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Biomedical subjects

H Lewis

Publications and source records attributed to H Lewis.

At least 163 records · Page 9Linked to original sources
PubMed1982

Chemical synthesis and cloning of a gene for human beta-urogastrone.

A DNA duplex coding for the 53 amino acids of human beta-urogastrone has been synthesised. Computer assisted design of the gene included restriction endonuclease sites for plasmid insertion, a termination codon and two triplets coding for lysine at the 5'-end of the structural gene. The synthesis involved preparation of 23 oligodeoxyribonucleotides by phosphotriester procedures coupled to rapid HPLC techniques. The gene was constructed in two halves by enzymatic ligation of the oligonucleotides and cloned into a specially constructed chimeric plasmid vector. Escherichia coli K12 MRC8 was transformed by the plasmid and clones containing the full gene sequence were isolated and characterised.

Amino Acid Sequence↗
PubMed1982

Value, purpose and accountability: the language of organizational intentions.

A schemata is proposed which provides a framework that associates value, purpose and accountability, in a manner that contributes to a common language with recognizable meanings in discussion and analysis of organizational intentions. The definition of key terms, their hierarchical relationships, and characteristics of the grammar that tie value, purpose and accountability together to assure meaningful dialogues among administrators and those with whom they discuss organizational work, is suggested.

Models, Theoretical↗
PubMed1981

Lactose enemas plus placebo tablets vs. neomycin tablets plus starch enemas in acute portal systemic encephalopathy. A double-blind randomized controlled study.

A randomized, double-blind comparison of lactose enemas plus placebo tablets vs. starch enemas plus neomycin tablets was performed on 18 patients with acute portal systemic encephalopathy. Ten patients received starch enemas (10%; 1000 ml t.i.d.) plus neomycin tablets and 8 patients received lactose enemas (20%; 1000 ml t.i.d.) plus placebo tablets. A significant mental state improvement was demonstrated in the group of patients treated with starch enemas-neomycin tablets (p less than 0.05) and in the group of patients treated with lactose enemas-placebo tablets (p less than 0.025). Both treatments significantly improved the frequency of asterixis, ammonia blood levels, and electroencephalograms. In addition, patients treated with lactose enemas showed significant improvement in number-connection test times (p less than 0.02), and their stools showed a more acid pH (p less than 0.05). No side effects were evident with either treatment. Lactose enemas are a safe and effective treatment for acute portal systemic encephalopathy.

Acute Disease↗
PubMed1980

The expression in E. coli of synthetic repeating polymeric genes coding for poly(L-aspartyl-L-phenylalanine).

Two dodecadeoxynucleotides of defined sequence have been synthesised by phosphotriester methodology. They can be polymerised to give a double stranded DNA which codes, when read in the correct phase, for the repeating dipeptide poly(aspartyl-phenylalanine). This polymeric DNA has been cloned in E. coli K12 using as vector a plasmid having a controllable bacterial promoter upstream of the insertion site. Clones containing genes coding for up to 150 repeats of (aspartyl-phenylalanine) have been isolated and characterised. The polymeric inserts appear to be stable over many generations and are expressed in E. coli under the control of the bacterial promoter, to give a polymer of phenylalanine and aspartic acid which may be broken down enzymically to yield aspartyl-phenylalanine.

Amino Acid Sequence↗
PubMed1980

Diagnostic evaluation of headache. Impact of computerized tomography and cost-effectiveness.

One hundred sixty-one highly selected patients with headache were studied to assess the impact of computerized tomography (CT) on diagnostic evaluation and to determine cost-effectiveness of neurodiagnostic evaluation of headache. Fewer nuclide brain scans were performed after availability of CT, but diagnostic charges stayed about the same. A careful history and physical and neurological examinations were adequate screens to detect intracranial mass lesions or systemic disease associated with headache. In patients with normal findings from neurological examination, no clinically important abnormalities were detected by CT, skull roentgenogram, angiography, or nuclide brain scan. The cost of finding a case of brain tumor was estimated to be at least $1,265 for patients with abnormalities on neurological examination and $11,901 for patients with normal findings on neurological examination. Neurodiagnostic evaluation of headache patients with normal findings from neurological examination is expensive and was clinically unrewarding in this series.

Brain↗
PubMed1980

Nucleotide sequence of the proximal portion of the RNA polymerase beta subunit gene of Escherichia coli.

The nucleotide sequence of the 5'-proximal portion of the RNA polymerase beta subunit gene (rpoB) has been determined. From the nucleotide sequence it is possible to predict that NH2-terminal 390 amino acid residues of the protein. The codon utilization in this portion of the rpoB gene is similar to the utilization in the adjacent cluster of ribosomal protein genes. The NH2-terminal portion of the protein is rich in both acidic (59/390) and basic (54/390) amino acid residues; more than half of the basic residues are clustered within limited stretches of the polypeptide and may play a role in RNA polymerase-nucleic acid interaction.

Amino Acid Sequence↗
PubMed1979

Nucleotide sequence of the ribosomal protein gene cluster adjacent to the gene for RNA polymerase subunit beta in Escherichia coli.

The 3072-nucleotide-long sequence of a segment from the 88-min region of the Escherichia coli chromosome has been determined. The sequence covers the genes for ribosomal proteins L11 (rplK), LI (rplA), L10 (rplJ), and L7/L12 ((rplL), and the 5' end of the gene for the beta subunit of RNA polymerase (rpoB), along with the presumed regulatory regions for these genes. The probable locations of the promoter for the first two genes (the L11 operon) and the promoter for the latter three genes (the proximal part of the beta operon) have been identified. We have also found that the four ribosomal protein genes preferentially use codons that are recognized efficiently by the most abundant tRNA species. These and other features of the sequence results are discussed in relation to available information obtained from both in vitro and in vivo experiments on the expression of these ribosomal and RNA polymerase subunit genes.

Base Sequence↗
PubMed1979

Joint practice making progress but meeting with problems.

Officers of the National Joint Practice Committee, representatives of health care organizations, and nurses from four demonstration projects who were assembled at the Third National Conference on Joint Practice discuss the need for nurse-physician collaboration, what is required to make it work, and the problems and progress occurring at the project hospitals.

Attitude of Health Personnel↗
PubMed1975

Thermal inactivation and gradient studies of the active agent in rheumatoid arthritis.

Ten day embryonated eggs have been used for testing supernatants of pooled RA synovial tissues for the presence of the RA-active agent. A high thermal resistance of the agent was observed up to 40 min of heating both at 100 and 121 degrees C with complete loss of infectivity only after 60 min at 121 degrees C. The high thermal resistance at 121 degrees C suggested that the active agent does not depend on a double-stranded DNA or RNA. It probably has no protein component and has a minimal number of subunits for replication. The CsC1 ultracentrifugation identified a concentration of high infectivity at densities in the range of 1.440-1.490 g/ml in five experiments.

Animals↗
PubMed1972

Variation in accessible cell surface immunoglobulin among antibody-firming cells.

Spleen cells from CBA mice that had been primarily or secondarily immunized with sheep red blood cells were reacted at 0 degrees C with a (125)I-labeled polyvalent rabbit anti-mouse globulin reagent. After suitable washing, the cells were placed in a plaque-revealing monolayer and warmed to 37 degrees C. Plaques appeared within 10-20 min. Single plaque-forming cells (PFC) were taken from the middle of plaques, were washed by micromanipulation, and were singly dried on glass slides. The amount of attached antireceptor was assessed by quantitative radioautography. Great variation in "receptor density" was encountered among the 258 single cells studied. However, early, immature PFC in both primary and secondary responses had statistically significantly more receptors than late, mature PFC. On any given day point, no difference was found between IgM- and IgG-forming cells. The results were consistent with the view that cells still able to be driven to further proliferation by antigen retain receptors, and conversely that cells, as they mature, lose both receptors and ability to be influenced by antigen.

Animals↗