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Biomedical subjects

C Hughes

Publications and source records attributed to C Hughes.

At least 271 records · Page 15Linked to original sources
PubMed1987

Doppler microwave. A clinical assessment of its efficacy as an arterial pulse sensing technique.

A new Doppler microwave device designed for noninvasive arterial pulse detection by assessment of arterial wall motion was clinically evaluated. Carotid pulse tracings obtained with the microwave device were compared with simultaneously obtained intra-aortic pressure pulse waves. Ease and quality of the recording were also evaluated in 25 consecutive patients undergoing echocardiography. In 92% of the patients tested, good quality carotid pulse tracings could be obtained. T1/2 values and systolic time intervals were calculated from these recordings and correlated well with the known disease states of these patients, which ranged from aortic stenosis and aortic insufficiency to chronic heart failure. Finally, microwave tracings were faithful reproductions of invasive recordings of arterial pressures when compared on the basis of left ventricular ejection times and pulse contour.

Aged↗
PubMed1986

Squamous cell carcinoma of bladder: an increased incidence in blacks.

In a ten-year review of bladder cancer cases at the University Hospital, Cincinnati, Ohio, there was an apparent increased incidence of squamous cell histology in black patients. We report the findings of our local study as well as the results of our literature search on bladder cancer histology in racial subgroups. Squamous cell carcinoma represents 10 to 15 per cent of bladder cancer cases in blacks and approximately 5 per cent of bladder cancer cases in whites.

Adult↗
PubMed1985

Structure of the galactokinase gene of Escherichia coli, the last (?) gene of the gal operon.

We present the nucleotide sequence of the galactokinase gene (galK) of Escherichia coli including its 5' and 3' flanking regions. This DNA sequence derives from the lambda gal8 transducing phage and is identical to the sequence present in the galK gene fusion vectors, pKO and pKG, commonly used to study transcriptional regulatory elements. We define the precise 3' junction between the bacterial and phage sequences in lambda gal8 and demonstrate that this junction probably results from a homologous recombination event between identical 9 bp sequences common to the gal operon and phage lambda. Moreover, we examine the 300 bp region located immediately beyond galK for transcription termination function and find no gal operon terminator. Lastly, we compare the galK genes of E. coli and the yeast S. cerevisiae and find several regions of strong homology among which is a potential ATP-binding site homology shared by a variety of ATP-binding proteins including protein kinases encoded by mammalian oncogenes.

Adenosine Triphosphate↗
PubMed1985

The inflammatory response in the synovium of a patient with Ross River arbovirus infection.

Ross River virus has been incriminated in the etiology of many sporadic and epidemic cases of polyarthritis in Australia and the Pacific. Both synovium and synovial exudate fluid recovered from the knee of an epidemic polyarthritis patient showed a predominantly mononuclear leucocyte infiltrate. Infectious virus could not be recovered from the synovial exudate. Functional natural killer cells were detected in the synovial fluid. Their level of cytotoxic activity was similar to that detected in the peripheral circulation.

Arthritis, Infectious↗
PubMed1985

Cloning and characterization of genes involved in production of mannose-resistant, neuraminidase-susceptible (X) fimbriae from a uropathogenic O6:K15:H31 Escherichia coli strain.

The uropathogenic Escherichia coli strain 536 (O6:K15:H31) exhibits a mannose-resistant hemagglutination phenotype (Mrh) with bovine erythrocytes and delayed Mrh with human and guinea pig erythrocytes. Neuraminidase treatment of the erythrocytes abolishes mannose resistant hemagglutination, which is typical for X fimbriae. E. coli strain 536 synthesizes two different fimbriae (Fim phenotype) protein subunits, 16.5 and 22 kilodaltons in size. In addition the strain shows mannose-sensitive hemagglutination and common type I (F1) fimbriae. The cosmid clone E. coli K-12(pANN801) and another nine independently isolated Mrh+ cosmid clones derived from a cosmid gene bank of strain 536 express the 16.5-kilodalton protein band, but not the 22-kilodalton protein, indicating an association of the Mrh+ property with the "16.5-kilodalton fimbriae." All cosmid clones were fimbriated, and they reacted with antiserum produced against Mrh+ fimbriae of the E. coli strain HB101(pANN801) and lacked mannose-sensitive hemagglutination (F1) fimbriae. From the Mrh fim cosmid DNA pANN801, several subclones coding for hemagglutination and X fimbriae were constructed. Subclones that express both hemagglutination and fimbriae and subclones that only code for the hemagglutination antigen were isolated; subclones that only produce fimbriae were not detected. By transposon Tn5 mutagenesis we demonstrated that about 6.5 kilobases of DNA is required for the Mrh+ Fim+ phenotype, and the 1.5- to 2-kilobase DNA region coding for the structural protein of the fimbriae has been mapped adjacent to the region responsible for the Mrh+ phenotype. Two different regions can thus be distinguished in the adhesion determinant, one coding for hemagglutination and the other coding for fimbria formation. Transformation of plasmid DNA from these subclones into a Mrh- Fim- mutant of E. coli 536 and into a galE (rough) strain of Salmonella typhimurium yielded transformants that expressed both hemagglutination and fimbria production.

Animals↗
PubMed1985

Oropharyngeal Candida prophylaxis in pediatric bone marrow transplant patients.

The effect of a multi-agent regimen on oropharyngeal candidiasis (OPC) prophylaxis in 16 consecutive pediatric bone marrow transplant patients was assessed. The multi-agent regimen consisted of: 1) debriding all mucous membrane surfaces within the oropharyngeal cavity with povidone-iodine 4 times a day, 2) swabbing all mucous membrane surfaces within the oropharyngeal cavity with nystatin 4 times a day, and 3) Ketoconazole given daily by mouth. Multi-agent regimen therapy was initiated on the day marrow ablative therapy began, and was terminated when the patient's absolute neutrophil count recovered to above 500/mm3. Baseline oropharyngeal fungal cultures indicated that 8 out of 16 (50%) of the patients were Candida carriers. Subsequent surveillance cultures indicated that 13 out of 16 (81.3%) of the patients had negative oropharyngeal fungal cultures during the entire period they were on the multi-agent regimen. The remaining three patients had negative oropharyngeal fungal cultures by the end of the experimental period. None of the patients developed Candida esophagitis or sepsis. The above regimen is an effective and non-toxic method to prevent oropharyngeal candidiasis in pediatric BMT patients.

Adolescent↗
PubMed1984

Electrical conductivity of a docusate sodium coacervate system.

The conductivity of three xanthines (caffeine, theobromine, and theophylline) and three sugars (glucose, sucrose, and glucose-6-phosphate) was measured as part of a docusate coacervate system. The conductivity of the coacervate phase was always lower than the equilibrium phase. Conductivity of xanthines showed that caffeine had the highest conductivity, followed by theobromine and theophylline. At high concentrations, these values fell and the highest conductivity was seen in samples containing theobromine, caffeine, and theophylline. For sugars at high concentrations, the lowest values of conductivity were seen in sucrose samples. Saturated theophylline samples exhibited an increased volume in the coacervate phase volume. These findings are discussed with reference to various clinical parallels and thus supply evidence that coacervates can provide a useful model for human cytoplasm.

Caffeine↗
PubMed1984

Expression and regulation of the plasmid-encoded hemolysin determinant of Escherichia coli.

As a first approach towards studying the regulation of hemolysin synthesis in Escherichia coli, we have fused lacZ into the four hly genes (hlyC, hlyA, hlyBa and hlyBb) using the Mud-1 (Mu::lacZ, Y, Apr) phage. The sites of insertion of Mud-1 within the various hly genes of the Hly plasmid pHly152 were determined by the hemolytic phenotype of the Hly- mutants (Hly-ex/Hly-in or Hly-ex/Hly+in) and by complementation of these Hly- mutants with recombinant plasmids carrying cloned hly genes. It was found that hlyC, hlyA and hlyBa are transcribed from a relatively weak promoter (hlypL) located in front of hlyC. The activity of beta-galactosidase is considerably lower when Mud-1 is integrated in hlyBa than when it is inserted in hlyC, suggesting a considerable decline in hly gene expression from hlyC to hlyBa. The DNA sequence upstream of the coding region of hlyC was found to promote galK gene expression when a fragment covering this region was inserted into the promoter-probe vector pKO-11. A putative promoter sequence, which could correspond to hlypL, was identified in this sequence. The hlyBb gene appears to be transcribed from a different promoter and the direction of transcription seems to be opposite to that of the hlyC, A, Ba operon. The strength of this promoter (hlypR), based on the level of beta-galactosidase activity of Mud-1 insertion mutants in hlyBb, is considerably higher than that of hlypL.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1984

Microbial characteristics of the human dental caries associated with prolonged bottle-feeding.

Plaque samples from caries lesions, white spot margins of these lesions, and caries-free smooth enamel surfaces, obtained from seven subjects with nursing bottle caries, all contained unusually high proportions of Streptococcus mutans. The proportion of lactobacilli present in plaque from caries lesions was statistically greater (p less than 0.01) than the proportion present in plaque obtained from white spot margins of these lesions or caries-free smooth enamel surfaces.

Bottle Feeding↗
PubMed1983

Stimulation and inhibition by magnesium ions of intrinsic protein phosphorylating systems in synaptosomal membrane fragments from rat brain.

Synaptosomal membrane fragments from rat brain were incubated with [gamma-32P]ATP in the presence of cyclic AMP or Ca2+ plus calmodulin and a range of Mg2+ concentrations. Incorporation of 32P into membrane polypeptides was examined by electrophoresis and radioautography. Cyclic AMP-stimulated reactions were stimulated by low concentrations and inhibited to varying degrees by high concentrations of Mg2+ in the range 1-50 mM. In general the Ca2+ plus calmodulin-stimulated reactions were maximally active in the range 30-50 mM Mg2+, but the Ca2+ plus calmodulin dependent phosphorylation of Protein I was progressively inhibited by concentrations of Mg2+ above 5 mM. These results emphasize the importance of establishing optimum Mg2+ concentrations in the study of specific membrane protein phosphorylating systems.

Animals↗