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Biomedical subjects

D McConnell

Publications and source records attributed to D McConnell.

At least 19 recordsLinked to original sources
PubMed2001

Testosterone concentrations in women aged 25-50 years: associations with lifestyle, body composition, and ovarian status.

While there is substantial evidence of the importance of endogenous and exogenous estrogen in reproductive health and chronic disease, there is little consideration of androgens in women's health. In the Michigan Bone Health Study (1992-1995), the authors examined the correlates of testosterone concentrations in pre- and perimenopausal women (i.e., age, menopausal status, body composition, and lifestyle behaviors) in a population-based longitudinal study including three annual examinations among 611 women aged 25-50 years identified through a census in a midwestern community. Current smokers had the highest testosterone concentrations with decreasing values in former and nonsmokers (p = 0.0001). Body composition measures (body mass index, body fat (%), weight (kg), lean body mass (kg), and fat mass (kg)) were significantly and positively associated with total testosterone concentrations in a dose-response manner. Hysterectomy with oophorectomy was associated with significantly lower testosterone concentrations. Alcohol consumption, physical activity, and dietary macronutrient intake were not associated with testosterone concentrations. This is one of the first studies to examine correlates of serum testosterone concentrations in anticipation of the growing interest in the role of androgens in women's health. The greater circulating levels of testosterone in obese women and smokers suggest that testosterone concentrations should be considered in the natural history of disease conditions where obesity and smoking are risk factors, including cardiovascular disease.

Adult↗
PubMed2000

Patient satisfaction with a new nurse practitioner service.

In the UK the role of the Nurse Practitioner (NP) has been slower to develop than in the USA (Tye 1997). However, since its inception, studies of the role have found positive results in areas of patient satisfaction (Touche Ross 1994). James and Pyrgos (1989) reported 94% of patients suitable to seen by a NP would use a NP if introduced. A study by Freij et al. (1996) concluded that emergency NPs were as competent at interpreting X-rays as casualty officers. Despite such evidence, Meek et al. (1995) noted opposition to this new advanced practice from other disciplines who wished to maintain the 'status quo'. In light of these findings, a study was undertaken to examine the new NP Service at Antrim Hospital, Northern Ireland. A patient satisfaction survey, a retrospective X-ray audit and a subjective assessment by other disciplines, were carried out in order to evaluate the service.

Clinical Competence↗
PubMed2000

The effects of 17 alpha-methyltestosterone on myocardial function in vitro.

Testosterone analogs have been used as performance enhancers by athletes for more than 40 yr. We asked whether the anabolic steroid 17 alpha-methyl-4-androstene-17-ol-3-one (17 alpha-MT) would affect intrinsic contractile function of the heart. Male Sprague-Dawley rats, 125-150 g, were treated with 17 alpha-MT either parenterally or orally for up to 8 wk. Intrinsic contractile function of the hearts was assessed utilizing both the isolated working heart and isovolumic perfused heart preparations. Isolated working hearts from 17 alpha-MT-treated rats had a 45% decrease in heart work attributable largely to a similarly decreased stroke volume. Isovolumic perfused hearts from treated animals had elevated left ventricular systolic and diastolic pressures at similar interventricular volumes compared to controls. Rates of ventricular pressure development (+dP/dT) or relaxation (-dP/dT) were unchanged as a result of the treatment. However, static elastance was reduced in potassium-arrested hearts from the 17 alpha-MT treatment (63% increase in interventricular pressure), consistent with a limitation being imposed on stroke volume by a decreased myocardial compliance. Hydroxyproline content of the hearts was not altered by 17 alpha-MT treatment suggesting that increased stiffness was not a consequence of collagen proliferation. Treatment of the steroid rats with beta-aminopropionitrile, a compound that inhibits lysyl oxidase, restored the left ventricular volume-pressure relationship (elastance curve) to that of control hearts. Thus, chronic treatment with anabolic steroids appears to reduce left ventricular compliance, possibly related to an enhanced activity of lysyl oxidase, and results in increased crosslink formation between collagen strands in the extracellular matrix.

Administration, Oral↗
PubMed2000

Variation in utilization of computed tomography scanning for the investigation of minor head trauma in children: a Canadian experience.

OBJECTIVES: To compare the utilization rates of CT scans in investigating minor head trauma in children in Canada, to identify the injuries determined by these scans, and to identify clinical findings that are highly associated with its diagnosis and the injury itself. METHODS: A retrospective cohort study involving nine pediatric hospitals in Canada was conducted. A structured data collection method was used. Inclusion criteria included age 16 years or less, history of blunt head trauma, and a Glasgow Coma Scale score (GCS) greater than or equal to 13. Data collected included demographic information, type of injury, relevant clinical information, computed tomography (CT) scan data, and clinical outcome. Clinical findings associated with CT scan and positive CT scan were identified using logistic regression. RESULTS: One thousand one hundred sixty-four children were included in the study. One hundred seventy-one (15%) had a CT scan, of which 60 (35%) were abnormal. There was a significant difference in the rate of ordering of CT scans among the participating hospitals, but no significant difference in the rate of abnormal CT scans. Mechanism of injury, GCS, and loss of consciousness were significantly related to the presence of an abnormal CT scan. CONCLUSIONS: Although there is a significant difference in the utilization of CT scans to investigate minor head trauma in children across Canada, there is no significant difference in the frequency of head injuries in these patients. This suggests that it may be possible to determine clinical criteria that are predictive of a head injury in these patients.

Adolescent↗
PubMed1999

Audiotapes and letters to patients: the practice and views of oncologists, surgeons and general practitioners.

A range of measures have been proposed to enhance the provision of information to cancer patients and randomized controlled trials have demonstrated their impact on patient satisfaction and recall. The current study explored the practice and views of oncologists, surgeons and general practitioners (GPs) with regards to providing patients with consultation audiotapes and summary letters. In stage 1, 28 semi-structured interviews with doctors were conducted to provide qualitative data on which to base a questionnaire. In stage 2, 113 medical oncologists, 43 radiation oncologists, 55 surgeons and 108 GPs completed questionnaires. Only one-third of doctors had ever provided patients with a copy of the letter written to the oncologist or referring doctor, and one-quarter had provided a summary letter or tape. The majority of doctors were opposed to such measures; however, a substantial minority were in favour of providing a letter or tape under certain conditions. More surgeons and GPs (> two-thirds) were opposed to specialists providing a consultation audiotape than oncologists (one-third). Gender, years of experience and attitude to patient involvement in decision-making were predictive of doctors' attitudes. The majority of doctors remain opposed to offering patients personalized information aids. However, practice and perspectives appear to be changing.

Audiovisual Aids↗
PubMed1999

Improving the letters we write: an exploration of doctor-doctor communication in cancer care.

Referral and reply letters are common means by which doctors exchange information pertinent to patient care. Twenty-eight semi-structured interviews were conducted exploring the views of oncologists, referring surgeons and general practitioners. Twenty-seven categories of information in referral letters and 32 in reply letters after a consultation were defined. The letters to and from six medical oncologists relating to 20 consecutive new patients were copied, and their content analysed. Oncologists, surgeons and general practitioners Australia wide were surveyed using questionnaires developed on data obtained above. Only four of 27 categories of referral information appear regularly (in > 50%) in referral letters. Oncologists want most to receive information regarding the patient's medical status, the involvement of other doctors, and any special considerations. Referring surgeons and family doctors identified delay in receiving the consultant's reply letter as of greatest concern, and insufficient detail as relatively common problems. Reply letters include more information regarding patient history/background than the recipients would like. Referring surgeons and family doctors want information regarding the proposed treatment, expected outcomes, and any psychosocial concerns, yet these items are often omitted. Consultants and referring doctors need to review, and modify their letter writing practices.

Correspondence as Topic↗
PubMed1998

Analysis of cytokine signaling in patients with extrinsic asthma and hyperimmunoglobulin E.

BACKGROUND: Recent data suggest that the regulation of class switching to IgE by cytokines is mediated by STAT transcription factors. The induction of IgE by IL-4 and IL-13 occurs through the activation of the intracellular signal-transducing protein Stat6, whereas the inhibition of IgE class switching by interferon-y (IFN-gamma) occurs through the activation of Statl. OBJECTIVE: We hypothesized that in extrinsic asthma or in cases of markedly elevated IgE (ie, hyperimmunoglobulin E [HIE]) increased levels of IgE may be associated with alterations in the cytokine levels or the activation of Stat6. METHODS: PBMCs and sera from 8 patients with extrinsic asthma (mean IgE, 285+/-100 IU/mL), 3 patients with HIE (mean IgE, 7050+/-1122 IU/mL), and 14 nonatopic control subjects (mean IgE, 112+/-28 IU/mL) were analyzed. RESULTS: The mean IL-4 level detected by ELISA was much greater in patients with HIE than control subjects (88.6+/-11.5 pg/mL vs 11.5+/-7.1 pg/mL, P = .005), and increased IL-4 levels among patients with both asthma and HIE correlated with the increased IgE levels. In contrast, IL-13 levels were not elevated. Levels of Stat6 protein present in PBMCs did not differ in the patients and control subjects. Examination of Stat6 DNA-binding activity demonstrated no activation of IL-4 signaling in patients with either HIE or acute asthma. Interestingly, evidence for the presence of B cells that have already switched to IgE was seen in PBMCs of several patients with asthma or HIE. CONCLUSION: These results indicate that (1) IgE production in asthma and HIE usually is associated with elevated levels of IL-4, but not IL-13, in the peripheral blood; (2) the increased sera IL-4 levels in asthma and HIE are not sufficient to induce Stat6 activation in PBMCs; and (3) evidence of switch recombination to epsilon may be detected in isolated cases of elevated IgE. This implies that high levels of IgE in these patients either results from B cells that have already undergone class switching, from Ig class switching that is localized to target tissues, or both.

Adult↗
PubMed1998

Information booklets about cancer: factors influencing patient satisfaction and utilization.

Providing patients with adequate information is an important component of care. This exploratory study investigated factors influencing patient satisfaction with and utilization of information booklets. The research was conducted in two stages. In stage 1, five commonly used cancer information booklets were reviewed by 36 Australian patients who were either receiving chemotherapy or had just completed treatment. Data were collected on patient satisfaction with, preference for and utilization of information booklets. In addition data were collected on variables identified in the literature as potentially influencing patient satisfaction, including patient characteristics, presentation and readability of booklets, and the timing of provision. A high level of satisfaction was found for all five information booklets, although a clear preference for one particular booklet emerged. The most notable feature of this booklet was its readability level (grade 8); in contrast the other booklets were written at levels equivalent to grades 11-12. Stage 2 focused on the side effects of patient information preference style on their satisfaction and recall of information presented in two booklets in the course of their treatment. No differences were found between patients who seek information and those who avoid it. The findings of this study suggest that patients' information needs may be better met if information booklets are written in plain English, and presented to patients prior to treatment. Future studies incorporating a larger sample of patients and greater selection and variety of information booklets are required to further determine if patient characteristics and features of booklet presentation influence patient satisfaction and preference.

Adolescent↗
PubMed1994

Axillofemoral grafting with externally supported polytetrafluoroethylene.

OBJECTIVE: To evaluate the results of axillofemoral bypass grafting using externally supported polytetrafluoroethylene. DESIGN: Consecutive patients who were operated on by us from 1983 to the present were prospectively followed up in a vascular registry. The results of surgery with respect to morbidity and mortality, patency, limb salvage, and patient survival were determined by life-table methods. PATIENTS: A standardized operative technique was used to perform 184 axillofemoral bypass procedures in 164 consecutive patients (age range, 14 to 90 years; mean age, 67 years; female, 33%). Follow-up ranged from 0 to 95 months (mean, 23 months). RESULTS: Ischemia was the indication for 83% of the procedures, and aortic sepsis was the indication for 16%. There were nine operative deaths (5%) and 17 major complications. Life-table primary patency, limb salvage, and survival rates at 5 years were 71%, 92%, and 52%, respectively. Indication for surgery, patency of the superficial femoral artery, and the performance of multilevel procedures did not significantly influence patency. CONCLUSIONS: The results of axillofemoral grafting using polytetrafluoroethylene are equivalent to those achieved with other accepted methods of treatment for lower extremity ischemia, including balloon angioplasty, aortofemoral bypass, and infrainguinal bypass. Axillofemoral bypass is an appropriate technique that is deserving of more widespread use.

Adolescent↗
PubMed1989

Consequences of behavior influence the effect of alcohol.

Four groups of six male social drinkers learned a complex psychomotor task and then performed it 20 times after drinking a dose of 0.60 g alcohol/kg. Group C received money contingent on the display of nonimpaired performance under alcohol. Group I received a less valuable outcome (information only). Group R received money scheduled randomly with respect to compensatory performance, and group N received no outcome for performance under drug. A briefer duration of impairment, faster recovery at higher BACs, and less impairment during declining alcohol levels was displayed by group C, followed in order by I, R, and N, which displayed least resistance to alcohol. These results are consistent with other evidence demonstrating that these particular treatments have a similar effect on chronic alcohol tolerance. Taken together, the findings imply that the learned expectation of some valuable consequence for drug compensatory performance enhances behavioral tolerance to single and repeated doses of alcohol.

Adult↗
PubMed1988

Mandibular reconstruction in an irradiated field using median sternotomy and anterior rib axial graft.

Mandibular reconstruction in an irradiated field continues to be a challenge to the reconstructing surgeon. Several methods use rib grafts to bring vascularized tissue to the mandibular region. A median sternotomy provides excellent exposure to harvest the internal mammary artery and anterior axial rib graft for subsequent mandibular reconstruction. The modified technique described provides an alternative method of bringing a vascularized rib graft to an irradiated field for mandibular reconstruction avoiding multiple rib resections and microvascular anastomosis. This technique has been used in two patients who had anterior mandibular resection and irradiation therapy for advanced squamous cell carcinoma. The results from this technique were excellent and without major complications.

Graft Survival↗
PubMed1986

Integrable alpha-amylase plasmid for generating random transcriptional fusions in Bacillus subtilis.

An integrable plasmid, pOK4, which replicated independently in Escherichia coli was constructed for generating transcriptional fusions in vivo in Bacillus DNA. It did not replicate independently in Bacillus subtilis, but it could be made to integrate into the chromosome of B. subtilis if sequences homologous to chromosomal sequences were inserted into it. It had a selectable marker for chloramphenicol resistance and carried unique sites for EcoRI and SmaI just to the 5' side of a promoterless alpha-amylase gene from Bacillus licheniformis. When B. subtilis DNA fragments were ligated into one of these sites and the ligation mixture was used to transform an alpha-amylase-negative B. subtilis strain, chloramphenicol-resistant transformants could be isolated conveniently. Many of these were alpha-amylase positive, owing to the fusion of the plasmid amylase gene to chromosomal operons. In principle, because integration need not be mutagenic, it is possible to obtain fusions to any chromosomal operon. The site of each integration can be mapped, and the flanking sequences can be cloned into E. coli. The alpha-amylase gene can be used to detect regulated genes. We used it as an indicator to detect operons which are DNA-damage-inducible (din), and we identified insertions in both SP beta and PBSX prophages.

Bacillus subtilis↗
PubMed1984

Physical map of Salmonella typhimurium LT2 DNA in the vicinity of the proA gene.

More than 55 kilobases of chromosomal DNA of Salmonella typhimurium LT2, including the gpt, proA, ataA, and newD genes, were cloned in plasmid vector pULB113. The locations of the genes and selected restriction endonuclease cleavage sites were established, and some of the restriction enzyme fragments were subcloned in plasmid vector pBR322.

Bacterial Proteins↗
PubMed1983

Quantitative biliary dynamics: introduction of a new noninvasive scintigraphic technique.

We used a Tc-99m-labeled hepatobiliary agent to measure the partition of hepatic bile between gallbladder and intestine in sixteen normal patients and nine patients with cholelithiasis. In normal subjects, the fractions of the hepatic bile that flow into the gallbladder and the small intestine were widely variable, with mean values of 69 +/- 7% (s.e.) and 31 +/- 7% respectively. Bile reflux into the common hepatic duct was rare, occurring during the first 2/3 of the gallbladder ejection period and only when the ejection fraction was greater than 59%. The gallbladder's mean latent period, ejection period, ejection fraction, and ejection rate were 2 +/- 1 min, 11 +/- 1 min, 59 +/- 4%, and 5.9%/min respectively. In patients with cholelithiasis, the fraction of hepatic bile flowing into the gallbladder was normal, but the ejection fraction was significantly reduced (p less than 0.005). For an equivalent dose of cholecystokinin, the gallbladder in cholelithiasis is less responsive than in normal subjects.

Adult↗