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Biomedical subjects

B S Lewis

Publications and source records attributed to B S Lewis.

At least 37 records · Page 2Linked to original sources
PubMed2000

A pilot study examining patient response to a weight loss workbook designed to Be used in a family medicine outpatient setting.

This study measured patient response to a self-help weight loss workbook designed for use in an outpatient, family medicine practice. The primary measures were 2 follow-up telephone calls, the first at 1 week and the second at 1 month after the book was given to the patient. Initially, patients were enthusiastic about the book and had read it, and 24 (70%) intended to use it. On the other hand, at 1 month, only 8 (32%) of those called were actually using the book. Reasons for this change are explored.

Adult↗
PubMed2000

Enteroscopy.

Enteroscopy in the new millennium will involve the development of instruments and accessories to allow deeper therapeutic intervention in the small bowel. There are also four new areas of development that involve the field of enteroscopy. These areas are the development of improved push enteroscopes, the development of laparoscopically assisted enteroscopy, the development of virtual enteroscopy, and gene research in the field of vascular anomalies of the gut.

Endoscopes, Gastrointestinal↗
PubMed2000

Small intestinal bleeding.

Bleeding from the small intestine may be difficult to diagnose, because of the organ's length, free intraperitoneal location, and the nature of the lesions that bleed in the small bowel. Although there are several causes of intestinal bleeding, angiodysplasias are most common. Several different tests can be used to identify a bleeding site preoperatively and intraoperatively, including enteroscopy.

Female↗
PubMed2000

Therapeutic angiogenesis for ischemic syndromes.

Disease caused by atherosclerosis are the most common causes of morbidity and mortality in western societies. The inadequacy of current therapeutic modalities is most pronounced in the significant proportion of patients with arterial obstructive disease, in whom anatomical and technical limitations rule out the possibility of angioplasty or surgery. Therefore, less invasive approaches are necessary to treat these patients. The development of collateral circulation improves blood flow to ischemic tissues and to alleviate ischemia-related symptoms. Our project concentrates on enhancement of the natural mechanism of angiogenesis by adenoviral based vector encoding vascular endothelial growth factor as an angiogenic factor. The aim of our study was to determine the efficacy of human vascular cell infection by adenoviral based vectors in vitro and in vivo. Human saphenous vein endothelial cells and smooth muscle cells were infected by adenoviral vectors encoding the lacZ and VEGF genes (rAdlacZ, rAdVEGF). VEGF expression by adenoviral vector-infected cells was detected by western analysis and its biological activity was examined by proliferation assay. The feasibility of adenoviral based gene transfer in vivo was evaluated after direct femoral artery injection of rAdlacZ in the rat. Vascular endothelial and smooth muscle cells expressed high levels of VEGF following rAdVEGF infection. The mitogenic effect of VEGF was validated by threefold increase in EC proliferation rate in comparison to the control groups. In vivo gene transfer was demonstrated using lacZ gene transfer to arterial wall cells in the superficial femoral artery. Efficient adenoviral based gene delivery was demonstrated both in vitro and in vivo. VEGF over-expression enhanced endothelial cell proliferation, which is the key step for induction of angiogenesis.

Adenoviridae↗
PubMed1999

Same-day combined coronary angioplasty and minimally invasive coronary surgery.

Integrated myocardial revascularization combines the advantages of angioplasty, stenting, and minimally invasive surgery to revascularize patients with multivessel coronary artery disease without cardiopulmonary bypass. This pilot study showed that a new same-day management strategy, consisting of percutaneous coronary intervention followed immediately by minimally invasive surgery, was feasible and provided complete all-arterial revascularization with minimal surgical trauma, short hospital stay, and excellent early therapeutic result in 14 patients with multivessel coronary disease.

Aged↗
PubMed1999

Usefulness of coronary MR angiography prior to angioplasty.

The range of indications for percutaneous transluminal coronary angioplasty (PTCA) has increased greatly since the procedure was initially introduced. The success rate depends on the anatomy and length of the occlusion and on the state of the distal vessel. We present a case where the use of magnetic resonance angiography (MRA) allowed to evaluate the length of a subtotal occlusion prior to PTCA, and thus could have had an impact on therapeutic decisions. Coronary MR angiography is one of the many applications of breathhold MRI, where breathholding and segmented k-space acquisition are combined to provide anatomical images of coronary vessels. Coronary MR angiography allows reproducible visualization of coronary vessels. Even under adverse circumstances (poor cardiac triggering) the images are sometimes of sufficient quality to help make a diagnosis. This capability may increase the as yet limited clinical use of MR technology in the practice of cardiology.

Angina, Unstable↗
PubMed1999

Effect of isosorbide-5-mononitrate on exercise performance and clinical status in patients with congestive heart failure. Results of the Nitrates in Congestive Heart Failure (NICE) Study.

BACKGROUND AND AIMS: Nitrate therapy improves hemodynamics in patients with heart failure, but the chronic effects of oral nitrates on exercise performance and clinical status have not been well studied. METHODS: Oral isosorbide-5-mononitrate (ISMN) (50 mg once daily) or placebo was administered to 136 patients (NYHA Class 2-3) treated for heart failure, all receiving captopril and most also furosemide. Endpoints were treadmill exercise time at 12 weeks by modified Naughton protocol (primary), with an additional 12-week follow-up period. Secondary endpoints included left ventricular dimensions, ejection fraction, cardiothoracic ratio, functional class, quality of life, hospitalizations and plasma norepinephrine and atrial natriuretic peptide in a four-center substudy. RESULTS: Intention-to-treat analysis showed that mean change in treadmill exercise duration tended to be greater in patients receiving ISMN than placebo (treatment difference +42 s, 95% CI -5, +90 s at 12 weeks and +21 s, 95% CI -25, +74 s after 24 weeks) (NS). Treatment difference was greater in the prespecified subgroup with ejection fraction 31-40% (+55 s, 95% CI -11, +136 s at 12 weeks and +65 s, 95% CI +3, +147 s) (p = 0.035) at 24 weeks. No deleterious effects (i.e. hypotension) were observed with ISMN, although headache was reported in 19% of the active treatment group (p = 0.0001). CONCLUSIONS: ISMN added to captopril increased treadmill exercise time in patients with heart failure and a lesser reduction in baseline ejection fraction, although for the group as a whole, the increase in treadmill time was not significant.

Administration, Oral↗
PubMed1999

Medical and hormonal therapy in occult gastrointestinal bleeding.

In this age of modern technology and aggressive but noninvasive therapies, the idea of treating an identifiable but discrete bleeding lesion with systemic medical therapy seems an anachronism. But medical therapy can be the treatment of choice for some bleeding vascular lesions of the gut. Though most vascular lesions appear similar endoscopically and are a cause of gastrointestinal bleeding, they consist of various pathologic identities. These different lesions have not only different pathologic appearances, but also different prognoses. The natural history of many of these lesions remains largely unknown. Long-term success in controlling bleeding must be measured in the context of the responsible lesion's frequency of occurrence and recurrence. Medical therapy can include hopeful watchful waiting, routine blood transfusions, or specific medications. Medical therapy has been pursued along two lines. The most common form of medical therapy has been simple supportive care. This may include iron therapy and avoidance of aspirin and other anticoagulants. Transfusions may be necessary, occasionally or on a regular basis. The second form of medical therapy has been the use of estrogens. There have been other medical attempts to control bleeding from intestinal vascular lesions. Somatostatin has been used in an uncontrolled fashion, as has aminocaproic acid. Vascular lesions of the bowel are not all the same. Medical therapy of vascular lesions is contrary to general present practice. Endoscopic or surgical therapy is presently considered best because of its ease, relatively good long-term results, and the lack of a clearly effective, well-tolerated medical therapy. Medical therapy is usually reserved for diffuse vascular diseases of the bowel, for vascular lesions located in relatively inaccessible locations, for patients with continued bleeding despite endoscopic or surgical management, and for patients who are not candidates for either endoscopic or surgical therapy.

Aged↗
PubMed1999

The history of enteroscopy.

Enteroscopy was initially a technology with little application. The small intestine was thought to be a rare site for any pathology and the ability to look at the most proximal and distal ends, during upper endoscopy and colonoscopy, was all that was needed in the evaluation of most patients. The power to peer into the small bowel has changed medical practice. This is especially true when dealing with patients with unexplained gastrointestinal bleeding. Enteroscopy helped determine causes of bleeding in such cases, and helped determine the most appropriate treatment algorithms.

Endoscopes↗
PubMed1999

Radiology versus endoscopy of the small bowel.

Since the development of endoscopy, physicians have been comparing radiographic studies with endoscopic examinations. Colonoscopy and upper endoscopy have largely replaced barium enema and upper gastrointestinal series. Unfortunately, many study protocols comparing colonoscopy with barium enema have been retrospective and the radiologic examination is compared with colonoscopy in a cohort group. The greatest difficulty with interpreting results of these studies is the inclusion of clinically insignificant findings in the calculation of the diagnostic yield. For example, in most studies barium enema is more successful than colonoscopy in diagnosing diverticular disease, and inclusion of this clinically insignificant entity increases the overall yield.

Angiography↗
PubMed1998

Long-term (10-year) outcome in patients with unstable angina pectoris treated by coronary balloon angioplasty.

OBJECTIVES: We sought to examine completed 10-year survival and event-free survival in patients with stable and unstable angina pectoris treated by coronary balloon angioplasty. BACKGROUND: Patients with unstable angina are at increased risk for recurrent acute coronary events. METHODS: The study included 208 consecutive patients (133 with stable and 75 with unstable angina pectoris) undergoing angioplasty from 1984 to 1986. The balloon crossed the lesion in 185 patients (121 with stable and 64 with unstable angina pectoris). Angioplasty was performed in patients with unstable angina pectoris 12+/-15 days (median 8) after symptom onset. Patients with unstable angina pectoris were classified retrospectively into Braunwald class I (n=3), class II (n=20), class III (n=28), class B (n=52) and class C (n=12). Follow-up data were obtained from hospital charts, telephone interview and official death certificates where applicable. The study had >80% power to detect a clinically significant 20% difference in survival and a 20% difference in event-free survival between the stable and unstable patient groups. RESULTS: Despite similar baseline characteristics, early (40-day) mortality was slightly higher in patients with unstable angina (4.7% [3 of 64 patients] vs. 0.8% [1 of 121 patients], p=NS). Long-term outcome was not different, because survival curves were parallel thereafter (10-year survival was 83% for those with stable and 77% for those with unstable angina, p=NS). Survival free of myocardial infarction or coronary artery bypass graft surgery at 10 years was 53% in patients with stable and 47% in patients with unstable angina (p=NS), and survival free of infarction, bypass surgery or repeat angioplasty was 32% for both groups at 10 years. In patients with Braunwald class III unstable angina, 10-year survival was 80%, as compared with 85% in other patients with unstable angina, due to the early hazard (p=NS). Survival and event-free survival were similar in patients who had had a recent myocardial infarction (Braunwald class C) and in patients with acute electrocardiographic changes. Repeat hospital admissions were not more frequent in patients with unstable angina (3.1+/-3.5 vs. 3.0+/-2.6, p=NS). CONCLUSIONS: Ten-year survival and event-free survival were similar in patients with stable and unstable angina pectoris treated by coronary balloon angioplasty, with no evidence of an increased rate of recurrent cardiovascular events in the unstable group.

Aged↗
PubMed1998

Importance of diabetes mellitus and systemic hypertension rather than completeness of revascularization in determining long-term outcome after coronary balloon angioplasty (the LDCMC registry). Lady Davis Carmel Medical Center.

The study examined the 10-year outcome in a cohort of 227 unselected, consecutive patients (age 58+/-10 years) undergoing coronary balloon angioplasty between 1984 and 1986 and followed in a single cardiac center (Lady Davis Carmel Medical Center registry). In particular, we sought to identify the relative importance of the systemic risk factors diabetes and hypertension and the extent of coronary disease as opposed to procedure-related technical variables, the immediate success of the procedure, or completeness of revascularization. By life-table analysis (99% follow-up), 94% of the patients were alive at 5 years, and 77% at 10 years after angioplasty. Ten-year survival was reduced in patients with diabetes mellitus (59% vs 83%, p = 0.0008), in patients with previous myocardial infarction (68% vs 85%, p = 0.01), in patients with ejection fraction <50% (55% vs 82%, p = 0.005), and in patients with 3-vessel disease (58% vs 84% and 86% for 1- and 2-vessel disease, respectively, p = 0.04). Diabetes mellitus was the major independent predictor of poor survival (adjusted odds ratio 3.1, 95% confidence interval 1.55 to 6.19, p = 0.001). Survival at 10 years was identical in 199 patients in whom angioplasty was complete and in 25 in whom the balloon catheter did not cross the lesion, although bypass surgery was more frequent in the latter group (45% vs 21%, p = 0.001). Incomplete revascularization did not predict poor survival (72% vs 79% with complete angioplasty, p = NS). Event-free survival at 10 years for the whole group was 29%, and 49% of patients survived with no event other than a single repeat angioplasty procedure. Multivessel disease, hypertension, and diabetes mellitus were independent predictors of decreased event-free survival, but incomplete revascularization was not. Thus, long-term outcome after coronary balloon angioplasty was related to diabetes mellitus, systemic hypertension, and extent of coronary disease, but not to the immediate success of the procedure or completeness of revascularization.

Adult↗
PubMed1998

Accuracy of exercise-induced left axis QRS deviation as a specific marker of left anterior descending coronary artery disease.

In this prospective study, we examined the diagnostic accuracy of exercise-induced left QRS axis deviation as a marker of LAD coronary artery stenosis. The mean frontal QRS axis of 66 consecutive patients with chest pain and exercise-induced ST segment depression referred for diagnostic coronary angiography was analyzed and related to the angiographic findings. An exercise-induced leftward QRS axis deviation was found in 9/40 patients with and 0/26 patients without obstructive (> or = 70%) LAD disease (sensitivity 23%, specificity 100%, p = 0.025). In 7 of the 9 patients with left axis deviation, the lesion was proximal to and in 2 in the region of the first septal perforator. Inclusion of patients with 0 degrees exercise-induced QRS axis deviation provided a more sensitive but less specific marker of LAD disease [sensitivity 53% (21/40), specificity 81% (21/26), p = 0.015]. The findings were similar in patients with single and with multivessel coronary artery disease. Grouping all patients in the present prospective and two previous retrospective studies (n = 165), the sensitivity was 29% and specificity 100% (p < 0.0001). Exercise-induced left QRS axis deviation was a highly specific marker of LAD coronary artery stenosis.

Adult↗