Heavy-top-quark decay into a W boson and a photon (gluon).
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Journal Article↗
Biomedical subjects
J Reid
Publications and source records attributed to J Reid.
Chlorophyll a/b binding (CAB) polypeptides of CP29, the internal chlorophyll a/b complex of PSII: characterization of the tomato gene encoding the 26 kDa (type I) polypeptide, and evidence for a second CP29 polypeptide.
CP29, the core chlorophyll a/b (CAB) antenna complex of Photosystem II (PSII), has two nuclear-encoded polypeptides of approximately 26 and 28 kDa in tomato (Lycopersicon esculentum). Cab9, the gene for the Type I (26 kDa) CP29 polypeptide was cloned by immunoscreening a tomato leaf cDNA library. Its identity was confirmed by sequencing tryptic peptides from the mature protein. Cab9 is a single-copy gene with five introns, the highest number found in a CAB protein. In vitro transcription-translation gave a 31 kDa precursor which was cleaved to about 26 kDa after import into isolated tomato chloroplasts. The Cab9 polypeptide has the two highly conserved regions common to all CAB polypeptides, which define the members of this extended gene family. Outside of the conserved regions, it is only slightly more closely related to other PSII CABs than to PSI CABs. Sequence analysis of tryptic peptides from the Type II (28 kDa) CP29 polypeptide showed that it is also a member of the CAB family and is very similar or identical to the CP29 polypeptide previously isolated from spinach. All members of the CAB family have absolutely conserved His, Gln and Asn residues which could ligate the Mg atoms of the chlorophylls, and a number of conserved Asp. Glu, Lys and Arg residues which could form H-bonds to the polar groups on the porphyrin rings. The two conserved regions comprise the first and third predicted trans-membrane helices and the stroma-exposed segments preceding them.
Amino Acid Sequence↗
Pilgrimage of pain: the illness experiences of women with repetition strain injury and the search for credibility.
Repetition strain injury (RSI), a non-specific and controversial constellation of work-related hand, arm and neck symptoms, became epidemic in Australian industry in the early 1980s. Fifty-two women who worked in a telecommunications organisation and a chicken processing factory and had been diagnosed as having RSI were interviewed about their perceptions and experiences of the illness. Their accounts of the search for caring and treatment, including their encounter with health and medical practitioners, suggest that the need to be believed and to establish their integrity dominated their 'pilgrimage'. The failure of the dominant explanations of RSI to accommodate the psychosocial and political dimensions of the illness thwarted this quest and, it is argued, contributed to its chronicity.
Adult↗
Assessment of physician perceptions on the fatality of cancer.
A questionnaire was developed to evaluate internists' perceptions about patients' survival of cancer as compared with other diseases. The questionnaire consisted of four pairs of survival-matched cancer and non-cancer diseases. The questionnaire was administered to 42 faculty members and 37 resident physicians in the Department of Medicine at the University of Missouri-Columbia. Physicians rated patients' survival of cancer to be significantly lower than patients' survival of comparable non-cancer diseases (p less than 0.001). Resident physicians estimated patients' survival of breast cancer to be significantly lower (p less than 0.007) and estimated the survival of lung cancer to be significantly higher than the faculty members' estimate (p less than 0.003). These physicians' perceptions could adversely affect the quality of care and the degree of consideration given to both cancer and non-cancer patients. The differences observed in faculty members' and resident physicians' responses were attributed to the greater knowledge and clinical experience of faculty rather than differences in attitudes toward cancer.
Health Knowledge, Attitudes, Practice↗
Invariance of the Doppler bandwidth with flow displacement in the illuminating field.
It is known that if single frequency continuously transmitted ultrasound or electromagnetic energy is reflected from "straight line flow," defined here as one or more scatters moving with constant velocity along an infinite straight line, the Doppler effect will shift the echo spectrum center frequency from the transmitted value, and broaden its bandwidth. It is proved that if such straight line flow is shifted laterally or in range anywhere in the field, i.e., without change of orientation, its Doppler bandwidth remains unchanged. (The "Doppler bandwidth" is here defined as the frequency difference between the extrema of the echo power spectrum.) The theorem holds true even though the time domain echo changes dramatically with motion of the flow path, and is believed to be valid for electromagnetic as well as ultrasound waves. Its implications with respect to flow measurement, as well as preliminary experimental and computational confirmation, will be discussed.
Blood Flow Velocity↗
Psychosocial needs of torture survivors.
Growing recognition that the world faces a modern epidemic of torture has stimulated widespread interest amongst mental health professionals in strategies for the treatment of survivors. In this article we outline the distinctive experiences of torture survivors who present for treatment in western countries. These survivors are usually refugees who, in addition to torture, have suffered a sequence of traumatic experiences and face ongoing linguistic, occupational, financial, educational and cultural obstacles in their country of resettlement. Their multiple needs call into question whether "working through" their trauma stories in psychotherapy will on its own ensure successful psychosocial rehabilitation. Drawing on our experience at a recently established service, we propose a broader therapeutic aim.
Adaptation, Psychological↗
Successful aging as adaptation to stress.
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Adaptation, Psychological↗
Two stage audit of cerebrovascular and coronary heart disease risk factor recording: the effect of case finding and screening programmes.
The level of recording of risk factors for cardiovascular disease by general practitioners in north east Scotland has been audited. The effect of the audit on recording levels has also been determined by means of a second audit one year later. Twenty four practices in Grampian took part in the study, each auditing a random selection of 100 records of male patients aged 35-64 years. The risk factors chosen were blood pressure, smoking habit, alcohol consumption, weight and height. Blood pressure was recorded in the majority of the records (68.0%) and the mean level of recording of all of the risk factors increased between the two audits. The increase in the recording of smoking habit, alcohol consumption and weight was statistically significant. Practices with organized systems of data collection had higher levels of risk factor recording than those without. The levels of recording achieved were thus dependent on factors that existed in the practices prior to the study. This suggests that to increase recording levels, future educational intervention should be aimed at changes of motivation.
Adult↗
Determinants of OmpF porin antigenicity and structure.
Sixty-six murine hybridomas raised to Escherichia coli B/r porin were used to identify and differentiate the epitopes of this outer membrane protein. Anti-porin monoclonal antibodies (mAb) were raised against outer membrane fragments, purified native trimeric porin (trimer), and purified sodium dodecyl sulfate-denatured monomeric porin (monomer). Immunochemical and flow cytometric methods identified five distinct cell surface-exposed determinants on OmpF. The peptide composition of porin epitopes was determined by analysis of mAb reactivity with cyanogen bromide-generated peptide fragments. Four of 43 anti-monomer mAb reacted with surface exposed sites on OmpF, defining epitopes that consist of residues within CNBr peptides d2, d3, and B. The anti-porin mAb panel was also used to evaluate changes in porin antigenic structure in strains with short ompF deletions. Flow cytometric experiments indicated that despite changes in porin permeability, little if any alteration of surface epitopes occurred in these strains. Western immunoblot analysis of the mutant porins showed loss of reactivity with numerous mAb, which was caused by changes in three spatially distinct epitopes at residues 108-111, 118-123, and 124-129. Our findings indicate that in these ompF mutants the residues responsible for altering porin permeability are not exposed on the cell surface, but are buried within the tertiary structure of the protein. One of these regions, which is apparently involved in the determination of channel permeability characteristics, is conserved among 15 of 16 different porin molecules which were screened with the anti-OmpF mAb panel.
Amino Acid Sequence↗
On the detection of the radiation amplitude zero in e+/-p collisions.
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Journal Article↗
Biogenesis of prokaryotic pores.
The prokaryotic pore-forming proteins are synthesized in the cytoplasm, and are assembled in their functional form in the outer membrane. They begin to traverse the cytoplasmic membrane via the SecY/SecA export pathway, which is shared also by periplasmic proteins. The sorting signals that direct these proteins to the outer membrane could be present in the three-dimensional conformations of the proteins, but some results suggest that they may be present in short, contiguous sequences. Outer membrane proteins share a rather hydrophilic amino acid composition, and appear to be rich in beta-sheets (with the exception of lipoproteins). This observation as well as the demonstration of periplasmic export intermediates favor the secretion pathway through the periplasm, as opposed to export through fusion sites between the inner and the outer membrane, but such intermediates have not yet been observed with the wild type proteins under physiological conditions.
Amino Acid Sequence↗
(+)-sotalol causes significant occupation of beta-adrenoceptors at concentrations that prolong cardiac repolarization.
The racemate (+/-) and the two enantiomers of sotalol were studied with regard to the effects on cardiac repolarization. In addition, the affinity to cardiac beta-adrenoceptors was investigated for the enantiomers. The effect on left ventricular monophasic action potential duration was assessed in the isolated perfused guinea-pig heart and the beta-adrenoceptor affinity of the compounds was studied, using a radioligand binding technique, in cellular membranes prepared from the left ventricular free wall of the cat. Moreover, the beta-adrenoceptor blocking potency of (+)-sotalol was studied in isolated strips of guinea-pig papillary muscles. Both the racemate and the two enantiomers of sotalol caused a concentration-dependent prolongation of the ventricular monophasic action potential duration. The maximal effect and the concentration causing half maximal effect (EC50 = 13 mumol/l) were similar for the racemate and the enantiomers, indicating lack of stereoselectivity for this effect. The beta-adrenoceptor affinity (equilibrium dissociation constant) of (+)-sotalol was 11 mumol/l and 4 mumol/l as estimated by the binding technique and in the isolated muscle strips, respectively. The affinity for (-)-sotalol, estimated by binding, was 0.6 mumol/l. Thus, at concentrations of (+)-sotalol required for a significant prolongation of cardiac repolarization, this isomer may cause significant beta-blockade. In this study the enantiomeric purity was better than 98%, so that the degree of beta-blockade may be even more pronounced if the enantiomeric purity of the (+)-enantiomer is less than 98%.
Action Potentials↗
A sensitive method for the assay of glutamine synthetase.
The method for the assay of glutamine synthetase (GlnS) relies on the gamma-glutamyl transferase reaction, i.e. the formation of glutamyl-gamma-hydroxamate from glutamine and hydroxylamine, and the chromatographic separation of the reaction product from the reactants. The method is not only simple and reliable, but also has a sensitivity comparable to those methods applying radioactively labelled substrates. This new procedure has been applied to the assay of GlnS in cultured rat cortical astroglial cells which have been treated with a homologous series of alpha, omega-bis-(dimethylamino)alkanes. Effects of these drugs on astroglial development are reported.
Alkanes↗
Genetic control of avian scleroderma.
The inheritance of avian scleroderma, a fibrotic autoimmune disease of chickens resembling human scleroderma, was investigated. Comb inflammations and lesions were used to determine the state of disease of 4-week-old chickens. All line 200 males and 60% of female line 200 chicks showed abnormalities. Crosses (F1) between line 200 and eight partially inbred lines of chickens maintained at the University of California at Davis were all normal. Backcrosses of F1 cocks to line 200 hens showed a higher incidence of scleroderma in males than in females for all lines. The incidence of affected birds varied between backcrosses from a low of 42% for backcross line 217 males derived from a New Hampshire line, to 88% for males of backcross line 213 derived from a partially inbred Leghorn line, demonstrating the presence of genes modifying the penetrance of presumed major genes causing the disease. Backcross genotypes segregating for haplotypes of the major histocompatibility complex (MHC) derived from inbred lines showed consistently lower penetrance of scleroderma than homozygotes carrying the line 200 haplotype. Thus B3Bs (lines 211 and 215), B14Bs (line 217), and B15Bs (lines 212, 213, 216, and 218) all had fewer affected individuals than BsBs homozygotes from the same families.
Animals↗
On the behavior of instantaneous frequency estimators implemented on Doppler flow imagers.
Analytical and experimental results have been used to examine the behavior of the "autocorrelator" or instantaneous frequency detector (IFD) applied to color-coded Doppler flow mapping. Two effects were studied. The first was the influence of noise, as modified by a stationary echo canceler, on the Doppler frequency detector. Our theoretical considerations predict that uncorrelated input noise signals become partially correlated after cancellation, and bias the response to flow signals. This effect was confirmed by experiment. The canceler introduces a constant negative bias into the denominator of the algorithm implemented by the estimator, thus changing the indicated frequency. The second phenomenon, examined through processing computer simulated Doppler signals added to real noise, is related to the possible ambiguity, called aliasing, of measurements of the mean frequency for wide-band Doppler spectra. We show that aliasing cannot be observed with these spectra unless the signal is first processed by a canceler. Thus, regions of apparent reversed flow direction on two-dimensional flow images of turbulence must usually be due to real reversal of the flow direction.
Algorithms↗
The development of the New South Wales Service for the Treatment and Rehabilitation of Torture and Trauma Survivors (STARTTS): the first year.
Many immigrants to Australia are refugees, some of whom have experienced acute stress and trauma, including torture, prior to or during their escape from their home countries. In response to a growing recognition that the health care services may not be meeting the needs of these people the NSW Department of Health funded the establishment of a community-based rehabilitation service for traumatised refugees. This paper provides an overview of the recent history of the service, some of the organisational and staffing issues faced during its first year, some characteristics of the first 200 clients, principles of treatment, clinical, nosological and therapeutic issues and relationships with other agencies.
Adult↗
Postsurgical care of elderly women with fractures of the proximal femur.
The outcome for elderly women suffering a fracture of the proximal femur remains poor. Attempts to improve care in the past have mainly focused on surgical and perioperative techniques. More recently evidence has become available showing the impact of postoperative and rehabilitative care in these frail elderly patients. This article highlights this evidence and provides practical guidelines for good clinical practice.
Aged↗