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Biomedical subjects

R Jones

Publications and source records attributed to R Jones.

At least 289 records · Page 16Linked to original sources
PubMed1999

Maternal urine hyperglycosylated hCG in pregnancies with Down syndrome.

Stored maternal urine samples were used to determine the distribution of hyperglycosylated human chorionic gonadotrophin (H-hCG) levels in pregnancies with Down syndrome. A total of 349 samples from singleton pregnancies, including 45 with Down syndrome, were tested at 10-19 weeks' gestation. Urinary concentration was allowed for by expressing H-hCG in ng per mmol creatinine. The median level in Down syndrome was 3.63 multiples of the gestation-specific median in unaffected pregnancies (p<0.0001, Wilcoxon rank-sum test, two-tail). However, creatinine levels were relatively low in cases and creatinine did not fully correct for concentration. When this bias was allowed for, the median level was 3.34 multiples of the normal median (MoM). The H-hCG elevation in affected pregnancies was more marked at 14 weeks' gestation or later: a median of 4.64 MoM and allowing for creatinine bias 4.46 MoM.

Case-Control Studies↗
PubMed1999

The accessibility of information systems for patients: use of touchscreen information systems by 345 patients with cancer in Scotland.

AIM: To examine cancer patients' use, and satisfaction with touchscreen information systems. By examining the experience of subgroups, to address issues of equality of access. PATIENTS: 345 patients starting radiotherapy at the Beatson Oncology Centre (BOC), Glasgow. METHODS: Patients were invited to use a touchscreen computer at the start of treatment. They were sent a printout of what they saw on screen. Patients had open access to the system. Data were collected at recruitment, intervention, 3 weeks and 3 months. Predictor variables included: patients' demographics, information preferences, technology use, and psychological state. Outcome variables included: use and views of the computer and printout. RESULTS: Younger, broadsheet readers with previous computer use were more likely to find the system easy to use. Older, tabloid readers were more likely to find the content new and relevant. DISCUSSION: We need to make systems adapt to users' different needs. More effort should be made to provide affordable information for older, generally less literate and technologically less literate groups in suitable locations.

Age Factors↗
PubMed1999

Evaluation of filter paper blood lead methods: results of a pilot proficiency testing program.

BACKGROUND: Lead testing on dried filter paper (FP) blood spots is used routinely by some laboratories for lead poisoning screening. Proficiency testing (PT) as required under CLIA '88 laboratory regulations has not been available for these methods. METHODS: We describe a suitable PT scheme and evaluate FP laboratory performance based on program results. Monthly testing events consisting of five FP specimens were provided to six participating laboratories. Results were evaluated against target values determined by referee laboratories. RESULTS: Preliminary FP laboratory results showed poor agreement with specimen target values, exhibiting a mean absolute bias of 0.29 micromol/L (5.9 microg/dL). Five of six participating laboratories demonstrated significant improvement in later testing events, with bias decreasing to 0.12 micromol/L (2.5 microg/dL). Performance varied widely between the participating laboratories and appeared to be method dependent. When evaluated using CLIA blood lead acceptability criteria, the proportion of acceptable individual specimen results (n = 35) ranged from 54% to 100%. On a testing event basis (n = 7), the proportion of acceptable events ranged from 29% to 100%. CONCLUSIONS: A suitable FP PT program now exists to capably assist and monitor FP laboratories. Based on overt PT results, properly utilized FP testing methods can accurately measure blood lead concentration.

Blood Specimen Collection↗
PubMed1999

Does teaching during a general practice consultation affect patient care?

BACKGROUND: General practice differs from hospital medicine in the personal nature of the doctor-patient relationship and in the need to address social and psychological issues as well as physical problems. Recent changes in undergraduate medical education have resulted in more teaching and learning taking place in general practitioner (GP) surgeries. AIM: To explore patients' experiences of attending a surgery with a medical student present. METHOD: A questionnaire was designed, based on semi-structured interviews. Questionnaires were posted to patients who had attended teaching surgeries in London and Newcastle-upon-Tyne. RESULTS: Four hundred and eighty questionnaires were sent; of these, 335 suitable for analysis were returned. The response rate in Newcastle was 79%, and in London 60%. Ninety-five per cent of responders agreed that patients have an important role in teaching medical students. Patients reported learning more and having more time to talk, however, up to 10% of responders left the consultation without saying what they wanted to say and 30% found it more difficult to talk about personal matters. CONCLUSION: The presence of a student has a complex effect on the general practice consultation. Future developments in medical education need to be evaluated in terms of how patient care is affected as well as meeting educational aims.

Family Practice↗
PubMed1999

A trial of a test-and-treat strategy for Helicobacter pylori positive dyspeptic patients in general practice.

Computer models of different strategies for the management of dyspepsia in primary care indicate that a 'test-and-treat' approach is likely to be associated with the lowest costs and acceptable clinical outcomes. We present information on computer modelling studies and report the findings of a randomised trial comparing a Helicobacter pylori test-and-treat strategy with referral to direct access endoscopy in the management of dyspepsia in general practice. We compared costs and clinical outcomes in patients managed for one year in study (test-and-treat) and control (endoscopy) practices in south London. Patients aged less than 45 years presenting with persistent dyspepsia without alarm symptoms (141 study patients, 91 control patients) were studied. In the one-year follow-up period there were 17 endoscopies in the study group: all the control patients underwent initial endoscopy and five further endoscopies were performed. None revealed peptic ulcer or cancer. Forty-three (30%) of the study patients compared with 16 (17%) of the controls were referred to hospital clinics (p < 0.025). The cost of management per patient for one year in the study group was 205.67 Pounds, compared with 404.31 Pounds in the control group (p < 0.0001). Clinical outcomes in both groups at one year were comparable. An H. pylori test-and-treat strategy for dyspeptic patients aged less than 45, employing office-based serology testing, appears to be associated with substantially lower costs than initial endoscopy and with similar clinical outcomes.

Adult↗
PubMed1999

Attitudes towards, and utility of, an integrated medical-dental patient-held record in primary care.

BACKGROUND: The need for closer coordination between primary care medical and dental services has been recognized. AIM: To assess the attitudes of general medical practitioners (GMPs), general dental practitioners (GDPs), and patients to an integrated medical-dental patient-held record (integrated medical-dental PHR); to examine patients' use of these records, and the utility of the records for doctors and dentists. METHOD: A three-phase study was carried out: (1) postal survey of GMPs and GDPs; (2) randomized trial of patients, using postal questionnaires before and one year after the issue of integrated medical-dental PHRs to cases; (3) assessment by doctors and dentists of anonymized integrated medical-dental PHRs from this trial. The study was carried out in medical and dental practices in affluent and deprived areas in Greater Glasgow Health Board. Two hundred and thirteen GMPs, 183 GDPs, and 369 patients registered with GMPs and GDPs were surveyed. Eighteen GDPs and GMPs assessed the integrated medical-dental PHRs. RESULTS: Eighty per cent of dentists had contacted a doctor and 16% of doctors had contacted a dentist in the previous three months; 87% of dentists and 68% of doctors thought an integrated medical-dental PHR would be of some use. Twenty-one per cent of dentists and 85% of doctors had practice computers. Most patients wanted to be able to see and read their own records. Twenty-four per cent of patients said there were mistakes and 30% noticed omissions in the integrated medical-dental PHR issued. Experience of having an integrated medical-dental PHR made patients more positive towards the idea of having a patient-held record and being able to check the accuracy of records. Integrated medical-dental PHRs contained important information for half the GDPs and one-third of the GMPs. CONCLUSION: Both professionals and patients have reasonably positive attitudes towards the use of patient-held records. Among patients, the experience of having the integrated medical-dental PHR led to greater enthusiasm towards the idea. Dentists in particular would benefit from the transfer of information from doctors, but better methods are needed to ensure that patients take the integrated medical-dental PHR with them. Given the current lack of ability to easily produce an integrated medical-dental PHR, further examination of the routine issue of a copy of their medical summary, by GMPs, to all patients would be worthwhile.

Attitude of Health Personnel↗
PubMed1999

Stent design favorably influences the vascular response in normal porcine coronary arteries.

OBJECTIVES: The purpose of this study was to compare the arterial response following implantation of a stainless-steel, balloon-expandable, tubular slotted stent with that of a novel computer-designed, multi-cellular stent in normal porcine coronary arteries. BACKGROUND: Intracoronary stent placement has evolved into the primary strategy for percutaneous revascularization of symptomatic coronary arterial lesions. Presently there is intense interest in developing new stent designs to improve stent delivery and biocompatability. METHODS: Computer-assisted design was utilized to develop a balloon-expandable stent with symmetric expansion properties, uniform arterial wall coverage, longitudinal flexibility and radial strength. Quantitative coronary angiography and histological assessment of the stented arteries was used to evaluate the acute and chronic vascular responses to a stainless-steel, balloon-expandable, tubular slotted stent as compared to the computer-designed BX stent in the normolipemic swine. RESULTS: Forty stents (24 BX, 16 tubular slotted) were implanted in 19 miniature swine at a mean inflation pressure of 9 atm using identical delivery systems. Eight of the BX and none of the tubular slotted stents were post-dilated with a non-compliant balloon at 12-14 atm. The mean stent-to-artery ratio was similar for the BX (1.03 +/- 0.06) and tubular slotted (1.04 +/- 0.11; p = 0.59) designs. Protrusion or asymmetric radial flaring of a strut at the stent margin was present in 1 of 23 BX stents (4.3%) and 10 of 15 tubular slotted stents (66.7%; p < 0.0001). The mean arterial injury score was significantly less for the BX stent (0.2 +/- 0.2) as compared with the tubular slotted stents (0.4 +/- 0.4; p = 0.025). At 3 days, thrombus area was similar for the BX and tubular slotted designs (0.42 +/- 0.16 mm2 versus 0.44 +/- 0.18 mm2, respectively; p = 0.88). The mean neointimal area was significantly less for the BX at 2 months (1.09 +/- 0.25 mm2 versus 2.93 +/- 2.26 mm2 in the tubular slotted stent) and at 6 months (1.10 +/- 0.26 mm2 versus 2.07 +/- 0.65 mm2 in the tubular slotted stent; p = 0.01), resulting in approximately 50% less in-stent stenosis. CONCLUSIONS: The arterial response to a balloon-expandable stent can be favorably influenced by computer-assisted modification of design in an experimental model. Further study is warranted to determine the impact of stent design upon clinical in-stent restenosis.

Angioplasty, Balloon, Coronary↗
PubMed1999

Evaluations of aggressive women: the effects of gender, socioeconomic status, and level of aggression.

Research finds gender differences in aggression and suggests that female violence is viewed differently from male violence. Participants were 94 female and 38 male students from a mid-size public university in the Southeast. Participants read a mock trial and answered questions about their attitudes concerning an aggressor in the scenario. The study was a 2 (male or female) by 2 (high socioeconomic status or low socioeconomic status) by 2 (verbal aggression or physical aggression) between-subjects factorial design. The participants responded to a revised version of the Attitudes Toward Women Scale (Nelson, 1988). As hypothesized aggressive women were evaluated more negatively than aggressive men and participants evaluated the female aggressor who used physical aggression more negatively than the female who used verbal aggression. The hypothesis that the female aggressor would be perceived as more in need of counseling than the male aggressor was not supported. Contrary to another hypothesis, respondents did not evaluate higher socioeconomic status aggressors more negatively than those of lower status. As hypothesized people with traditional views of women evaluated the female aggressor more negatively than people with more liberal views of women, and liberal participants evaluated the male and female aggressors similarly. The more negative evaluation of female aggressors and, in particular, females who use physical aggression, may result in unfair treatment of such females. These social biases may cloud perceptions of aggressive females, suggesting that their actions are more inappropriate than those of a male who committed the same act.

Adult↗
PubMed1999

Ranolazine (Roche Bioscience).

Ranolazine is a metabolic modulator that is being developed by CV Therapeutics (CVT), under license from Roche (formerly Syntex), as a potential treatment for angina. In August 1999, the first of two pivotal phase III clinical trials in patients with stable angina was completed. In August 1999, CVT announced initial results from this trial, designated the MARISA trial, of ranolazine in patients with stable angina. At each of the three doses studied, ranolazine significantly increased patients' treadmill exercise duration compared to placebo, the primary endpoint for this trial. MARISA (monotherapy assessment of ranolazine in stable angina) was a randomized, double-blind, placebo-controlled trial of a sustained release formulation of ranolazine used in 175 patients who were not receiving other anti-anginal drugs. Compared to placebo, ranolazine taken bid at doses of 500, 1000 or 1500 mg significantly increased exercise duration at trough plasma concentrations, which occur at about 12 h after the previous dose. In addition, two key secondary endpoints, exercise time to onset of angina and exercise time to the electrocardiographic appearance of ischemia were also significantly increased by ranolazine compared to placebo at all three doses. The company plans on presenting additional data at a major medical conference, including safety and tolerability data, which are still under analysis. In July 1999 CVT initiated its second phase III trial. The CARISA trial (combination assessment of ranolazine in stable angina) is a randomized, double-blind, placebo-controlled trial of ranolazine used in combination with other anti-anginal drugs, in approximately 450 patients. The primary endpoint for this trial, duration of exercise on a treadmill, is identical to that used in phase II clinical trials. The CARISA trial, along with the pivotal phase III MARISA trial which completed treatment in June 1999, is expected to form the basis of the company's NDA submission to the FDA. In June 1999, results of a randomized, double-blind, placebo-controlled phase II study of ranolazine in chronic stable angina pectoris were published in the July 1, 1999 issue of the American Journal of Cardiology. The study of 312 patients demonstrated that ranolazine may increase exercise time in chronic stable angina patients. The results also indicate that there may be no change in heart rate or blood pressure among any of the ranolazine dosing regimens. In January 1999, CVT received regulatory clearance in Canada, the Czech Republic and Poland and initiated its first pivotal phase III trial for ranolazine in these countries. These new clinical trial centers complement the US centers enrolling American patients. The compound allows maintenance of energy output by muscle cells by improving oxygen metabolism to make the heart pump more efficiently. Ranolazine may be especially useful in angina patients in whom other therapies are ineffective. Clinical studies suggest that ranolazine lowers the heart's demand for oxygen, by increasing its ability to use carbohydrate rather than fat as a fuel. This is thought to be due to activation of pyruvate dehydrogenase, and also by modulating the activities of L-type calcium channels. This is achieved without reducing heart rate or blood pressure, or impairing pumping ability. In August 1998, CVT signed an agreement with Catalytica Pharmaceuticals, which will manufacture specified quantities of ranolazine for use in clinical trials.

Journal Article↗
PubMed1998

Cation-exchange displacement chromatography for the purification of recombinant protein therapeutics from variants.

Removal of low level impurities that are closely related to the bioproduct is a commonly encountered challenge in the purification of biopharmaceuticals. These separations are typically carried out by using shallow linear salt gradients at relatively low column loadings, significantly limiting the throughput of the purification process. In this manuscript we examine the utility of displacement chromatography for the purification of recombinant human brain-derived neurotrophic factor, rHuBDNF. The utility of displacement chromatography is compared to gradient elution for the removal of variants of the rHuBDNF. The results demonstrate that displacement chromatography is capable of achieving high yields and purity at high column loadings. Displacements developed on 20 microns and 50 microns cation-exchange resins are shown to provide 8-fold and 4.5-fold increases in production rates, respectively, when compared to an existing linear gradient elution operation. These results demonstrate the efficacy of displacement chromatography for the purification of therapeutic proteins from complex feed streams.

Brain-Derived Neurotrophic Factor↗
PubMed1998

A trypanosome oligopeptidase as a target for the trypanocidal agents pentamidine, diminazene and suramin.

African trypanosomes contain a cytosolic serine oligopeptidase, called OP-Tb, that is reversibly inhibited by the active principles of three of the five most commonly used trypanocidal drugs: pentamidine, diminazene and suramin. OP-Tb was inhibited by pentamidine in a competitive manner, and by suramin in a partial, non-competitive manner. The inhibition of OP-Tb by a variety of suramin analogues correlated with the trypanocidal efficacy of these analogues (P=0.03; by paired Student's t-test). Since intracellular (therapeutic) concentrations of pentamidine and suramin are reported to reach approximately 206Ki and 15Ki respectively, we suggest that these drugs may exert part of their trypanocidal activity through the inhibition of OP-Tb.

Animals↗
PubMed1998

Hyphenosis.

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Humans↗