A functional cellulose synthase from ascidian epidermis

Among animals, urochordates (e.g., ascidians) are unique in their ability to biosynthesize cellulose. In ascidians cellulose is synthesized in the epidermis and incorporated into a protective coat know as the tunic. A putative cellulose synthase-like gene was first identified in the genome sequences of the ascidian Ciona intestinalis. We describe here a cellulose synthase gene from the ascidian Ciona savignyi that is expressed in the epidermis. The predicted C. savignyi cellulose synthase amino acid sequence showed conserved features found in all cellulose synthases, including plants, but was most similar to cellulose synthases from bacteria, fungi, and Dictyostelium discoidium. However, unlike other known cellulose synthases, the predicted C. savignyi polypeptide has a degenerate cellulase-like region near the carboxyl-terminal end. An expression construct carrying the C. savignyi cDNA was found to restore cellulose biosynthesis to a cellulose synthase (CelA) minus mutant of Agrobacterium tumefaciens, showing that the predicted protein has cellulose synthase activity. The lack of cellulose biosynthesis in all other groups of metazoans and the similarity of the C. savignyi cellulose synthase to enzymes from cellulose-producing organisms support the hypothesis that the urochordates acquired the cellulose biosynthetic pathway by horizontal transfer.     

Repeated adeno-associated virus serotype 2 aerosol-mediated cystic fibrosis transmembrane regulator gene transfer to the lungs of patients with cystic fibrosis: a multicenter, double-blind, placebo-controlled trial

STUDY OBJECTIVES: The primary objective was to determine the safety and tolerability of repeated doses of aerosolized adeno-associated serotype 2 vector containing cystic fibrosis transmembrane conductance regulator (CFTR) complementary DNA (cDNA) [tgAAVCF], an adeno-associated virus (AAV) vector encoding the complete human CFTR cDNA. Secondary objectives included evaluation of pulmonary function assessed by spirometry, lung abnormalities by high-resolution CT (HRCT), airway cytokines, vector shedding, serum neutralizing antibody to AAV serotype 2 (AAV2), and gene transfer and expression in a subset of subjects undergoing bronchoscopy with bronchial brushings. DESIGN: Randomized, double-blind, placebo-controlled, phase II trial. SETTING: Eight cystic fibrosis (CF) centers in the United States. SUBJECTS: CF patients with mild lung disease, defined as FEV(1) > or =60% predicted. INTERVENTIONS: Subjects were randomized to inhale three aerosolized doses of 1 x 10(13) deoxyribonuclease-resistant particles of tgAAVCF or matching placebo at 30-day intervals using the Pari LC Plus nebulizer (PARI; Richmond, VA). Measurements and results: Of 42 subjects randomized, 20 subjects received at least one dose of tgAAVCF and 17 subjects received placebo. No difference in the pattern of adverse events or laboratory abnormalities was noted between the two treatment groups. Improvements in induced-sputum interleukin-8 (p = 0.03) and FEV(1) (p = 0.04) were observed at day 14 and day 30, respectively, in the group receiving tgAAVCF when compared to those receiving placebo. No significant differences in HRCT scans were noted. Vector shedding in sputum was observed at low levels up to 90 days after the third dose of vector. All subjects receiving tgAAVCF exhibited an increase (by at least fourfold) in serum AAV2-neutralizing antibodies and detectable levels in BAL fluid from five of six treated subjects undergoing BAL. Gene transfer but not gene expression was detected in a subset of six tgAAVCF subjects who underwent bronchoscopy. CONCLUSIONS: Repeat doses of aerosolized tgAAVCF were safe and well tolerated, and resulted in encouraging trends in improvement in pulmonary function in patients with CF and mild lung disease.     

Teaching and maintaining behavior management skills in the nursing home

PURPOSE: To examine the efficacy of a comprehensive behavior management skills training program for improving certified nursing assistants' (CNA) skill performance in the nursing home, to assess the effectiveness of a staff motivational system for maintaining newly acquired behavior management skills for a 6-month period, and to evaluate any resulting effects on resident agitation. DESIGN AND METHODS: This study used a randomized clinical trial of 88 residents with behavior disturbances and 106 CNAs who cared for them in two urban nursing homes. After CNAs received 4 weeks of behavior management training, supervisory nursing staff implemented formal staff management (FSM), designed to maintain training effects over time. The supervisory staff used conventional staff management (CSM, usual supervisory routine) on control units. We completed behavioral observations and paper-and-pen assessments at baseline and repeated them during a 4-week post-intervention phase and at 3- and 6-month follow-ups. RESULTS: During the immediate post-training phase, both the FSM and CSM groups improved five out of seven communication skills and the ability to delay physical assistance during care routines. Although CNAs showed a reduction in the use of ineffective behavior management strategies, they did not increase their use of effective behavioral strategies. Follow-up assessments suggested that the FSM system was more effective than CSM for maintaining and even improving communication skills over time. Resident agitation was reduced during care interactions and maintained at follow-up. IMPLICATIONS: The behavior management skills training program improved CNAs' ability to interact with behaviorally disturbed nursing home residents and produced sustained reductions in agitation. The FSM system was more effective for maintaining communication skills 6 months after training.     

Nitric oxide and cyclic GMP levels in sickle cell patients receiving hydroxyurea

Recent studies suggest that nitric oxide (NO) may partly be responsible for the beneficial effect of hydroxyurea (HU) in sickle cell disease (SCD) patients. NO stimulates cyclic guanosine monophosphate (cGMP) production, which mediates vasodilatation. We investigated the association between NO, cGMP and fetal haemoglobin (HbF) levels after HU administration. Our data showed that chronic HU significantly increased NO, cGMP, and HbF levels in SCD. Recently it was shown that HbF production was stimulated by cGMP-dependent protein kinase. Our results suggest that NO stimulates cGMP production, which then activates a protein kinase and increases the production of HbF.     

Combined assessment of thrombolysis in myocardial infarction flow grade, myocardial perfusion grade, and ST-segment resolution to evaluate epicardial and myocardial reperfusion

The restoration of epicardial and myocardial flow remains the primary goal of reperfusion therapy in patients with ST-segment elevation myocardial infarction, but the optimal method to assess this goal has not been defined. Thrombolysis In Myocardial Infarction flow grade (TFG), myocardial perfusion grade (MPG), and ST-segment resolution (STRes) were combined to formulate a new measure of successful reperfusion in 649 patients who received pharmacologic reperfusion therapy in 3 recent phase II clinical trials of ST-segment elevation myocardial infarction. Coronary angiograms and electrocardiograms were analyzed at 60 minutes (before any intervention) after the initiation of reperfusion therapy. The complete restoration of perfusion, or the "trifecta," defined as the presence of TFG 3, MPG 3, and complete (> or =70%) STRes, occurred in 117 patients (18%). The achievement of this trifecta was associated with low rates of 30-day mortality (0% vs 3.9%, p = 0.02), congestive heart failure (CHF) (0.9% vs 7.1%, p = 0.01), and the combination of death or CHF (0.9% vs 10.7%, p = 0.001). When the results were stratified with respect to subsequent percutaneous coronary intervention (PCI) from 60 to 120 minutes, attainment of the trifecta at 60 minutes remained a strong predictor of better clinical outcomes, particularly in those patients who underwent early PCI. The achievement of TFG 3, MPG 3, and complete STRes at 60 minutes after fibrinolytic therapy and before PCI occurred in only 18% of patients but was associated with very low rates of death and CHF at 30 days. This new end point is proposed to evaluate the success of reperfusion therapy in patients who undergo early angiography.     

Dexamethasone-induced apoptotic mechanisms in myeloma cells investigated by analysis of mutant glucocorticoid receptors

The mechanism by which the glucocorticoid (GC) dexamethasone induces apoptosis in multiple myeloma (MM) cells is unknown, although previous work suggests that either transactivation through the glucocorticoid response element (GRE), transrepression of NF-kappaB, phosphorylation of RAFTK (Pyk2), or induction of Bim is important. We studied this question by ectopically expressing mutant glucocorticoid receptors (GRs) in the dexamethasone-resistant MM1R cell line, which has lost its GR. Lentiviral-mediated reexpression of wild-type GR restored GRE transactivation, NF-kappaB transrepression, RAFTK phosphorylation, Bim induction, and dexamethasone-induced apoptosis. We then reexpressed 4 GR mutants, each possessing various molecular effects, into MM1R cells. A perfect correlation was present between induction of GRE transactivation and induction of apoptosis. In contrast, NF-kappaB transrepression and RAFTK phosphorylation were not required for apoptosis. Although not required for dexamethasone-mediated apoptosis, NF-kappaB inhibition achieved by gene transfer suggested that NF-kappaB transrepression could contribute to apoptosis in dexamethasone-treated cells. Dexamethasone treatment of MM1R cells expressing a mutant incapable of inducing apoptosis successfully resulted in RAFTK (Pyk2) phosphorylation and Bim induction indicating the latter GR-mediated events were not sufficient to induce apoptosis. MM1R cells expressing mutant GRs will be helpful in defining the molecular mechanisms of dexamethasone-induced apoptosis of myeloma cells.     

Molecular epidemiology of Plasmodium falciparum resistance to antimalarial drugs in Indonesia

The extent of gene polymorphisms associated with resistance to chloroquine and sulfadoxine-pyrimethamine was examined in field isolates of Plasmodium falciparum from Indonesia. Eight malaria-endemic areas, representing a broad region of the western and eastern Indonesian Archipelago were surveyed. Blood from 20-50 patients was collected at each site, DNA was isolated, and the sequences of four different genes (dihydrofolate reductase [dhfr], dihydropteroate synthase [dhps], P. falciparum multidrug resistance 1 [pfmdr1], and P. falciparum chloroquine resistance transporter [pfcrt]) were analyzed using polymerase chain reaction and restriction fragment length polymorphisms to detect polymorphisms previously shown to be associated with resistance. This analysis identified polymorphisms in dhfr at 108-Asn/Thr, 16-Val, and 59-Arg. Polymorphisms in dhps were found less frequently, either 437-Gly alone or paired with 540-Glu. The pfcrt 76-Thr polymorphism was fixed in all parasite populations and pfmdr1 86-Tyr polymorphisms in all populations except in the most eastern regions. The pfmdr1 1042-Asp polymorphism occurred less frequently. These findings indicate that polymorphisms in genes associated with drug resistance in P. falciparum are found across a broad region of Indonesia.     

Influence of the HLA-DQB1*0201 allele on the immune response in a Schistosoma mansoni infection

We previously reported the association of the major histocompatibility complex class II HLA-DQB1*0201 allele with hepatosplenic schistosomiasis. The aim of this study was to evaluate the cytokine responses of peripheral blood mononuclear cells (PBMCs) and the serum levels of immunoglobulin isotypes. The study population was selected from a schistosomiasis endemic area. No significant differences in cytokine profiles were detected in PBMCs stimulated with Schistosoma mansoni soluble egg antigen (SEA), regardless of the subjects DQB1*0201 genotype or infection status. However, previously infected DQB1*0201 positive individuals had significantly lower levels of IgG4 compared to DQB1*0201 negative individuals (P<0.05).