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Biomedical subjects

T R Magee

Publications and source records attributed to T R Magee.

At least 55 records · Page 3Linked to original sources

Varicose veins on the internet.

OBJECTIVES: to evaluate the quality of information on the Internet concerning varicose veins. DESIGN: review of retrieved pamphlets and their scoring for educational value. MATERIALS: a sample of 41 documents were retrieved from the Internet using four "search engines". METHODS: characteristics, including country of origin, authorship, length, and presence of references were recorded. Based on factors such as disease summary, treatment options and complications a weighted score was created by two independent observers. RESULTS: eleven documents were published by an academic institution or professional organisation. Twenty-seven documents originated from private practice groups, the source of three was unidentifiable. The median weighted score was 21.5 (interquartile range: 7.5-48.5). Scores originating from non-profit making organisations were significantly higher than those from private practice groups (44.5 vs 13, p=0.04). The length of the document showed a significant positive correlation with its educational quality as measured by the information score (r=0.82, p<0.001). CONCLUSION: there is a plethora of data concerning varicose veins on the Internet. Some documents offer comprehensive information but many are confusing or misleading. Longer pamphlets and information presented by non-profit making organisations are more reliable than short documents and information offered by private medical groups.

Female↗

Expression of penile neuronal nitric oxide synthase variants in the rat and mouse penile nerves.

Penile erection is mediated by nitric oxide (NO) synthesized by the neuronal nitric oxide synthase (nNOS). In the rat penis, the main nNOS mRNA variant, PnNOS, differs from cerebellar nNOS (CnNOS) by a 102 base pair insert encoding a 34-amino acid sequence. In the mouse, two nNOS mRNAs have been identified: nNOSalpha, encoding a 155-kDa protein, and an exon 2-deletion variant, nNOSbeta, encoding a 135-kDa protein that lacks a domain where a protein inhibitor of nNOS (PIN) binds. We wished to determine whether PnNOSalpha and beta are expressed in the rat penis and are located in the nerves and whether the beta form persists in the potent nNOS knock-out mouse (nNOS( big up tri, open big up tri, open)). A PnNOS antibody against the insert common to both PnNOSalpha and beta detected the expected 155-kDa protein in PnNOSalpha-transfected cells. This antibody, and the one common to PnNOS/CnNOS, showed (on Western blots) the 155- and 135-kDa nNOS variants in rat penile tissue during development and aging. PnNOSalpha mRNA and its subvariants were found as the main nNOS in the penile corpora, the cavernosal nerve, and the pelvic ganglia, with lower levels of PnNOSbeta mRNA. In tissue sections, PnNOS protein was immunodetected in the penile nerve endings in the rat and in the nNOS wild-type and nNOS( big up tri, open big up tri, open) mice. An antibody against the sequence encoded by exon 2 did not react (on Western blots) with the 135-kDa band, which confirms that this protein is the beta form. In conclusion, both PnNOSalpha and beta are expressed in the rat penis at all ages and are located in the nerves. The beta form may allow nitric oxide synthesis during erection to be partially insensitive to PIN. The residual expression of PnNOS, and possibly CnNOS, in the penis of the nNOS( big up tri, open big up tri, open) mouse occurs through transcription of the beta mRNA, and this may explain the retention of erectile function when the expression of nNOSalpha is disrupted.

Amino Acid Sequence↗

Regional variation in varicose vein operations in England 1989-1996.

AIM: To determine accuracy of Office of Population Censuses and Surveys (OPCS) codes for varicose vein (VV) operations and differences in regional activity over 7 years. METHODS: OPCS codes were obtained for VV operations (L85, L87) for the 8 English regions 1989/90-1995/96. Data were also obtained for the 4 districts of the old Oxford Region. Centrally collected codes for one hospital were compared with audit data from the same hospital. RESULTS: There was a marked inter-regional variation in VV activity, e.g. in 1995/96 the range of operations/100,000 population was 102 (Anglia & Oxford) to 138 (West Midlands). There was a gradual increase in the number of operations carried out nationally from 98/100,000 in 1989/90 to 121/100,000 in 1995/96. The numbers peaked in 1991/92, coinciding with a 'waiting list initiative'. When compared with audit data, accuracy of coding improved throughout the study period. There was a 55% inaccuracy in 1989/90 compared with 2% in 1995/96. In each year, codes overestimated the volume of work actually carried out. CONCLUSION: OPCS codes broadly reflect VV activity. Difference in VV activity in different parts of the country are apparent.

Documentation↗

Variation in vascular activity in the United Kingdom: an analysis of five regions.

BACKGROUND: The aim of this study was to define variations in vascular activity that may exist between different demographic regions of the UK. METHODS: Five regions were studied. Data were obtained on OPCS codes for vascular surgery 1994-95 from the Department of Health or Welsh Office. Mortality and cause of death statistics were calculated for each region from OPCS data. RESULTS: Ranges of vascular reconstruction, iliac and superficial femoral artery angioplasty and major amputation were 26.2-44, 10.5-23.0 and 11.5-15.7 per 100,000 population, respectively. The highest rates of amputation were seen in areas of high standard mortality and highest death rate from atheroma and ischaemic heart disease. Rates of amputation also rose in proportion to the number of men in the population aged > 60 years. CONCLUSION: Variations exist in vascular activity between different regions. This may be caused by demographic differences in the population. It needs to be considered when calculating the number of vascular surgeons required in different areas of the country.

Amputation, Surgical↗

Retinoic acid mediates down-regulation of the alpha-fetoprotein gene through decreased expression of hepatocyte nuclear factors.

alpha-Fetoprotein (AFP), a protein highly induced during fetal liver development, is down-regulated by retinoids in the human hepatoma cell line Hep3B, in contrast to up-regulation observed in other cell types. Previously, we have documented that such up-regulation involves direct effects through cis-retinoid X receptor-binding sites in the AFP enhancer. In this report, we show a distinctive effect of all-trans-retinoic acid (RA) in Hep3B cells. RA caused a marked decrease in AFP transcripts. Deletion analysis of the upstream regulatory region of the AFP gene revealed that cis-acting sites required for down-regulation resided near the promoter. Gel mobility shift assays for factors binding to key elements in the AFP promoter region demonstrated that hepatocyte nuclear factor (HNF) 1 binding was diminished in nuclear extracts from RA-treated cells. In addition, HNF4, which is not known to bind to the AFP promoter but does regulate HNF1, was also diminished. The levels of HNF1 and HNF4 mRNA were also decreased following RA treatment. AFP promoter-chloramphenicol acetyltransferase transient transfection assays demonstrated that the level of HNF1 had a direct impact on basal transcription as well as RA-mediated down-regulation of the AFP gene, and that co-transfection of HNF1 and HNF4, but not transfection of either factor alone, reversed the RA-mediated inhibition. Taken together these data point to an interaction among the RA, HNF1, and HNF4 signals, which is reflected in decreased expression of AFP.

Animals↗

Functional analysis of the stress response element and its role in the multistress response of Saccharomyces cerevisiae.

The DDR2 gene of Saccharomyces cerevisiae is a multistress response gene whose transcription is rapidly and strongly induced by a diverse array of xenobiotic agents, and environmental and physiological conditions. The multistress response of this gene requires the pentanucleotide, 5' CCCCT, (C4T;STRE (STress Response Element)) and the zinc-finger transcription factors, Msn2p and Msn4p. A 51bp oligonucleotide (oligo 31/32) containing two STREs from the DDR2 promoter region was previously shown to direct heat shock activation of a lacZ reporter gene. In this work we demonstrate that the same element conferred a complete multistress response to an E. coli galK reporter gene introduced into yeast cells. A variant oligonucleotide in which both the STRE spacing and neighboring sequences were altered responded to the same spectrum of stresses, while substitution of nucleotides within the pentanucleotide completely abolished the multistress response. These results directly demonstrate that STREs are not only necessary but are sufficient for mediating a transcriptional response to a surprisingly diverse set of environmental and physiological conditions.

Base Sequence↗

Retinoic acid differentially regulates retinoic acid receptor-mediated pathways in the Hep3B cell line.

Retinoic acid (RA) up-regulates retinoic acid receptor beta (RAR beta) gene expression in a variety of cell lines. Whether up-regulation of the RAR beta gene reflects increased activity in a RAR beta-mediated biological process is unclear since RAR beta tends to heterodimerize with retinoid x receptor (RXR). In F9 teratocarcinoma cell line, RA-induced differentiation is accompanied by increased expression of the RAR beta, RXR alpha, and alpha-fetoprotein (AFP) genes. Previously, we have shown that the RA-mediated regulation of the AFP gene is through RXR alpha homodimers. In contrast to F9 cells, Hep3B is unique in that the AFP gene is down-regulated by RA in a manner reminiscent of down-regulation of AFP in postfetal liver. In this paper, we have examined the RA-mediated regulation of the RAR, RXR, peroxisome proliferator-activated receptor (PPAR), and AFP genes in Hep3B cells. RA induced the expression of RAR alpha, beta, and gamma mRNA in Hep3B cells. However, the expression of RXR alpha mRNA was down-regulated, and the levels of RXR beta and RXR gamma mRNA remained unchanged after RA treatment. In addition, the expression of the PPAR alpha, beta, and gamma genes was also unchanged. Gel retardation assays demonstrated that RA decreased the overall binding of nuclear receptors to the RA and PPAR response elements. By super-shift assays using specific anti-RAR and -RXR antibodies, RA treatment decreased the amount of RXR alpha while increasing the amount RAR beta bound to retinoic acid response element-DR1 (direct repeat with spacer of one nucleotide), indicating the levels of RAR/RXR heterodimer, RXR/RXR homodimer, or RAR/RAR homodimers were altered upon RA treatment of Hep3B cells. In addition, the RA-mediated reduction of RXR alpha in part results in down-regulation of the AFP gene. Our data indicates that RA exerts its effects by differentially regulating its own receptor gene expression.

Animals↗

Accuracy of centrally recorded OPCS codes for vascular surgery in the United Kingdom.

AIM: Centrally recorded OPCS codes are based upon district returns. The aim of this study is to determine the accuracy of this system with regard to vascular surgery. METHODS: Prospectively recorded audit data for vascular and endovascular procedures were compared with those obtained from the Department of Health and Welsh Office. Five U.K. hospitals were involved in the study. Data were obtained for the twelve months, 1 April 1994-30 March 1995 (these being the most up to date figures available). RESULTS: The total number of arterial reconstructions based on audit data was 1082. Those recorded by the OPCS codes were 743. This represents a discrepancy of -31.3% (range for the five hospitals: -13.1% to -63.8%). When examining specific codes similar discrepancies were seen. For example, in one hospital 38 AAA repairs were carried out but only two were centrally recorded. However, examination of ICD9 codes (relating to hospital admissions) for that hospital showed that 38 patients with AAA were admitted. A similar wide variation was seen when examining iliac and superficial femoral artery endovascular procedures. Despite the discrepancies of audit and OPCS data, the codes for reconstructions did reflect relative workload of the different hospitals. CONCLUSION: This study shows that there is a marked underestimate of vascular workload when comparing central recorded data with that obtained from local audit. Marked variation is seen in the accuracy of data submitted from different hospitals.

Angioplasty, Balloon↗

A survey of current attitudes of British and Irish vascular surgeons to venous sclerotherapy.

AIM: To determine current practice amongst vascular surgeons regarding venous sclerotherapy. METHOD: A postal questionnaire was sent to 350 members of the Vascular Surgical Society of Great Britain and Ireland. RESULTS: There were 218 replies (62%). Forty surgeons (18.3%) never injected varicose veins (VV) although six injected venous flares. Most surgeons (n = 168, 77.1%) reserved sclerotherapy for residual VV postoperatively. Primary varicose veins without proximal incompetence were injected by 152 (69.7%) and recurrent VV without proximal incompetence by 141 (64.7%). Sixteen surgeons only injected residual postoperative VV. Few surgeons injected VV in the presence of proximal incompetence. Where specified, 46% of respondents were injecting fewer VVs than in previous years. Only 5% were injecting more. By contrast, 44% were injecting more venous flares than previously (p < 0.001). Eight different sclerosants were used, the commonest being STD (146 surgeons) and Sclerovein (33). The median number of patients treated with sclerotherapy was 11-50 per year compared with 51-150 per year who were operated upon. The median time advised for compression was 2 weeks (range--a few minutes--2 months). Treatment was repeated at a median of 4 weeks (0-6 months). Thirty-two surgeons obtained written consent. All but eight respondents discussed potential complications, the commonest being staining and ulceration. Forty-six surgeons had patients who had experienced serious complications, the commonest being ulceration. There was one reported death from a pulmonary embolus. CONCLUSION: Sclerotherapy is being used less frequently for VV. Most surgeons use it for residual VV and for those without proximal incompetence.

Attitude of Health Personnel↗

Early experience with stenting for iliac occlusive disease.

OBJECTIVES: To review our experience of iliac artery stenting for occlusive disease. DESIGN: Prospective study of 50 consecutive patients with iliac occlusive disease, November 1993-November 1996. The indications for stenting were complete iliac occlusion (37) restenosis (four), donor site inflow for bypass grafting (four) and difficult stenoses (> 90% and/or > 5 cm) (five). The majority of patients (41) presented with intermittent claudication. RESULTS: All 13 stenoses were successfully stented. One occluded but the rest remain patent. There were no other complications. By contrast, it was not possible to place a stent across 10 of the 37 complete iliac occlusions. In this group there were nine major complications, including five patients who required early embolectomy (four femoral, one brachial) and one patient who developed a false aneurysm at the site of the stent. The "intention to treat" primary cumulative patency for iliac occlusions was 65% at 2 years but after excluding technical failures was 88%. CONCLUSIONS: There is a sharp learning curve and significant complication rate associated with stenting complete occlusions. However, following successful stenting patency rates are around 90% for both iliac stenoses and occlusions.

Aged↗

The fate of patients undergoing surveillance of small abdominal aortic aneurysms.

OBJECTIVES: Increasing numbers of patients with small abdominal aortic aneurysms (AAA) are being diagnosed. The aim of this paper is to define the fate of those patients undergoing surveillance of small AAAs. SETTING: U.K. district general hospital. METHODS: A prospective study has been carried out of all patients undergoing surveillance. At the time of the first consultation the patient was assessed, a Detsky score calculated and the referral source noted. End points of the study were elective repair of the aneurysm, aneurysm rupture or death of the patient. RESULTS: Details of 267 patients were analysed. The referral source was general practitioner in 39%, patients with peripheral vascular disease in 32% and department of urology in 21%. None were referred from population screening. The cumulative 5-year risks of rupture, elective repair or non-AAA related deaths were 15%, 26% and 46% for all patients, 4%, 13% and 38% for patients initially presenting with AAA less than 4 cm diameter and 21%, 42% and 54% for patients presenting with an AAA 4-5.5 cm diameter. All but one of 11 patients whose aneurysm ruptured were unfit or had declined elective repair. There were 56 non-AAA related deaths, the majority due to cardiovascular causes. Those patients with low Detsky scores had a 5-year survival of 62%, those with high scores 44%. The age/sex matched survival or a normal population at 5 years in 80%. CONCLUSION: Overall the non-AAA related mortality was greater than the risks of rupture or elective repair. It is important to bear in mind the poor prognosis of this group of patients compared with a normal population when considering elective repair of small AAAs.

Actuarial Analysis↗

Prospective evaluation of quality of life after conventional abdominal aortic aneurysm surgery.

OBJECTIVES: To evaluate the changes in quality of life following conventional abdominal aortic aneurysm repair. DESIGN: Prospective study. MATERIALS AND METHODS: Fifty-nine consecutive patients (50 men; nine women) in two surgical centres were investigated preoperatively, and at 6 weeks, 3 months and 6 months postoperatively. Quality of life was measured using the Short Form 36 (SF 36) questionnaire and the York Quality of Life questionnaire, from which the Rosser index was calculated. RESULTS: Rosser index assessment showed restoration of quality of life to preoperative levels by 3 months, and significant improvement at 6 months. Changes in the SF 36 revealed significant improvement in mental health, and physical role limitation at all times postoperatively. Social function worsened at 6 weeks but improved to preoperative levels by 3 and 6 months after surgery. CONCLUSIONS: Quality of life was improved after open aortic aneurysm repair. The time course of recovery shows a predominant improvement between 6 weeks and 3 months postoperatively.

Aged↗

Minimally invasive superficial femoral artery endarterectomy: early experience with a modified technique.

OBJECTIVES: To describe our experience of a modified technique for carrying out remote endarterectomy for superficial femoral artery occlusive disease. METHODS: A 4-French arterial dilator is inserted using a Smart needle into the popliteal artery below the occlusion. A remote endarterectomy is carried out through an arteriotomy in the proximal superficial femoral artery. The atheroma is cut distal to the lower extent of disease using a Moll ring cutter. The lower flap of atheroma is secured with an intraluminal stent inserted from the arteriotomy in the superficial femoral artery. The arteriotomy is extended into the common femoral artery and closed with a vein patch. RESULTS: The procedure was completed in 21 of 26 limbs. In 18 cases the superficial femoral artery remained patent at 30 days. Of the 21 cases all but four stayed in hospital for one night. A successful femoropopliteal bypass was carried out in the five patients in whom the procedure was not completed. CONCLUSION: Insertion of the dilator into the popliteal artery distal to the occlusion before carrying out the remote endarterectomy has two advantages. Firstly, the stent insertion is carried out in the correct plane and prevents dissection of the distal cut atheroma when attempting to pass the guidewire from above. Secondly, the procedure can be carried out under simple image intensification without sophisticated radiological equipment. The early results are encouraging and further evaluation of the technique is justifiable.

Arteriosclerosis↗

Survey of changes in the provision of vascular surgical services in the Oxford Region over 5 years.

AIM: This study aimed to examine changes in the provision of vascular services in the Oxford region over 5 years. METHODS: A questionnaire was sent to all general surgeons in the region asking of their involvement in vascular surgery. Data were obtained from the Department of Health concerning vascular procedures and inpatient codes for each district in the Oxford Region from 1990-1991 to 1994-1995. Office of Population Censuses and Surveys (OPCS) data for abdominal aortic aneurysm repair and femoral artery reconstruction were validated against data collected prospectively for West Berkshire. RESULTS: Eighteen of 45 surgeons who replied to the questionnaire carried out elective and emergency arterial work. All were members of the Vascular Surgical Society of Great Britain and Ireland (VSS). All but one took part in the general surgical rota. Eight surgeons carried out emergency arterial surgery only; only two of these were members of the VSS. Of 19 surgeons undertaking no arterial surgery, 15 operated on primary and 11 on recurrent varicose veins. The number of arterial reconstructions rose from 20.8 per 100000 population to 28 per 100000 throughout the study. The greatest increase occurred in districts where a new vascular consultant had been appointed. Similar results were obtained with endovascular procedures. The number of major amputations remained fairly constant at approximately 11 per 100000 population. The number of inpatient episodes for arterial disease also rose, from 35.7 to 47.6 per 100000. In validating OPCS codes against prospectively collected data, discrepancies for individual years were noted but the annual trend was reflected fairly accurately by the codes. CONCLUSION: There has been an increase in vascular activity in the region, but variations still exist between different districts.

Amputation, Surgical↗

Feasibility of pre-admission nurse clerking of patients with vascular disease.

A prospective study has been undertaken to determine the feasibility of nurse-led pre-admission clerking of patients with vascular disease. A total of 249 of 300 patients with planned admissions attended the clinic; 91% of patients with varicose veins, 83% of patients about to undergo endovascular procedures and 24% of patients awaiting arterial reconstruction were seen in the clinic. Patients with arterial disease were significantly more likely to rely on other people to bring them to the clinic than those with varicose veins. As a result of their age and frailty and their presenting symptoms, patients with arterial disease are less likely to benefit from a pre-admission clinic than patients with either varicose veins or general surgical disorders.

Adult↗

A prospective survey of patients presenting with abdominal aortic aneurysm.

OBJECTIVES: To define the presentation and management of patients presenting with abdominal aortic aneurysm (AAA) DESIGN AND SETTING: A prospective survey was carried out of all patients presenting to hospitals within the Oxford region. MATERIALS AND METHODS: Data were collected by one surgeon in each hospital. Full details were collected onto data sheets. RESULTS: One hundred and ninety patients presented, 141 electively, 46 with ruptured AAA and three with acute AAAs. In 53 patients presenting electively the aneurysm was small and surveillance started. Fifty-six patients underwent an operation, three patients died. Of 46 patients with a ruptured aneurysm 24 (52%) died. In 11 no operation was carried out and all of these patients died within 24 h. Operative mortality was 13 of 35 patients (37%). More patients with a ruptured AAA were transferred to the teaching hospital compared with a district general hospital (p < 0.05). This was reflected in a lower operative mortality in the teaching hospital. CONCLUSIONS: The presentation of AAA in this study was approximately 15 per 100,000 population. Approximately one-third of patients presenting electively had small AAAs which required surveillance. A further third underwent an operation, the remaining patients being unfit. Approximately one-quarter of patients with a ruptured aneurysm did not undergo an operation. The operative mortality was 37%.

Acute Disease↗