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Selepe HL, Thomas DJ. The beliefs and practices of traditional birth attendants in the Manxili area of KwaZulu, South Africa: a qualitative study. J Transcult Nurs 2000; 11:96-101. [PMID: 11982050 DOI: 10.1177/104365960001100203] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The World Health Organization recommends that people be within an hour of the nearest health care facility. In the Manxili region of KwaZulu, South Africa, difficult terrain and tribal fighting make this nearly impossible for pregnant women. Therefore, traditional birth attendants provide much of the midwifery services in this area. They have no medical training, and their beliefs and practices are not well understood. This study, therefore, gathered data on the beliefs and practices of seven attendants, using a case study analysis. Beneficial as well as harmful customs were identified and suggestions made for education of the attendants.
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Larner AJ, Thomas DJ. Can myasthenia gravis be diagnosed with the 'ice pack test'? A cautionary note. Postgrad Med J 2000; 76:162-3. [PMID: 10684328 PMCID: PMC1741529 DOI: 10.1136/pmj.76.893.162] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The ice pack test may be helpful in establishing that ptosis is due to ocular myasthenia gravis, since cold improves neuromuscular transmission. However, the role of the test in determining whether diplopia is of myasthenic origin has yet to be established.
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Abstract
Heart failure is the number one hospital admission for the elderly and a leading client population for home care with numbers expected to rise steadily during the next decade. This article discusses systolic and diastolic heart failure, compensatory mechanisms, pathophysiology, and the signs and symptoms of right and left-sided heart failure. The most current treatment regimen for managing the heart failure patient in the home including medication, diet, activity, and patient education is presented.
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Youngblut JM, Brady NR, Brooten D, Thomas DJ. Factors influencing single mother's employment status. Health Care Women Int 2000; 21:125-36. [PMID: 10818834 PMCID: PMC2792579 DOI: 10.1080/073993300245357] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Changes in the welfare system limit the length of time a person can receive welfare benefits, thus mandating employment for many current welfare recipients. Single mothers with young children who do not become employed will lose financial support for housing, food, clothing, and health care and place their own and their children's health and safety at risk. The purpose of this qualitative study was to explore women's experiences of being unemployed and to examine the barriers to employment perceived by single mothers who expressed a desire to be employed. Nine mothers were recruited from a larger sample of single mothers who had participated in a quantitative study about employment conducted 1 to 2 years earlier. Using focus group interviews, mothers were asked what it was like to be a single mother, and then what barriers to their employment they perceived. Two dimensions were identified from the mothers' statements. The first, a sense of obligation, included themes of "being there" for their own and their child's benefit and doing what it takes to optimize the child's growth and development. The second, negotiating the obstacles, referred to problems regarding child care, lack of involvement of the child's father and lack of support from relatives and friends for the mother's efforts toward securing employment. These findings have important implications for welfare reform, namely, that efforts aimed at moving nonemployed single mothers into the workforce will fail if these factors are not considered.
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Thomas DJ, Morgan JA, Whipps JM, Saunders JR. Plasmid transfer between the Bacillus thuringiensis subspecies kurstaki and tenebrionis in laboratory culture and soil and in lepidopteran and coleopteran larvae. Appl Environ Microbiol 2000; 66:118-24. [PMID: 10618212 PMCID: PMC91794 DOI: 10.1128/aem.66.1.118-124.2000] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plasmid transfer between Bacillus thuringiensis subsp. kurstaki HD1 and B. thuringiensis subsp. tenebrionis donor strains and a streptomycin-resistant B. thuringiensis subsp. kurstaki recipient was studied under environmentally relevant laboratory conditions in vitro, in soil, and in insects. Plasmid transfer was detected in vitro at temperatures of 5 to 37 degrees C, at pH 5.9 to 9.0, and at water activities of 0.965 to 0.995, and the highest transfer ratios (up to 10(-1) transconjugant/donor) were detected within 4 h. In contrast, no plasmid transfer was detected in nonsterile soil, and rapid formation of spores by the introduced strains probably contributed most to the lack of plasmid transfer observed. When a B. thuringiensis subsp. kurstaki strain was used as the donor strain, plasmid transfer was detected in killed susceptible lepidopteran insect (Lacanobia oleracea) larvae but not in the nonsusceptible coleopteran insect Phaedon chocleriae. When a B. thuringiensis subsp. tenerbrionis strain was used as the donor strain, no plasmid transfer was detected in either of these insects even when they were killed. These results show that in larger susceptible lepidopteran insects there is a greater opportunity for growth of B. thuringiensis strains, and this finding, combined with decreased competition due to a low initial background bacterial population, can provide suitable conditions for efficient plasmid transfer in the environment.
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Youngkin EQ, Thomas DJ. Vitamins: common supplements and therapy. Nurse Pract 1999; 24:50, 53, 57-60 passim; quiz 68-9. [PMID: 10618814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Vitamin supplements and therapies have recently gained popularity because of current scientific studies supporting their benefits. Although many consumers are taking vitamins and other supplements, they may not be aware of the numerous benefits and hazards associated with many of these over-the-counter substances. Clinicians should be familiar with common vitamin products so that they may prescribe and monitor their use. This article provides an overview of fat- and water-soluble vitamins, and addresses functions, deficiency effects, recommended dietary allowances, therapy uses, toxicity concerns, and food sources.
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Gnanapragasam VJ, Ramsden PD, Murthy LS, Thomas DJ. Primary in situ extracorporeal shock wave lithotripsy in the management of ureteric calculi: results with a third-generation lithotripter. BJU Int 1999; 84:770-4. [PMID: 10532969 DOI: 10.1046/j.1464-410x.1999.00284.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To review the results of primary in situ extracorporeal shock wave lithotripsy (ESWL) for the treatment of ureteric stones using a third-generation lithotripter, the Dornier MFL 5000 (Dornier Medizentechnic, Germany). PATIENTS AND METHODS The study comprised a retrospective review of treatment outcome in 180 patients with 196 stones who were treated with primary in situ ESWL, assessing the success of this approach and establishing reasons for failure. RESULTS At the 3-month follow-up, 88% of patients were stone-free; 21 patients failed ESWL and were treated by ureteroscopic stone extraction with no complications. Stone-free rates were 90% for upper ureteric, 89% for middle-third and 86% for lower-third calculi. Twenty-one patients required auxiliary procedures in the form of JJ stenting or nephrostomy. Failure of ESWL was associated with stone size (>1.3 cm) but not location or inadequate treatment. CONCLUSION Where prompt access to ESWL is available, primary in situ ESWL remains an effective form of treatment for all ureteric calculi, although stone-free rates are lower for larger stones.
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Lin S, Cullen WR, Thomas DJ. Methylarsenicals and arsinothiols are potent inhibitors of mouse liver thioredoxin reductase. Chem Res Toxicol 1999; 12:924-30. [PMID: 10525267 DOI: 10.1021/tx9900775] [Citation(s) in RCA: 176] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Thioredoxin reductase (TR, EC 1.6.4.5) was purified 5800-fold from the livers of adult male B6C3F1 mice. The estimated molecular mass of the purified protein was about 57 kDa. The activity of the purified enzyme was monitored by the NADPH-dependent reduction of 5, 5'-dithiobis(2-nitrobenzoic acid) (DTNB); this activity was fully inhibited by 1 microM aurothioglucose. Arsenicals and arsinothiols, complexes of As(III)-containing compounds with L-cysteine or glutathione, were tested as inhibitors of the DTNB reductase activity of the purified enzyme. Pentavalent arsenicals were much less potent inhibitors than trivalent arsenicals. Among all the arsenicals, CH(3)As(III) was the most potent inhibitor of TR. CH(3)As(III) was found to be a competitive inhibitor of the reduction of DTNB (K(i) approximately 100 nM) and a noncompetitive inhibitor of the oxidation of NADPH. The inhibition of TR by CH(3)As(III) was time-dependent and could not be reversed by the addition of a dithiol-containing molecule, 2,3-dimercaptosuccinic acid, to the reaction mixture. The inhibition of TR by CH(3)As(III) required the simultaneous presence of NADPH in the reaction mixture. However, unlike other pyridine nucleotide disulfide oxidoreductases, there was no evidence that mouse liver TR was inactivated by exposure to NADPH. Treatment with CH(3)As(III) did not increase the NADPH oxidase activity of the purified enzyme. Thus, CH(3)As(III), a putative intermediate in the pathway for the biomethylation of As, is a potent and irreversible inhibitor of an enzyme involved in the response of the cell to oxidative stress.
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Fletcher LL, Thomas DJ. The challenge of diagnosing the cause of jaundice. Nurse Pract 1999; 24:98-102. [PMID: 10546262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
The patient presenting with jaundice may have a variety of hepatobiliary or hematologic conditions. Understanding the causes of jaundice and the history and physical examination hallmarks provide the basis for choosing the most efficacious laboratory and diagnostic studies. A case report illustrating the reasoning involved in distinguishing between the different causes of jaundice is presented.
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Hughes MF, Kenyon EM, Edwards BC, Mitchell CT, Thomas DJ. Strain-dependent disposition of inorganic arsenic in the mouse. Toxicology 1999; 137:95-108. [PMID: 10521146 DOI: 10.1016/s0300-483x(99)00068-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Recent studies have suggested that polymorphisms in the methylation of inorganic arsenic (iAs) exist in animals and humans. Methylation of iAs is an important step in the elimination of arsenic. The objective of this study was to examine whether there are differences in iAs disposition, and hence methylation, between three strains of mice. Ninety-day-old female mice (strains: C3H/HeNCrlBR, C57BL/6NCrlBR, and B6C3F1/CrlBR) were administered [73As]arsenate or [73As]arsenite orally at dose levels of 0.5 or 5.0 mg As/kg. Another group of mice were administered [73As]arsenate (5.0 mg As/kg) intraperitoneally (i.p.). Disposition of [73As] was assessed by whole-body counting, and analysis of urine, feces and tissues for radioactivity. Urine was analyzed by chromatography for arsenic metabolites. Several strain- and dose-related effects in the disposition of [73As] were observed with both arsenicals. After oral administration, the clearance of [73As]arsenate, measured by whole-body counting, was dependent on the strain. However, because there was no strain dependence on clearance of [73As]arsenate administered i.p., the effect after oral administration may be due to a difference in absorption of arsenate between the strains. With increased oral dose of arsenate and arsenite, the clearance of [73As] was slower and there was higher tissue retention of [73As]. The percentage of metabolites excreted in urine also was affected by the administered dose. With increased dose, the percentage of arsenite and monomethylarsonic acid were significantly increased, and dimethylarsinic acid decreased. However, our results suggest there is no overall difference between these strains of mice with respect to disposition of iAs. A better understanding of the role of phenotype in the disposition and toxicity of iAs would reduce the uncertainty in arsenic risk assessment.
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Thomas DJ. Haemochromatosis and breast cancer: a rare cause of a rare disease? Int J Clin Pract 1999; 53:487. [PMID: 10622082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
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Calderon RL, Hudgens E, Le XC, Schreinemachers D, Thomas DJ. Excretion of arsenic in urine as a function of exposure to arsenic in drinking water. ENVIRONMENTAL HEALTH PERSPECTIVES 1999; 107:663-7. [PMID: 10417365 PMCID: PMC1566491 DOI: 10.1289/ehp.99107663] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Urinary arsenic (As) concentrations were evaluated as a biomarker of exposure in a U.S. population chronically exposed to inorganic As (InAs) in their drinking water. Ninety-six individuals who consumed drinking water with As concentrations of 8-620 microg/L provided first morning urine voids for up to 5 consecutive days. The study population was 56% male, and 44% was younger than 18 years of age. On one day of the study period, all voided urines were collected over a 24-hr period. Arsenic intake from drinking water was estimated from daily food diaries. Comparison between the concentration of As in individual urine voids with that in the 24-hr urine collection indicated that the concentration of As in urine was stable throughout the day. Comparison of the concentration of As in each first morning urine void over the 5-day study period indicated that there was little day-to-day variation in the concentration of As in urine. The concentration of As in drinking water was a better predictor of the concentration of As in urine than was the estimated intake of As from drinking water. The concentration of As in urine did not vary by gender. An age-dependent difference in the concentration of As in urine may be attributed to the higher As dosage rate per unit body weight in children than in adults. These findings suggest that the analysis of a small number of urine samples may be adequate to estimate an individual's exposure to InAs from drinking water and that the determination of the concentration of InAs in a drinking water supply may be a useful surrogate for estimating exposure to this metalloid.
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Styblo M, Del Razo LM, LeCluyse EL, Hamilton GA, Wang C, Cullen WR, Thomas DJ. Metabolism of arsenic in primary cultures of human and rat hepatocytes. Chem Res Toxicol 1999; 12:560-5. [PMID: 10409394 DOI: 10.1021/tx990050l] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The liver is considered a major site for methylation of inorganic arsenic (iAs). However, there is little data on the capacity of human liver to methylate iAs. This work examined the metabolism of arsenite (iAs(III)), arsenate (iAs(V)), methylarsine oxide (MAs(III)O), methylarsonic acid (MAs(V)), dimethylarsinous acid (DMAs(III)), and dimethylarsinic acid (DMAs(V)) in primary cultures of normal human hepatocytes. Primary rat hepatocytes were used as methylating controls. iAs(III) and MAs(III)O were metabolized more extensively than iAs(V) and MAs(V) by either cell type. Neither human nor rat hepatocytes metabolized DMAs(III) or DMAs(V). Methylation of iAs(III) by human hepatocytes yielded methylarsenic (MAs) and dimethylarsenic (DMAs) species; MAs(III)O was converted to DMAs. The total methylation yield (MAs and DMAs) increased over the range of 0.1 to 4 microM iAs(III). However, DMAs production was inhibited by iAs(III) in a concentration-dependent manner, and the DMAs/MAs ratio decreased. iAs(III) (10 and 20 microM) inhibited both methylation reactions. Inhibition of DMAs synthesis resulted in accumulation of iAs and MAs in human hepatocytes, suggesting that dimethylation is required for iAs clearance from cells. Methylation capacities of human hepatocytes obtained from four donors ranged from 3.1 to 35.7 pmol of iAs(III) per 10(6) cells per hour and were substantially lower than the methylation capacity of rat hepatocytes (387 pmol of iAs(III) per 10(6) cells per hour). The maximal methylation rates for either rat or human hepatocytes were attained between 0.4 and 4 microM iAs(III). In summary, (i) human hepatocytes methylate iAs, (ii) the capacities for iAs methylation vary among individuals and are saturable, and (iii) moderate concentrations of iAs inhibit DMAs synthesis, resulting in an accumulation of iAs and MAs in cells.
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Styblo M, Del Razo LM, LeCluyse EL, Hamilton GA, Wang C, Cullen WR, Thomas DJ. Metabolism of arsenic in primary cultures of human and rat hepatocytes. Chem Res Toxicol 1999. [PMID: 10409394 DOI: 10.1021/tx9900501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The liver is considered a major site for methylation of inorganic arsenic (iAs). However, there is little data on the capacity of human liver to methylate iAs. This work examined the metabolism of arsenite (iAs(III)), arsenate (iAs(V)), methylarsine oxide (MAs(III)O), methylarsonic acid (MAs(V)), dimethylarsinous acid (DMAs(III)), and dimethylarsinic acid (DMAs(V)) in primary cultures of normal human hepatocytes. Primary rat hepatocytes were used as methylating controls. iAs(III) and MAs(III)O were metabolized more extensively than iAs(V) and MAs(V) by either cell type. Neither human nor rat hepatocytes metabolized DMAs(III) or DMAs(V). Methylation of iAs(III) by human hepatocytes yielded methylarsenic (MAs) and dimethylarsenic (DMAs) species; MAs(III)O was converted to DMAs. The total methylation yield (MAs and DMAs) increased over the range of 0.1 to 4 microM iAs(III). However, DMAs production was inhibited by iAs(III) in a concentration-dependent manner, and the DMAs/MAs ratio decreased. iAs(III) (10 and 20 microM) inhibited both methylation reactions. Inhibition of DMAs synthesis resulted in accumulation of iAs and MAs in human hepatocytes, suggesting that dimethylation is required for iAs clearance from cells. Methylation capacities of human hepatocytes obtained from four donors ranged from 3.1 to 35.7 pmol of iAs(III) per 10(6) cells per hour and were substantially lower than the methylation capacity of rat hepatocytes (387 pmol of iAs(III) per 10(6) cells per hour). The maximal methylation rates for either rat or human hepatocytes were attained between 0.4 and 4 microM iAs(III). In summary, (i) human hepatocytes methylate iAs, (ii) the capacities for iAs methylation vary among individuals and are saturable, and (iii) moderate concentrations of iAs inhibit DMAs synthesis, resulting in an accumulation of iAs and MAs in cells.
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Butterworth RJ, Thomas DJ, Wolfe JH, Mansfield AO, Al-Kutoubi A. Endovascular treatment of carotid dissecting aneurysms. Cerebrovasc Dis 1999; 9:242-7. [PMID: 10393413 DOI: 10.1159/000015963] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND PURPOSE Cervical arterial dissection is a well-recognised cause for acute ischaemic stroke. Dissecting aneurysms commonly occur in the affected vessels contributing to the clinical presentation. Persistence of these aneurysms may provide a source of future embolic events as well as causing local symptoms or even be at risk of spontaneous rupture. METHODS We describe 4 patients with traumatic internal carotid artery (ICA) dissections with aneurysm formation at the skull base. Three of the 4 patients still had carotid aneurysms on follow-up investigations and so underwent endovascular procedures using stenting and coil techniques. The carotid aneurysm resolved spontaneously in the fourth patient. RESULTS The endovascular procedures resulted in significant reduction or obliteration of the flow within the carotid aneurysms with restoration of the true lumen diameter in the adjacent ICA in all 3 patients. No perioperative complications were experienced except for transient headache in 2 patients. CONCLUSIONS In patients with persistent aneurysms the exact risk of subsequent ischaemic events remains unknown and prospective long-term studies are needed to ascertain this risk. If recurrent stroke rates are found to be high, then carotid stenting (with or without coil insertion) is a feasible invasive approach which could be considered in these patients.
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Thomas DJ, Thomas JB, Prier SD, Nasso NE, Herbert SK. Iron superoxide dismutase protects against chilling damage in the cyanobacterium synechococcus species PCC7942. PLANT PHYSIOLOGY 1999; 120:275-282. [PMID: 10318704 PMCID: PMC59259 DOI: 10.1104/pp.120.1.275] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/1998] [Accepted: 02/11/1999] [Indexed: 05/22/2023]
Abstract
A strain of Synechococcus sp. PCC7942 lacking functional Fe superoxide dismutase (SOD), designated sodB-, was characterized by its growth rate, photosynthetic pigments, inhibition of photosynthetic electron transport activity, and total SOD activity at 0 degrees C, 10 degrees C, 17 degrees C, and 27 degrees C in moderate light. At 27 degrees C, the sodB- and wild-type strains had similar growth rates, chlorophyll and carotenoid contents, and cyclic photosynthetic electron transport activity. The sodB- strain was more sensitive to chilling stress at 17 degrees C than the wild type, indicating a role for FeSOD in protection against photooxidative damage during moderate chilling in light. However, both the wild-type and sodB- strains exhibited similar chilling damage at 0 degrees C and 10 degrees C, indicating that the FeSOD does not provide protection against severe chilling stress in light. Total SOD activity was lower in the sodB- strain than in the wild type at 17 degrees C and 27 degrees C. Total SOD activity decreased with decreasing temperature in both strains but more so in the wild type. Total SOD activity was equal in the two strains when assayed at 0 degrees C.
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Thomas DJ, Mitschang L, Simon B, Oschkinat H. Signal selection in high-resolution NMR by pulsed field gradients. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 1999; 137:10-24. [PMID: 10053127 DOI: 10.1006/jmre.1998.1637] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We describe a new and powerful computer program called TRIPLE GRADIENT which calculates optimized pulsed field gradient sequences for specific coherence pathway selection or rejection. Sequences can be computed for gradient coils acting along one, two, or three perpendicular axes. The program is based on the computational minimization of a penalty function formed from the summed amplitudes of the unwanted signals. The underlying mathematical analysis makes use of a vectorial representation of the way in which a gradient sequence suppresses different signals. It is argued that experiments using well-calculated gradient sequences are quicker and generally perform better than those using extensive phase cycling, especially when suppressing extremely strong solvent signals, and it is shown that in many cases gradient experiments of optimal signal-to-noise ratio can be performed. These claims are illustrated by spectra obtained from an HQQC experiment.
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Thomas DJ, Roberts JT, Hall RR, Reading J. Radical transurethral resection and chemotherapy in the treatment of muscle-invasive bladder cancer: a long-term follow-up. BJU Int 1999; 83:432-7. [PMID: 10210567 DOI: 10.1046/j.1464-410x.1999.00970.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the treatment of patients with muscle-invasive bladder cancer (T2-T4a) by radical transurethral resection (TUR) and cisplatin-methotrexate systemic chemotherapy. PATIENTS AND METHODS Fifty patients with transitional cell carcinoma (TCC) of the bladder (nine T2, 36 T3 and five T4a) were treated by 'complete' TUR of the bladder tumour followed by 2-6 cycles of cisplatin (70 mg/m2) and methotrexate (40 mg/m2) chemotherapy. The median (range) tumour size was 3 (1-7 cm). In six patients, attempted TUR at the dome of the bladder led to intraperitoneal perforation; the tumour was excised by partial cystectomy in these patients. The latest follow-up results from 57 patients treated by radical TUR and methotrexate alone, reported previously, are included. RESULTS At the first evaluation cystoscopy immediately after completing chemotherapy, 38 patients were tumour-free, eight had persistent muscle-invasive TCC and four had Ta, T1+CIS disease. With an overall median follow-up of 47 months, 10 additional patients relapsed with muscle-invasive carcinoma in the bladder after a median interval of 15.6 months; three patients developed Ta, T1 tumours, three Ta, T1 + CIS, and six CIS only. Six of the 10 recurrent invasive tumours were at the same site, but four were at a different site in the bladder. Although during follow-up 12 patients developed superficial recurrence that required endoscopic treatment, the bladder was preserved (free of muscle-invasive cancer) in 37 of 50 patients. In 30 of these 37, this was achieved with no need for salvage radiotherapy or cystectomy. Six patients died from metastatic TCC with no tumour in the bladder. CONCLUSION In this selected group of patients, muscle-invasive bladder cancer was controlled by TUR and systemic chemotherapy, preserving normal bladder function in 60% of patients without apparently comprising overall survival.
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Hill AF, Butterworth RJ, Joiner S, Jackson G, Rossor MN, Thomas DJ, Frosh A, Tolley N, Bell JE, Spencer M, King A, Al-Sarraj S, Ironside JW, Lantos PL, Collinge J. Investigation of variant Creutzfeldt-Jakob disease and other human prion diseases with tonsil biopsy samples. Lancet 1999; 353:183-9. [PMID: 9923873 DOI: 10.1016/s0140-6736(98)12075-5] [Citation(s) in RCA: 449] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Prion diseases are associated with the accumulation of an abnormal isoform of cellular prion protein (PrPSc), which is the principal constituent of prions. Prions replicate in lymphoreticular tissues before neuroinvasion, suggesting that lymphoreticular biopsy samples may allow early diagnosis by detection of PrPSc. Variant Creutzfeldt-Jakob disease (variant CJD) is difficult to distinguish from common psychiatric disorders in its early stages and definitive diagnosis has relied on neuropathology. We studied lymphoreticular tissues from a necropsy series and assessed tonsillar biopsy samples as a diagnostic investigation for human prion disease. METHODS Lymphoreticular tissues (68 tonsils, 64 spleens, and 40 lymph nodes) were obtained at necropsy from patients affected by prion disease and from neurological and normal controls. Tonsil biopsy sampling was done on 20 patients with suspected prion disease. Tissues were analysed by western blot to detect and type PrPSc, by PrP immunohistochemistry, or both. FINDINGS All lymphoreticular tissues obtained at necropsy from patients with neuropathologically confirmed variant CJD, but not from patients with other prion diseases or controls, were positive for PrPSc. In addition, PrPSc typing revealed a consistent pattern (designated type 4t) different from that seen in variant CJD brain (type 4) or in brain from other CJD subtypes (types 1-3). Tonsil biopsy tissue was positive in all eight patients with an adequate biopsy sample and whose subsequent course has confirmed, or is highly consistent with, a diagnosis of variant CJD and negative in all patients subsequently confirmed to have other diagnoses. INTERPRETATION We found that if, in the appropriate clinical context, a tonsil biopsy sample was positive for PrPSc, variant CJD could be diagnosed, which obviates the need for a brain biopsy sample to be taken. Our results also show that variant CJD has a different pathogenesis to sporadic CJD.
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Naquib IM, Christy A, Hall I, Nolan MF, Thomas DJ. Quadrupole moments of the first 2+states of doubly even nuclei in the Z=50 region. ACTA ACUST UNITED AC 1999. [DOI: 10.1088/0305-4616/3/4/012] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Styblo M, Thomas DJ. Binding of arsenicals to proteins in an in vitro methylation system. Toxicol Appl Pharmacol 1997; 147:1-8. [PMID: 9356301 DOI: 10.1006/taap.1997.8256] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The dynamics of interactions between rat liver cytosolic proteins and arsenicals were examined in an in vitro methylation system that contained cytosol, glutathione, S-adenosylmethionine, and 1 microM -73As-arsenite. After incubation at 37 degrees C for up to 90 min, low-molecular-weight components of the assay system (<10 kDa) were removed by ultrafiltration and cytosolic proteins were separated by size-exclusion chromatography on Sephacryl S-300 gel. Five 73As-labeled protein peaks were found in chromatographic profiles. The estimated molecular masses of 73As-labeled proteins eluting in the three earliest peaks were as follows: Vo, >/=1000 kDa; A, 135 kDa; and B, 38 kDa. Peak C eluted immediately before the total volume (VT) of the chromatographic column; peak D eluted after the VT. 73As bound to proteins was released by CuCl treatment and speciated by thin-layer chromatography. Amounts and ratios of inorganic As, methyl As, and dimethyl As associated with cytosolic proteins depended upon the incubation interval. Inorganic As was present in all protein peaks. Methyl As was primarily associated with peaks A and C; dimethyl As was associated with peaks B and C. To examine the effect of valence on the binding of methylarsenicals to cytosolic proteins, trivalent or pentavalent 14C-labeled methyl As or dimethyl As was incubated in an in vitro system designed to minimize the enzymatically catalyzed production of methylated arsenicals. Proteins in peaks A, B, and C bound preferentially trivalent methyl and dimethyl As. Peak D bound either trivalent or pentavalent methyl and dimethyl As. Protein-bound inorganic and methyl As were substrates for the production of dimethyl As in an in vitro methylation system, suggesting a role for protein-bound arsenicals in the biomethylation of this metalloid.
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Hall LL, George SE, Kohan MJ, Styblo M, Thomas DJ. In vitro methylation of inorganic arsenic in mouse intestinal cecum. Toxicol Appl Pharmacol 1997; 147:101-9. [PMID: 9356312 DOI: 10.1006/taap.1997.8269] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The capacity of mouse intestinal cecal microflora to methylate inorganic arsenicals (iAs) was examined in vitro under conditions of restricted bacterial growth. Cecal contents incubated under anaerobic conditions at 37 degrees C for 21 hr methylated up to 40% of either 0.1 microM arsenite (iAsIII) or 0.1 microM arsenate (iAsV). Methylarsenic (MAs) was the predominant metabolite; however, about 3% of either substrate was converted to dimethylarsenic (DMAs). Over the first 6 hr, the rate of methylation was several times greater for iAsIII than for iAsV. There was a 3-hr delay in the production of methylated metabolites from iAsV, suggesting that reduction of iAsV to iAsIII before methylation could be rate limiting. Over the concentration range of 0.1 to 10 microM of iAsIII or iAsV, there was an approximately linear increase in the production of MAs and DMAs. There was evidence of saturation or inhibition of methylation at 100 microM of either substrate. Substrate concentration had little effect on MAs/DMAs ratio. Incubation of cecal contents at 0 degrees C abolished methylation of either arsenical. Under aerobic or anaerobic conditions, cecal tissue homogenates produced little MAs or DMAs from either arsenical. Addition of potential methyl group donors, L-methionine and methylcobalamin, into cecal contents significantly increased the rate of methylation, especially for iAsV. Addition of glutathione, but not L-cysteine, had a similar effect. Selenite, a recognized inhibitor of iAs methylation in mammalian tissues, inhibited methylation of either substrate by cecal contents. These data suggest that cecal microflora are a high capacity methylation system that might contribute significantly to methylation of iAs in intact animals.
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Thomas DJ, Allsopp J. A survey in the West Midlands on the use of the courtesy title 'Dr' by UK dental practitioners. Br Dent J 1997; 183:289-92. [PMID: 9375442 DOI: 10.1038/sj.bdj.4809497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To assess the 1995 General Dental Council's decision to remove restrictions on GDPs using the courtesy title 'Dr'. METHODS In 1996 this survey undertook a qualitative analysis of the views of four groups involved in primary dental care: 72 GDPs, 25 medical practitioners, 46 vocational dental practitioners, 89 patients. RESULTS These indicated that some respondents thought that there would possibly be better quality of patient care due to improved medical history taking, that the public's image of the dental profession might be enhanced and that 87% of newly qualified dentists were in favour of the use of the title 'Dr'. CONCLUSIONS Use of the title appears to be on the increase and if use of the title does become widespread, then all practitioners will need to re-evaluate their choice of personal titles. GDPs need to consider if using the title 'Dr' will encourage patients to give more detailed medical histories.
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Ching RP, Thompson DC, Thompson RS, Thomas DJ, Chilcott WC, Rivara FP. Damage to bicycle helmets involved with crashes. ACCIDENT; ANALYSIS AND PREVENTION 1997; 29:555-562. [PMID: 9316704 DOI: 10.1016/s0001-4575(97)00008-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The objective was to evaluate the relationship between helmet damage and head injuries in helmeted bicyclists in a sub-study of a large case-control study of bicycle injuries and helmet effectiveness. The setting consisted of seven hospital emergency departments in Seattle, WA. Hospitalized patients and medical examiners cases were included. The participants in the study were helmeted bicyclists who suffered a head injury or who damaged or hit their helmet in a crash. The Snell Memorial Foundation laboratory evaluated the helmets, blinded to crash circumstance and injury diagnosis. Damage was scored on a five-point scale (0 = none to 4 = destroyed). The damage location for each helmet was coded into regions (six longitudinal and three latitudinal) and mapped onto a three-dimensional CAD (computer-aided design) model of a helmet. The same procedure was also followed for injury location, which was mapped onto a three-dimensional ISO (International Organization for Standardization) headform for visualization of head-injury distribution. 785 helmeted subjects met the criteria for inclusion in the sub-study, and 527 helmets were purchased and evaluated (67%). 316 (60%) of the helmets had no or minimal damage, and 209 (39.7%) had significant damage (score 2, 3 or 4). Helmet types were 49.7% hard shell, 34.2% thin shell and 16.1% no shell. The risk of head and brain injury increased if the helmet was destroyed: OR = 5.3 (95% CI 2.9, 9.9) and OR = 11.2 (95% CI 3.5, 37.9), respectively. A high proportion of helmet impacts were along the front edge of the helmet, with a preponderance of head injuries in the same region. The large number of impacts to the front rim of the helmet, combined with the substantial number of riders with injuries to the forehead, indicate that some helmets, because of poor fit or wearing style, expose the forehead to injury. In addition, the data indicate that for a small proportion of injuries, the energy to the helmet may exceed design limits.
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