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Biomedical subjects

M Regan

Publications and source records attributed to M Regan.

At least 37 records · Page 2Linked to original sources
PubMed1999

Video-assisted coronary artery bypass in patients with preexisting tracheostomy.

A new technique allowing revascularization of the left coronary artery through a small thoracotomy after videoscopic harvesting of both mammary arteries is proposed in patients with total laryngectomy. This anterior thoracotomy approach, of real interest in patients with a preexisting tracheostomy, needs to be compared with a classic sternotomy in terms of functional recovery and the prevention of mediastinal sepsis in certain high-risk categories of patients (e.g., obesity, diabetes) for bilateral mammary artery harvesting.

Aged↗
PubMed1999

Social factors associated with increases in tuberculosis notifications.

This study assessed the contribution of immigration and deprivation to the changes in tuberculosis notifications in Liverpool over the last 20 yrs. Ethnic origin was retrospectively assigned to all named cases from 1974 to 1995. Average tuberculosis rates were calculated for the 33 council wards in Liverpool for 1981-1985 and 1991-1995. Multiple regression was used to determine the independent effects of socioeconomic and population measures from the 1981 and 1991 censuses in explaining these ward-based rates. Since 1974, there has been a steady increase in the percentage of non-Caucasian cases of tuberculosis, from 8.7% in 1975-1977, 15.1% in 1981-1983, 17.5% in 1987-1989 to 28.0% in 1993-1995. Multiple regression analysis showed that in 1981 only unemployment had a significant independent relationship with tuberculosis rates, but in 1991 two indices of deprivation and ethnicity had a significant influence. The increasing proportion of non-Caucasian tuberculosis cases, both while the number of notifications was declining before 1987 and increasing afterwards, is not necessarily consistent with the concept that immigration has influenced the recent increase. However, the fact that ethnicity now independently explains some of the council ward variations but did not in the early 1980s suggests that immigration does influence the distribution of disease within the city.

Adolescent↗
PubMed1999

Perioperative management in minimally invasive coronary surgery.

OBJECTIVE: It is important to apply the same rules used for classical coronary revascularization to beating heart coronary surgery. The surgeons must have a strategy, and be prepared for adverse events, and complications. METHODS: A careful analysis of the coronarography is essential to predict eventual contraindications or causes of possible operative difficulties. All the team must be involved in the surgical protocol. Three main problems need to be solved: the prevention of ischemia during the procedure, good stabilization of the anastomotic site and arterial occlusion. The first goal is reached by using a pre-conditioning technique or an intracoronary shunt. Vessel stabilization may be obtained by several methods: pressure adhesion devices, patch technique or suction devices. The final problem is to have a blood free field, this requires arterial occlusion which may be achieved in several ways: silastic Snares or sutures, aclan clamps, coronary occluder. RESULTS: We have developed at la Pitié a protocol to apply all these principles. From February 1997 to November 1998, multiple revascularization was performed on 167 patients. A total of 344 coronary anastomosis were carried out (mean: 2.05 graft/patient). CONCLUSION: Some simple rules had to be applied to reduce the rate of complications to the minimum: a good clinical case selection, use of a routine protocol, and recognize the need to adapt the indications to the learning curve of the operator.

Coronary Angiography↗
PubMed1998

Left centrifugal pump cardiac assist with transseptal percutaneous left atrial cannula.

Left cardiac support postcardiotomy requires a second operation for removal of the atrial cannula following weaning from assistance. To avoid the risk of this procedure, we used a transseptal cannula prototype. The cannula was introduced percutaneously through the femoral vein and advanced into the left atrium guided by the finger of the surgeon. Optimal positioning of the tip of the cannula was verified by perioperative transesophageal echocardiography. A long arterial cannula was positioned in the descending aorta via the femoral artery and a Carmeda circuit with a centrifugal pump was connected to both cannulas. This procedure was used in 3 patients with low cardiac output who underwent emergency surgery, a 63-year-old patient referred for aortic and mitral valve replacement, a 54-year-old man for aortic valve replacement, and a 64-year-old patient in the acute phase of myocardial infarction after myocardial revascularization. The assistance was used systematically at the end of the operation. The assist flow was 1.2-2.6 L/min. The patients were all weaned from support between 18 h and 8 days later. No complications related to the device occurred. Both cannulas were removed surgically from the femoral vessels without reopening the chest. This new procedure is of interest for 2 reasons: the systematic implantation allows for early assistance, and the use of a percutaneous approach avoids the risk of reopening the chest. More cases are needed to confirm this initial good impression.

Aortic Valve Insufficiency↗
PubMed1998

Evidence for genetic anticipation in nodal osteoarthritis.

OBJECTIVE: Evidence was sought for genetic anticipation (disease occurring at an earlier age in subsequent generations, with increasing severity) in nodal osteoarthritis (NOA). METHODS: Age at symptom onset and disease severity was compared within 30 parent/offspring pairs with NOA. Correlation between the offspring age of disease onset and the parental age at conception was also assessed. RESULTS: The age at onset of nodal symptoms was earlier in the offspring (43 years (95% confidence intervals (CI) 38 to 47) v 61 (CI 58 to 65); mean difference 18 years (CI 13 to 22): p < 0.001) as was larger joint symptom onset (48 years (CI 41 to 55) v 67 (CI 61 to 73); mean difference 20 years (CI 13 to 27): p < 0.01). A negative correlation existed between age of offspring symptom onset and parental age at conception. Fifteen (50%) offspring had similar or more extensive disease than their parents. CONCLUSIONS: These results suggest genetic anticipation occurs in NOA and if confirmed a search for trinucleotide repeats is warranted.

Adult↗
PubMed1997

Thoracoscopic internal mammary artery harvesting: technical considerations.

BACKGROUND: Technical details of thoracoscopic harvesting of the internal mammary artery (IMA) are reported. This procedure allows a complete dissection of the left IMA from its origin at the subclavian artery to the sixth intercostal branches with transection of all collateral branches. METHODS: Between September 1995 and September 1996, thoracoscopic harvesting of the left IMA was performed on 32 patients who had undergone a minimally invasive coronary artery bypass grafting procedure. RESULTS: There were no conversions to a standard approach because of an injury to the graft and no reoperations for bleeding. The mean duration of the IMA harvesting procedure was 58.7 minutes (range, 20 to 130 minutes). CONCLUSIONS: This procedure enlarges the field of minimally invasive coronary artery bypass grafting techniques. The thoracoscopic harvest of the full length of the IMA allows the procedure to more closely replicate the open approach.

Endoscopy↗
PubMed1997

Video-assisted coronary bypass surgery: clinical results.

OBJECTIVE: Clinical experience with a video-assisted coronary artery bypass grafting procedure using the internal mammary artery is reported. The technique consists of a videoscopic harvesting of the left internal mammary artery (LIMA) to revascularise the left anterior descending artery (LAD) through a 4-cm left thoracotomy. METHODS: Between September 1995 and July 1996, we performed this procedure on 30 patients (29 males, 1 female; aged 38-71) with an isolated proximal LAD stenosis (n = 21) or occlusion (n = 9). All patients were symptomatic despite appropriate medication. A history of non-transmural myocardial infarction with myocardial viability was found in nine patients. Fourteen patients had a restenosis after previous percutaneous transluminal coronary angioplasty (PTCA). Mean left ventricular ejection fraction was 0.61 (< 0.3 in two patients). The LAD LIMA anastomosis was performed on the beating heart without cardiopulmonary bypass (CPB) in 26 patients. Femoral-femoral CPB was used in three patients because of unstable angina (n = 1) and intramyocardial LAD (n = 2). Conversion to sternotomy and standard CPB was necessary in one patient for extensive endarterectomy of the LAD. RESULTS: There were no operative complications and no reoperations for haemorrhage. Pulmonary infection was observed in one patient and wound infection in one patient. Patients who underwent the complete procedure on the beating heart without conversion or CPB were ready for discharge on the 5th postoperative day (36 h-13 days). Control coronary angiography was performed in 20 patients. In all cases, the graft was patent. In 17 cases, there was a patent graft with no evidence of anastomotic stenosis. An occlusion of the distal segment of the LAD with a retrograde perfusion of the proximal segment and septal branches by the LIMA was found in one case. This patient was symptom-free and the stress test was negative. An anastomotic stenosis was noted in two patients and was treated by angioplasty (n = 1) or conventional surgery (n = 1). CONCLUSION: In conclusion, the efficiency of this minimally invasive approach should be prospectively compared with similar revascularisation with PTCA or surgical approaches using sternotomy with or without CPB.

Angioplasty, Balloon, Coronary↗
PubMed1996

Morphometric and metabolic profile of the distal segment of the internal mammary artery: caution on its use for coronary anastomoses.

OBJECTIVE: Elastic arteries were found to be less prone to intimal hyperplasia than muscular arteries. The internal mammary artery (IMA), which is elastic in its proximal segment, presents a gradual decrease of media elastic fibers along its downstream course. Metabolic and morphometric studies of the distal end of the IMA with regard to its local susceptibility to develop intimal changes were undertaken in order to evaluate the reliability of its use as an anastomotic site for bypass grafting. METHODS: Twenty distal segments of IMA were harvested from patients who had undergone myocardial revascularization. Histologic, enzyme-histochemical and morphometric studies were undertaken on these arterial segments. RESULTS: Histologic examinations indicated an elastomuscular structure in 13 patients, a muscular structure in 6 and an elastic structure in 1. Of the 20 IMAs, none was found to have intimal thickening of greater than 25% of the diameter of the lumen. The enzyme-histochemical profile of the proliferating cells found in the intimal thickening differed from normal contractile smooth muscle medial cells in the loss of myosin and mitochondrial ATPase, plasma membrane 5' nucleotidase, moderately decreased aerobic dehydrogenase and increased lactate dehydrogenase activity and ribonucleoprotein-linked pyroninophilia. Lysosomal beta-glucuronidase and sulfatase were strongly active. This enzyme behavior is unfavorable to contractile function and favorable to cell proliferation and lipid accumulation, two events strongly involved in the atherogenic process. CONCLUSION: Intimal proliferative changes were observed in the distal segment of the IMA. Although there was no histologic evidence of atherosclerotic plaque, the enzyme-histochemical profile of this intimal thickening was favorable to cell proliferation and lipid accumulation. These findings suggest that it may be beneficial to avoid coronary anastomoses with the distal end of the IMA and to use a more proximal/elastic segment.

5'-Nucleotidase↗
PubMed1996

Association of two loci on chromosome 2q with nodal osteoarthritis.

OBJECTIVE: To search for genetic association between microsatellite marker loci and sibling pairs with nodal osteoarthritis (NOA). METHODS: Using the affected sibling pair method of analysis, genomic DNA from 66 sib pairs with NOA was analysed for association with highly polymorphic microsatellite marker loci. The microsatellite markers were amplified using polymerase chain reaction and typed on polyacrylamide gels. RESULTS: A significant association (p < 0.05) was identified between NOA and two loci on the short arm of chromosome 2 (2q 23-35). Candidate genes for osteoarthritis in this region include: fibronectin, a glycoprotein present in the extracellular matrix of normal cartilage; the alpha 2 chain of collagen type V, a major constituent of bone; and the interleukin-8 receptor, important in the regulation of neutrophil activation and chemotaxis. CONCLUSIONS: The chromosomal region 2q 23-35 requires further detailed study in NOA. Confirmation of these findings in large independent data sets and further analysis of candidate genes in this region will be important in unravelling the molecular basis for this common disease.

Adult↗
PubMed1996

Association between synovial fluid levels of inorganic pyrophosphate and short term radiographic outcome of knee osteoarthritis.

OBJECTIVE: To test the hypothesis that high concentrations of extracellular inorganic pyrophosphate (PPi), which associate with increased cell synthesis and turnover in cartilage, may act as a marker for structural outcome in knee osteoarthritis (OA). METHOD: One hundred and thirty five consecutive patients referred to hospital with knee OA (59 men, 76 women; mean age 71 years, range 41-88) were followed prospectively for a median of 2.5 years (interquartile range 1.75-3.0). Synovial fluid (SF) aspirated at presentation (202 OA knees: 68 bilateral, 66 unilateral) was assessed for PPi content by radiometric assay. Knee radiographs at presentation and at final review were assessed for change in global (Kellgren) and individual features (narrowing, osteophyte, sclerosis, cyst, attrition) of OA. RESULTS: The median SF PPi level was 10.5 mumol (range 0.07-72.4). At baseline, high PPi was significantly associated with presence of calcium pyrophosphate crystals, chondrocalcinosis, and bone attrition. Radiographic change was observed in 164 knees. High PPi levels were negatively associated with change in Kellgren and Lawrence grade, further narrowing, and increase in osteophyte, but positively associated with development of attrition. In the 68 patients from whom bilateral data were obtained, there was correlation between right and left knees for PPi levels, all baseline radiographic scores, and changes in radiographic features. Multiple logistic regression analysis for PPi as a continuous variable (age, gender, and patient number included in model) showed a negative correlation with change in global Kellgren and Lawrence grade (odds ratio (OR) 0.97, 95% confidence interval (CI) 0.95 to 0.99) and a positive correlation with attrition (OR 1.04, 95% CI 1.02 to 1.07). CONCLUSION: High SF levels of PPi are associated with favourable radiographic outcome in terms of progressive change in Kellgren grade. Such elevated PPi levels, however, may inhibit new bone formation and remodelling in knee OA.

Adult↗
PubMed1995

Fear conditioning, preparedness, and the contingent negative variation.

Psychophysiological research on preparedness has previously focused on autonomic nervous system parameters. The present study used electrocortical indices of fear conditioning. Subjects (n = 10) were tested under fear-relevant and fear-irrelevant conditions (1 week apart, order of conditions counterbalanced). Each condition comprised acquisition and extinction sessions. The contingent negative variation (CNV) was elicited in anticipation of forewarned slides (fear relevant: small animals; fear irrelevant: landscapes). In acquisition, reinforced conditioned stimulus (CS+) (but not nonreinforced conditioned stimulus [CS-]) slides were followed by white noise as an unconditioned stimulus (UCS). In extinction, the UCS was omitted. In the fear-relevant condition, CNV amplitude was significantly larger for CS+ than CS- in both acquisition and extinction. In the fear-relevant condition, CNV amplitude was significantly larger for CS+ than CS- in both acquisition and extinction. In the fear-irrelevant condition, CNV differentiation between CS+ and CS- was weak in both sessions. CNV was significantly larger in the fear-relevant than in the fear-irrelevant condition, for CS+ but not CS-. The findings are consistent with a preparedness interpretation and suggest that CNV under such circumstances may represent an automatic affective response to fear-relevant stimuli. Electrocortical measures could be particularly useful in examining information processing mechanisms in phobia and cognition-affect relationships generally.

Adolescent↗
PubMed1995

Clinical experience with a total artificial heart as a bridge for transplantation: the pitie experience.

Since April 1986, 82 patients have received a pneumatic total artificial heart, 62 a JARVIK-7, and 20 a Cardiowest. The duration of support ranged from less than 1 day to 603 days (mean duration: 27 +/- 82). The indications were for acute shock (38 cases) or for chronic deterioration on the transplant waiting list (44 cases). The etiology was mainly due to idiopathic and ischemic cardiomyopathy. With the help of our scoring system, we divided our patients in three groups: Chronic Implantation, represented by two females staying on device for 6 and 19 months, respectively; a High-Risk group of 29 patients characterized by high-risk indications; graft failure, rejection, postcardiotomy patient, postpartum cardiomyopathy, and valvular and congenital reoperation. In addition, the dilated and ischemic cardiomyopathy patients with a score over 6 were included in this group; and an Elective Indication group (51 patients) represented all of the dilated and ischemic cardiomyopathy patients with a score under 6. Due to the shortage of donors, our criteria for transplantation are very strict. Transplants should be made only in cases of hemodynamic stability, on an extubated patient with normal renal and liver functions, without coagulation problems or infection. With such criteria, in the high-risk group, only four patients could be transplanted and of these two are still alive. In contrast, in the elective group, 31 were transplanted (61%), and 71% of these patients were discharged. The rate is improved in the most recent cases, with 90% of the Cardiowest patients being survivors.

Acute Disease↗
PubMed1995

Factors affecting radiographic progression of knee osteoarthritis.

OBJECTIVES: To evaluate the prognostic significance of patient characteristics and radiographic features at the knee for outcome of knee osteoarthritis. METHODS: This was a prospective observational study of 350 osteoarthritic knees. Clinical and radiographic data were obtained on 188 hospital referred patients (mean age 70, range 34-91 years). RESULTS: Median duration of follow up was two years (range 1-5 years). The majority of patients (48%) reported deterioration, but 23% experienced improvement in symptoms during the study period. Reported exercise tolerance remained unchanged in the majority (62%) and deteriorated in 35%. Change in at least one individual radiographic feature of osteoarthritis was seen in 252 (72%) knees: increase in joint space narrowing occurred in 52%, osteophyte in 32%, cysts in 19%, sclerosis in 14%, and attrition in 30%. Increase in Kellgren grade occurred in 137 (39%) knees. Knee effusion, osteoarthritis at multiple joint sites, and nodal change associated with change in Kellgren grade (odds ratios 1.03, 2.39, and 1.80; 95% confidence intervals (CI) 1.01 to 1.05, 1.16 to 4.93, and 1.02 to 3.17, respectively); warmth at the knee associated with change in any radiographic feature (odds ratio 2.22; 95% CI 1.19 to 4.14). Development of, or increase in, attrition and joint space narrowing associated with worsening symptoms and function and occurred with increased frequency in knees with effusions, clinical warmth and calcium pyrophosphate crystals in synovial fluid (p < 0.05). CONCLUSIONS: A high rate of change, radiographic more than clinical, was seen in osteoarthritic knees during this study. Poor clinical and radiographic outcome associated with calcium pyrophosphate crystal deposition and clinical inflammation as reflected by knee effusion and warmth.

Adult↗