymorphism, and inter-simple sequence repeat, were used to determine genetic distances between parents. Correlations of genetic distances with progeny performances, within-family coefficients of variation and specific-combining abilities were established for height and basal diameter traits. Significant positive correlations were found between progeny performances of growth traits and genetic distances of parents based on sequence-related amplified polymorphism markers or a combination of all 3 marker systems. This revealed that crosses between genetically distant parents produced progenies with excellent growth performances. The lack of correlations between parental genetic distances and within-family coefficients of variation or specific-combining abilities suggested that these characteristics were unpredictable. The results of this study represent a potential criterion to predict progeny performances and choose parents in the breeding program.

Expression of ERCC1 and BRCA1 predict the clinical outcome of non-small cell lung cancer in patients receiving platinum-based chemotherapy

We examined mRNA expression levels of ERCC1, BRCA1, RRM1, and human β-tubulin-III (TUBB3) in non-small-cell lung carcinoma (NSCLC) patients and investigated the association between expression of these genes and the clinical outcome of NSCLC treatment. A total of 366 patients who underwent surgery for NSCLC were included in this study. All patients received third-generation platinum-based chemotherapy as first-line treatment. The relative cDNA quantification for ERCC1, RRM1, BRCA1, and TUBB3 was determined using a fluorescence-based, real-time detection method. We found that low expression of ERCC1 and BRCA1 was associated with a good response to platinum-based chemotherapy, with an odds ratio [95% confidence interval (CI)] of 2.09 (1.33-3.27) and 2.92 (1.85-4.62), respectively. Multivariate Cox regression analysis indicated that patients with low expression of ERCC1 and BRCA1 attained a longer overall survival time than those with high expression, with a hazard ratio (95%CI) of 0.42 (0.23-0.77) and 0.39 (0.21-0.71), respectively. However, RMM1 and TUBB2 expressions were not correlated with clinical outcome of NSCLC. In conclusion, we found that low expression of ERCC1 and BRCA1 can be useful for selecting NSCLC patients who would benefit from chemotherapy and warrants further investigation in prospective studies.

Targeting heterochromatin formation to transposable elements in Drosophila: potential roles of the piRNA system

Successful heterochromatin formation is critical for genome stability in eukaryotes, both to maintain structures needed for mitosis and meiosis and to silence potentially harmful transposable elements. Conversely, inappropriate heterochromatin assembly can lead to inappropriate silencing and other deleterious effects. Hence targeting heterochromatin assembly to appropriate regions of the genome is of utmost importance. Here we focus on heterochromatin assembly in Drosophila melanogaster, the model organism in which variegation, or cell-to-cell variable gene expression resulting from heterochromatin formation, was first described. In particular, we review the potential role of transposable elements as genetic determinants of the chromatin state and examine how small RNA pathways may participate in the process of targeted heterochromatin formation.

First Report of Corynespora Leaf Spot Caused by C. cassiicola on Golden Vicary Privet (Ligustrum × vicaryi) in China

Golden vicary privet (Ligustrum × vicaryi Rehd.), a hybrid between L. ovalifolium 'Aureum' Rehd. and L. vulgare L., is widely used as a landscape shrub for horticultural ornamentation. From 2009 to 2011, a leaf spot disease of L. × vicaryi was observed in the parks in Luoyang, Henan Province, China. Lesions were initially brown and punctiform, and with age the lesions turned into elliptic, subcircular to irregular and pale brown, faintly zonate, and depressed. Fully mature lesions were mostly irregular to circular, 5 to 15 mm in diameter, centers tan to dark brown, with reddish brown to reddish purple margins of varying width. The disease eventually caused substantial premature defoliation. After infected leaves were collected from parks and maintained in a humid atmosphere, a layer of black mold developed on the surface of the lesions. Conidiophores were cylindrical, straight to slightly curved, brown, unbranched (2 to 7 septa), and were 98.5 to 403.9 μm in length, 4.5 to 6.6 μm in width. Conidia were solitary or in short chains containing two to five spores, and were cylindrical or obclavate, straight or flexuose (3 to 19 pseudosepta), pale olivaceous brown or brown when mature, and were 78.8 to 315.2 μm in length by 5.3 to 12.3 μm in width. Morphological characteristics of the fungus were similar to those of Corynespora cassiicola (Berk. & Curt.) Wei (1). Lesions on leaves were excised, surface sterilized, and plated on potato dextrose agar (PDA) and incubated at 25°C for 2 to 3 days. A fungus was isolated from the lesions, and pure isolates that were obtained after from single spored isolates were cultured on PDA. Colonies on PDA formed concentric growth rings, abundant aerial mycelia, and were grey or dark brown in color. The isolate ST1 was selected as a representative for molecular identification. The ITS1-5.8S-ITS2 region of the isolate was amplified by PCR with primers ITS1/ITS4 (3) and sequenced. BLAST analysis of the 559 bp amplicon (GenBank Accession No. KC138855) indicated 100% sequence similarity with C. cassiicola (GU138988) (2). To validate Koch's postulates, pathogenicity tests were performed by spraying leaves of five healthy potted L. vicaryi with a 10⁶ conidia per ml aqueous suspension. Control plants were inoculated with sterile water. Plants were covered with plastic bags for 24 h after inoculation and maintained at 25°C. After 3 days, all inoculated plants showed typical symptoms, whereas water sprayed controls remained healthy. C. cassiicola was consistently reisolated from these lesions. The reisolated conidia showed the same morphological characteristics as described above. To our knowledge, this is the first report of leaf spot caused by C. cassiicola on L. × vicaryi in China. Its confirmation is a significant step toward management recommendations for growers. References: (1) M. B. Ellis et al. Corynespora cassiicola. CMI Descriptions of Pathogenic Fungi and Bacteria, no. 303. Commonwealth Mycological Institute, Kew, UK, 1971. (2) X. B. Liu et al. Plant Dis. 94:916, 2010. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

Polymorphisms of the PNPLA3 gene and their associations with chicken growth and carcass traits

1. An F(2) resource population of Gushi chickens crossed with Anka broilers was used to investigate the genetic effects of the chicken PNPLA3 gene on growth and adipose accumulation. 2. Associations between three SNPs (g.40006G > T, g.42344T > C and g.42404A > T) and broiler traits were determined using linkage disequilibrium, haplotype construction and association analysis. 3. The g.40006G > T mutation was associated with body weights at 4, 6, 8, 10 and 12 weeks of age, carcass weight, evisceration weight and semi-evisceration weight (P < 0.05). 4. Haplotypes of the g.42344T > C and g.42404A > T mutations were associated with body weight at 12 weeks, carcass weight, evisceration weight, and semi-evisceration weight (P < 0·05) and were associated with significant dominance effects. 5. The results suggest that the PNPLA3 gene may be in linkage with the causative mutation or a QTL controlling growth traits in chickens. In contrast to human studies, the polymorphisms were not associated with fat related traits.

Protein-losing enteropathy and premature ovarian failure in a young woman with systemic lupus erythematosus

Protein-losing enteropathy (PLE) and autoimmune oophoritis are unusual manifestations of systemic lupus erythematosus (SLE). Autoimmune oophoritis may result in menstrual disturbance and spontaneous premature ovarian failure. However, there is no validated examination to confirm the diagnosis and it is easily neglected in patients with ovarian insufficiency. A 31-year-old woman with SLE presented with PLE and autoimmune oophoritis during the long course of flares and remissions in her lupus activity. The synchronism implied the association between the two. Moreover, both conditions simultaneously had a good response to cyclosporine A (CsA) therapy.

Hemodynamics of portal venous stenosis before and after treatment in pediatric liver transplantation: evaluation with Doppler ultrasound

AIM

The aim of this study was to evaluate portal vein stenosis (PVS) in pediatric liver transplantation (PLT) using Doppler ultrasound (DUS) before and after interventional management for hemodynamic changes.

MATERIALS AND METHODS

From 2000 to 2010, we encountered 11 PVS cases among 180 PLT that were evaluated using DUS and computed tomography (CT) angiography (CTA); all underwent portal stenting. DUS was used to monitor portal hemodynamics. For the diagnosis of PVS, we investigated multiple parameters including stenotic size (SS), stenotic ratio (SR) (SR [%]=PRE-SS/PRE [PRE=stenotic size]), portal flow velocity ratio (VR) (VR=VS/PRE [PRE=velocity at prestenotic site; VS=peak velocity at stenotic site]), spleen size, and platelet count.

RESULTS

The incidence of PVS was 5.6% (11/180). The PV was 2.5 mm using DUS and 2.7 mm using CTA. The average SR was 65% fitting the criterion. Low prestenotic portal flow<12 cm/sec and high peak velocity in the stenotic segment (up to 147 cm/sec) were observed in 6 cases. The VR value was high at 7.5:1 and there was splenomegaly with thrombocytopenia. After portal vein stenting, hyperperfusion occurred might after reopening the stenosis: the flow increased to an average of 34 cm/sec and then flow decreased slowly to a stable level 2 weeks later. The size of the spleen decreased from 17 to 12 cm and the thrombocytopenia also improved with platelet counts increasing from 67×10(3) to 178×10(3)/μl at 2 months follow-up. The changes in portal flow, portal vein size, spleen size, and platelet count were significant (P<.05).

CONCLUSION

PVS is diagnosed using DUS by increased intrahepatic PV dilatation, peak flow at the stenotic site, discrepant VR. Early portal stenting showed a better prognosis. DUS is essential and effective for hemodynamic monitoring and management of PVS.

Genotoxicity of fenpropathrin and fenitrothion on root tip cells of Vicia faba

The genotoxicity of fenpropathrin and fenitrothion on root tip cells of Vicia faba was studied. The symptoms were investigated about the mitotic index, the micronucleus frequency and chromosomal aberration frequency of root tip cells of Vicia faba which were induced by different concentrations of fenpropathrin and fenitrothion (1 × 10(-10)-1 × 10(-2) g L(-1)). Results showed that fenpropathrin and fenitrothion could induce the micronucleus of root tip cells of Vicia faba. It occurred in a dose-dependent manner. Peaks were observed at 1 × 10( -6) g L(-1) fenpropathrin and 1 × 10(-4) g L(-1) fenitrothion, and micronucleus frequency reached 14.587 ± 1.511‰ and 14.164 ± 1.623‰, respectively. From 1 × 10(-10) g L(-1) to 1 × 10( -6) g L(-1) fenpropathrin and 1 × 10(-4) g L(-1) fenitrothion, the micronucleus frequency increased with the increase of the concentrations, but beyond this range, the micronucleus frequency decreased with the further increase of the concentrations. A similar trend was observed for mitotic index. Moreover, fenpropathrin and fenitrothion could induce various types of chromosome aberration, such as lagging chromosomes, chromosome fragment, chromosome bridge, multipolar, nuclear buds, karyorrhexis, etc.

Comparable efficacy of self-monitoring of quantitative urine glucose with self-monitoring of blood glucose on glycaemic control in non-insulin-treated type 2 diabetes

AIM

To assess whether self-monitoring of quantitative urine glucose or blood glucose is effective, convenient and safe for glycaemic control in non-insulin treated type 2 diabetes.

METHODS

Adults with non-insulin treated type 2 diabetes were recruited and randomized into three groups: Group A, self-monitoring with a quantitative urine glucose meter (n = 38); Group B, self monitoring with a blood glucose meter (n=35); Group C, the control group without self monitoring (n=35). All patients were followed up for six months, during which identical diabetes care was provided.

RESULTS

There was a significant decrease in HbA1c within each group (p < 0.05). At the study conclusion, mean changes in HbA1c from baseline were -1.9% for Group A, -1.5% for Group B and -1.0% for Group C, and the proportion of patients achieving HbA1c ≤ 6.5% were 38.9%, 35.3% and 20.0% respectively. However, no significant differences between the groups were found. The average monitoring frequency was significantly higher in Group A than in Group B. The incidence of hypoglycaemia and quality of life scores were similar between the groups.

CONCLUSIONS

This study suggests that self-monitoring of urine glucose has comparable efficacy on glycaemic control, and facilitates better compliance than blood self monitoring, without influencing the quality of life or risk of hypoglycaemia.

Responses of bioaugmented ryegrass to PAH soil contamination

The physiological and biochemical responses of ryegrass (Lolium multiflorum) to PAH induced stress in soils contaminated with phenanthrene and pyene were investigated, in the presence of PAH-degrading bacteria (Acinetobacteria junii) or arbuscular mycorrhizal fungi (AM fungi, Glomus mossae). The parameters monitored included chlorophyll content, chlorophyll a/b ratio, soluble-carbohydrate content, soluble-protein, malondialdehyde and electrolyte leakage, and superoxide dismutase (SOD) and peroxidase (POD) activities. Ryegrass showed good resistance and acclimation to PAH stress in soil, however, PAH contamination resulted in adverse effects such as damage of photosynthetic function and acceleration of shoot senescence. At PAH level of 100 mg kg(-1), chlorophyll contents were 14% lower than control (no PAH). Activities of SOD and POD were more sensitive indicators of PAH stress as compared to other parameters. However, all parameters showed trends based on either the bioaugmentation of the plants or PAH treatment level. It was concluded that the inoculation of AMF and PAH-degrading bacteria, especially the former, have a positive effect on alleviation of PAH toxicity to ryegrass plants. Furthermore, the inoculation of AMF increased the shoot and biomass of ryegrass by 11-19% and 18-78%, respectively. Bioaugmented ryegrass plants show promise as a host plants in the phytoremediation of PAH contaminated soils.

Association of androgen receptor CAG repeat polymorphism with VO₂max response to hypoxic training in North China Han men

The purposes of this study were to investigate the distribution characteristics of CAG repeat polymorphism in exon 1 of androgen receptor gene and the association of CAG polymorphism with VO₂max response to hypoxic training in North China Han men. Sixty-five healthy young men completed a 30-day HiHiLo training (living high, exercise high and training low) in a simulated normobaric hypoxic environment. All subjects slept in 14.3-14.8% O₂ concentration, and participated in hypoxic training three times a week in 15.4% O₂ concentration. VO₂max (peak oxygen consumption) and body weight were measured before and after hypoxic training. A total of 15 repeat alleles were observed by CAG genotype analyze, in which (CAG)22 was most common. When using 21 and 22 alleles, respectively, as cut-off points, we found that the baseline body weight of two shorter genotype groups was significantly lower than that of longer ones, and that the ΔVO₂max and ΔrVO₂max (Δrelative value of VO₂max) of two shorter genotype groups were significantly higher than those of longer ones after hypoxic training. These findings indicated that AR CAG repeat polymorphism was associated with the exercise performance after simulated normobaric hypoxic HiHiLo training in North China Han men, and that the shorter genotypes had a better individual response to hypoxic training.

THE PROBLEM OF THE SIGNIFICANCE OF THE INCLUSION BODIES FOUND IN THE SALIVARY GLANDS OF INFANTS, AND THE OCCURRENCE OF INCLUSION BODIES IN THE SUBMAXILLARY GLANDS OF HAMSTERS, WHITE MICE, AND WILD RATS (PEIPING)

1. Acidophilic intranuclear inclusion bodies occur in the salivary glands of Chinese infants dying from miscellaneous causes. The lesion is similar to that previously described in infants in Europe and America. 2. Attempts to prove that this lesion is due to an infectious agent by its production in animals have been unsuccessful. 3. Acidophilic intranuclear inclusion bodies have been found in the submaxillary glands of hamsters, white mice, and wild rats. 4. Evidence is presented to show that the lesion in hamsters, white mice, and wild rats is due to a virus, which is specific for each species, being transmissible to normal individuals of this breed, and which is very similar to the submaxillary gland virus of guinea pigs.

Rapid determination of transgene copy number in tobacco by competitive PCR using a pair of SSR primers

We developed a straightforward, rapid, and inexpensive method to determine transgene copy number in tobacco. The plasmid (pSSRCopy) used for tobacco transformation contains a simple sequence repeat (SSR) locus, PT1199, which was partially deleted in the middle, a homogenous SSR locus in tobacco K326. A 168-bp segment of the cloned PT1199 was shortened to 95 bp by deleting a 73-bp internal fragment. Using a pair of SSR primers, competitive PCR was amplified from genomic DNA from transgenic tobacco harboring pSSRCopy, and the two expected bands were found. The 168-bp band (SSR-168) corresponds to endogenous PT1199 and the 95-bp band (SSR-95) comes from the integrated pSSRCopy. A single copy of a transgene can be easily distinguished from multiple copies by comparing band densities.

Alleviation effect of alginate-derived oligosaccharides on Vicia faba root tip cells damaged by cadmium

Cadmium has been shown to prevent Vicia faba growth by inhibiting cell mitosis. In this study we investigated the role of Alginate-derived Oligosaccharides (ADO) in alleviating Vicia faba root tip cells damaged by 6 and 8 mg L(-1) CdCl2. Micronucleus assay and chromosomal aberration assay were used to determine mitotic index, micronucleus frequency and chromosomal aberration frequency. The results showed that micronucleus frequency of Vicia faba root tip cells was inhibited under all the ADO concentrations. Especially, the inhibition ratio of 0.125% ADO highly reached 66.11 and 67.17% in 6 and 8 mg L(-1) CdCl2, respectively. Furthermore, the mitotic index increased (p < 0.05) and chromosomal aberration frequency decreased (p < 0.05) under all the ADO concentrations. This indicated that ADO had a significant alleviation effect on Vicia faba root tip cells damaged by cadmium.

Identification of immune responsible fibrinogen beta chain in the liver of large yellow croaker using a modified annealing control primer system

In this article, we used a modified ACP system (mACP) developed in our laboratory to analyze differentially expressed genes in the liver of large yellow croaker, Pseudosciaena crocea (Richardson). By using 20 pairs of mACPs, 7 differentially expressed genes were obtained. One of the genes we identified encodes for a fibrinogen beta chain (FGB). The full-length cDNA of FGB was 1645 bp, including 5 bp of 5' untranslated region (5'-UTR), 1479 bp of open reading frame (ORF), and 161 bp of 3'-UTR. The ORF was capable of encoding 492 amino acids with an estimated molecular mass of 55.6 kDa, giving it a predicted pI of 5.94. The deduced amino acid sequence included an FGB profile (V(238)-Y(488)) and an FGB family signature (WWYNRCHSANPNG). Multiple sequence alignments indicated that the large yellow croaker FGB showed homology with FGB sequences of other species (45-77% identity). Real time PCR analysis demonstrated that the expression of FGB in the liver of large yellow croaker injected with Vibrio parahaemolyticus was significantly (P < 0.05) lower than that of the control group at 8 d, which confirmed the expression patterns of the results of mACP differential display.

Anhedonia and activity deficits in rats: impact of post-stroke depression

Animal models may allow investigation into the aetiology and treatment of various human disorders. In the present study, a rat model for post-stroke depression (PSD) has been developed using middle cerebral artery occlusion (MCAO), followed by an 18-day chronic mild stress (CMS) paradigm in conjuncture with isolation rearing. The open-field test (OFT) and the sucrose consumption test were used to assess depression-like behaviour and the effects of the antidepressant citalopram. CMS induced behavioural changes in the ischemic animals, including decreased locomotor and rearing activity and reduced sucrose preference (compared with baseline, control and stroke groups respectively), all these behaviours were reversed by chronic administration of citalopram. During the recovery period for the PSD models, the open-field activity and preference for sweet sucrose solution decreased continually, opposed to rats subjected to stress only. Decreased locomotor and rearing represents activity deficits, whereas reduced sucrose preference may indicate desensitisation of the brain reward mechanism (anhedonia). Our findings suggest that anhedonia, one of the core symptoms in patients with PSD, and activity deficits can be found in the MCAO+CMS group of animals. Furthermore, citalopram can ameliorate the behavioural abnormalities observed in these animals. With high validity, good operability and repeatability, our findings suggest that the ischemic rat CMS model is an appropriate model for further PSD research.

A liquid-filled tunable double-focus microlens

A novel microlens design with tunable double-focus is presented. It is fabricated by adding only one SU-8 photolithography step to the well-developed liquid-filled microlens fabrication process. The thickness of this layer determines the thickness difference between the central and peripheral region of the membrane, the deformation of which is used to define the surface profile of the microlens. The stepped thickness variation is finally manifested as the difference in deformation contour at two different regions of the membrane when subjected to uniform applied pressure, thereby causing two focal lengths to appear. Experimental and simulation results are presented, from which the tunability of the focal lengths of the double-focus microlens is demonstrated to be effective over a wide range through combining the structural design with pressure control. The successful demonstration of this unconventional microlens design concept will potentially extend t application of liquid-filled microlens technology.

The impact of clinical risk factors in the conversion from acute lung injury to acute respiratory distress syndrome in severe multiple trauma patients

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are different stages of the same disease, the aggravated stage of ALI leading to ARDS. Patients with ARDS have higher hospital mortality rates and reduced long-term pulmonary function and quality of life. It is, therefore, important to prevent ALI converting to ARDS. This study evaluated 17 risk factors potentially associated with the conversion from ALI to ARDS in severe multiple trauma. The results indicate that the impact of pulmonary contusion, APACHE II score, gastrointestinal haemorrhage and disseminated intravascular coagulation may help to predict conversion from ALI to ARDS in the early phase after multiple-trauma injury. Trauma duration, in particular, strongly impacted the short- and long-term development of ALI. Being elderly (aged > or = 65 years) and undergoing multiple blood transfusions in the early phase were independent risk factors correlated with secondary sepsis, deterioration of pulmonary function and transfusion-related acute lung injury due to early multiple fluid resuscitation.

Aberrant gene expression in deceased transgenic cloned calves

Several transgenic cloned species have been obtained; however, the efficiency of transgenic cloning remains very low, even lower than cloning. Many experiments have demonstrated abnormal growth and development, and inappropriate gene expression in cloned animals. In this study, we examined the expression of 19 development-related genes in lungs of three normal controls and three aberrant transgenic cloned calves. Results showed in transgenic cloned calves, 84.2% genes had decreased expression levels, however, 5.3% genes had increased levels. This study suggests transgenic cloning and the aberrant expression would cause abnormal growth and development in transgenic cloned calves. To our knowledge, this is the first time that gene expression was examined in transgenic cloned cattle. These findings may have some implications in understanding the low efficiency of the transgenic cloning.

Differential gene expression of aldolase C (ALDOC) and hypoxic adaptation in chickens

Two sequence variants of the aldolase C (ALDOC) gene were discovered based on comparison of the sequences from an altiplano chicken breed (Tibetan chicken) and two lowland breeds (White Leghorn and ShouGuang). Gel-shift results indicated that one of these variants, L25375:c.310-258G>A, was able to bind hypoxia-induced factor-l (HIF1A), therefore, functioning as a hypoxia response element (HRE). The combined activity of the HRE and HIF1A could increase under the influence of a hypoxic stimulus. Hypoxia leads to increased death rates of chicken embryos, while the L25375:c.310-258G>A described herein is prevalent in healthy embryos grown under hypoxic conditions. Fluorescence quantitative real-time PCR results revealed that HIF1A upregulated the transcript level of the glycolytic enzyme ALDOC in the brain and skeletal muscle of animals subjected to hypoxia. Thus, a large amount of ATP is produced by increased glycolysis, allowing the organism to meet energy metabolism demands. As such, we believe this sequence variant is an adaptation to external anoxic environment.

Paraneoplastic Pemphigus and Bronchiolitis Obliterans in a Patient with Splenic B-cell Lymphoma

Paraneoplastic pemphigus (PNP), also called paraneoplastic autoimmune multiorgan syndrome, is a rare disorder associated with underlying neoplasia. The common underlying neoplasms include non-Hodgkins lymphoma, chronic lymphocytic leukemia, and Castlemans disease. Though B-cell lymphoma is the most common underlying malignancy, only one case associated with splenic B-cell lymphoma has been recognized. The prognosis of PNP is very poor, and PNP-associated bronchiolitis obliterans (BO) is not uncommon. Herein, we report a 44-year-old woman who initially presented with multiple oral ulcers, conjunctivitis, and numerous cutaneous blisters. Serial workup established the diagnosis of PNP and revealed an underlying splenic B-cell lymphoma. Although the mucocutaneous lesions gradually healed after splenectomy and chemotherapy, deteriorating respiratory function developed 7 months later with pathologically proven BO. She finally succumbed to respiratory failure 12 months after presentation despite intensive respiratory care.

Monitoring release of ketoprofen enantiomers from biodegradable poly(d,l-lactide-co-glycolide) injectable implants

A stereoselective reversed-phase HPLC assay was developed that could simultaneously quantify S-(+) and R-(-) enantiomers of ketoprofen in release samples. Racemic ketoprofen (rac-KET) and its S-(+) enantiomer (S-(+)-KET) were dissolved in an injectable viscous polymer solution consisting of the biodegradable poly(D,L-lactide-co-glycolide, 70:30) (D,L-PLG) and a solvent, N-methyl-2-pyrrolidone (NMP). Once injected into an aqueous environment, the polymeric mixture solidified into a solid implant due to the leaching of NMP. In vitro release studies show that such implants with ketoprofen can provide sustained release of the drug lasting about three months in a pH 7.4 release medium. Moreover, a preferential faster S-(+)-KET release over R-(-)-KET was observed for the implants containing 4%, 7%, and 10% of racemic ketoprofen in the neutral pH 7.4 release medium. Stereoselective release was minimal in the first 42 days in vitro but became very pronounced at later time points. When S-(+)-KET was incorporated into the polymeric mixture, its release was also faster than that of the racemic ketoprofen, confirming the stereoselective release of ketoprofen from the d,l-PLG implants. The observed stereoselective release of KET at pH 7.4 was most likely produced by chiral interactions between KET enantiomers and transiently produced D-lactic acid or L-lactic acid rich domains within the implants during D,L-PLG degradation. However, such stereoselective release was not observed in pH 10.0 release medium, probably due to a much faster and homogeneous polymer degradation. The study suggests possible stereoselective release of racemic drugs from D,L-PLG microspheres and implants in vivo.

Liver graft-to-recipient spleen size ratio as a novel predictor of portal hyperperfusion syndrome in living donor liver transplantation

Portal hyperperfusion in a small-size liver graft is one cause of posttransplant graft dysfunction. We retrospectively analyzed the potential risk factors predicting the development of portal hyperperfusion in 43 adult living donor liver transplantation recipients. The following were evaluated: age, body weight, native liver disease, spleen size, graft size, graft-to-recipient weight ratio (GRWR), total portal flow, recipient portal venous flow per 100 g graft weight (RPVF), graft-to-recipient spleen size ratio (GRSSR) and portosystemic shunting. Spleen size was directly proportional to the total portal flow (p = 0.001) and RPVF (p = 0.014). Graft hyperperfusion (RPVF flow > 250 mL/min/100 g graft) was seen in eight recipients. If the GRSSR was < 0.6, 5 of 11 cases were found to have graft hyperperfusion (p = 0.017). The presence of portosystemic shunting was significant in decreasing excessive RPVF (p = 0.059). A decrease in portal flow in the hyperperfused grafts was achieved by intraoperative splenic artery ligation or splenectomy. Spleen size is a major factor contributing to portal flow after transplant. The GRSSR is associated with posttransplant graft hyperperfusion at a ratio of < 0.6.

Prediction of heat-induced collagen shrinkage by use of second harmonic generation microscopy

Collagen shrinkage associated with denaturation from thermal treatment has a number of important clinical applications. However, individualized treatment is hindered by the lack of reliable noninvasive methods to monitor the process of collagen denaturation. We investigate the serial changes of collagen denaturation from thermal treatment of rat tail tendons at 58 degrees C by use of second harmonic generation (SHG) microscopy. We find that rat tail tendon shrinks progressively from 0 to 9 min of thermal treatment, and remains unchanged in length upon further thermal treatment. The SHG intensity also decreases from 0 to 9 min of thermal treatment and becomes barely detectable from further thermal treatment. Collagen shrinkage and the SHG intensity are well correlated in a linear model. In addition, SHG imaging reveals a tiger-tail-like pattern of collagen denaturation. The bands of denatured collagen progressively widen from increased thermal treatment and completely replace the adjacent bands of normal collagen after 9 min of thermal treatment. Our results show that collagen denaturation in rat tail tendon from thermal treatment is inhomogeneous, and that SHG intensity can be used to predict the degree of thermally induced collagen shrinkage. With additional development, this approach has the potential to be used in biomedical applications.

Dual activities of human prolidase

The cDNA encoding human liver prolidase derived from a healthy adult's liver was cloned into the expression vector pPIC9K of Pichia pastoris to construct the recombination expression vector pPIC9K-P. The pPIC9K-P was digested by restriction enzyme Pme I, and then transformed into P. pastoris GS115 by electroporation. Transformants (the insertion recombinant) were induced by methanol to express the recombination protein. The optimal induction conditions (medium pH, methanol concentration and induction time) of the insertion transformant with the highest enzymatic activity were estimated by orthogonal experimental design L9(3(4)). The SDS-PAGE of the recombinant human prolidase (rh-prolidase) in induction medium showed a molecular weight of 73 kDa. The activities of the rh-prolidase and organophosphoric acid anhydrolases (OPAA) were assayed by colorimetric methods. The recombinant enzyme catalyzed the hydrolysis of organophosphorous compound soman as well as the hydrolysis of dipeptide Gly-Pro. Under the optimal induction conditions, the maximal activities of prolidase and OPAA came to 44.1 and 54.8 nmol/min/mg protein respectively in the medium supernatant. The rh-prolidase purified from the supernatant by ion exchange gradient chromatography (DEAE-Sepharose Fast Flow) and gel filtration chromatography (Sephacryl S-200 High Resolution) showed a single band by SDS-PAGE analysis. The purified rh-prolidase could decompose soman via hydrolytic reaction in vitro.

Controlled release of levonorgestrel from biodegradable poly(D,L-lactide-co-glycolide) microspheres: in vitro and in vivo studies

Poly(D,L-lactide-co-glycolide) (PLG) biodegradable microspheres containing a contraceptive drug, levonorgestrel (LNG), were prepared using both the solvent evaporation method and a modified solvent extraction-evaporation method. The microspheres prepared with the solvent evaporation process had porous surfaces with low product yields and poor encapsulation efficiencies. On the other hand, the microspheres prepared using the modified solvent extraction-evaporation method were nonporous with encapsulation efficiencies close to 100%. In vitro drug release showed the nonporous microspheres had a lower initial burst and a slightly prolonged duration of release than those porous microspheres. In vivo release kinetics of the low burst microspheres were determined by measuring LNG plasma levels after a single intramuscular injection to female rats. At a LNG dose of 41.1 mg/kg, average plasma LNG levels were 6-10 ng/ml in the first 24 h and subsequently remained above 1 ng/ml until 126 days. The duration above the minimum effective LNG plasma level of 0.2 ng/ml was 168 days. By comparison, a similar dose of LNG microcrystals used as control produced a much higher plasma level of 15-21 ng/ml in the first day followed by a fast and continuous decline of LNG levels with a duration of only about 35 days.

Prevention of colon cancer by low doses of celecoxib, a cyclooxygenase inhibitor, administered in diet rich in omega-3 polyunsaturated fatty acids

Epidemiologic and animal studies suggest that a high-fat diet containing mixed lipids promotes colorectal cancer, whereas fish oil lacks promoting effect. Although cyclooxygenase-2 (COX-2) inhibitors are effective chemopreventive agents against colon carcinogenesis, administration of high doses of these agents over time may induce side effects. Here, we compared the efficacy of moderately high and low doses of celecoxib administered in diets high in mixed lipids (HFML) or fish oil (HFFO) against azoxymethane-induced colon carcinogenesis in male F344 rats. One day after the last azoxymethane treatment (15 mg/kg body weight once weekly for 2 weeks), groups of rats were fed the HFML and HFFO diets containing 0, 250, 500, and 1,000 ppm celecoxib. Rats were killed 26 weeks later and colon tumors were subjected to histopathologic examination and analyzed for total COX and COX-2 synthetic activities and COX-2 expression. Rats fed the HFFO diet showed significantly lower colon tumor incidence and multiplicity compared with rats fed the HFML diet. Celecoxib at 250, 500, and 1,000 ppm in either diet significantly suppressed colon carcinogenesis. Inhibition of colon adenocarcinomas were more pronounced in animals given 250 ppm celecoxib in HFFO diet compared with 250 ppm celecoxib given in HFML diet, suggesting some synergism between omega-3 polyunsaturated fatty acids (PUFA) and celecoxib. Inhibition of colon tumors by celecoxib was associated with lower levels of COX-2 activity and expression in colon tumors. These studies support the use of low doses of celecoxib in omega-3 PUFA-rich diet as a promising approach for clinical trials.

Onychomycosis in Taiwan

The pathogens of onychomycosis have implications in choosing therapy. We aimed to survey the pathogens of onychomycosis in Taiwan and further analyse the distribution of pathogens in various conditions. We also compared the distribution of pathogens in Taiwan with those in various countries. This study included 182 cases of onychomycosis who attended our clinic between January and December 2001. Histopathologic examination and fungus culture of the nail specimens were performed to confirm the diagnosis and identify the pathogens. The pathogens were dermatophytes in 101 patients (55.5%), Candida in 66 (36.3%), and non-dermatophyte moulds in 16 (8.2%). Candida was more frequently seen in patients older than 60 years (40.9%), females with fingernail onychomycosis (66.7%) or combined fingernail and toenail onychomycosis (58.3%), and presence of paronychia (57.9%). Dermatophytes are the predominant pathogens in temperate Western countries; meanwhile, Candida and non-dermatophyte moulds are prevailing in Mediterranean and tropical countries including Taiwan. Clinicians should appreciate that the pathogens of onychomycosis may vary in different patient groups and geographical locations, and choose optimal antifungal agents accordingly.

The Significance of Hepatic Vein Outflow Volume in Hepatic Outflow Insufficiency of Living Right Liver Graft Evaluated by Doppler Ultrasound

The color Doppler ultrasound has been used to evaluate hepatic vein (HV) outflow insufficiency based on flow velocity and waveforms. In our experience, some cases with flat waveforms are clinically asymptomatic. The parameters of HV flow velocity and waveforms are not always correlated with clinical problems. So, we proposed that total HV flow volume (HVFV) may be a more reliable index. From August 2001 to July 2003, 31 cases among 48 adult-to-adult living related transplants of a right liver graft had one HV anastomosis. HV velocity, waveforms, and HVFV were compared both before and after transplantation. We set the minimal HVFV ratio at 80% based on the original HVFV before graft retrieval. There was no significant difference in HVFV before liver graft retrieval between the 2 groups, but there was a significant change after transplantation. There were no cases of HV insufficiency among group A patients (>80%), whose HVFV ranged from 397 to 1181 mL/min with ratios from 75% to 180% (mean 115%). In group B, there were 4 complicated cases with prolonged severe ascites (<80%) with HVFV ratios from 56% to 76% (mean 66%). Fisher exact test showed a great significance (P < .001). Thus the preliminary criteria of 80% minimal HVFV ratio allows detection of HV insufficiency for further interventional management.

Hepatic venous stenosis in partial liver graft transplantation detected by color Doppler ultrasound before and after radiological interventional management

Hepatic outflow insufficiency remains one of the major complications causing postoperative graft failure especially among partial liver graft transplantations (PLT) including living donor liver transplantation (LDLT), reduced size liver transplantation (RLT), and split liver transplantation (SLT). These procedures are different from the whole liver graft transplantations (OLT), which include multiple vascular anastomoses. Color Doppler ultrasound (CDUS) was used to evaluate the hepatic venous outflow from grafts before and after radiological interventional management and to document treatment effects. From June 1994 to March 2003, our 136 cases of PLTs included 131 LDLTs, two RLTs, and three SLTs. Seven cases (six children and one adult) showed postoperative hepatic vein outflow obstruction and persistent massive ascites, as detected by color Doppler ultrasound (CDUS) and confirmed by interventional angiography. The CDUS showed a monophasic flat waveform with a relatively low hepatic vein average peak velocity (Va) in all cases (mean 11 cm/s). Successful interventional procedures included balloon dilatation in three cases and metallic stent replacement in four cases. CDUS was used with guidance during the procedure to confirm restoration of normal hepatic vein flow with a multiphasic waveform and an objective increase of average flow velocity (high to average 66 cm/s). Ascites disappeared dramatically after the procedure. In conclusion CDUS is the prime modality to diagnose and document a treatment response.

Over-expression of Bcl-2 against Pteris semipinnata L-induced apoptosis of human colon cancer cells via a NF-kappa B—related pathway

Ent-11 alpha-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F), an antitumor component, is a chemical compound isolated from Pteris semipinnata L (PsL), a Chinese traditional herb. We examined whether 5F could affect apoptosis in human colon cancer HT-29 cells, and test whether and how the over-expression of Bcl-2 and Bcl-xL could offset the effect of 5F on cell growth. The result demonstrated that 5F significantly induced apoptosis of HT-29, as shown by MTT assay and DNA fragmentation measurement. Treatment of HT-29 with 5F increased both p38 and iNOS levels, suggesting these two molecules may contribute to the apoptotic effect of 5F. Over-expression of Bcl-2 or Bcl-xL attenuated the increase of p38 and iNOS induced by 5F. The cells with Bcl-2 or Bcl-xL over-expression showed an elevation of nuclear factor kappa B (NF-kappa B) activity, accompanying a significant reduction of 5F-induced apoptosis. Furthermore, inhibition of NF-kappa B by I k B alpha SR, which is a powerful inhibitor of NF-kappa B, restored the ability of 5F to induce apoptosis in the cells transfected with Bcl-2. These data strongly indicated that the apoptotic effect of 5F on HT-29 was closely associated with the activity of NF-kappa B, which was up-regulated by Bcl-2 and Bcl-xL. In conclusion, 5F induced apoptosis in HT-29 cells and this apoptotic effect was associated with the high level of p38 and iNOS expression. The apoptotic effect of 5F could be significantly offset by over-expression of either Bcl-2 or Bcl-xL. Bcl-2, and to the less extent, Bcl-xL, were able to increase the activity of NF-kappa B, which was a known anti-apoptotic molecule in human colon cancer cells.

Induction of colon cancer cell death by 7-hydroxystaurosporine (UCN-01) is associated with increased p38 MAPK and decreased Bcl-xL

UCN-01, a selective inhibitor of protein kinase C, is known to inhibit the growth of cancer cells. Although it is currently undergoing clinical evaluation, information about its effect on human colon cancer is limited and the mechanism responsible is lacking. The objective of this study was to examine the cytotoxicity of UCN-01 to human colon cancer cells in vitro and its effect on the apoptotic molecules. HT-29, a radiation- and chemotherapy-resistant human colon cancer cell, was used in the study. Cell death/apoptosis was determined by the MTT assay and DNA fragmentation measurement. NF-kappaB activity was measured by an enzyme immunoassay method. Western blot was employed to examine the expression of relevant apoptotic molecules. The result showed that UCN-01 could induce apoptosis of human colon cancer cells in a time- and dose-dependent manner. It markedly reduced the expression of Bcl-xL, but enhanced the level of p38 MAPK. In addition to Bcl-xL and p38 MAPK, UCN-01 also increased both caspase-3 and peroxisome proliferator activated receptor gamma protein levels. HT-29 cells transfected with exogenous Bcl-xL showed a significant increase in NF-kappaB activity and prevented apoptosis induced by UCN-01. The overexpression of Bcl-xL also reversed other relevant molecular changes observed in UCN-01-treated cells. In conclusion, UCN-01 exerted an antitumor effect in human colon cancer cells by inducing apoptosis. The mechanism responsible appeared to be related to reduction of Bcl-xL and increased p38 MAPK. The overexpression of Bcl-xL can significantly prevent apoptosis induced by UCN-01.

Analysis of rotation-driven electrokinetic flow in microscale gap regions of rotating disk systems

In the present study, a novel theoretical model is developed for the analysis of rotating thermal-fluid flow characteristics in the presence of electrokinetic effects in the microscale gap region between two parallel disks under specified electrostatic, rotational, and thermal boundary conditions. The major flow configuration considered is a rotor-stator disk system. Axisymmetric Navier-Stokes equations with consideration of electric body force stemming from streaming potential are employed in the momentum balance. Variations of the fluid viscosity and permittivity with the local fluid temperature are considered. Between two disks, the axial distribution of the electric potential is determined by the Poisson equation with the concentration distributions of positive and negative ions obtained from Nernst-Planck equations for convection-diffusion of the ions in the flow field. Effects of disk rotation and electrostatic and thermal conditions on the electrokinetic flow and thermal characteristics are investigated. The electrohydrodynamic mechanisms are addressed with an interpretation of the coupling nature of the electric and flow fields. Finally, solutions with electric potential determined by employing nonlinear or linearized Poisson-Boltzmann equation and/or invoking assumptions of constant properties are compared with the predictions of the present model for justification of various levels of approximation in solution of the electrothermal flow behaviors in rotating microfluidic systems.

Theoretical analysis of electrokinetic flow and heat transfer in a microchannel under asymmetric boundary conditions

The main theme of the present work is to investigate the electrokinetic effects on liquid flow and heat transfer in a flat microchannel of two parallel plates under asymmetric boundary conditions including wall-sliding motion, unequal zeta potentials, and unequal heat fluxes on two walls. Based on the Debye-Huckel approximation, an electrical potential solution to the linearized Poisson-Boltzmann equation is obtained and employed in the analysis. The analytic solutions of the electrical potential, velocity distributions, streaming potential, friction coefficient, temperature distribution, and heat transfer rate are obtained, and thereby the effects of electrokinetic separation distance (K), zeta-potential level (zeta;(1)), ratio of two zeta potentials (r(zeta) identical with zeta;(2)/zeta;(1)), wall-sliding velocity (u(w)), and heat flux ratio (r(q) identical with q"(2)/q"(1)) are investigated. The present results reveal the effects of wall-sliding and zeta-potential ratio on the hydrodynamic nature of microchannel flow, and they are used to provide physical interpretations for the resultant electrokinetic effects and the underlying electro-hydrodynamic interaction mechanisms. In the final part the results of potential and velocity fields are applied in solving the energy equation. The temperature distributions and heat transfer characteristics under the asymmetrical kinematic, electric, and thermal boundary conditions considered presently are dealt with.

Healthcare-associated outbreak due to pan-drug resistant Acinetobacter baumannii in a surgical intensive care unit

Acinetobacter baumannii is ubiquitous and has recently become one of the most important healthcare-associated (HA) pathogens in hospitals. Infection caused by this organism often leads to significant morbidity and mortality. Outbreaks of pan-drug resistant Acinetobacter baumannii (PDRAB) have rarely been reported. During a two-month period, an outbreak of PDRAB colonization and infection affecting 7 patients occurred in our surgical intensive care unit (SICU). The colonized sites were respiratory tract (N = 7) and central venous catheter (N = 2). One of the patients had a surgical wound infection. Extensive environmental contamination was identified, including sites such as bed rails, bedside tables, surface of ventilators and infusion pump, water for nasogastric feeding and ventilator rinsing and sinks. All of the isolates were analysed by pulsed-field gel electrophoresis (PFGE) and showed an identical pattern. After use of strict cohort nursing, hand hygiene environmental cleaning, and replacement of a dysfunctional high-efficiency particulate air filter (HEPA), the outbreak was controlled.

Fall characteristics, functional mobility and bone mineral density as risk factors of hip fracture in the community-dwelling ambulatory elderly

Hip fracture is the most serious consequence of osteoporosis, frequently occurring in the elderly; however, no research has been performed to identify the fall characteristics, functional mobility and bone mineral density (BMD) concurrently as risk factors. We investigated the risk factors of hip fractures using a multifactorial approach for a further preventive strategy. This age- and sex-matched case-control study was conducted in a community-based general hospital. A total of 252 consecutive community-dwelling ambulatory elderly, aged between 65 and 85 years, were studied: 127 patients (faller with hip fracture) and 125 controls (faller without hip fracture). Body mass index (BMI), predisposing medical conditions, fall characteristics, functional mobility and BMD of the hip were evaluated by direct interview and clinical examination. In the final model of multivariate regression analysis, risk factors for hip fracture were direct hip impact (adjusted odds ratio (OR), 4.9; 95% confidence interval (CI), 2.7-8.8), previous stroke (adjusted OR, 2.9; 95% CI, 1.3-6.3), sideways fall (adjusted OR, 2.5; 95% CI, 1.6-3.9), functional mobility (a decrease of 1 SD; adjusted OR, 2.0; 95% CI, 1.1-3.5), BMI (a decrease of 1 SD; adjusted OR, 1.8; 95% CI, 1.1-2.8) and femoral neck BMD (a decrease of 1 SD; adjusted OR, 1.7; 95% CI, 1.0-2.8). The effect of risk factors remained the same in different analysis sets, and adding or removing femoral neck BMD did not change other risk factors, though BMD was significantly correlated with functional mobility and BMI. Importantly, both sideways fall and direct hip impact are independent predictors of hip fracture. From these results, we suggest a preventive strategy of hip fracture in the elderly: besides the maintenance of BMD, keeping an appropriate body weight and maintaining a physically active lifestyle might be crucial.

Structure and topology of a peptide segment of the 6th transmembrane domain of the Saccharomyces cerevisae alpha-factor receptor in phospholipid bilayers

A detailed analysis of the structure of an 18-residue peptide AQSLLVPSIIFILAYSLK [M6(252-269, C252A)] in 1,2-dimyristoyl-sn-glycero-phosphocholine bilayers was carried out using solid state NMR and attenuated total reflection Fourier transform infrared spectroscopy. The peptide corresponds to a portion of the 6th transmembrane domain of the alpha-factor receptor of Saccharomyces cerevisiae. Ten homologs of M6(252-269, C252A) were synthesized in which individual residues were labeled with (15)N. One- and two-dimensional solid state NMR experiments were used to determine the chemical shifts and (1)H-(15)N dipolar coupling constants for the (15)N-labeled peptides in oriented dimyristoylphosphatidylcholine bilayers on stacked glass plates. These parameters were used to calculate the structure and orientation of M6(252-269, C252A) in the bilayers. The results indicate that the carboxyl terminal residues (9-14) are alpha-helical and oriented with an angle of about 8 degrees with respect to the bilayer normal. Independently, an attenuated total reflection Fourier transform infrared spectroscopy analysis on M6(252-269, C252A) in a 1,2-dimyristoyl-sn-glycero-phosphocholine bilayer concluded that the helix tilt angle was about 12.5 degrees. The results on the structure of M6(252-269, C252A) in bilayers are in good agreement with the structure determined in trifluoroethanol/water solutions (B. Arshava et al. Biopolymers, 1998, Vol. 46, pp. 343-357). The present study shows that solid state NMR spectroscopy can provide high resolution information on the structure of transmembrane domains of a G protein-coupled receptor.

QT interval effects of cisapride in the clinical setting

PURPOSE

The clinical effect of cisapride on QT intervals was prospectively studied.

SUBJECTS

Consecutive adult patients were recruited in whom cisapride was indicated for gastroesophogeal reflux, gastric ulcer, duodenal ulcer, diabetic gastroparesis or chronic constipation refractory to laxatives. Exclusion criteria included disorders and medications affecting cardiac conduction, electrolyte homeostasis, drug clearance and membrane stability.

METHODS

Seventy-five patients were included and followed at 1 to 2 week intervals. Patients took cisapride 5 mg thrice daily for 1 to 4 weeks (lower dose stage), followed by 10 mg thrice daily for another 1 to 4 weeks (higher dose stage). Twelve-lead ECGs were performed before commencing cisapride (group B), at completion of the lower dose stage (group L) and at completion of the higher dose stage (group H).

RESULTS

No patients experienced presyncope or syncope. Seventeen patients failing to comply, and 7 complaining of abdominal discomfort or diarrhea were excluded, leaving 51 participants. Group H's corrected QT interval (QTc) was longer than group B's by 13+/-15 ms (P<0.001), and longer than group L's by 7+/-11 ms (P<0.001). Group L's QTc was longer than group B's by 7+/-21 ms (P<0.05). QT dispersion did not differ significantly among groups. Neither torsade de pointe nor ventricular tachycardia were noted in Holter monitoring of 33 patients during the higher dose stage.

CONCLUSION

cisapride dose-dependently prolongs the QT interval. Further study is needed to examine the arrhythmogenicity of cisapride in higher doses and for longer durations.

The heterogeneous nuclear ribonucleoprotein K (hnRNP K) interacts with dengue virus core protein

Heterogeneous nuclear ribonucleoprotein K (hnRNP K), a component of hnRNP particles, is involved in several steps of gene expression regulation. Dengue (DEN) virus, a member of the Flaviviridae, is the primary cause of illnesses such as dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. In mature DEN virus particles, the core protein is a structural protein that forms a nucleocapsid complex with genomic RNA. Very little of its biologic functions is known. Here, using an in vitro binding assay and coimmunoprecipitation analysis, we report a protein-protein interaction between the DEN virus core protein and hnRNP K. The C-terminal hydrophilic region of the DEN virus core protein, spanning amino acid residues 73 to 100, is required for such interaction. Results of glutathione-S transferase binding assays indicated that the core protein-hnRNP K interaction might be abolished in the presence of hnRNP K cognate nucleic acids. Furthermore, in a cotransfection experiment, the repressive effect of hnRNP K on C/EBPbeta-mediated transcription activation could be reversed by full-length DEN virus core protein but not by a truncated form containing amino acids 1-72. Our results suggest that, on DEN virus infection, the multiple functions of cellular hnRNP K may be affected by the virus core protein.

Electrophysiologic characteristics of ventricular extrastimulation-induced dissipation of functional bundle branch block associated with supraventricular tachycardia

INTRODUCTION

Linking-related anterograde functional bundle branch block during supraventricular tachycardia (SVT) is due to repetitive concealed retrograde conduction of impulses from the contralateral bundle branch and can be eliminated by a critically timed premature ventricular beat (PVB). We assessed the electrophysiologic characteristics of PVB-induced dissipation of functional bundle branch block during SVT.

METHODS AND RESULTS

During SVT with functional bundle branch block, PVB was delivered from the right ventricular apex, scanning the tachycardia cycle length (CL) with 10-msec decrements in the coupling interval in 14 patients (3 AV nodal reentrant tachycardia and 11 orthodromic AV reciprocating tachycardia). Dissipation was achieved in group 1: functional right bundle branch block (RBBB) in 4, functional left bundle branch block (LBBB) in 4, and both functional RBBB and LBBB in 1 with a dissipation zone occupying 4% to 13% (mean 8.5%) of the tachycardia CL. The outer limits were 22+/-16 msec and 68+/-14 msec < tachycardia CL; the inner limits were 56+/-18 msec and 90+/-24 msec < tachycardia CL for RBBB and LBBB, respectively (both P < 0.05). Dissipation could not be achieved in group 2 (4 RBBB and 1 LBBB) due to CL-dependent bundle branch block and/or local ventricular refractoriness.

CONCLUSION

During SVT, functional bundle branch block due to "linking" often can be dissipated by timely PVB delivered from the right ventricular apex within a narrow zone of the tachycardia CL. Our findings suggest that the dissipation zone is affected by the pattern of functional bundle branch block relative to the site of PVB delivery.