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Biomedical subjects

J McDougall

Publications and source records attributed to J McDougall.

At least 19 recordsLinked to original sources
PubMed1991

DNA sequence and analysis of the bet genes encoding the osmoregulatory choline-glycine betaine pathway of Escherichia coli.

The sequence was determined of 6493 nucleotides encompassing the bet genes of Escherichia coli which encode the osmoregulatory choline-glycine betaine pathway. Four open reading frames were identified: betA encoding choline dehydrogenase, a flavoprotein of 61.9kDa; betB encoding betaine aldehyde dehydrogenase (52.8kDa); betT encoding a proton-motive-force-driven, high-affinity transport system for choline (75.8kDa); and betl, capable of encoding a protein of 21.8kDa, implicated as a repressor involved in choline regulation of the bet genes. Identification of the genes was supported by subcloning, physical mapping of lambda placMu53 insertions, amino acid sequence similarity, or N-terminal amino acid sequencing. The bet genes are tightly spaced, with betT located upstream of, and transcribed divergently to, the tandemly linked betIBA genes.

Alcohol Oxidoreductases↗
PubMed1989

The complete amino acid sequence of ribosomal protein S18 from the moderate thermophile Bacillus stearothermophilus.

The amino acid sequence of ribosomal protein S18 from Bacillus stearothermophilus has been completely determined by automated sequence analysis of the intact protein as well as of peptides derived from digestion with Staphylococcus aureus protease at pH 4.0 and cleavage with cyanogen bromide. The carboxy-terminal region was verified by both amino acid analyses of chymotryptic peptides and by mass spectrometry from the terminal region. The protein contains 77 amino acid residues and has an Mr of 8838. Comparison of this sequence with the sequences of the S18 proteins from tobacco and liverwort chloroplasts and E. coli shows a relatively high similarity, ranging from 42 to 55% identical residues with the B. stearothermophilus S18 protein. The regions of homology common to all four proteins consist of several positively charged sections spanning the entire length of the protein.

Amino Acid Sequence↗
PubMed1989

Transsynaptic spread of varicella zoster virus through the visual system: a mechanism of viral dissemination in the central nervous system.

We report a patient with pathologic evidence of anterograde spread of varicella zoster virus (VZV) through the visual system. A 29-year-old homosexual man developed the acquired immunodeficiency syndrome (AIDS) 2 months before the onset of left herpes zoster ophthalmicus. During the next 11 months, the zoster infection progressed to involve the left eye, with resultant keratitis, iritis, retinitis, and eventual blindness. Later, the patient developed bilateral blindness, left hemiparesis, and fatal pneumonia. At autopsy, the brain revealed destruction of the visual system and adjacent structures, with sparing of the remainder of the brain. Glial cells near the areas of necrosis showed Cowdry type A intranuclear inclusions. In situ hybridization with probes to VZV nucleic acid sequences were positive in the necrotic brain and retinal areas. Hybridization with probes to cytomegalovirus, herpes simplex virus type II, human immunodeficiency virus, and Epstein-Barr virus were negative. Electron microscopy revealed characteristic herpes group nucleocapsids. This case provides insight into the mechanisms of virus dissemination and the production of encephalitis.

Acquired Immunodeficiency Syndrome↗
PubMed1989

A study of the basic principles determining the performance of several high-flux dialyzers.

The clearance characteristics of several commercially available high-flux dialyzers made from cellulose acetate, polyacrylonitrile, polysulphone, and polymethylmethacrylate were studied in vivo. The impact of increasing surface area and adding ultrafiltration on the clearances of small- and larger-molecular-weight species was assessed. The results show there are major differences in large-molecular-weight substance substance handling by different dialyzers as shown by differences in beta 2-microglobulin clearance, independent of ultrafiltration capacity. Membranes made from similar material, eg, Asahi's PAN and Hospal's AN-69 membrane, both made from polyacrylonitrile, differ significantly in their beta 2-microglobulin clearance. Increased surface area results in much greater increase in large-molecular-weight substance clearance. The present study clearly demonstrates that high water flux is not related to high large-molecular-weight permeability. Decisions with respect to impact on dialysis must be based on a knowledge of both the large- and small-molecular-weight permeabilities of the various membranes.

Acrylic Resins↗
PubMed1989

The dead father: on early psychic trauma and its relation to disturbance in sexual identity and in creative activity.

This paper explores the origins of two clinical phenomena which are frequently related in analytic practice, namely sexual deviancy and inhibition in creative or intellectual work. The analysands in question seek psychoanalytic help not for their sexual acts and object-choices but because of blockage in their professional activities. In the author's opinion the roots of both sexual deviancy and creativity may often be traced back to early psychic trauma. The sexual 'solution' and the creative activity both represent ways of attempting to overcome the traumatic situation of infancy. These propositions are illustrated by the case of an author who sought help because her writing was completely blocked and because her homosexual love-relations caused tension and concern. The sudden death of her father when she was fifteen months old and her mother's disturbed way of handling the tragic situation were decisive factors in both the patient's sexual and professional life.

Adult↗
PubMed1989

Vision screening of school age children in Missouri.

In this report, vision screenings conducted by schools in the state of Missouri are reviewed. Data were generated by the 127 participating schools in 38 school districts that responded to four research questions. In general, many inadequacies exist in schools regarding vision screening. Recommendations include greater participation in the public school arena by vision specialists and the development of consistent criteria for vision screening in school districts.

Adolescent↗
PubMed1988

Extended N-terminal sequencing of proteins of archaebacterial ribosomes blotted from two-dimensional gels onto glass fiber and poly(vinylidene difluoride) membrane.

Previously uncharacterized proteins from intact ribosomes and ribosomal subunits of the extreme halophile Halobacterium marismortui (Haloarcula marismortui) were isolated and separated by high-resolution two-dimensional electrophoresis (2DE). N-Terminal amino acid sequences of 14 of these acidic large-subunit proteins were obtained by direct blotting of the separated proteins from two-dimensional electrophoresis gels to sequencer-stable supports followed by excision of the protein spots and sequencing. Furthermore, long internal sequences were obtained by in situ enzymatic cleavage of halobacterial proteins in gel pieces obtained from two-dimensional gels followed by electrophoretic separation of the fragments, blotting, and sequencing. Precautions are outlined for avoidance of N-terminal blockage of proteins, and the preparation and selection of suitable supports for obtaining extended N-terminal sequences are described. The results suggest that when prior fractionation is carried out to enrich for cell organelles, subcellular components of cells, or cell membranes, it is routinely possible to obtain numerous N-terminal sequences from one or a few 2DE gels of such fractions. Our results also indicate that, with appropriate precautions, proteins are routinely obtainable from 2DE gels in a form suitable for both N-terminal and internal sequence determination and show no detectable evidence for N-terminal blockage or destruction or modification of labile amino acid residues.

Acetates↗
PubMed1987

Structure and evolution of the 4.5-5S ribosomal RNA intergenic region from Glycine max (soya bean).

The nucleotide sequence for the 4.5-5S ribosomal DNA region from the chloroplastids of soya beans was determined as the basis of further comparative studies on the structure and evolution of this intergenic region. Comparisons with other plant sequences as well as equivalent sequences in eubacteria suggest that the longer internal transcribed spacer regions of plants have evolved, at least in part, by DNA sequence duplications and that the presence of the 4.5S rRNA in chloroplast may result from the accidental acquisition of a RNA maturation site during the evolution of longer internal transcribed spacer regions. Estimates of the secondary structures also indicate only a very limited retention of structural features and suggest that the primary role of the intergenic sequences may be to bring processed sites into close proximity.

Bacillus subtilis↗
PubMed1987

Evolutionary changes in the higher order structure of the ribosomal 5S RNA.

Comparative studies have been undertaken on the higher order structure of ribosomal 5S RNAs from diverse origins. Competitive reassociation studies show that 5S RNA from either a eukaryote or archaebacterium will form a stable ribonucleoprotein complex with the yeast ribosomal 5S RNA binding protein (YL3); in contrast, eubacterial RNAs will not compete in a similar fashion. Partial S1 ribonuclease digestion and ethylnitrosourea reactivity were used to probe the structural differences suggested by the reconstitution experiments. The results indicate a more compact higher order structure in eukaryotic 5S RNAs as compared to eubacteria and suggest that the archaebacterial 5S RNA contains features which are common to either group. The potential significance of these results with respect to a generalized model for the tertiary structure of the ribosomal 5S RNA and to the heterogeneity in the protein components of 5S RNA-protein complexes are discussed.

Animals↗
PubMed1986

Accessibility of phosphodiester bonds in the yeast ribosomal 5 S RNA protein complex.

The tertiary structure of the protein-associated yeast ribosomal 5 S RNA was examined using ethylnitrosourea reactivity as a probe for phosphodiester bonds. A reduced reactivity was consistently observed in at least nine residues within four distinct regions of the RNA sequence. Seven of these were also observed in three regions of the free RNA molecule while two, A27 and G30, were only present in the ribonucleoprotein complex. The results strongly suggest that the tertiary structure of the free eukaryotic 5 S RNA is largely conserved in the 5 S RNA-protein complex although it appears to be further stabilized in interaction with the ribosomal protein.

Base Sequence↗
PubMed1986

Extended secondary structure in 5S rRNAs from a sulphur metabolizing archaebacterium, Thermococcus celer.

While this sequence shares a significant homology with the 5S RNAs of other archaebacteria and is consistent with current models for the secondary structure of 5S RNAs, it contains three unusual features. The G + C content (72-74%) is significantly higher than other 5S RNAs; the secondary structure is distinguished by unusually stable and extended helical structures and, most important, there is evidence for sequence heterogeneity in the form of complementary base substitutions and precursor processing. This supports recent evidence (Newmann, H., Gierl, A., Tu, J., Leibrock, J., Staiger, D. and Zillig, W. (1983) Mol. Gen. Genet. 192, 66-72) that, like many of the higher eukaryotes, this group of sulphur-metabolizing bacteria may contain multiple 5S RNA genes.

Archaea↗
PubMed1986

Complications resulting from spurious fields produced by a microwave applicator used for hyperthermia.

Microwave hyperthermia applicators are generally characterized at two or three frequencies. These frequencies usually are at the extremes of the applicator's operating range. However, such applicators are often used at arbitrary frequencies within their range. The most common reason for choice of frequency is to achieve acceptable coupling in the clinical configuration with a given patient. Occasionally a spurious transmission pattern will result from the frequency chosen that can lead to undetected high power densities well away from the target volume. In the present report, such a situation is discussed. The transmission pattern resembled "horns" reported at the field edge of certain accelerators. This pattern resulted in the inability to heat the target volume and the production of thermal blisters outside that volume. Such an occurrence underscores the need to characterize the transmission characteristics of a microwave hyperthermia applicator at all the frequencies used.

Diathermy↗
PubMed1986

The trans-cis isomerization of trans-4'-(2-hydroxy-3,5-dibromo-benzylamino)cyclohexanol in vivo and in vitro in different species.

Isomerization of trans-4'-(2-hydroxy-3,5-dibromo-benzylamino)cyclohexanol (HDBC) in vivo has been investigated in horse, cow, dog, rat and man. Following oral administration of 4'-trans-HDBC to the horse, a very efficient first-pass trans-cis isomerization was observed. In the urine of the horse and cow, 40% and 29% respectively of the conjugated alcohols consisted of the 4'-cis isomer. Isomerization in rat and dog took place only to a small extent, and in man no 4'-cis isomer was detected. Oxidation of HDBC to the corresponding ketone, at pH 9.0, was highest with horse- and rat-liver 10 000 g supernatants and lowest with dog-liver supernatant. Reduction of the ketone with 10 000 g liver supernatants and with cryst. horse-liver alcohol dehydrogenase led to the formation of the alcohol containing 42-69% as the 4'-cis isomer, whereas after reduction with NaBH4 the alcohol contained only 20% of the 4'-cis isomer. This indicates that the conformer with the lower energy (1' and 4' position equatorially substituted) preferentially formed only during chemical reduction. A correlation between the formation of the ketone in vitro and the formation of 4'-cis-HDBC in vivo was observed in the horse, cow and dog. No similar correlation was found in the rat, where a high in vivo trans-cis isomerization might have been expected from the in vitro data.

Administration, Oral↗
PubMed1986

Identifications, neoneeds and neosexualities.

With regard to perversions, the pertinent question is not which acts and which object-preferences are to be deemed deviant, but when is deviance to be regarded as a simple variation or version of adult sexuality and when is it to be judged symptomatic. This paper proposes that only relationships may aptly be termed perverse. The term neosexualities is chosen to emphasize the innovative and somewhat unreal character of deviant sexual acts and relationships. These are a response to incoherent communications and unconscious problems on the part of parents. The concept of addictive sexuality or neoneeds is also introduced in reference to the compulsivity that invariably accompanies perverse sexuality. Its dynamic and economic aspects are summarized as follows: those who have created a neoreality in terms of sexual acts and objects in the service of libidinal homeostasis, and neoneeds in the service of narcissistic homeostasis, have short-circuited the elaboration of phallic-oedipal castration anxiety and at the same time through disavowing the problems of separateness and of infantile sadism have also circumvented what Klein termed the elaboration of the depressive position. A clinical vignette is given to illustrate the above theoretical propositions.

Adult↗