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Biomedical subjects

A Jones

Publications and source records attributed to A Jones.

At least 451 records · Page 25Linked to original sources
PubMed1993

Long term trigger ventilation in neonatal respiratory distress syndrome.

Experience of using an SLE 2000 neonatal trigger ventilator as the sole means of ventilation in 68 infants with respiratory distress syndrome was reviewed. No death or complication was seen in 22 infants with a birth weight above 1500 g. Forty five infants under 1500 g birth weight including 18 infants between 23 and 28 weeks' gestation were trigger ventilated throughout. Six infants died, four of whom were under 28 weeks' gestation. Two infants under 1500 g birth weight sustained a pneumothorax while being ventilated. Nine of 61 infants (15%) had radiological evidence of pulmonary interstitial emphysema, which was mild in seven infants. Intraventricular haemorrhage occurred in 10 babies under 1500 g, four of these being grade III or IV. Twenty two (48%) of the babies under 1500 g required added oxygen at 28 days. The preliminary clinical experience of this trigger ventilator suggests that it is capable of providing respiratory support from birth to extubation in even the most immature infants with respiratory distress syndrome. A controlled clinical trial is now required to compare the safety and efficacy of patient triggered ventilation with conventional neonatal ventilation.

Humans↗
PubMed1993

Radiographic patterns and associations of osteoarthritis of the knee in patients referred to hospital.

OBJECTIVES: To investigate differing patterns and associations of osteoarthritis of the knee in patients referred to hospital. METHODS: Two hundred and fifty two consecutive patients (161 women, 91 men; mean age 70 years, range 34-91 years) referred to hospital with osteoarthritis of the knee underwent clinical, radiographic, and synovial fluid screening. RESULTS: Radiographic changes of osteoarthritis of the knee (definite narrowing with or without osteoarthritic features) were bilateral in 85% of patients. Of 470 knees affected, 277 (59%) were affected in two compartments and 28 (6%) in three compartments. Unilateral and isolated medial tibiofemoral osteoarthritis were more common in men. Calcium pyrophosphate crystal deposition was common (synovial fluid identification in 132 (28%) knees; knee chondrocalcinosis in 76 (30%) patients) and associated with disability, bilateral, multicompartmental and severe radiographic osteoarthritis, marked osteophytosis, attrition, and cysts. Multiple clinical nodes (58 (23%) patients) and radiographic polyarticular interphalangeal osteoarthritis (66 (26%) patients) were associated with a higher frequency of inactivity pain, disability, multicompartmental and severe radiographic change. Forestier's disease predominated in men but showed no other associations. CONCLUSIONS: In a group of patients referred to hospital osteoarthritis of the knee is usually bilateral and affects more than one compartment. Severe and multicompartmental radiographic changes are associated with calcium pyrophosphate crystal deposition, nodal change, and polyarticular interphalangeal osteoarthritis.

Adult↗
PubMed1993

A new restriction fragment length polymorphism at the DXS101 locus allows carrier detection in a family with X linked agammaglobulinaemia.

The gene responsible for X linked agammaglobulinaemia (XLA) lies in Xq22 and has recently been identified as atk. DXS101 is a polymorphic locus which is closely linked to the disease locus. In this report we describe the identification, by pulsed field gel electrophoresis, of a new polymorphism at the DXS101 locus with a predicted heterozygosity of 4.9%. Despite this low value, we show how this polymorphism has been important in carrier status determination in a family with XLA where assessment was not possible by other means.

Agammaglobulinemia↗
PubMed1993

Rural hospital administrators and strategic management activities.

This study examines the association of characteristics of rural hospital administrators and the adoption of seven strategic activities in a national sample of 797 U.S. rural hospitals during the period 1983-1988. Based on the premise that managerial activities can affect organizational change, we test five hypotheses relating head administrator characteristics to strategic adaptation, controlling for environment-market and hospital-related variables. Bivariate analysis of the strategic adoption showed a positive association with administrative turnover and a negative association with head administrator age. Multivariate logistic regression showed that only high levels of turnover were associated with strategic activities, net of control variables. The implications of these findings and the lack of predictive power of other rural hospital administrator characteristics--especially affiliation with the American College of Healthcare Executives--are discussed within the context of a "strategic management policy" for rural hospitals.

Age Factors↗
PubMed1993

Racial differences in sexual behaviors related to AIDS in a nineteen-city sample of street-recruited drug injectors. NADR Consortium.

Questionnaire data from almost 12,000 street-recruited drug injectors in 19 cities were analyzed to determine racial differences that may affect transmission of the human immunodeficiency virus (HIV). Self-reported sexual behaviors of drug injectors differ by city-type. White male drug injectors reported less unprotected vaginal sex than black or Latino males in multicultural--black/white/Mexican-origin and biracial cities. Black drug users of both sexes were less likely than white or Latino drug users to report unprotected and sex in multicultural--black/white/Mexican-origin and multicultural--black/white/Puerto Rican cities. The reported percentage of sex acts in which a condom was used was similar for black, white, and Puerto Rican men, and for black and white women, in all city types, but Puerto Rican women reported more condom use than black women. Mexican-origin drug injectors of each gender were least likely to report using condoms in multicultural--black/white/Mexican-origin cities. Black drug injectors are particularly likely to report having sex partners who do not inject drugs, as are Puerto Rican men and as are whites in multicultural--black/white/Mexican-origin cities. High-risk sex without condoms is widely reported among all groups of drug injectors studied: Each racial/gender group in each city-type averaged 15 or more episodes of unprotected vaginal sex per month, and 10% of most subgroups report having anal sex within the past 6 months. At least 45% of subjects in each city-type reported sex with noninjectors of the opposite gender. Without continued and expanded intervention, these data are consistent with HIV spreading to drug injectors, their sexual partners, and their future children, in all racial/ethnic groups.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Comparison of risk factors for coronary heart disease among attenders and non-attenders at a screening programme.

Few objective comparative data are available from primary care on the prevalence of risk factors for coronary heart disease among those who do and do not attend screening programmes. This study set out to examine differences in risk factors between attenders and non-attenders at such a coronary heart disease screening programme. The 2402 patients in the age range 25-55 years who attended the original health check were examined by a practice nurse, and a questionnaire about health issues was completed. A one in 10 systematic sample of the 1398 patients who did not attend the original screening programme were approached and after considerable effort 98 were persuaded to attend for the same examination and questionnaire analysis. The 98 non-attenders were found to be older and to have a higher mean body mass index, mean cholesterol level, mean systolic blood pressure and mean diastolic blood pressure than the 2402 attenders. The non-attenders were more likely to be in the lower social classes, to have a personal or family history of coronary heart disease and to smoke than attenders. They were less likely to be highly educated and to have an unacceptably high level of alcohol consumption. The results of this study suggest that clinics that invite patients to attend are likely to attract those with lower risk factor profiles. For coronary heart disease prevention to be effective there is a need to cater for patients opportunistically.

Adult↗
PubMed1993

Collaboration in coronary heart disease prevention.

Health visitors are ideally placed in primary care to offer effective dietary and life-style advice as part of a team approach to coronary heart disease prevention, write Alan Jones et al. Results from a dietary and life-style intervention trial programme suggest that dietitians, who are limited in numbers, should be used as a resource to provide expert dietary advice and training to the more numerous health visitors. In this way CHD risk factor identification can be developed into effective intervention.

Adult↗
PubMed1992

Tooth mutilation in Angola.

In common with many countries throughout sub-Saharan Africa, some of the many tribes which comprise the indigenous population of Angola practise various forms of tooth mutilation. Three examples associated with distinctive tribes are described and compared with similar practices in neighbouring countries and their references from the literature.

Angola↗
PubMed1992

Ion-spray tandem mass spectrometry in peptide synthesis: structural characterization of minor by-products in the synthesis of ACP(65-74).

Ion-spray triple quadrupole mass spectrometry was used to investigate the products from the solid phase synthesis of the decapeptide (H)-Val-Gln-Ala-Ala-Ile-Asp-Tyr-Ile-Asn-Gly-(OH) [acyl carrier protein(65-74)]. The target sequence was assembled in stepwise fashion from the C-terminal using Boc chemistry on a Bly-OCH2-Pam-copoly(styrenedivinylbenzene) resin. The product was deprotected and cleaved from the resin by treatment with HF/p-cresol for 1 h at 0 degrees C. The crude product was analyzed by reverse-phase HPLC and contained a single major peptide component, one significant minor (late-eluting) component and several trace-level peptide by-products. The components were separated by HPLC and the fractions directly analyzed by mass spectrometry and tandem mass spectrometry. The major product was confirmed as the desired ACP(65-74). The significant minor component was apparently from incomplete deprotection of Asp70, an artifact of this particular experiment. The trace by-products were found to arise from succinimide formation at Asp70, succinimide formation at Asn73, acylation of the Tyr71 side chain phenolic hydroxyl leading to a branched heptadecapeptide, and tert-butylation of the decapeptide. The possible origins of these by-products are discussed in light of known peptide chemistry. Also notable was the absence, to very low detection levels, of by-products frequently reported to occur in peptide synthesis, illustrating the high degree of refinement and the accuracy of currently used synthetic methods.

Acyl Carrier Protein↗
PubMed1992

Arrest of embryo development in Brassica napus mediated by modified Pseudomonas aeruginosa exotoxin A.

Intracellularly expressed cytotoxins are useful tools both to study the action of plant regulatory sequences in transgenic plants and to modify plant phenotype. We have engineered a low mammalian toxicity derivative of Pseudomonas aeruginosa exotoxin A for intracellular expression in plant cells by fusing the ADP ribosylating domain of the exotoxin gene to plant regulatory sequences. The efficacy of exotoxin A on plant cells was demonstrated by transient expression of the modified exotoxin gene in tobacco protoplasts: the exotoxin gene inhibited the expression of a co-electroporated beta-glucuronidase gene. An exotoxin with an introduced frameshift mutation was also effective at inhibiting beta-glucuronidase expression in the transient assay; the activity of the frameshifted gene was presumably a result of frameshifting during translation or initiation of translation at a codon other than AUG. When fused to napin regulatory sequences, the exotoxin gene specifically arrested embryo development in the seeds of transgenic Brassica napus plants concomitant with the onset of napin expression. The napin/exotoxin chimeric gene did not have the same pattern of expression in tobacco as in B. napus; in addition to exhibiting an inhibition of seed development, the transgenic tobacco plants were male-sterile.

2S Albumins, Plant↗
PubMed1992

Influence of aminoglutethimide on plasma oestrogen levels in breast cancer patients on 4-hydroxyandrostenedione treatment.

The clinical and biochemical effects of combined treatment with the two aromatase inhibitors aminoglutethimide and 4-hydroxyandrostenedione were evaluated in 10 patients suffering from advanced breast cancer. All patients had become resistant to treatment with one of the drugs before having combined treatment. Seven patients progressing on 4-hydroxyandrostenedione who had aminoglutethimide added to their treatment and achieved a further suppression of plasma oestradiol by a mean of 40.0% (p < 0.05). Plasma oestrone was suppressed by a mean of 40.6% (p < 0.025) and plasma oestrone sulphate was suppressed by a mean of 63.6% (p < 0.025). Two of the patients, neither of whom had responded to 4-hydroxyandrostenedione alone, experienced objective tumour regression when aminoglutethimide was given in concert. Three patients progressing on aminoglutethimide who had 4-hydroxyandrostenedione added showed no further suppression of their plasma oestrogen levels, and no tumour regression was observed. These findings suggest a dose-response relationship between plasma oestrogen suppression at low postmenopausal levels and objective tumour response in breast cancer.

Adult↗
PubMed1992

Direct measurement of quantal changes underlying long-term potentiation in CA1 hippocampus.

The modification responsible for the long-term synaptic potentiation (LTP) that follows a brief conditioning period is not known. To elucidate this change, we have resolved quantal levels of transmission before and after induction of LTP. We find an increase both in the number of quanta released and in quantal amplitude, consistent with combined pre- and postsynaptic modifications. On average, about 60% of LTP can be accounted for by presynaptic enhancement. The increase in either quantal amplitude or quantal content varies significantly among different experiments, but is inversely correlated with its initial value. These results may help to reconcile the different views concerning the site of LTP expression.

Animals↗