Random-priming in vitro recombination: an effective tool for directed evolution

A simple and efficient method for in vitro mutagenesis and recombination of polynucleotide sequences is reported. The method involves priming template polynucleotide(s) with random-sequence primers and extending to generate a pool of short DNA fragments which contain a controllable level of point mutations. The fragments are reassembled during cycles of denaturation, annealing and further enzyme-catalyzed DNA polymerization to produce a library of full-length sequences. Screening or selecting the expressed gene products leads to new variants with improved functions, as demonstrated by the recombination of genes encoding different thermostable subtilisins in order to obtain enzymes more stable than either parent.     

Further evolution toward effective therapy for acute ischemic stroke

The effective treatment of acute ischemic stroke remains an important goal of modern medicine and substantive advances are occurring. Recently, thrombolytic therapy with tissue-type plasminogen activator was approved for selected patients with acute ischemic stroke when therapy is started within 3 hours of onset. Streptokinase therapy for acute ischemic stroke has not been shown to be effective and is associated with an increased risk of hemorrhage, although it was not evaluated as early after stroke onset as tissue-type plasminogen activator. Various types of neuroprotective interventions are effective in animal models, but none has yet been proven effective in patients. In the future, combinations of thrombolytic and neuroprotective drugs may be used to attempt maximum rates of recovery after acute ischemic stroke. For combination therapy to achieve its maximum potential, patients with acute ischemic stroke will have to be carefully selected and treated.     

Atorvastatin: an effective lipid-modifying agent in familial hypercholesterolemia

Hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors are the drugs of choice in heterozygous familial hypercholesterolemia (FH), which has a high risk of ischemic heart disease. An open-label study was conducted to test the efficacy and safety of atorvastatin, a new synthetic HMG-CoA reductase inhibitor in proven FH. After a 4-week placebo phase, 22 subjects were randomized to either 80 mg atorvastatin at night (n = 11) or 40 mg twice a day for 6 weeks. The two dosage groups were well matched and had no difference in lipoprotein responses. After 6 weeks, the LDL cholesterol concentration was reduced by 57%, from 8.16 +/- 1.15 to 3.53 +/- 0.99 mmol/L (P < .001). The total cholesterol concentration decreased from 9.90 +/- 1.32 to 5.43 mmol/L (P < .001). HDL cholesterol concentration increased from 1.19 +/- 0.31 to 1.49 +/- 0.43 mmol/L (P < .001). Triglyceride concentrations decreased from 1.34 +/- 0.66 to 0.88 +/- 0.36 mmol/L (P < .01). Three subjects had single, transient increases of serum transaminase of up to twice the upper limit of normal. Apolipoprotein B concentration decreased significantly by 42%. Changes in apolipoproteins AI and (a) were not statistically significant. Nondenaturing gradient gel electrophoresis revealed increases in the size of smaller LDL particles in four subjects. Plasma fibrinogen concentration increased by 44%. The drug was well tolerated. One subject withdrew for personal reasons. Atorvastatin is a powerful and safe lipid-modifying agent for LDL cholesterol; it also modifies HDL cholesterol and triglyceride concentrations, and may suffice as a single agent for many subjects with heterozygous FH.     

Temporal limitations in the effective binding of attended target attributes in the mutual masking of visual objects.

The problem of feature binding has been examined under conditions of distributed attention or with spatially dispersed stimuli. We studied binding by asking whether selective attention to a feature of a masked object enables perceptual access to the other features of that object using conditions in which spatial attention was directed at a single location where all objects appeared. In an identification condition, the task required reporting the same property of each object. High rates of identification showed good perceptual availability. In a search condition, the task required reporting the property (e.g., shape) that was associated with a specific value of the searched property (e.g., surface texture) of the same object. Focusing of attention on a target’s searched property value did not result in a high rate of identifying the target’s other property, and strong object masking was found. Backward masking between spatially superimposed visual objects appears to be primarily due to a difficulty in feature binding of a target object rather than to a substitution of an integrated object by the following stimulus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How to design an effective practice brochure

The practice brochure is an effective marketing tool. But should you do it yourself or hire a designer? Each option has its pros and cons, as this marketing expert explains.     

Evaluating Temporal Variability in Bacterial Indicator Samples for an Urban Watershed

Temporal variability in water quality sampling can lead to under or overestimation of pollution. More frequent sampling during times of expected high variability can reduce temporal bias. However, bacterial indicator measurements require manual sampling and time-intensive and expensive laboratory analysis. Thus, methods to assess the effect of temporal variability would be useful. In this work, fecal coliform and E. coli samples were taken weekly during the recreational season at 25 sites in an urban watershed. The data were categorized into wet versus dry days, and upper versus lower watershed, and the geometric means and geometric standard deviations of various five-sample data sets were analyzed to determine if sample data selection would result in different stream classifications. Results indicate if the bacterial indicator samples are near the regulated limits for water contact recreational use, temporal bias could sway impairment classification decisions. To reduce the temporal bias, sampling data submitted for stream classification should include several sampling groups within the recreational season, particularly for sites near point sources of pollution or with low fecal indicator contamination.     

Discharge planning: establishing an effective coordination team

This article investigates the developing role of the discharge coordinator and explores how safe, effective and timely discharge from hospital can be achieved. In January 1996, a team of four discharge coordinators were jointly appointed by the King's Healthcare NHS Trust in partnership with the local social services department. The coordinators were appointed to work with the multidisciplinary teams to improve trustwide discharge planning practice. The team focused on six core objectives: central coordination, open interagency communication, continuing education, patient advocacy, information resource and audit of discharges. Despite the ward staff's early difficulties regarding the nature of the role, the team did begin to collaborate effectively when working alongside all members of the multidisciplinary team and with patients and families.     

Cytogenetic abnormalities and clonal evolution in an adult hepatoblastoma

Hepatoblastomas usually occur in children < 3 years of age, and only occasional adult cases have been described. To date, 20 cytogenetically abnormal childhood hepatoblastomas have been reported. Karyotypic investigations have shown that most hepatoblastomas are diploid or hyperdiploid, often displaying trisomies for chromosomes 2 and 20. We have cytogenetically investigated an adult hepatoblastoma for which no previous karyotypic data exist. A hypertriploid stemline with multiple numerical and structural chromosomal aberrations, including +2 and +20, was found. In addition, the tumor displayed extensive clonal evolution with 11 subclones. Although the tumor thus displayed some chromosomal abnormalities commonly observed in childhood tumors, providing further support for the importance of these abnormalities in the development of hepatoblastoma, the level of genomic complexity seen in the present case has never been described in childhood hepatoblastomas and may suggest a different etiology or pathogenesis.     

Temporal lobe asymmetry and dyslexia: an in vivo study using MRI

A new, sensitive method of measurement of current-voltage characteristics (CVC) of the type i(U) approximately U(1 + beta U2) was applied to study ionic channels formed by gramicidin D in bilayer lipid membranes (BLM). The values of the non-linearity coefficient beta of the CVC of membranes modified by gramicidin D depended on electrolyte concentration, C, and expressed the weak nonlinearity of the CVC. In symmetric electrolyte conditions, the coefficient beta(A) increased with the increasing electrolyte concentration from -17 V-2 at 0.03 mol/l KCl to 8 V-2 at 3 mol/l KCl. In asymmetric electrolyte conditions (different electrolyte concentrations at the two sides of the BLM) the coefficient beta(A) also increased with increasing C. A theory is proposed describing the weak nonlinearity of CVC of ionic channels based on electrodiffusion model. This theory assumes that the electrochemical potential mu(x) of an ion within the ion channel depends on the coordinate x along the channel axis. According to the proposed model, CVC nonlinearity is mainly determined by the ends of the ion channel. We showed that the structure of gramicidin D ionic channel is sensitive to the concentration of ions, and in fact changes at one end of the channel influence the parameters of the other channel end.     

Extensive skin candidosis in an adult: effective treatment with itraconazole

A 34-year-old man with 6 years' untreated erythematous scaling of the skin was diagnosed as having extensive skin candidosis. Oral itraconazole was administered for 4 weeks (400 mg day-1 for the first 3 weeks and 200 mg day-1 for the last week). At the end of the 4-week treatment period, the rash was completely cleared from all skin sites, and Candida albicans was absent in culture tests on tissue samples. No adverse events were reported by the patient, and laboratory analysis revealed no abnormalities in the liver, kidney and haematological systems. Oral itraconazole is therefore an effective treatment for extensive skin candidosis.