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Biomedical subjects

M Jones

Publications and source records attributed to M Jones.

At least 19 recordsLinked to original sources
PubMed1992

Intensive surveillance for infections in a three-year study of nursing home patients.

The authors report the results of a 3-year (August 1984-May 1987) prospective study of intensive surveillance for nursing home-associated infections in 666 patients in a 300-bed nursing home in San Diego, California. Ninety-three percent (666 of 714) of the eligible subjects enrolled; 75% were women. The mean age of the subjects was 81.6 years. Lengths of stay ranged from 1 day to 1,025 days, with a mean of 166 days; the cumulative length of stay for all subjects was 110,746 days (303 years). Operational definitions that were heavily dependent on evaluation of clinical signs and symptoms were used by nurse practitioners in weekly or biweekly assessments of all patients to identify infections. The overall incidence of nursing home-associated infection was 7.1 infections/1,000 patient-days. Many of the infections would not have been recognized by persons less skilled than nurse practitioners. Among the 788 nursing home-associated infections identified, 362 (47%) were in the respiratory tract (286 lower respiratory and 76 upper respiratory); 200 (25%) were associated with skin and subcutaneous and mucous membranes; 140 (18%) were symptomatic urinary tract infections; 13 (2%) were bacteremia; and 73 (9%) were other infections.

Adult↗
PubMed1992

Epithelioid hemangioendothelioma of bone. A report of two cases and review of the literature.

Epithelioid hemangioendothelioma is the prototype of a group of vascular tumors characterized by epithelioid or histiocytoid endothelial cells. Epithelioid hemangioendothelioma of bone is a rare lesion that constitutes fewer than 1% of primary malignant skeletal neoplasms. We describe two cases that illustrate the spectrum of radiographic features seen with this neoplasm, and also present its appearance on magnetic resonance imaging.

Adult↗
PubMed1992

Human ovarian-carcinoma cell lines and companion xenografts: a disease-oriented approach to new platinum anticancer drug discovery.

A disease-oriented approach to the discovery of novel platinum anticancer drugs has been established through the setting up of parallel human ovarian-carcinoma cell lines and xenografts. The correlation between in vitro and in vivo antitumour activity was determined for four reference platinum agents (cisplatin, carboplatin, iproplatin and tetraplatin) in eight companion lines. Two methods of assessing antitumour effect were used in vitro (tritiated thymidine incorporation and sulforhodamine B staining) and three were applied in vivo [28-day treated/control (T/C) ratio, growth delay and specific growth delay]. In vitro, large differences in cytotoxicity across the cell lines were observed for each drug. This was also reflected in the xenografts for cisplatin and carboplatin and, to a lesser extent, for iproplatin. A correlation analysis of in vitro vs in vivo data revealed a high, statistically significant positive correlation for cisplatin and a strong positive correlation for carboplatin. However, for the two platinum(IV) drugs, the correlation was less good. In particular, tetraplatin was markedly less active in vivo (showing a general lack of activity against all of the tumour lines) than its in vitro potency against the cell lines predicted, resulting in poor correlation coefficients. These human tumour panels may be valuable for the elucidation of both cellular/molecular and corresponding in vivo pharmacological mechanisms of platinum drug resistance. Moreover, the HX/62 and SKOV-3 tumour lines, which exhibit a level of intrinsic resistance to the four reference agents both in vitro and in vivo (and which were derived from patients who had not received prior platinum therapy), represent particularly useful evaluation models for the discovery of novel broad-spectrum platinum drugs.

Antineoplastic Agents↗
PubMed1992

Enteric and central contributions to intestinal dysmotility in irritable bowel syndrome.

The aim of the study was to further elucidate the pathophysiology of irritable bowel syndrome and its subgroups by examining and comparing alterations in small bowel motility, specifically phase II and phase III components of the migrating motor complex. Prolonged recordings of interdigestive small bowel motility were obtained during both diurnal and nocturnal periods in 20 patients with irritable bowel syndrome--10 with predominant constipation and 10 with predominant diarrhea--and in 10 healthy subjects. Diurnal amplitude (mean +/- SD) of phase III activity fronts was lower (P less than 0.05) in constipation-predominant patients (16.3 +/- 3.1 mm Hg) than in diarrhea-predominant patients (20.2 +/- 3.1) or controls (20.9 +/- 2.7). Similar findings were observed nocturnally. Phase III cycle length was also significantly prolonged diurnally in constipation-predominant patients when compared to the other groups. In the diarrhea-predominant group repetitive and rapidly propagated bursts of contractions were observed in eight patients, and this pattern occupied a significantly greater proportion of phase II motor activity than in controls. These alterations in phase II and in phase III components of the migrating motor complex suggest that both local (enteric) and more central mechanisms may operate to produce intestinal dysmotility in the irritable bowel syndrome and that these mechanisms differ according to the predominant alteration of bowel habit.

Adult↗
PubMed1992

The acute appendicitis syndrome: psychological aspects of the inflamed and non-inflamed appendix.

The aetiological importance of stressful life events and psychological characteristics was assessed amongst 280 appendicectomy patients of whom 80% were classified with 'acutely inflamed' (organic) appendicitis and 20% with 'non-inflamed' (non-organic) appendicitis. Patients were compared with a community comparison group. Specific characteristics of life stressors, namely severe goal frustration for organic patients and severe threat for non-organic patients, were the best predictors of patient outcome. Whilst psychological characteristics were not useful in discriminating between patients, depression in particular, was clearly associated with both conditions, with 38% of non-organic and 28% of organic patients with depression scores in the clinical range. As the patient's clinical depression status failed to modify the effect of the life stress predictors, it was concluded that life stress played an important role in the development of the patients GI symptoms, irrespective of their clinical depression status.

Adolescent↗
PubMed1992

Resuscitation. Patient and staff attitudes in the context of cancer.

One hundred oncology and hematology cancer patients from a major teaching hospital and their treating doctors were studied regarding their attitudes toward cardiopulmonary resuscitation (CPR). A descriptive approach was used, incorporating semistructured interviews of patients and medical staff and established questionnaire measures, examining knowledge of and attitudes toward disease and treatment, and projected attitude toward CPR and current psychological functioning. One-third of the patient sample anticipated a time when they would not consent to cardiopulmonary resuscitation. This was significantly associated with good disease prognosis. Patients with a psychiatric past history were also overrespresented. It appears that patient attitude to treatment withdrawal and refusal of CPR is related to disease progression and likely to change over time. This supports a dynamic and evolving model of advance directives rather than any fixed decree. Medical staff reported that they planned to provide half the sample with intensive medical treatment (including Intensive Care support in the event of their cardiac arrest), and 32% were designated for ward-based resuscitation only. Eighteen percent would not be resuscitated. These patients were older, had more treatment side effects, and a poorer quality of life. Those patients with either a psychiatric past history or higher ratings of depressive affect were also overincluded in the doctors' "Do-Not-Resuscitate" (DNR) group. These results suggest that there are other qualitative factors (e.g., current psychological functioning and past psychiatric history) that contribute to DNR decisions beyond the usual disease-based criteria seen in formal DNR protocols.

Adult↗
PubMed1992

Relationship between angiographic infarct size and left ventricular filling.

Infarct size may influence left ventricular filling after acute myocardial infarction. Pulsed Doppler transmitral flow velocities were compared in 47 patients at 7 +/- 6 days following acute myocardial infarction and 47 age-matched controls. Patients were stratified by angiographic infarct size into Groups I, II, III (corresponding angiographic hypokinetic scores less than 2; 2-2.99; greater than or equal to 3 SD/cord). Early diastolic transmitral Doppler flow velocities did not differ between infarct groups but atrial transmitral Doppler flow measurements did: peak A velocity (p = 0.001), A velocity time integral (p less than 0.001), and total velocity time integral (p = 0.001). Compared to controls atrial transmitral Doppler flow was augmented in Group I, whilst atrial and total transmitral Doppler flow were depressed in Group III. Peak A velocity and A velocity time integral were inversely related to infarct size (R = -0.44 to -0.54) and directly to left ventricular ejection fraction (R = 0.59 to 0.65). Large infarct size following myocardial infarction is associated with lower atrial and total transmitral Doppler flow velocities.

Adult↗
PubMed1992

Arthroscopic surgery of the knee: its role in the support of U.S. troops during Operation Desert Shield on USNS mercy.

The role of arthroscopy in the preconflict deployment of a large number of military troops is not well defined. Between September 1990 and January 1991, while deployed to the Persian Gulf for Operation Desert Shield 73 patients underwent on-board elective arthroscopy on the USNS Mercy. There were 71 men and two women with an average age of 27 years (range 19-47). Indications for arthroscopy included clinical diagnosis of meniscus tear, acute hemarthrosis, chronic effusion, and intra-articular loose body. Findings at the time of arthroscopy included 34 patients (47%) with meniscus tears; 17 (23%) with anterior cruciate ligament tears; five (7%) with isolated grade II-IV chondromalacia involving the patella, trochlea, femoral condyles, or tibial plateaus; six (8%) with synovitis; four (5%) with osteochondritis dissecans of the medial femoral condyle; two (3%) with a medial retinacular tear secondary to patella dislocation; and 10 (14%) with normal arthroscopic examinations. Forty-nine patients (66%) were returned to duty at an average of 6 days postoperatively, obviating the need to evacuate these patients from the Middle East theatre.

Adult↗
PubMed1992

The pain and discomfort experienced during orthodontic treatment: a randomized controlled clinical trial of two initial aligning arch wires.

A randomized controlled clinical trial was performed to compare the nature, prevalence, intensity, and duration of pain related to the use of a relatively recently developed superelastic arch wire and a more traditional multistranded steel arch wire. Other factors likely to influence the pain experience were also investigated. Forty-three subjects participated in the study, the pain response being assessed by each of the visual analogue scales, the questionnaires, and an analgesic consumption record. In 18 of the 43 subjects a standardized preliminary dental extraction procedure was used as a control. Subsequent to the random allocation of an initial arch wire in 43 patients, 22 of them underwent a second arch wire in the opposing arch, the wire again being determined by random allocation. It was found that the prevalence, intensity, and duration of pain after the insertion of the two types of wire was similar but much greater than in the postextraction control phase. The pain score peaked on the morning after the placement of the arch wire, lasting typically for 5 to 6 days. The pain and discomfort experienced after the insertion of the second arch wire was similar to that of the first, no conditioning response being evident. Overall a diurnal variation was found with a tendency to an increase in pain in the evenings and nights, although this did not greatly affect sleep. The pain response was found to be highly and consistently subjective, not related to the dental arch, crowding, sex, or social class; however, a statistically significant association was found between the age and the pain experienced.

Adolescent↗
PubMed1992

The development of a light curing prosthesis for chest wall replacement.

In conjunction with colleagues in the chemical industry, we have developed and evaluated a new plastic prosthesis which we hope will supplant presently used materials for chest wall replacement. We have modified the basic chemical of a reactive resin routinely used in orthopaedic and dental work by the inclusion of a polypropylene mesh. The resultant material is thin enough to cut with scissors and yet supple enough to shape to fit the defects. It is hardened by exposure to UV light and has a practical cure time when exposed to normal light in the operating theatre. When set it is strong and rigid. The mechanical properties have been studied with the Flexural 3-point bend test and compared with the best of the presently available prostheses. The inert nature of the material was studied in a subcutaneous implant in 29 rats over 3 months. Histology has shown a lack of reactivity. The stability in vivo was studied using the material to replace portions of the chest wall in rabbits for up to 6 months. Subsequent histology and in-vitro testing have proved satisfactory. The ability of this material to withstand the dynamic stresses of the chest wall have been studied by its implantation into the chest wall of 3 minipigs for 6 months. The material looks promising and has proved more "user friendly" than existing prostheses for flat bone replacement. We hope to refine its production to allow its use in humans.

Animals↗
PubMed1992

Evaluation of bcl-2 protein expression and 14;18 translocation as prognostic markers in follicular lymphoma.

Conflicting results have been published on the prognostic significance of t(14;18) in follicular lymphoma: Yunis et al. (1989) reported that its presence indicated poor response to therapy and short survival, whereas Levine et al. (1988) showed no difference in prognosis between cases with and without the translocation. However these results were based on small series of cases and on follow-up periods (no longer than 7 years) which are relatively short for a disease with such a slow clinical evolution. Here we report an investigation of 70 cases of follicular lymphoma with long term follow-up data (up to 17 years). This series has been studied for the presence of the 14;18 translocation and for the expression of bcl-2 protein. Our results show that there are no grounds for considering either the 14;18 translocation or the expression of the bcl-2 protein to be useful prognostic markers in clinical practice.

Blotting, Southern↗
PubMed1992

Molecular and biological properties of an abrin A chain immunotoxin designed for therapy of human small cell lung cancer.

An immunotoxin (IT) comprising abrin A chain attached to the mouse monoclonal antibody SWA11, recognising a cell surface antigen highly associated with human small cell lung cancer (SCLC), was synthesised using a hindered disulphide crosslinker, N-succinimidyl 3-(2-pyridyldithio) butyrate (SPDB), and purified by Blue Sepharose CL-6B affinity chromatography. The IT preparation contained monomeric conjugate, composed of one abrin A chain molecule linked to one SWA11 molecule, and was free from unconjugated A chain or antibody. The IT fully retained the cell-binding capacity of the antibody component and the ribosome-inactivating activity of the A chain. In cytotoxicity assays using the SW2 SCLC cell line in tissue culture, SWA11-SPDB-abrin A chain inhibited the incorporation of 3H-leucine by 50% at a concentration of 10 pM and by 99% at a concentration of 1 nM. The anti-tumour efficacy of the IT was tested in nude mice bearing established s.c. solid SW2 tumour xenografts. A single i.v. injection of SWA11-SPDB-abrin A chain at a non-toxic dose induced a significant 7 to 10 day growth delay that could not be matched by administration of equivalent doses of either unconjugated SWA11 or abrin A chain alone. The results of this study indicate that the antigen recognised by SWA11 is an effective target for therapy of SCLC with A chain ITs in vivo.

Abrin↗
PubMed1992

Effects of oral contraceptives containing oestrogen combined with norethisterone or levonorgestrel on erythrocyte cation transport in normal women.

1. Studies were undertaken in pre-menopausal women to examine the effects of treatment with standard oestrogen-progestogen and progestogen-ony oral contraceptives on erythrocyte Na+,K+ co-transport and Na(+)-Na+ countertransport over 3- and 6-month periods. Concurrent observations were made on other erythrocyte cation transport components, plasma lipid concentrations, plasma renin activity, plasma aldosterone concentration and blood pressure. 2. Na+,K+ co-transport, measured as the ouabain-resistant, frusemide-sensitive component of 86Rb+ influx, and Na(+)-Na+ countertransport, measured as the ouabain-resistant, phloretin-sensitive component of 22Na+ influx, were both increased in women taking, on days 1-21 of their cycle, ethinyloestradiol (30-50 micrograms) combined with norethisterone (1000 micrograms or 500-1000 micrograms) for 3 or 6 months. Neither of these fluxes was increased in a control group of women, or in women treated for the same time periods with ethinyloestradiol combined with levonorgestrel. 3. In a separate study of erythrocyte cation transport (excluding Na(+)-Na+ countertransport), in which women undertook treatment with norethisterone only (350 micrograms/day) for 6 months starting 6 weeks post partum, no changes in Na+,K+ co-transport were observed at 3 or 6 months; there were no changes in cation transport in a corresponding control group. 4. The results of these studies confirm that certain oral contraceptive compounds can alter erythrocyte cation transport, and indicate that norethisterone in higher dose preparations is the component predominantly responsible. The alterations observed could not be explained by a direct link with concurrent changes in plasma triacylglycerol concentrations or in the renin-aldosterone axis and were not closely associated with elevation of blood pressure.

Adolescent↗
PubMed1992

Stresses induced by edgewise appliances in the periodontal ligament--a finite element study.

The quantification of stress in the periodontal ligament is an important concept, as stress in this tissue is transmitted to the alveolus, with subsequent bone remodelling and tooth movement. A number of clinical studies have suggested figures for such an optimal stress range. This study makes use of a finite element technique to determine the stress induced in the periodontal ligament in three dimensions when a maxillary canine tooth is subjected to an orthodontic force similar to that produced by an edgewise appliance. The maximum stress induced at the cervical margin of the periodontal ligament was 0.072 N/mm2, while the maximum stress induced at the level of the apical foramen was 0.0038 N/mm2. These results are discussed in the light of known clinical experience and compared with the stresses produced in the periodontal ligament by other orthodontic forces. The findings would suggest that even with 'perfect' edgewise mechanics it would be difficult to obtain canine movement by pure translation or 'bodily movement.'

Alveolar Process↗
PubMed1992

Candidemia in a tertiary care hospital: epidemiology, risk factors, and predictors of mortality.

Demographic information, risk factors, therapy, and outcome for all patients who had candidemia at Barnes Hospital, St. Louis, between 1 September 1988 and 1 September 1989 were retrospectively reviewed. One hundred six candidemic patients were identified, representing 0.5% of all medical and surgical discharges and 0.33% of total patient discharges. These percentages represent a 20-fold increase in the incidence of candidemia at our hospital in comparison with that during 1976-1979. Candida albicans was the most frequently isolated species (63%), followed by Candida tropicalis (17%), Candida glabrata (13%), Candida parapsilosis (6.5%), and Candida krusei (0.9%). Overall mortality was 57%, and 14 (23%) of 60 deaths occurred within 48 hours of the detection of candidemia. Mortality was associated with higher APACHE II scores (25 for nonsurvivors vs. 16 for survivors; P = .0001), the presence of a rapidly fatal underlying illness (P = .0009), and sustained positivity of blood cultures (P = .02). In cases of sustained candidemia, the isolation of non-albicans Candida species also correlated with increased mortality (8 of 8 vs. 10 of 21; P = .005). Thirty candidemic patients (28%) did not receive any antifungal therapy, and 19 (63%) of these untreated patients died. Eleven untreated patients (37%) survived without sequelae. There has been a marked increase in the incidence of candidemia in our institution that is associated with a high overall mortality. Candidemia lasting less than 24 hours was associated with a lower mortality than was that of longer duration. Severity of illness and duration of candidemia should be used as stratifying factors in prospective studies to determine optimum therapy.

Adolescent↗
PubMed1992

Development and follicular localization of tolerant B lymphocytes in lysozyme/anti-lysozyme IgM/IgD transgenic mice.

To analyse mechanisms of immunological self-tolerance, a detailed comparison of the development and fate of lysozyme-specific B lymphocytes was carried out in transgenic mice expressing rearranged anti-lysozyme IgM/IgD Ig transgenes in the absence or presence of an additional transgene encoding lysozyme itself. In the absence of lysozyme, B cell development, localization, and differential expression of transgene-encoded IgM and IgD occurred in the normal sequence in Ig transgenic mice, establishing that these animals provide a physiological model for studies of B cell selection in vivo. By contrast, in lysozyme-expressing double-transgenic mice, tolerant lysozyme-reactive B cells persisted within the follicular mantle zones in the spleen, lymph nodes, and Peyer's patches, but were eliminated from the splenic marginal zones. It could be shown that lysozyme-binding and induction of tolerance occurred as soon as surface Ig was expressed on immature B cells in the bone marrow of the double-transgenic mice although this did not prevent maturation, emigration from the bone marrow, and localization in peripheral lymphoid follicles. These findings, together with recent examples of aborted maturation of self-reactive B cells, indicate two functionally distinct antigen receptor signalling events in immature B cells and suggest a unique role for the follicular microenvironment.

Animals↗
PubMed1992

The effectiveness of preemployment drug screening in the prediction of employment outcome.

Studies of adverse employment outcomes associated with positive preemployment drug screens have tracked employees for only about 1 year. Changes in drug use after hire may invalidate the predictions of employment outcome in later years which are essential for cost-benefit analyses. This blinded, prospective cohort study tracks absence, industrial accidents, occupational injuries, discipline, and turnover in 2537 screened employees through an average of 2 years. Marijuana-positive urines predicted increased turnover, accidents, injuries, discipline, and absence, but these risks appeared lower in the second year than the first. Cocaine-positive urines predicted increased turnover, accidents, injuries, discipline, and absence at levels not consistently different than the first year. Cost-benefit analyses of drug screening project employment risks throughout employees' careers. This study raises the possibility that elevated risks may decrease after the first year.

Boston↗