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Biomedical subjects

P Jones

Publications and source records attributed to P Jones.

At least 109 records · Page 6Linked to original sources
PubMed2000

The ion chromatographic separation of high valence metal cations using a neutral polystyrene resin dynamically modified with dipicolinic acid.

A neutral polystyrene resin column, dynamically loaded with dipicolinic acid at a concentration of 0.1 mM in 1 M potassium nitrate eluent, was investigated for the separation characteristics of a number of high valence metal cations over the pH range 0-3. The metal species studied were Th(IV), U(VI), Zr(IV), Hf(IV), Ti(IV), Sn(IV), V(IV) and V(V), Fe(III) and Bi(III), of which Ti(IV), Sn(IV), V(IV) and Fe(III) did not show any retention. For the remaining metal ions, significant retention was obtained with good peak shapes, except for Th(IV), which moved only slightly from the solvent front with some tailing. The retention order at pH 0.3 was Th(IV) < V(V) < Bi(III) < U(VI) < Hf(IV) < Zr(IV). A notable feature of this separation system was the high selectivity shown for uranium, zirconium and hafnium, the last two being nearly resolved in 15 min on the relatively short 10 cm column.

Journal Article↗
PubMed2000

Pharmacological protection of auditory function against noise and hypoxia with MK 801

INTRODUCTION: Pharmacological protection of cochlear function is one of the most exciting goals of inner ear medicine. The selective glutamate antagonist MK 801 may be neuro-protective to the cochlea.1 This study aims to investigate whether round window administration of MK 801 protects cochlear function against a combination of noise and atmostpheric hypoxia. METHODS: Eight guinea-pigs were studied. Round Window E. Catheters (Durect Inc., USA) were implanted through a trans-bulla approach and EcoG thresholds determined at 8, 16, 24 and 30 kHz. Artificial perilymph (n = 4) or 10 mM MK 801 (n = 4) was then perfused onto the round window membrane. After 15 min the anaesthetized animals were exposed to 100 dB white noise in 11.5-12. 5% atmospheric oxygen. Thresholds were determined before and 15 min after exposure. RESULTS: The mean threshold shifts from pre-perfusion at 8, 16, 24 and 30 kHz were 40, 33, 35 and 17 dB, respectively (in control animals) and 29, 28, 33 and 41 dB, respectively (in treated animals). A marginal protective effect was demonstrated at 8 kHz (P = 0.06). The 30-kHz thresholds in the treated group fell by 61 dB before noise exposure compared to < 1 dB in the controls (P = 0.0007), suggesting that at high frequencies, 10 mM MK 801 may itself be ototoxic. CONCLUSIONS: These results partially support existing data suggesting that pharmacological protection against noise/hypoxia is possible. Administration of round window NMDA antagonists may affect normal auditory threshold making detailed evaluation of the toxicity of potential inner ear therapies essential before clinical use is contemplated.

Journal Article↗
PubMed2000

Becoming professional: when and how does it start? A comparative study of first-year medical and law students in the UK.

AIM: The purpose of this study is to investigate whether differences identified between first-year law and medical students in North America in the 1950s apply in the UK in the 1990s. First-year law and medical students are compared in terms of commitment to career, alternative career choices and length of time the student has wished to study for his/her chosen profession. METHOD: Questionnaires were administered to first-year law students at the University of East Anglia and Essex University and to first-year medical students at Liverpool University Medical School and St George's Hospital Medical School. A total of 162 questionnaires were completed by law students and 195 questionnaires from medical students. ANALYSIS: The questionnaire responses provided by law and medical students were analysed using a series of two-sample comparisons. Differences between the two groups were examined using t and chi-squared tests. In each of the seven questions answered by students, the differences between the law and medical students were found to be significant. This suggests a difference in career aspirations and perceptions between the two groups. RESULTS AND CONCLUSIONS: The study shows a greater commitment of medical students than law students to their chosen career. This is demonstrated by medical students' greater desire to pursue their career, their greater satisfaction with their choice of career and finding that more medical students would persist with reapplying for medicine than law students would in reapplying for law. It is also shown that medical students are twice as likely as law students to have a family member within the profession.

Attitude↗
PubMed2000

Improving the standards of care for women having caesarean sections.

Improvement in the uptake of prophylactic antibiotics at caesarean section was chosen as a priority at the 1994 ASQUAM (Achieving Sustainable Quality in Maternity) meeting. The interventions used were guidelines, cyclical audit of cases and a patient-specific reminder stamp in the notes. A more detailed qualitative assessment of standards of communication and outcome was undertaken on a smaller cohort of women. Data on antibiotic prophylaxis were obtained from an audit record completed for every caesarean section undertaken at North Staffordshire Hospital from 1996 to 1998. Information on morbidity following caesarean section and on counselling was obtained from a review of the case records of a consecutive series of 75 caesarean sections and from a telephone call. In the baseline audit, 75% of women had received antibiotics; this increased to 92% in the remainder of 1996, 95% in 1997 and 98% in 1998. Fifty-eight of the 75 women were contactable by telephone (77%); of these 16 (28%) had a 'wound infection', 12 of which developed after discharge from hospital. Only 25 women (43%) remembered being counselled about the caesarean section. It is possible to achieve significant improvements in the quality of care for women having caesarean sections through the use of local guidelines, cyclical audit and reminder stamps. However, this audit, with community follow-up, raises questions about the adequacy of single dose prophylaxis. It also suggests the need for improved compliance with RCOG communication following caesarean section guidelines.

Journal Article↗
PubMed2000

One year survey of maternal mortality associated with eclampsia in Dhaka Medical College Hospital.

Data was collected prospectively from 763 eclamptic patients hospitalised at Dhaka Medical College Hospital. Comparisons were made between the patients that died and survivors based on determinants already known to be important. The cause of death was taken from the clinical history. The 'Case fatality rate' was 14.7%. The principle mortality risk factors were age, parity, number of convulsions and time between onset of convulsions and admission to hospital. Less than 10% in both groups had received antenatal care. The hospital mortality rate was significantly higher than that found in the Collaborative Eclampsia Study. Urgent interventions are required to increase public awareness of the need for antenatal care, to raise the level of understanding and improve attitudes and practice in relation to eclampsia.

Journal Article↗
PubMed2000

Democratic prioritization of maternity care: a rational basis for planning a clinical effectiveness programme.

BACKGROUND: The aim of the study was to evaluate the use of a democratic process for prioritizing the ASQUAM (Achieving Sustainable Quality in Maternity) clinical effectiveness programme. METHODS: Twenty-two improvements in the standards of maternity care were chosen as top-topic priorities at the 1996 and 1997 ASQUAM meetings. We wished to assess the relative priorities of local and national delegates, by comparing their voting patterns at the two meetings. The setting was North Staffordshire ASQUAM prioritization days, and the subjects were all the delegates at the 1996 and 1997 ASQUAM meetings. Main outcome measures were comparison of numbers of votes cast by local and national delegates for each of the 20 topics presented at the two ASQUAM meetings, and proportions of the 11 top-topics decided at each meeting that were chosen by local and national delegates. RESULTS: In 1996, significantly more local than national delegates voted for two topics related to maternal mortality or morbidity (incontinence and hypertensive diseases of pregnancy), but there were no statistically significant differences between the proportions of votes cast for any of the other 18 topics presented on the day. Indeed, local delegates had prioritized 11/11 of the final top-topics, and only one was omitted by the national delegates (10/11). In 1997, significantly more national than local delegates voted for three topics relating to professional stress levels, user involvement in working groups and antibiotic prophylaxis, but there were no statistically significant differences between the proportions of votes cast for any of the other 17 topics presented on the day. Again, local delegates had prioritized 11/11 of the final topics, with only one being omitted by the national delegates (10/11). CONCLUSION: There appeared to be a remarkable concordance between local and national delegates at both meetings, suggesting an underlying rationality to decision making. We believe this to be a reflection of the process of careful evaluation of outcome and intervention supported by the protection of a secret ballot, allowing free expression of individual's values.

Community Health Planning↗
PubMed2000

Isolation and analysis of thermotolerant mutants of wheat.

Thermotolerant mutants of wheat cv. Guardian were isolated by selecting survivors from 5-d-old seedlings of M2 populations exposed to 47 degrees C for 90 min. Progeny testing, using triphenyl tetrazolium chloride reduction as a measure of tissue viability, following heat stress treatment for 120 min at each of three temperatures (32, 38 and 50 degrees C), confirmed the thermotolerant nature of seedlings of 13 mutants. Mutants were isolated at frequencies of 0.1% and 0.2% following the use of sodium azide and ethyl methanesulphonate, respectively. The relative thermotolerance of ten of the mutants and 'Guardian' was then tested by exposing plants to heat stresses of 38 degrees C for 6 h in every 24 h for five successive days at one of four growth stages between seedling and anthesis. Pmax (light-saturated net photosynthetic rate) and chlorophyll content were compared in stressed and unstressed plants. The Pmax of 'Guardian' was depressed by at least 23% by heat stress at each stage; this inhibition was least at ear emergence and greatest at anthesis, the latter being associated with reduced sink size as a result of lowered seed set. The stress-induced inhibition of Pmax in 'Guardian' plants at anthesis had not recovered 3 d after removal of the stress. Mutant lines exhibited different developmental profiles of Pmax thermostability. Mutant tht (thermotolerant) 10, for example, exhibited partial thermostability at each growth stage tested while the Pmax of mutant tht 2 was completely unaffected by heat stress at second node and ear emergence, but was as inhibited as that of 'Guardian' at anthesis; heat stress applied at anthesis in tht 2, but not tht 10, was associated with reduced seed set. Generally, the inhibitory effect of heat stress on Pmax in the mutants was reflected in declines in chlorophyll content. The ten mutants were grouped into nine categories, on the basis of thermotolerance characteristics.

Adaptation, Physiological↗
PubMed2000

Reliability and validity of a psycho-social problem inventory for childhood epilepsy.

In response to the need for formal psychosocial assessment in childhood epilepsy, a 25-question inventory was constructed from raw items based on multidisciplinary inputs and tested for practicality, and psychometric attributes. Weighted inter-rater and test-retest reliability estimates were 61.8% and 63.9% respectively. A measure of concurrent validity was satisfactory though a modest discrepancy was observed between two raters (P = 0.019 and 0.0064). Discriminant validity was very satisfactory (average P 0.001) based on compared means of ratings from two groups of subjects with disparate prognosis. The inventory should be useful in the assessment of similar chronic childhood disabilities but interpretations of data should be in a wider clinical context including inputs of informant and school authorities as indicated.

Child↗
PubMed1999

Unusual cluster of mild invasive serogroup C meningococcal infection in a university college.

The objective of this study was to describe the epidemiology and public health response to an apparent cluster of Neisseria meningitidis serogroup C infection in university students in a residential college. A conventional epidemiological approach was taken, supported by routine and novel diagnostic techniques. Over the two days of 21-22 August 1997, three cases of suspected meningococcal infection were notified from a residential college complex at a university campus in the Sydney metropolitan area. Neisseria meningitidis was grown from throat swabs of all three cases, and was isolated from the blood of one case only. All three isolates were typed as C:2a:P1.5,2. Seroconversion was demonstrated by a novel method in the three cases. Rifampicin was given to all identified contacts. Forty-seven days after the index case, a 19 year old female living in the same complex was diagnosed with bacterial meningitis, and identified contacts given rifampicin. When this isolate was found to be group C, it was decided to vaccinate residents of the college complex. Genotyping and serotyping (C:2a:P1.5) later revealed the fourth isolate to be distinct from isolates from Cases 1-3. In conclusion the authors note that Australia's increasing capacity to type meningococcal strains is essential to understanding the epidemiology of this disease. Furthermore, typing information is of critical importance when decisions are made regarding mass vaccination. As early antibiotic treatment may inhibit isolation of the organism, development of novel approaches to diagnosis and typing should be supported.

Adolescent↗
PubMed1999

Colesevelam hydrochloride (cholestagel): a new, potent bile acid sequestrant associated with a low incidence of gastrointestinal side effects.

OBJECTIVES: To compare colesevelam hydrochloride (Cholestagel), a nonabsorbed hydrogel with bile acid-sequestering properties, with placebo for its lipid-lowering efficacy, its effects on laboratory and clinical safety parameters, and the incidence of adverse events. METHODS: Following diet and placebo lead-in periods, placebo or colesevelam was administered at 4 dosages (1.5, 2.25, 3.0, or 3.75 g/d) for 6 weeks with morning and evening meals to men and women with hypercholesterolemia (low-density lipoprotein cholesterol level >4.14 mmol/L [>160 mg/dL]). Patients returned to the clinic every 2 weeks throughout the treatment period for lipid parameter measurements and adverse event assessments. Samples were collected for serum chemistry profiles, hematologic studies, coagulation studies, and vitamin level assessment at baseline and after 6 weeks of treatment. RESULTS: Among the 149 patients randomized, 137 completed the study. Low-density lipoprotein cholesterol concentrations decreased in a dosage-dependent manner by 0.11 mmol/L (4.2 mg/dL) (1.8%) in the 1.5-g/d colesevelam treatment group and up to 1.01 mmol/L (39 mg/dL) (19.1%) in the 3.75-g/d colesevelam treatment group. Low-density lipoprotein cholesterol concentrations at the end of treatment were significantly reduced from baseline levels in the 3.0- and 3.75-g/d colesevelam treatment groups (P = .01 and P<.001, respectively). Total cholesterol levels demonstrated a similar response to colesevelam treatment, with an 8. 1% decrease from baseline in the 3.75-g/d treatment group (P<.001). High-density lipoprotein cholesterol levels rose significantly in the 3.0- and 3.75-g/d colesevelam treatment groups, by 11.2% (P=.006) and 8.1% (P=.02), respectively. Median triglyceride levels did not change from baseline, nor were there any significant differences between treatment groups. The incidence of adverse events was similar among all groups. CONCLUSIONS: Colesevelam therapy is effective for lowering low-density lipoprotein cholesterol concentrations in persons with moderate hypercholesterolemia. It lacks the constipating effect of other bile acid sequestrants, demonstrating the potential for increased compliance.

Adult↗
PubMed1999

Nitrite determination in human plasma and synovial fluid using reactions of nitric oxide with 3, 5-dibromo-4-nitrosobenzenesulphonate (DBNBS).

DBNBS (3,5-dibromo-4-nitrosobenzenesulphonate) reacts with nitric oxide (NO) produced from nitrite ions in acid solution to give a radical with a characteristic electron spin resonance spectrum, attributable to a 'DBNBS-NO' product, and comprising a triplet with alphaN=0.96 mT. This is identical with the spectrum obtained when NO, introduced from the gas phase, reacts with DBNBS. Under certain conditions, an additional signal is observed, attributable to oxidation of DBNBS to the radical cation, DBNBS*+ (a triplet with alphaN=1.32 mT). Conditions are described for the determination of nitrite, which avoid this DBNBS oxidation. The height of the low-field signal from the DBNBS-NO product is directly proportional to the nitrite concentration up to about 0.08 mM nitrite. The method has been applied to the measurement of nitrite concentrations in whole blood, plasma and synovial fluid taken from rheumatoid arthritis patients. In order to avoid the oxidation of DBNBS when analysing biological samples of this type, it is necessary to treat the specimen by ultrafiltration as soon as possible after collection and before addition of DBNBS.

Arthritis, Rheumatoid↗
PubMed1999

School performance in Finnish children and later development of schizophrenia: a population-based longitudinal study.

BACKGROUND: We examined whether children who are diagnosed as having schizophrenia in adulthood could be distinguished from their peers on performance in elementary school. METHODS: We used a case-control study design nested within a population-based birth cohort of all individuals born in Helsinki, Finland, between January 1, 1951, and December 31, 1960. Case ascertainment was from 3 national health care registers. Elementary school records were obtained for 400 children who were diagnosed as having schizophrenia in adulthood and for 408 controls. Results were analyzed for the 4 years of schooling (ages 7-11 years) that were common to all pupils. School subjects were entered into a principal components analysis and produced 3 factors: academic, nonacademic, and behavioral. These factors were compared between cases and controls after adjusting for sex and social group. Eligibility for high school and progression to high school were investigated among cases and controls. RESULTS: Cases performed significantly worse than controls only on the nonacademic factor (which loaded sports and handicrafts). There were no differences between the groups on the academic or behavioral factors, and there were no significant clinical correlates of factor scores. Cases were significantly less likely than controls to progress to high school, despite similar eligibility. CONCLUSIONS: Poor performance in sports and handicrafts during elementary school, which may indicate a motor coordination deficit, appears to be a risk factor for later schizophrenia. Poor academic performance in elementary school was not a risk factor for schizophrenia in this study. Lack of expected progression to high school among cases, despite good academic grades, provides evidence for deteriorating premorbid functional adjustment in schizophrenia.

Achievement↗
PubMed1999

Changes in serum cartilage marker levels indicate altered cartilage metabolism in families with the osteoarthritis-related type II collagen gene COL2A1 mutation.

OBJECTIVE: The Arg5l9-Cys mutation in type II collagen results in severe, precocious familial osteoarthritis (OA) in 100% of carriers within the first 3 decades of life. The carrier population provided a well-defined patient population for the study of serum markers of familial OA with respect to pathogenesis, diagnosis, and prognosis. METHODS: Serum was obtained from 31 mutation-positive individuals and 16 mutation-negative individuals. OA severity was determined by clinical and radiologic assessments. Levels of serum cartilage oligomeric matrix protein (COMP), keratan sulfate (KS) epitope, the 846 epitope of aggrecan, and the C propeptide of type II collagen (CPII) were measured and were correlated with the radiologic findings. RESULTS: COMP and KS levels, both of which have been suggested to be indicative of disturbed cartilage turnover, were significantly elevated in mutation-positive individuals and in the individuals with OA regardless of mutation status. There was no statistically significant difference between mutation-positive, mutation-negative, OA-positive, and OA-negative individuals with respect to serum concentrations of epitope 846 or CPII, both of which are putative markers of cartilage repair. CONCLUSION: Study of the macromolecular constituents of cartilage released into serum in subjects with familial OA revealed altered metabolism in OA, as demonstrated by elevated COMP and KS levels. Other constituents, the 846 epitope and CPII, were not altered, indicating dissociation of cartilage anabolism and breakdown. Future sequential studies will provide an opportunity to define biochemical changes as familial OA develops and to monitor therapeutic responses.

Adult↗