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M Regan

Publications and source records attributed to M Regan.

At least 55 records · Page 3Linked to original sources
PubMed1995

Cryopreserved small-diameter arterial allografts for arterial by-pass procedures: an experimental study.

The search of small-caliber vascular prosthesis for myocardial revascularization and arterial reconstruction has led to an investigation of cryopreserved arterial allografts in a sheep model. Carotid arteries with an internal diameter of 4 mm and length of 10 cm were harvested from donor sheep and soaked immediately in a cold saline solution. Nine arteries were cryopreserved in a nutrient media containing 10% DMSO as cryoprotectant and then were stored in a liquid nitrogen vapor at -150 degrees C to -170 degrees C. In recipient sheep from different species, arterial substitution of a 10 cm segment of carotid artery was realised by implantation of fresh (n = 9) or cryopreserved (n = 9) carotid artery allografts. After 3 months, the allografts were harvested. In both groups: 7/9 were patent at the time of explantation. Components of arterial allograft rejection were observed in most fresh and cryopreserved arteries: intimal thickening with cell proliferation was seen in fresh (3/7) and cryopreserved (4/8) arteries; Loss of smooth muscle medial cells was constant; Adventitia was involved by a marked inflammatory reaction. A non cellular fibrous intimal thickening and presence of large medial calcifications were essentially observed in cryopreserved arteries. In conclusion, these results show that at three months post implantation, there is little difference in the outcome of fresh and cryopreserved arterial allografts. Cryopreservation does not reduce the apparent antigenicity of small diameter arterial allografts.

Animals↗
PubMed1995

Evaluation of cryopreserved arteries as alternative small vessel prostheses.

Biologic or synthetic grafts have had limited success in small vessel applications. Studies were initiated to assess the potential use of cryopreserved (CP) arteries as coronary artery bypass conduits. Sheep carotid arteries (internal diameter: 4 mm; length: 10 cm) were cryopreserved in a nutrient media containing 10% DMSO and were stored in a nitrogen vapor at -150 degrees C. After thawing, histological, enzyme-histochemical and functional studies showed slight histological alterations, preservation of enzymal activities and an abolition of the contractile response. In a sheep model, arterial substitution of a 10 cm segment of carotid artery was realised by implantation of fresh autografts ( n = 4); fresh allografts (n = 9) and CP allografts (n = 9). After 3 months, all autografts were patent with slight histological alterations. Fresh and CP allografts showed similar modifications: patency rate was 7/9 in both groups. Intimal thickening with cell proliferation was seen in fresh (3/7) and CP (4/8) arteries; loss of smooth muscle medial cells was constant. Adventitia was always involved by a marked inflammatory reaction. One characteristic of CP allografts was the frequent presence of large dystrophic calcifications. In conclusion, morphologic and functional arterial changes occurred after freezing and thawing. In spite of vascular rejection, the patency rate of allografts after 3 months of implantation in arterial circulation remained high and does not seem influenced by cryopreservation.

Animals↗
PubMed1995

Effects of rilmenidine and clonidine on the electroencephalogram, saccadic eye movements, and psychomotor function.

Rilmenidine is a novel oxazoline derivative that is effective in the treatment of hypertension. Studies in animals have indicated that rilmenidine may reduce blood pressure without the associated central alpha 2 side effects of clonidine. The aim of this double-blind, crossover, placebo-controlled study was to evaluate the hypotensive and central sedative effects of single oral doses of rilmenidine (1 or 2 mg), clonidine (150 or 300 micrograms), and lorazepam (2.5 mg) in 12 healthy male volunteers. Drug effects were assessed with a test battery composed of resting electroencephalogram, auditory evoked responses (AERs), saccadic eye movements, psychomotor performance, and subjective ratings as well as blood pressure and heart rate. Rilmenidine and clonidine produced similar dose-dependent reductions in blood pressure without an effect on heart rate. Saccadic eye movements were not significantly impaired after rilmenidine (1 mg) treatment in contrast to after clonidine (150 micrograms) treatment. Peak saccadic velocity was impaired by all drugs except rilmenidine (1 mg), which was indistinguishable from placebo. The electroencephalographic spectral analysis also demonstrated greater sedation with lorazepam than with the other drugs and greater vigilance with placebo and rilmenidine (1 mg) than with lorazepam. AERs showed a differentiation in sedative effects between lorazepam and clonidine (300 micrograms) relative to placebo, rilmenidine (1 mg), and clonidine (150 micrograms). These results are consistent with the hypothesis that at lower doses, rilmenidine may act preferentially through imidazoline receptors, whereas at higher doses, alpha 2-adrenoceptors may become activated.

Adult↗
PubMed1994

[Chronic constrictive pericarditis. A retrospective study of a series of 84 patients].

Chronic constrictive pericarditis still poses diagnostic and therapeutic problems. A series of 84 cases (59 men-25 women; men age: 46 years) operated between 1979 and 1989 at the Pitié Hospital was reviewed. The majority of patients (72%) were in functional Classes III or IV; 88% had clinical signs of right ventricular failure and 18% had anasarca. The average duration of symptoms before diagnosis was 20 months. Chest X-ray showed pericardial calcification in 40% of cases. A characteristic dip-plateau pressure tracing was obtained in 76% of cases. A specific aetiology was only found in 36 cases (45%), only 12% being of tuberculous origin. A subtotal pericardectomy from phrenic to phrenic was carried out in 75 patients. The absence of planes of cleavage in 9 cases imposed a special operative technique consisting of "patchwork" sectioning of the visceral pericardium. The operative mortality was 2.3% (2 patients: pulmonary embolism and septicaemia). Non-fatal post-operative complications occurred in 8.2% of cases (7 patients). The survival rate excluding operative mortality was 94% at 3 years and 87% at 7 years. No patient was reoperated for recurrent constrictive pericarditis. At the last follow-up appointment, all patients were in functional Classes I or II. The authors conclude that the absence of specific symptoms, the low prevalence of the condition and the change in aetiology related to the decline in tuberculous infection make the diagnosis of chronic constrictive pericarditis very difficult. The diagnostic contributions of new imaging techniques such as CT and MR scanning should be assessed. This series confirms the efficacy of surgical treatment by subtotal pericardectomy.

Adult↗
PubMed1993

Treatment of rheumatoid hand synovitis with a regional block technique.

This study reports a novel technique for treating painful rheumatoid hand synovitis using a regional block technique. Nine patients with symptomatic rheumatoid hand synovitis were treated. Assessments of symptoms, grip strength and synovial swelling were made in each hand before the injection, and at 1 and 4 weeks after the procedure. A sphygmomanometer cuff was inflated, on the side of the patients most symptomatic hand, to 220mmHg and a solution of hydrocortisone sodium succinate 50mgs and lignocaine 10mls 0.5% was injected intravenously. The cuff was deflated slowly after 20 minutes. The injected hand improved symptomatically in 7 patients at 1 week, and further improvement was reported in 6 of these 7 at 1 month. Mean grip strength increased significantly in the injected hand both at 1 week (p = 0.01) and 1 month (p = 0.018). There was no change in the other hand. This technique is safe, reduced hand pain and improved grip strength in these patients with rheumatoid hand synovitis.

Arthritis, Rheumatoid↗
PubMed1993

Pseudogout provoked by pregnancy.

Four women with chondrocalcinosis are described. Each developed acute attacks of synovitis during pregnancy (confirmed pseudogout, two; presumptive pseudogout, two). All patients had recognized predisposing factors (metabolic, familial, traumatic) for premature calcium pyrophosphate deposition, and in three this was their first episode of synovitis. This first report of provocation of pseudogout by pregnancy is of interest in respect of putative mechanisms of crystal shedding.

Adult↗
PubMed1993

Is osteoarthritis in women affected by hormonal changes or smoking?

The influence of sex hormone related events and smoking on the development of OA in women was investigated in a case-controlled postal survey. One hundred and twenty-nine patients with nodal generalized osteoarthritis (NGOA) and 145 with non-nodal pauciarticular large joint osteoarthritis (LJOA) were identified from the database of a Nottingham OA clinic. For each patient, three age-matched controls were randomly selected from the same general practice. Sixty-three per cent of questionnaires (690/1096) were returned: NGOA, 95; NGOA controls, 226; LJOA, 113; LJOA controls, 256. There were no differences in age at menarche or menopause, rates of hysterectomy, oral contraceptive use, or hormone replacement use between cases and controls. Fewer OA patients had ever smoked [(Odds Ratio (OR) 0.65, 95% Confidence Interval (CI) 0.45-0.95)] and subset analysis demonstrated that this negative association occurred only in the LJOA group (OR 0.43, CI 0.25-0.72), particularly in those with knee OA (OR 0.29, CI 0.14-0.62). A previous successful pregnancy was negatively associated with NGOA (OR 0.47, CI 0.24-0.95). This study demonstrates no association between oestrogen-related hormonal events and OA, but a negative association between smoking and LJOA. Such data supports the concept that OA is a heterogeneous disease and underlines the need to differentiate OA subsets.

Age Factors↗
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

Radiographic assessment of patellofemoral osteoarthritis.

OBJECTIVES: To determine the feasibility of assessing patellofemoral osteoarthritis using the 'skyline' view and to compare its reproducibility with the standard lateral view. METHODS: Fifty patients attending a rheumatology outpatient department with osteoarthritis of the knee had standard radiographs taken of both knees: standing weightbearing anteroposterior; lateral supine radiograph in 30 degrees of flexion; and a skyline view of the patellofemoral joint. After an initial training period using 20 sets of films the remaining 30 sets were read blind by five observers. Intraobserver and interobserver variability was assessed using the kappa statistic. The minimum joint space in each compartment was measured using a ruler. Two views of a single normal subject were measured to determine the effect of knee flexion. RESULTS: The final 30 study films were from 20 women and 10 men, median age 72.5, range 18-91 years. A grading system comprising assessment of osteophytosis, joint space narrowing, sclerosis, cysts, and attrition could easily be applied to the skyline patellofemoral view. Intraobserver reproducibility was better than the interobserver reproducibility for all features. The skyline view performed more reproducibly and over a wider range of categorisation for joint space narrowing than the lateral radiograph. Measurement using a ruler was easy to perform and precise to within 1 mm for the medial tibiofemoral and lateral facet of the patellofemoral joint. In normal knees the degree of flexion significantly affected the measurement. CONCLUSIONS: Radiographic grading of the skyline patellofemoral view is readily achieved, is more reproducible than assessment of the lateral view, and allows more precise localisation of change. Such views should be considered in radiological surveys of osteoarthritis of the knee.

Adolescent↗
PubMed1993

[Tricuspid valve replacements in adults. Long-term results].

In the period between January 1979 and January 1989, 72 patients (46 women and 26 men, average age 46 years) out of 697 patients undergoing a tricuspid valve procedure, underwent prosthetic valve replacement for organic tricuspid valve disease. Sixteen patients had pure tricuspid regurgitation (Group I). The causal pathology was essentially traumatic (6 cases) and infections (endocarditis) (5 cases). Fifty-six patients (Group II) had organic tricuspid valve disease associated with a left-heart valvular lesion. The causal pathology was rheumatic fever in 52 cases and endocarditis in 4 cases. In 40 patients (71.5%) the procedure was a reoperation of a mitral and/or aortic and/or tricuspid valve prosthesis. In 21 cases, the initial operation had involved the tricuspid valve. All patients in Group I underwent valvular replacement with a bioprosthesis. In Group II, 40 patients were implanted with a bioprosthesis and 16 with a mechanical valve prosthesis. The follow-up was complete for an average period of 7 years (range 2 to 12 years) for a total of 295 patient-year. The hospital mortality was nil in patients with isolated tricuspid valve disease. Reoperation for deterioration of a porcine bioprosthesis was required after 4 years in 1 case. Terminal cardiac failure was responsible for one late death 7 years after surgery. The hospital mortality was 26.7% (15 patients) in Group II. The actuarial rate of patients free of reoperation at 7 years was 80 +/- 8%. The actual rate of patients free of any prosthetic valve related complication was 78 +/- 2%. The 7 year survival rate excluding operative mortality was 65 +/- 8%.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1993

Perioperative immune modulation.

BACKGROUND: The effects of operative trauma on systemic immunity were studied. The relative effects of skin incision and of breaching the peritoneum were determined. In addition, the role of the antiendotoxic agent taurolidine in preventing postoperative immune suppression was assessed. METHODS: Systemic immune responsiveness was measured as the delayed-type hypersensitivity (DTH) response to 2-4 dinitro l-fluorobenzene (DNFB) with an in vivo rat model. The effect of both laparotomy and taurolidine on the hepatic Kupffer cell population was determined by immunohistochemistry. RESULTS: This study confirmed that cellular immunity is significantly depressed after laparotomy (15.5%; range, 2.5%-24.0%) compared with unoperated controls (26.77%; range, 9.2%-38.0%). Opening the peritoneum appeared to be a critical factor in inducing this immunosuppression, in which animals undergoing a similar midline incision without opening of the peritoneum displayed minimal alteration in their DTH response (20.5%; range, 0.85%-41.5%). In addition, intraperitoneal administration of taurolidine in the perioperative period prevented this decrease in postoperative DTH response. Kupffer cell numbers were increased after intraperitoneal administration of taurolidine, compared with animals treated with intraperitoneal saline solution or unoperated controls. CONCLUSIONS: These findings confirm the presence of an operatively induced decrease in immune responsiveness and suggest that entering the peritoneum is an important factor in the induction of this effect. In addition, administration of taurolidine acts to prevent the impact of laparotomy on DTH response, possibly by preventing perioperative portal endotoxemia.

Animals↗
PubMed1991

Electron microscopic characterization of neonatal platelet ultrastructure: effects of sampling techniques.

Detailed ultrastructure of 720 neonatal platelets was systematically examined in 200-300 microliters cord blood samples from four normal term infants. There were no differences in platelet organelles between samples collected into standard sodium citrate anticoagulant and minimally heparinized samples collected into sodium citrate. Samples collected into EDTA showed significant differences from the other two solutions. There were also differences in organelle characteristics within a solution group, as time from sample collection to EM fixation varied. These results verify utilization of small minimally heparinized blood samples for examination of platelet ultrastructure. This system can now be expanded to the premature infant, where small blood sample requirements are essential, and minimally heparinized blood may be more readily available.

Anticoagulants↗
PubMed1991

Occupational hearing loss in New York dairy farmers.

A study of 49 randomly selected, full-time dairy farmers was performed to assess the prevalence and nature of hearing loss in this population. An age- and sex-matched group of rural, non-farmers was also studied. Medical, occupational, and recreational histories were taken and standard audiometric testing was administered. Sixty-five percent of farmers had hearing loss in the higher frequencies and 37% had losses in the mid-frequency range as compared to 37% and 12% of non-farmers respectively (p less than .01). Farmers' left ears were more severely affected. The age of the subjects and the number of years spent farming were highly correlated with hearing loss. Correlation and regression analyses supported the hypothesis that the difference in the prevalence of hearing loss between the dairy farmers and the non-farmers was due to occupational noise exposure on the farm.

Adult↗
PubMed1991

A proposed minimal rheumatological screening history and examination. The joint answers back.

We have developed a rapid, reliable locomotor screening procedure to identify regional locomotor problems. An initial screen was tested in general medical inpatients and modified in the light of this experience. The revised screen was subsequently retested in a similar group of patients and new referrals to a rheumatology outpatient clinic. The revised screen proved sensitive, quick, and acceptable to both patients and doctors. Such a screen could readily be adopted by undergraduates: its routine use should improve detection and awareness of rheumatological problems and form the foundation for development of rheumatological clinical skills.

Adult↗
PubMed1990

Histopathologic features of composite ganglioneuroblastoma. Immunohistochemical distinction of the stromal component is related to prognosis.

Histopathologic features of 18 cases of composite ganglioneuroblastoma (CGNB) were studied with immunohistochemical staining techniques using antibodies against S-100 protein (S-100), ferritin (FER), and leukocytic common antigen (LCA). Cases of CGNB were divided on the basis of the morphologic features of neuroblastic elements into three prognostic subgroups: "Type A Intermixed," having individual microscopic nests of neuroblasts (N = 4, 100% survival); "Type B Intermixed," having microscopic aggregates of multiple neuroblastic nests (N = 6, 67% survival); and "Nodular," having grossly visible nodule(s) of neuroblastic proliferation (N = 8, 0% survival). Survival rates are significantly different for the prognostic subgroups (P less than 0.025). Each prognostic subgroup demonstrated an immunohistochemically distinct pattern of stromal cell composition in the neuroblastic elements: Type A Intermixed had numerous S-100 cells and no FER cells, Type B Intermixed contained many S-100 cells and a moderate number of FER cells, and Nodular had few S-100 cells with many FER cells. The S-100 and FER scores, determined by counting the positive cells through a line sampling method, differed significantly between these prognostic subgroups. Lymphocytic aggregations in tumor tissue evaluated by volumetric assessment with LCA staining, on the other hand, showed no contribution in predicting the outcome of the patients. There was also an inverse relationship between S-100 and FER score, suggesting a relationship between the relative predominance of these stromal cell types, tumor histopathologic features, and the biologic behavior of CGNB.

Cell Aggregation↗
PubMed1990

Noise-induced hearing loss in randomly selected New York dairy farmers.

To understand better the effects of noise levels associated with dairy farming, we randomly selected 49 full-time dairy farmers from an established cohort. Medical and occupational histories were taken and standard audiometric testing was done. Forty-six males (94%) and three females (6%) with a mean age of 43.5 (+/- 13) years and an average of 29.4 (+/- 14) years in farming were tested. Pure Tone Average thresholds (PTA4) at 0.5, 1.0, 2.0, and 3.0 kHz plus High Frequency Average thresholds (HFA3) at 3.0, 4.0, and 6.0 kHz were calculated. Subjects with a loss of greater than or equal to 20 db in either ear were considered abnormal. Eighteen subjects (37%) had abnormal PTA4S and 32 (65%) abnormal HFA3S. The left ear was more severely affected in both groups (p less than or equal to .05, t-test). Significant associations were found between hearing loss and years worked (odds ratio 4.1, r = .53) and age (odds ratio 4.1, r = .59). No association could be found between hearing loss and measles; mumps; previous ear infections; or use of power tools, guns, motorcycles, snowmobiles, or stereo headphones. Our data suggest that among farmers, substantial hearing loss occurs especially in the high-frequency ranges. Presbycusis is an important confounding variable.

Adult↗