Search PubMed⌕ Search

Biomedical subjects

J L Glover

Publications and source records attributed to J L Glover.

At least 37 records · Page 2Linked to original sources
PubMed1994

Penetrating atherosclerotic ulcers of the aorta.

PURPOSE: This study investigates the natural history and optimal imaging modality of penetrating atherosclerotic ulcers of the aorta. METHODS: We reviewed our experience with 29 penetrating ulcers in 18 patients. Computed tomography (17 patients), magnetic resonance imaging (nine patients), and aortography (five patients) were used for diagnosis and follow-up. Patients were typically elderly (average age 74 years) and had hypertension and coronary artery disease. Ulcers were most common in the distal descending thoracic aorta (31%) and were characterized by a discrete ulcer crater (100%) and thickened aortic wall (89%). Modes of presentation included chest or back pain in four patients, distal embolization in two patients, and abnormal chest radiography results in one; the remaining were incidental findings. RESULTS: Follow-up was available in ten patients with 17 ulcers from 1 to 7 years. Recurrent pain occurred in two patients, recurrent embolization occurred in one patient, and seven patients remained symptom free. Progression to saccular pseudoaneurysm occurred in five ulcers, and fusiform aneurysm occurred in two ulcers. Two ulcers were associated with an increase in aortic diameter, and nine ulcers did not change. There were no cases of aortic dissection or rupture in the follow-up period. There were no deaths and only one patient underwent resection. CONCLUSION: The natural history of penetrating atherosclerotic ulcers is one of progressive aortic enlargement, with saccular and fusiform aneurysms the result if follow-up is sufficient. Aortic dissection, aortic rupture, and embolization can also occur but are less common. Contrast-enhanced computed tomography is the primary imaging modality.

Aged↗
PubMed1994

Management of pseudomembranous colitis.

Controversy exists as to the appropriate management of fulminant C. difficile-associated pseudomembranous colitis (PMC). We reviewed our most recent 5-year experience with 191 patients with PMC. Nine patients had an initial presentation of a surgical abdomen with clinical signs of peritonitis, elevated white blood cell count, and eight had received antibiotics prior to presentation. Two patients were placed on no cardiopulmonary resuscitation status at admission to the surgical intensive care unit; both died within 24 hours. The remaining seven patients had exploratory laparotomies. The four who had total abdominal colectomies with ileostomies recovered promptly. Two of the other three had no resection because there was edema of the colon, but no other gross pathological changes. The third had only a segmental colon resection. All three deteriorated postoperatively, and two were dead within 48 hours. The remaining patient was returned to the operating room 48 hours after the first procedure, and an abdominal colectomy and ileostomy was performed. She never recovered, however, and died 12 days later. We conclude that although most patients with PMC can be treated effectively medically, total abdominal colectomy with ileostomy is indicated when signs of peritonitis occur, even if the only finding at laparotomy is edema of the colon.

Aged↗
PubMed1994

The use of intravascular ultrasound in the management of thoracic outlet syndrome.

We have reviewed our early experience with intravascular ultrasound in the management of thoracic outlet syndrome. Eight patients presenting with symptoms of venous obstruction secondary to thoracic outlet syndrome have been evaluated by duplex ultrasound, contrast venography, and intravascular ultrasound (IVUS). IVUS was performed at the same time as venography, using the brachial venous access site. In all eight patients IVUS and venography were in agreement. IVUS was able to identify the etiology of the stenoses. Four of the six patients with abnormal IVUS studies have had surgery, and IVUS was used intraoperatively during three of these cases. Based on the demonstration of release of extrinsic compression by real time imaging, it was possible to limit the necessary dissection to two first rib resections alone and one resection of just the insertion of the pectoralis minor muscle. Three of the four patients have had complete resolution of their symptoms postoperatively. Currently, the average follow-up time is 13 months. One patient who was a current procedure has had a minor relapse at 6 months. There have been no complications. These results have shown that IVUS is a safe technique and is as accurate as venography in identifying the sites and degree of narrowing. IVUS provides additional data as well regarding the etiology of the underlying process. The intraoperative use of IVUS has proved helpful in decision-making to minimize the dissection necessary to release extrinsic venous compression. The operative results compare favorably with those found in the literature.

Adult↗
PubMed1993

Thymectomy for myasthenia gravis.

OBJECTIVES: To assess the change in clinical status of patients with generalized myasthenia gravis treated with thymectomy and to identify prognostic variables that may be of significance in optimizing patient selection. DESIGN: Retrospective review. Mean follow-up period was 41 months. SETTING: Large community hospital. PATIENTS: Thirty-seven patients (11 male and 26 female) with generalized myasthenia gravis who were referred for thymectomy if they were refractory to medical treatment or had a thymoma. This represents all patients undergoing thymectomy for myasthenia gravis between January 1982 and December 1991. INTERVENTIONS: Each patient underwent staging before and after thymectomy using a modified Osserman classification. Medication requirements were also recorded. All patients underwent transsternal thymectomy and complete mediastinal dissection. MAIN OUTCOME MEASURES: Changes in clinical stage and medication requirement before and after thymectomy; effect of patient age, sex, duration of disease, stage of disease, antibody status, histologic characteristics of the thymus, and duration of follow-up on outcome. RESULTS: Improvement after thymectomy was noted in all 37 patients. Complete remission was achieved in three patients (8%) and pharmacologic remission in 23 (62%). The remainder improved in stage, medication requirement, or both. Patients in preoperative stages IIb and IIc showed the greatest improvement. Age, sex, duration of disease, antibody status, histologic characteristics of the thymus, and duration of follow-up were not significant factors in assessing improvement. CONCLUSIONS: Transsternal thymectomy was found to be beneficial to all patients with generalized myasthenia gravis. Complete or pharmacologic remission was achieved in most patients (70%) following the procedure. Patients in preoperative stages IIb and IIc showed the greatest degree of postoperative improvement.

Adolescent↗
PubMed1993

Protective effects of enalaprilat against postischemic renal failure.

Prolonged intraoperative renal ischemia requires modalities to reduce the incidence of acute tubular necrosis, but there exists no definitive prophylactic regimen. We studied the effects of enalaprilat, an angiotensin-converting enzyme inhibitor, in an attempt to identify such a protective drug. Thirty-four mongrel dogs underwent 90 min of bilateral renal pedicle clamping. Group I was a control of 6 animals. Group II comprised 10 animals who received 12.5 g iv mannitol 15 min prior to clamping and 1 mg/kg iv furosemide immediately after clamp removal. Group III also comprised 10 animals who received enalaprilat 1 mg/kg iv enalaprilat each 15 min prior to clamp placement. Group IV consisted of 8 dogs, each of which received 12.5 g mannitol and 1 mg/kg iv enalaprilat 15 min prior to clamping and 1 mg/kg iv furosemide immediately upon removal of the clamps. Serum blood urea nitrogen (BUN) and creatinine levels were drawn preoperatively and at 12, 24, 48, and 72 hr postoperatively in each animal. The serum BUN levels in group III were significantly lower than those in group I at all times postoperatively (P < 0.05) and were not significantly different from those of group II at any time postoperatively. Similarly, the serum creatinine levels in group III were significantly lower than those of group I (P < 0.05) and were not significantly different from those in group II at any time postoperatively. Neither the serum BUN nor the serum creatinine levels in group IV were different from those of group I at any time postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1993

Cell washing versus immediate reinfusion of intraoperatively shed blood during abdominal aortic aneurysm repair.

Significant hematologic changes are known to occur following intraoperative autotransfusion of shed blood, but the clinical importance of cell washing prior to reinfusion has not been substantiated. To evaluate these changes and their relationship to the use of blood bank products and postoperative morbidity, 26 patients undergoing elective abdominal aortic aneurysm repair were prospectively randomized to reinfusion with washed shed blood or to the use of a collection system in which filtered, but unwashed, whole blood was reinfused intraoperatively. Each patient was evaluated with respect to standard metabolic and hematologic laboratory parameters preoperatively, immediately postoperatively, and 12 to 18 hours postoperatively. Patient demographic data were similar for both groups. Perioperative survival was 100% for both groups. Total blood loss and blood volume autotransfused were significantly greater in the unwashed cell group compared with the washed cell group (p = 0.00014 and p = 0.00011, respectively). Hemoglobin, fibrinogen, prothrombin time, and partial thromboplastin time levels were not significantly different between the two groups at any time perioperatively; fibrin split product and d-dimer levels were significantly higher in the unwashed cell group postoperatively (p = 0.016 and p < 0.001, respectively). Serum free hemoglobin levels were significantly higher in the immediate postoperative period in the unwashed cell group compared with the washed cell group (p = 0.0013); by 12 to 18 hours postoperatively, this difference was not significant. Haptoglobin levels were significantly lower in the unwashed cell group at both postoperative times (123 +/- 86 mg/dL versus 41 +/- 50 mg/dL, p = 0.0086; 102 +/- 66 mg/dL versus 24 +/- 36 mg/dL, p = 0.0001); however, there was no perioperative renal failure in either group. Furthermore, homologous blood product use was not significantly different between the two groups, with an average of 1.5 +/- 2.5 units of packed red blood cells given to patients in the unwashed cell group versus 0.8 +/- 1.7 units in the washed cell group (p = 0.419). Overall complications were higher and critical care and total hospital stays were longer in the unwashed cell group but did not result from autotransfusion of unwashed blood. We conclude that the intraoperative reinfusion of unwashed shed blood is safe and effective, causing transient hematologic abnormalities that normalize in the early postoperative period, and is not associated with increased mortality, or hematologic, cardiopulmonary, or renal complications.

Aged↗
PubMed1992

Limb perfusion. An objective measure of hemodynamic improvement after angioplasty.

Forty-four patients undergoing femoropopliteal angioplasty were studied by magnetic resonance blood flowmetry to determine quantitative limb perfusion. Baseline limb perfusion averaged 0.52 +/- 0.15 mL/min per 100 cc of tissue. Perfusion values for successful angioplasties rose within 72 hours to a mean of 1.40 +/- 0.31 mL/min per 100 cc of tissue. There were five early failures (less than 30 days), in which perfusion fell to 0.54 +/- 0.10 mL/min per 100 cc of tissue; at 6 months, 12 additional angioplasties had failed, with limb perfusion values of 0.68 +/- 0.16 mL/min per 100 cc of tissue. At 6 months, perfusion in four additional limbs had decreased to between 0.7 and 1.0 mL/min per 100 cc of tissue, with a mean change of 0.59 mL/min per 100 cc of tissue; duplex ultrasound imaging at these sites showed restenoses ranging from 50% to 75%. We conclude that lower-leg limb perfusion appears to be a reliable measure of hemodynamic improvement after femoropopliteal angioplasty and may provide an early indicator of impending failure.

Aged↗
PubMed1992

Hemodynamic effects of primary closure versus patch angioplasty of the carotid artery.

This study evaluated the hemodynamic changes associated with patch angioplasty compared to primary closure of the canine carotid artery. A standard arteriotomy was closed either primarily, with a 5x28 mm expanded polytetrafluoroethylene (ePTFE) patch, or with a 10x28 mm ePTFE patch. Measurements for the primary closure group showed a systolic pressure gradient of 17 mmHg across the closure and a peak systolic velocity increase of 58% at mid-closure compared to proximal inflows. Flow turbulence increased at mid-closure in the 10 mm patch group, with the percent spectral window lowered from 0.50 to 0.36. These data show that primary vessel closure creates a mild local stenosis with flow acceleration but no flow turbulence. No significant hemodynamic disturbances are caused by a moderate sized patch; however, a large patch relative to native vessel dimensions creates marked flow disturbances throughout the cardiac cycle. As turbulence and flow separation are felt to contribute to restenosis, care should be taken in the selection of patch size when used following carotid endarterectomy.

Angioplasty↗
PubMed1992

Atrial myocytes cultured from explanted human adult myocardium demonstrate DNA replication.

The current theory of myocardial development holds that after a limited number of divisions, the myocardiocytes of the developing heart are irreversibly withdrawn from the generation cycle. It is, therefore, considered impossible to grow adult human myocardiocytes in culture, making it necessary for studies of cardiac muscle in culture to be carried out using animal or fetal human models. Recently, we developed a method for isolating, culturing, and characterizing myocardiocytes derived from explanted adult human atrial myocardium. A highly pure fraction (93%) of one of four morphologically discrete cell populations was separated using selective attachment techniques. These cells possessed features consistent with those seen in animal and fetal myocardiocytes. Using immunoperoxidase stains, these cells stained positive for actin, myoglobin, and atrial natriuretic peptide, proving the cells are myocardial muscle cells. Electron microscopy showed numerous bundles of myofibrils with interspersed dense Z-bodies and pleomorphic mitochondria. Bromo-deoxyuridine incorporation confirmed that the cells were replicating their DNA. Thus, cell morphology, immunoperoxidase stains, electron microscopy, and cell proliferation testing showed these cells to be myocardiocytes undergoing DNA replication and mitosis. We must now reconsider our current thinking about myocardial development and investigate what factors contribute to the inhibition of myocardial cell proliferation after injury in vivo.

Bacteriological Techniques↗
PubMed1992

Characteristics of cerebrovascular accidents after coronary artery bypass grafting.

The records of all patients who had a cerebrovascular accident (CVA) following coronary artery bypass surgery were reviewed to determine the incidence, etiology, and outcome following such an event. Between January 1, 1987, and December 31, 1990, 3,428 patients underwent bypass grafting and 46 had a CVA, documented by head computed tomography (CT) after neurologic findings were appreciated, for an incidence of 1.3 per cent. In 16 patients, a neurologic deficit was documented less than 12 hours after surgery and was presumed to have been an intraoperative event. The remaining 30 patients became symptomatic between postoperative days 2 and 7. Twenty-five patients (54%) exhibited neurologic and CT findings suggestive of an embolic event, while the remaining 21 patients appeared to have sustained an infarct as a result of cerebral hypoperfusion. Nine patients with CVA had a carotid bruit documented in the preoperative period, and seven of these suffered their ischemic event in the ipsilateral distribution. Five patients had a documented CVA previously, and four were shown to have extended areas of previous infarction. The mortality following CVA was 35 per cent. Of the survivors, 70 per cent had some improvement in symptoms at the time of discharge; 60 per cent of survivors were discharged to their homes and the remainder to extended care facilities. Although CVA following coronary bypass grafting is an uncommon event, some patients at increased risk may benefit from more aggressive preoperative noninvasive evaluation and intraoperative monitoring. A better understanding of the etiology of postoperative stroke may help to prevent its high morbidity and mortality, which has been demonstrated.

Aged↗
PubMed1992

The role of renin and catecholamine production in postcarotid endarterectomy hypertension.

Correlation between increased cranial and peripheral norepinephrines and increased cranial to systemic renin ratio has been observed in a small number of patients with postcarotid endarterectomy hypertension. In an effort to confirm these findings, we studied cranial and peripheral levels of catecholamines and peripheral renin activity in 120 consecutive carotid endarterectomies. Samples were taken before carotid clamping (Sample I) and just after clamp release (Sample II). Norepinephrine, epinephrine and dopamine values did not correlate with postcarotid endarterectomy hypertension. There was no association between peripheral renin values and postcarotid endarterectomy hypertension.

Aged↗
PubMed1991

Results of surgical therapy for biliary dyskinesia.

One hundred eighty-seven patients who presented with symptoms consistent with biliary colic but had no ultrasonic evidence of cholelithiasis were observed in an effort to identify those with a functional gallbladder disorder that might benefit from surgical intervention. All patients underwent quantitative evaluation of gallbladder emptying using cholecystokinin biliary scanning, and ejection fractions less than 35% were considered abnormal. One hundred twenty-nine patients (69%) had abnormal ejection fractions, and 88 (68%) of these subsequently underwent cholecystectomy. Sixty of the surgical specimens revealed pathologic changes. Eighty-four percent of patients successfully contacted for follow-up experienced complete relief, and another 13% had partial relief of preoperative symptoms. Only two patients reported no change in symptom complex. Twenty-nine patients with abnormal ejection fractions elected not to undergo surgery. Fifty-nine percent of these patients continued to experience symptoms of biliary colic at a mean follow-up of 22 months. Of the 44 patients with normal ejection fractions, 35 (80%) reported resolution of symptoms during follow-up of medical treatment. Cholecystokinin biliary scanning can help identify patients with acalculous, functional gallbladder disease who may benefit from cholecystectomy.

Adult↗
PubMed1991

A method for the harvest, culture, and characterization of human adult atrial myocardial cells: correlation with age of donor.

Myocardial cell culture methods are now well established for animal and fetal human tissue. We present here a method for harvesting and culturing adult human atrial myocardiocytes. Cells are obtained from fresh atrial tissue normally discarded after being removed to cannulate the right atrium during open heart surgery. The atrial tissue is minced and then digested using collagenase. The single cell suspension is initially cultured in serum-containing growth medium, then transferred to defined medium, selective for myocardial cell growth. The cells are characterized by immunoperoxidase stains and transmission electron microscopy. The cultured cells stain positive for myoglobin, whereas control cultured fibroblasts and endothelial cells do not. Electron microscopy shows the presence of numerous myofibrils, Z-bodies, pleomorphic mitochondria, and secretory granules. The chronological age of the donor was an important factor in culturing the adult tissue, the younger tissue correlated with a higher success rate. This method provides a means for in vitro study of human adult myocardial cells and provides guidelines for appropriate atrial tissue to use.

Aging↗
PubMed1991

Comparison of immediate seeding of endothelial cells with culture lining of small diameter ePTFE carotid interposition grafts.

This study is the first to compare chronic healing characteristics of immediately seeded grafts with those of grafts lined by autogenous venous endothelial cells in tissue culture prior to implantation. Ten mongrel dogs had a segment of external jugular vein excised for enzymatic harvest of endothelial cells. After approximately 21 days growth in tissue culture, 4 X 10(6) cells/ml were inoculated into a 6-cm length of 4 mm i.d. ePTFE for formation of a confluent lining in culture media. The remaining external jugular vein had its endothelial cells enzymatically harvested for immediate seeding of an identical length of preclotted ePTFE. Both grafts were implanted end-to-end in the carotid position and excised after 30 days. In 6 of the 10 dogs, grafts were patent bilaterally; all others were occluded. Planimetric measurements on patent grafts with immediate seeding showed a thrombus-free surface area of 56 +/- 39% compared to 86 +/- 15% for culture-lined grafts (P = 0.046). Endothelial coverage was 70 +/- 24% for immediately seeded grafts and 29 +/- 21% for culture-lined grafts (P = 0.016). We conclude that immediate seeding and culture lining of autogenous endothelial cells in small diameter ePTFE grafts produce equivalent short-term patency. While culture-lined grafts have an initially less thrombogenic luminal surface, subsequent development of a confluent endothelial lining is slower than that with an immediate seeding preparation, and thus would appear to offer no significant clinical benefit, especially in light of the complexity culture lining adds to the procedure.

Animals↗
PubMed1991

Effect of papaverine on endothelial cell harvest from canine external jugular veins.

Endothelial cell seeding procedures have been developed to line prosthetic bypass grafts used in peripheral vascular disease; however, because of current inefficient cell harvest techniques a high ratio of vein-to-graft area is necessary. This study was done to determine if the use of papaverine, a smooth muscle cell relaxant, would affect the number or viability of endothelial cells harvested from canine external jugular veins. Using a 0.12 mg/ml solution of papaverine in tissue culture medium to bathe the veins during dissection and excision, the viable cell yield was 2.20 +/- 1.16 (cells x 10(4)/cm2). A control group of veins using standard dissection technique gave a yield of 0.97 +/- 0.40 (p = 0.025). A second group of veins dissected while bathed in tissue culture medium alone gave a yield of 1.82 +/- 0.75, compared to a yield of 2.73 +/- 0.45 for papaverine harvested veins (p = 0.009). Percent cell viability was not significantly different for any of the groups: 73, 70, and 76% for papaverine, control and media only veins, respectively. The papaverine-harvested cells and those harvested with medium alone grew to 95% confluence in tissue culture in 9.8 +/- 1.1 and 9.9 +/- 0.9 days, respectively. Compared to conventional surgical techniques, use of papaverine more than doubled the endothelial cell yield from excised vein segments without adversely affecting viability or rate of growth in cell culture.

Animals↗