Resolution of stress-induced myocardial ischemia during aggressive medical therapy as demonstrated by single photon emission computed tomography imaging.
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Angina Pectoris↗
Biomedical subjects
L Shaw
Publications and source records attributed to L Shaw.
Tooth surface pH during drinking of black tea.
OBJECTIVES: To investigate the composition of black tea in terms of its erosive potential. To determine the pH profile at the palatal surface of anterior and posterior sites of the dentition after drinking black tea. METHODS: Tea solution was analysed for its pH and anion composition to provide information on its acid content. A group of ten healthy subjects, aged 21-23 years were monitored for tooth surface pH on the palatal aspects of the maxillary anterior dentition and the maxillary molar dentition after drinking tea using a micro-pH electrode mounted on a vinyl splint. RESULTS: The pH of the tea solution was 4.9 and the major anions detected were oxalate and citrate. Tooth surface pH monitoring indicated that only small decreases in pH of less than 1 pH unit were observed after drinking tea and the minimum mean pH reached was 5.45. Maximum decrease in pH was observed after 20-25 seconds and resting pH levels were restored within approximately 2 minutes after drinking. CONCLUSION: The pH and anion profile of black tea are indicative of low acid composition. The very small pH decreases observed at the tooth surface after drinking tea indicate that it may be safely recommended as a substitute for more acidic drinks as a part of preventive measures for dental erosion.
Adult↗
Dental erosion in a group of British 14-year-old school children. Part II: Influence of dietary intake.
OBJECTIVES: The aims of the present study were first to investigate the dietary intake pattern of UK teenagers and secondly to determine the relationship, if any, between dental erosion and dietary intake in these children. METHODS: The study group consisted of a cluster random sample of 14-year-old school children in Birmingham, UK: 418 children were examined from 12 different schools; 209 were male and 209 female. Data on the rate and frequency of consumption of drinks, foods, and fruits were obtained from a self-reported questionnaire supplemented by a structured interview. The data were analysed using SPSS with Chi-square, and Spearman correlation analysis. RESULTS: Over 80% of the teenagers regularly consumed soft drinks but approximately half of these children had a relatively low weekly consumption. However, 13% and 10% respectively had more than 22 intakes per week of cola and other carbonated drinks. Almost a quarter of these 14-year-olds had alcoholic drinks, with significantly more males than females involved (Chi-square P < 0.05) . Girls had a greater intake of fruits. Statistically significant correlations were found between the prevalence of erosion and the consumption of soft drinks, carbonated beverages, alcohol drinks, fresh fruits, Vitamin-C tablets and foodstuffs (Spearman correlation analysis P < 0.05). CONCLUSION: It was concluded that consumption particularly of soft drinks was high and common in teenage school children in Birmingham, UK. In addition there was a relationship between dental erosion and acidic dietary intake. Further investigation of the erosive potential of these drinks and foods is required.
Adolescent↗
Dental erosion in a group of British 14-year-old, school children. Part I: Prevalence and influence of differing socioeconomic backgrounds.
OBJECTIVES: To establish the prevalence of erosion in a cluster random sample of 14- year-olds in Birmingham UK. To determine whether socioeconomic group influences the prevalence of erosion. METHODS: The study group consisted of a cluster random sample of 14-year-old school children in Birmingham UK: 418 children were examined from 12 different schools; 209 were male and 209 female. The level of tooth wear was recorded using a modification of the (TWI) index of Smith and Knight (1984). The ACORN classification was used to assess the socioeconomic status of all children. RESULTS: Results showed that 48% of the children had low erosion, 51% had moderate erosion and only 1% had severe erosion. There were statistically significant differences between males and females; more males had buccal/labial and lingual/palatal tooth surface erosion than females (Chi-square analysis P < 0.001). There was also significantly more erosion observed in teenagers in the lowest socioeconomic categories. CONCLUSION: It was concluded that moderate levels of dental erosion are common in 14-year-old school children and this may lead to increasing clinical problems. There was significantly more erosion in children from low socioeconomic groups. Possible aetiological factors need to be investigated further.
Adolescent↗
Characterization of the MHC class I region of the Japanese pufferfish (Fugu rubripes).
A BAC map of the Japanese pufferfish (Fugu) MHC class I region was constructed using a mixture of sequence scanning and sequence-tagged site mapping methodologies. The Fugu MHC class Ia genes are linked to genes which are found within the human classical MHC class II and extended class II regions, a situation which has been found in the MHC of all teleosts mapped so far. The 300-kb contig comprises 24 MHC-related genes and is bounded by six non-MHC genes, which are thought to represent an evolutionary breakpoint within the region. Comparative analysis with both human and zebrafish MHC maps indicates two blocks of genes (KNSL2, ZNF297, DAXX, TAPBP, FLOTILLIN; and PSMB8, PSMB10, PSMB9, ABCB3, FABGL, BRD2, COL11A2, RXRB) which have remained linked over 400 million years and may represent an ancestral arrangement of the vertebrate MHC. Zebrafish and Fugu diverged between 100-200 million years ago and differences exist between these two fish species. The position and number of MHC class Ia genes is not conserved between species, there is an inversion of a block of nine genes centering on the PSMB cluster, and additional genes are present in zebrafish coding for a transport-associated protein and a beta proteasome subunit. The extent of these differences has implications for the extrapolation of fish model organism data to commercial aquaculture species. The data presented here represent the most extensive analysis of a fish MHC class Ia region described so far and clearly delimit the extent of this region in Fugu and, potentially, all teleosts.
Animals↗
The bio-availability of fluoride from black tea.
OBJECTIVES: To investigate the oral retention of fluoride from tea and its association with the tooth surface and acquired pellicle. METHODS: Oral retention of fluoride after rinsing in vivo was assessed from expectorated samples with an ion specific electrode methodology. Interaction of fluoride with the tooth surface and acquired pellicle was examined in situ with enamel blocks mounted on partial removable appliances. In vitro models were used to examine fluoride binding to enamel particles. RESULTS: Thirty four percent of the fluoride was retained in the oral cavity after rinsing with tea. Differences in retention at the tooth surface in the presence and absence of an acquired pellicle were not statistically significant at incisor or molar sites. Fluoride from tea showed strong binding to enamel particles, which was only partially dissociated by solutions of ionic strength considerably greater than that of saliva. Binding studies demonstrated strong avidity of enamel for tea and salivary pellicle components. CONCLUSIONS: This study has demonstrated that tea can provide an effective vehicle for fluoride delivery to the oral cavity where it may interact with the oral tissues and their surface integuments. This may lead to local topical effects of the ingested fluoride as well as systemic effects following oral and gastro-intestinal absorption.
Adult↗
N-Glycolylneuraminic acid in human tumours.
N-Glycolylneuraminic acid (Neu5Gc) is an abundant sialic acid, occurring in the glycoconjugates of most deuterostome animals. Homo sapiens is a notable exception, since Neu5Gc is effectively absent from normal human tissues. This is due to a deletion in the human gene coding for CMP-Neu5Ac hydroxylase, the enzyme usually responsible for Neu5Gc biosynthesis. Despite this mutation, persistent reports in the literature suggest that Neu5Gc occurs in the glycoconjugates of many human tumours, where it might be responsible for the formation of so-called Hanganutziu-Deicher antibodies. However, the variety of systems studied and the various experimental approaches adopted have yielded a complex picture of Neu5Gc occurrence in human neoplasias. The aim of this paper is therefore to provide a critical review of the evidence for Neu5Gc in human tumours, paying particular attention to the analytical methods employed. The possible clinical applications of Neu5Gc-containing glycoconjugates and Hanganutziu-Deicher antibodies in the diagnosis and treatment of breast cancer and melanoma are also discussed. In view of the lack of CMP-Neu5Ac hydroxylase in human cells, alternative metabolic pathways for the biosynthesis of glycoconjugate-bound Neu5Gc are considered.
Antibodies, Heterophile↗
A comprehensive phylogenetic analysis of Rieske and Rieske-type iron-sulfur proteins.
The Rieske iron-sulfur center consists of a [2Fe-2S] cluster liganded to a protein via two histidine and two cysteine residues present in conserved sequences called Rieske motifs. Two protein families possessing Rieske centers have been defined. The Rieske proteins occur as subunits in the cytochrome bc1 and cytochrome b6f complexes of prokaryotes and eukaryotes or form components of archaeal electron transport systems. The Rieske-type proteins encompass a group of bacterial oxygenases and ferredoxins. Recent studies have uncovered several new proteins containing Rieske centers, including archaeal Rieske proteins, bacterial oxygenases, bacterial ferredoxins, and, intriguingly, eukaryotic Rieske oxygenases. Since all these proteins contain a Rieske motif, they probably form a superfamily with one common ancestor. Phylogenetic analyses have, however, been generally limited to similar sequences, providing little information about relationships within the whole group of these proteins. The aim of this work is, therefore, to construct a dendrogram including representatives from all Rieske and Rieske-type protein classes in order to gain insight into their evolutionary relationships and to further define the phylogenetic niches occupied by the recently discovered proteins mentioned above.
Amino Acid Motifs↗
Effects of the oestrous cycle and gender on acute vasodilatory responses of isolated pressurized rat mesenteric arteries to 17 beta-oestradiol.
The influence of the oestrous cycle and gender on responses of isolated pressurized mesenteric arteries to acute 17 beta-oestradiol was investigated. All vessels, pre-contracted with 60 mM KCl or 10 microM U46619 (9,11 dideoxy-11alpha, 9alpha-epoxy methano-prostaglandin), exhibited concentration-dependent vasodilatory responses to 17 beta-oestradiol (3 - 30 microM). The largest responses were seen in vessels from female rats in pro-oestrous (38.9+/-5.4% U46619 max and 63.1+/-4.0% KCl max for 30 microM oestradiol), the smallest from animals in di-oestrous (20.1+/-3.7% U46619 and 50.1+/-4.5% KCL - both P:<0.05 cf pro-oestrous (all n=8)). Responses of vessels from male rats were similar to those from pro-oestrous rats (41.5+/-9.1% U46619 (n=10) and 54.9+/-2.9% KCl (n =8)). All responsees were unaffected by inhibition of nitric oxide synthase (NOS). Female rats in pro-oestrous had the highest plasma concentrations of 17 beta-oestradiol and testosterone (40.76+/-4.73 pg ml(-1) and 0.29+/-0.05 ng ml(-1) respectively (n=8)) while those in di-oestrous had the lowest (15.24+/-3.94 pg ml(-1) for oestradiol and 0.08+/-0.03 ng ml(-1) for testosterone (n=8)). In male rats the concentration of oestrogen was 10.29+/-1.21 pg ml(-1) (n=7) while that of testosterone was 3.15+/-0.36 ng ml(-1) (n=7). Incubation of arteries isolated from male rats and from female rats in pro-oestrous and di-oestrous with testosterone (1 microM, 3 h) significantly enhanced the subsequent vasodilatory responses to acute 17 beta-oestradiol. Following incubation, the responses to 17 beta-oestradiol were similar in all groups. These observations suggest that gender and the oestrous cycle may influence the vascular responses to acute 17 beta-oestradiol administration.
Animals↗
Vegetarian children and dental erosion.
BACKGROUND: There have been recent changes in teenage lifestyle and diet. The increasing consumption of soft drinks and foods containing significant acidic components may play a role in the development of dental erosion. OBJECTIVE: The aims of this investigation were firstly to assess the prevalence of vegetarian children in a cluster random sample of 14-year-old children in Birmingham, United Kingdom. Secondly, to determine the prevalence of dental erosion in these children, and thirdly, to see if there were any differences between vegetarian and non-vegetarian children in the prevalence of dental erosion and dietary intake. DESIGN: A cluster random sample of 418 14-year-old children (209 males and 209 females) were examined from 12 different schools in Birmingham, United Kingdom; a dietary questionnaire was completed and the levels of tooth wear were recorded using a modification of the (TWI) index. All data were analysed using SPSS with t-test and Chi-square analysis. Significance was accepted at the P < 0.05 level. RESULTS: The results showed that 10% of the children were vegetarian; 52% of them had low dental erosion and 48% moderate dental erosion. Statistically there were no significant differences between vegetarian and non-vegetarian children in the prevalence of erosion; however, there were significant differences in some food and drink consumption. CONCLUSIONS: It was concluded that dental erosion is common in teenage children, but there were no significant differences in prevalence between vegetarian and non-vegetarian children.
Adolescent↗
Pulse rate over pressure evaluation (ROPE) is useful in the assessment of compensated haemorrhagic shock.
OBJECTIVE: To evaluate a calculation of pulse rate over pulse pressure as a method of predicting decompensation in patients with compensated haemorrhagic shock. METHODS: A retrospective cohort study was undertaken enrolling 184 adult victims of major road trauma who were not shocked on presentation to the emergency department. A pulse rate over pressure evaluation was calculated at presentation and vital signs were observed during the first 2 h of emergency department management. RESULTS: Thirty-one patients became shocked during their first 2 h. A ROPE value of greater than 3.0 had a positive predictive value of 53% and a value less than 3.0 had a negative predictive value of 86% for the development of decompensated shock. CONCLUSIONS: ROPE is an easily applied and useful clinical tool with a ROPE of less than 3.0 being predictive of a patient remaining well and a ROPE of above 3.0 being predictive of the patient developing decompensated shock.
Adolescent↗
Distribution and localization of CMP-N-acetylneuraminic acid hydroxylase and N-glycolylneuraminic acid-containing glycoconjugates in porcine lymph node and peripheral blood lymphocytes.
An immunohistochemical analysis was performed on paraplast-embedded sections of porcine lymph node with antibodies specific for CMP-N-acetylneuraminic acid hydroxylase (h-3 antibody) and glycoconjugate-bound N-glycolylneuraminic acid (Neu5Gc), which appears as a result of the hydroxylase reaction (a-Gc antibody). The observed localization of the enzyme in cells of the perifollicular zone, including lymphocytes, was reflected in a similar distribution of glycoconjugate-bound Neu5Gc. This result confirms previous biochemical investigations on the role of the hydroxylase in regulating Neu5Gc biosynthesis in vitro on a histological level. An analysis of lymphocytes isolated from porcine thymus, spleen, lymph node and peripheral blood revealed differences in the amount of Neu5Gc in the various lymphocytes that correlated well with the activity of the hydroxylase determined in these cells. The largest amount of Neu5Gc and highest activity of the enzyme were detected in the peripheral blood lymphocytes (PBL). Immunohistochemical studies with a-Gc and h-3 antibodies on sections of paraplast-embedded PBL showed that these antigens were located at the cell surface and in the cytosol, respectively. Ultrastructural immunocytochemistry with the h-3 antibody and immunogold labelling was used to investigate the subcellular localization of the hydroxylase. The enzyme was detected in the cytosol in the vicinity of the nuclear membrane and the outer membrane of mitochondria, in particular those close to the nucleus. The antigen was also detected on cytoplasmic tubular structures. In addition, a weak labelling of the Golgi apparatus was also observed occasionally. The possibility that this localization may be related to the availability of the substrate CMP-Neu5Ac and the redox partner cytochrome b5 is discussed.
Animals↗
Dens evaginatus on the labial surface of a central incisor: a case report.
A 7-year-old girl in the mixed dentition phase presented with abnormal morphology of the upper right central incisor. The diagnosis was a dens evaginatus, an anomaly of odontogenesis of unknown aetiology. This article describes the management of this anomaly and discusses the importance of maintaining space in the developing dentition. The aetiology and natural history of dens evaginatus are also considered.
Child↗
Clinical characteristics and long-term outcomes of patients with heart failure and preserved systolic function.
Although the syndrome of heart failure with preserved systolic function may occur in up to 40% of all heart failure patients, the clinical, angiographic characteristics, and long-term outcomes of these patients are poorly understood. We prospectively evaluated 2,498 consecutive patients with New York Heart Association class II to IV symptoms and ejection fractions of >40%, who underwent cardiac catheterization between January 1984 and December 1996 at Duke University Medical Center. The median age for the entire cohort was 63 years; 25% of the population was >71 years old. In addition, 55% of the patients were women, 65% had ischemic heart disease, 28% had a history of diabetes, and 62% had a history of hypertension. The median ejection fraction was 58%. One third of the patients had multivessel disease by coronary angiography. The overall 5-year mortality of the total population was 28%. The independent predictors of mortality (p <0.05) using a multivariable Cox proportional hazard model were age, class IV symptoms, ejection fraction, coronary artery disease index, diabetes, peripheral vascular disease, and minority ethnic group. Heart failure with preserved systolic function is characterized by unique clinical and angiographic characteristics associated with a 5-year mortality rate of 28%. Furthermore, several clinical and angiographic characteristics are predictive of long-term survival.
Aged↗
Development and characterization of human and mouse specific antibodies to CuZn-superoxide dismutase (SOD1).
Mutations in the copper/zinc superoxide dismutase (SOD1) gene are associated with 15-20% of the familial forms of motor neuron disease. Mice where a transgene has been incorporated that encodes for the human SOD1 mutation develop a form of motor neurone disease that closely resembles human forms of this disease. We have produced and characterized species-specific antibodies to epitopes in the SOD1 protein, amino acids 25-37, a region that distinguishes between the human and the mouse species of SOD1. The antisera generated were unable to immunoprecipitate the mouse or the human forms of SOD1 from tissue extracts unless the homodimeric complex of SOD1 was denatured. As SOD1 exists as a homodimeric complex in the cytoplasm of cells, this suggests that amino acids in position, 25-37 are close to the dimeric interface of SOD1.
Animals↗
RAFTK/Pyk2 tyrosine kinase mediates the association of p190 RhoGAP with RasGAP and is involved in breast cancer cell invasion.
Focal adhesions and actin cytoskeleton are involved in cell growth, shape and movement and in tumor invasion. Mitogen-induced changes in actin cytoskeleton are accompanied by changes in the tyrosine phosphorylation of several focal adhesion proteins. In this study, we have investigated the role of RAFTK, a cytoplasmic tyrosine kinase related to focal adhesion kinase (FAK), in heregulin-mediated signal transduction in breast cancer cells. Stimulation of T47D cells with heregulin (HRG) induced the tyrosine phosphorylation of RAFTK and the formation of a multiprotein complex. Analyses of the members of the HRG-stimulated complex revealed that RAFTK is associated with p190 RhoGAP (p190), RasGAP and ErbB-2, and plays an essential role in mediating the tyrosine phosphorylation of p190 by Src. Mutation of the Src binding site within RAFTK (402) abolished the phosphorylation of p190. In addition, upon HRG stimulation of T47D cells, association of ErbB-2 with RAFTK was observed and found to be indirect and mediated by Src. Expression of wild-type RAFTK (WT) significantly increased MDA-MB-435 and MCF-7 breast cancer cell invasion, while expression of the kinase-mutated RAFTK-R457 (KM) or the Src binding site mutant RAFTK (402) did not affect this cell invasion. Furthermore, HRG leads to the activation of MAP kinase which is mediated by RAFTK. These findings indicate that RAFTK serves as a mediator and an integration point between the GAP proteins and HRG-mediated signaling in breast cancer cells, and implicate RAFTK involvement in the MAP kinase pathway and in breast cancer cell invasion.
Breast Neoplasms↗
Development and evaluation of a stand-alone web-based CAL program. A case study.
The use of web browser technology allows the construction of computer-aided learning programs which will have a familiar interface to dentists. This paper reports on the evaluation of a web-based CAL program which covered the topic of tooth wear with an emphasis on the rôle of erosion in its aetiology. Evaluation of the software was made by 50 dentists contacted by an electronic mailing list. They completed a questionnaire which evaluated aspects of the functionality of the program educational objectives. The average age of the dentists was 39 years (range 24-70) and 82% were male. The average time of use was 1 h 10 min (range 15 min to 3 h). A significant change in their knowledge of tooth wear before and after using the program was recorded. Both the use of patient cases and leaflets scored highly with other aspects such as treatment planning and patient advice receiving high marks. All dentists commented that they had gained greater knowledge with particular reference to treatment and advice of tooth wear problems. 34 dentists (68%) found the web interface easy to use. Negative comments were mainly attributed to the quality of the pictures (4/50) which were corrected in the final release version. Respondents were asked to compare the program to other educational media on the same subject. 80% rated this CAL program as better than video, and 14% claimed it was as good as video. 84% rated it better than books, and 14% said it was as good as books. 98% preferred it to audio tapes and 86% preferred it to journals. The average amount that they would pay for a CAL package such as "tooth wear" would be 42 ECU. It is concluded that web browser software is a suitable medium for the use of a CAL program and this is reflected in its ease of use by dentists.
Adult↗
Mechanisms of 17 beta-oestradiol induced vasodilatation in isolated pressurized rat small arteries.
1. The influence of 17 beta-oestradiol on pressurized isolated rat mesenteric and coronary small arteries was investigated. 2. 17 beta-oestradiol caused rapid (t1.0 < 5 mins) concentration-dependent relaxations of pre-contracted pressurized (50 mmHg) isolated rat mesenteric and coronary arteries. Similar responses were observed in both vessel types. Significant relaxations were only observed at concentrations exceeding 3 microM. 3. The vasodilatory responses in both types of artery were unaffected by 10 microM L-nitro arginine (L-NNA) alone or in the presence of 10 microM indomethacin, inhibitors of nitric oxide and prostaglandin synthesis respectively. They were also unaffected by the pre-contracting agent used i.e. high K+ or U46619 (a thromboxane analogue). 4. Neither the oestrogen receptor antagonist ICI 182,780 (10 microM) nor the protein synthesis inhibitor cycloheximide (100 microM) had any effect on the responses of mesenteric arteries to 17 beta-oestradiol. 5. 17 alpha-oestradiol had only a minor effect on mesenteric arterial diameter over a concentration range similar to the effective vasodilatory range for 17 beta-oestradiol. 6. Membrane impermeant 17 beta-oestradiol conjugated to bovine serum albumin (beta-oestradiol-17-hemisuccinate-BSA) (E-H-BSA) resulted in a vasodilatation of pressurized arteries. 7. Wortmannin, an inhibitor of myosin light chain kinase, near maximally relaxed pressurized mesenteric arteries although the time course for the response was significantly slower than that for 17 beta-oestradiol. 8. These results taken together suggest that the acute effects of 17 beta-oestradiol on isolated pressurized arterial tone may be due to effects directly on the vascular smooth muscle via non-genomic mechanisms that involve a stereospecific interaction at the plasma membrane.
Androstadienes↗