Engineering trimeric fibrous proteins based on bacteriophage T4 adhesins.

The adsorption specificity of bacteriophage T4 is determined by genes 12 and 37, encoding the short tail-fibers (STF) and the distal part of the long tail-fibers (LTF), respectively. Both are trimeric proteins with rod domains made up of similar tandem quasi-repeats, approximately 40 amino acids long. Their assembly requires the viral chaperones gp57A and gp38.

Cerebral microembolism in patients with retinal ischemia.

Background And Purpose: We investigated the frequency of cerebral microembolism detected by transcranial Doppler ultrasonography in patients with clinical evidence of retinal ischemia, including transient monocular blindness, central and branch retinal artery infarction, and ischemic oculopathy, and assessed its correlation with carotid artery stenosis.

Methods: Records of 331 consecutive patients examined during a 47-month period at the Neurovascular Laboratory were reviewed. Of the original 453 intracranial arteries, 186 middle cerebral arteries (MCAs) satisfied qualifying criteria that excluded patients with cardiac embolic sources.

Creative employee scheduling in the health information management department.

What effect do schedules have on employees and department activities? Negative effects such as backlogs, poor employee morale, and absenteeism may be due to scheduling practices currently in place. The value of effective employee scheduling practices may be seen in areas of improved productivity. The process of developing schedules should include assessing department areas, understanding operational needs, choosing an option, and implementation.

Cardiac rhythmicities and attention in young children.

This study examined the changes in three cardiac rhythmicities (angiotensin-renin vasomotor [ARV], Traube-Hering-Meyer [THM], and respiratory sinus arrhythmia [RSA]) during prolonged attention in preschool children. Electrocardiogram data were collected from children during resting baseline and a 5-min attention condition at ages 3, 4, and 5 years in a longitudinal study. The ARV and THM rhythmicities decreased during prolonged attention for most participants.

Avian retrovirus U3 and U5 DNA inverted repeats. Role Of nonsymmetrical nucleotides in promoting full-site integration by purified virion and bacterial recombinant integrases.

The U3 and U5 termini of linear retrovirus DNA contain imperfect inverted repeats that are necessary for the concerted insertion of the termini into the host chromosome by viral integrase. Avian myeloblastosis virus integrase can efficiently insert the termini of retrovirus-like DNA donor substrates (480 base pairs) by a concerted mechanism (full-site reaction) into circular target DNA in vitro. The specific activities of virion-derived avian myeloblastosis virus integrase and bacterial recombinant Rous sarcoma virus (Prague A strain) integrase (approximately 50 nM or less) appear similar upon catalyzing the full-site reaction with 3'-OH recessed wild type or mutant donor substrates.

The extracellular domain of immunodeficiency virus gp41 protein: expression in Escherichia coli, purification, and crystallization.

The env gene of SIV and HIV-1 encodes a single glycoprotein gp 160, which is processed to give a noncovalent complex of the soluble glycoprotein gp120 and the transmembrane glycoprotein gp41. The extracellular region (ectodomain), minus the N-terminal fusion peptide, of gp41 from HIV-1 (residues 27-154) and SIV (residues 27-149) have been expressed in Escherichia coli. These insoluble proteins were solubilized and subjected to a simple purification and folding scheme, which results in high yields of soluble protein.

Refinement and comparisons of the crystal structures of pig cytosolic aspartate aminotransferase and its complex with 2-methylaspartate.

Two high resolution crystal structures of cytosolic aspartate aminotransferase from pig heart provide additional insights into the stereochemical mechanism for ligand-induced conformational changes in this enzyme. Structures of the homodimeric native structure and its complex with the substrate analog 2-methylaspartate have been refined, respectively, with 1.74-A x-ray diffraction data to an R value of 0.

Cerebral microembolism and early recurrent cerebral or retinal ischemic events.

Background And Purpose: We investigated whether cerebral microembolism as detected by transcranial Doppler ultrasonography (TCD) identifies patients at an increased risk for early, recurrent cerebral or retinal ischemic events.

Methods: Records of consecutive patients examined during a 40-month period in the Neurovascular Laboratory were reviewed for the presence of cerebral microembolism. Of the original 302 patients, 229 with 310 arteries met inclusionary criteria.

Crystal structures of a mutant (betaK87T) tryptophan synthase alpha2beta2 complex with ligands bound to the active sites of the alpha- and beta-subunits reveal ligand-induced conformational changes.

Three-dimensional structures are reported for a mutant (betaK87T) tryptophan synthase alpha2beta2 complex with either the substrate L-serine (betaK87T-Ser) or product L-tryptophan (betaK87T-Trp) at the active site of the beta-subunit, in which both amino acids form external aldimines with the coenzyme, pyridoxal phosphate. We also present structures with L-serine bound to the beta site and either alpha-glycerol 3-phosphate (betaK87T-Ser-GP) or indole-3-propanol phosphate (betaK87T-Ser-IPP) bound to the active site of the alpha-subunit. The results further identify the substrate and product binding sites in each subunit and provide insight into conformational changes that occur upon formation of these complexes.

A review of near patient testing in primary care.

Aims And Objectives: The aim was to identify publications relating to near patient testing (NPT), the use of alternative delivery systems between laboratory and general practice, including electronic data interchange (EDI), and computerised diagnostic decision support (CDDS), in the primary care setting to answer the following questions. What is the availability of NPT for primary care? What evidence is available to support the clinical effectiveness of NPT? What evidence is available on the accuracy and reliability of NPT within primary care? What evidence is available on the cost-effectiveness of different NPTs? How may CDDS improve the effectiveness of NPT? What evidence is available that compares NPT and existing laboratory services? What evidence is available on the cost-effectiveness of EDI or alternative delivery systems?

How The Research Was Conducted: Eight databases were searched, and the bibliographies from relevant publications checked for completeness. Unpublished work and publications not included in the databases were obtained by personal contact with collaborators, and from a postal survey sent to heads of academic departments of general practice and clinical chemistry and to researchers active or interested in the field worldwide.

The computer age impacts nurses.

The information for this article was collected at the Department of Veterans Affairs Domiciliary in White City, Oregon. The intent is to show the transition from a paper record to an entirely computerized patient record system and to show the impact on nursing practice at the Domiciliary. Clinicians using the paperless record have verbalized positive experiences and derived much benefit because of easier and quicker access to patient records, thereby allowing more time for direct patient care.

Emphysematous cystitis and pyelitis in a diabetic renal transplant recipient.

Emphysematous cystitis is a rare complication of urinary tract infection. Patients with diabetes mellitus, neurogenic bladder, bladder outlet obstruction, and recurrent urinary tract infection are at increased risk for the disease. We present a case of emphysematous cystitis and pyelitis in a diabetic renal transplant recipient.

Structure of bacteriophage T4 RNase H, a 5' to 3' RNA-DNA and DNA-DNA exonuclease with sequence similarity to the RAD2 family of eukaryotic proteins.

Bacteriophage T4 RNase H is a 5' to 3' exonuclease that removes RNA primers from the lagging strand of the DNA replication fork and is a member of the RAD2 family of eukaryotic and prokaryotic replication and repair nucleases. The crystal structure of the full-length native form of T4 RNase H has been solved at 2.06 angstroms resolution in the presence of Mg2+ but in the absence of nucleic acids.

Psychiatric intensive care in acute psychosis.

We have reviewed the development of psychiatric intensive care, focusing on organizational factors and the causes of psychiatric violence, suggesting guidelines for rapid tranquillization. The economics of running a psychiatric intensive care unit were subjected to an analysis of fixed, semi-fixed and variable costs. Variable costs (treatment and patient numbers) were shown to be more open to manipulation and possible cost savings.

Effect of time and cerebrovascular symptoms of the prevalence of microembolic signals in patients with cervical carotid stenosis.

Background And Purpose: High-intensity transient signals (HITS) detect ed by transcranial Doppler ultrasonography correspond to microemboli in intracranial arteries. The aim of this study was to determine the time course of cerebral microembolism in patients with symptomatic internal carotid artery stenosis and to assess its relation to specific symptoms of cerebral ischemia.

Methods: On the basis of criteria established a priori, 69 middle cerebral arteries were selected from a series of consecutive studies obtained at our neurovascular laboratory.

Using the evidence. A need for quantity, not quality?

The use of research evidence depends on more than its quality. If one considers other factors that influence the use of evidence, the quantity of accessible evidence and initiatives ensuring a wider understanding of it must be equally important. In consequence, improving the quality of research evidence alone will not necessarily lead to its greater use.

The type and quality of randomized controlled trials (RCTs) published in UK public health journals.

Background: Randomized controlled trials (RCTs) are increasingly being used to evaluate the effectiveness of health care interventions. Systematic reviews of RCTs form the basis of the Cochrane Collaboration, which aims to synthesize all RCTs concerned with the provision of health care. This paper reports the quantity and methodological quality of RCTs published in five UK public health journals, which were searched as part of a planned register of RCTs in public health.

Some clinical and methodological implications of a treatment outcome study of sexually abused children.

The clinical implications of the results of a treatment outcome study are presented for 47 sexually abused children and adolescents attending a specialist psychiatric facility. The children and their nonabusing parents or caregivers were randomly assigned to contrasting treatment programs. The treatment focused on family members allocating blame for the abuse appropriately, optimizing family relationships, and dealing with causes and effects of the abuse.

Metal-ion assisted, radiation-induced conversion of B- to Z-DNA in poly (dGdC) and two natural DNAs.

Metal-ion assisted, gamma-radiation-induced B-Z conformation changes have been observed with UV and circular dichroism spectroscopy for poly (dGdC), calf thymus and herring testis DNA. These conformational changes are similar to those induced by increasing multivalent metal ion concentrations in DNA containing alternating purine and pyrimidine base sequences. In both the metal-ion-induced and the metal-ion-assisted, radiation-induced conformation changes, the conversions were from the right-handed B-DNA to the left-handed Z-DNA conformation.

A motif in human histidyl-tRNA synthetase which is shared among several aminoacyl-tRNA synthetases is a coiled-coil that is essential for enzymatic activity and contains the major autoantigenic epitope.

In myositis, disease-specific autoantibodies may be directed against an aminoacyl-tRNA synthetase, usually histidyl-tRNA synthetase. To explore the basis for this phenomenon, we have made recombinant histidyl-tRNA synthetase in the baculovirus system. It was enzymatically active and recognized by human autoantibodies.

Clinical correlates of high-intensity transient signals detected on transcranial Doppler sonography in patients with cerebrovascular disease.

Background And Purpose: High-intensity transient signals detected by transcranial Doppler sonography have been associated with particulate cerebral emboli. Their clinical correlates are poorly understood. This study was undertaken to assess their relation to cerebral ischemia and to determine whether the severity of cerebral arterial stenosis has an impact on their occurrence.