PubMed Health⌕ Search

Biomedical subjects

J J Curtis

Publications and source records attributed to J J Curtis.

At least 55 records · Page 3Linked to original sources
PubMed1996

Should pulmonary lesions be resected at the time of open heart surgery?

The prevalence and malignant potential of pulmonary lesions found preoperatively in patients undergoing coronary artery bypass grafting (CABG) surgery are poorly defined. In a review of 3364 consecutive patients undergoing CABG, 191 (5%) were found to have pulmonary lesions. Granulomatous disease was suspected in all patients who had only calcified lesions (n = 151). These were empirically observed with no changes seen at follow-up. The 40 patients with noncalcified lesions (NCLs) were managed variously. Twenty patients underwent resection of the suspicious pulmonary lesion at the time of cardiac surgery. One patient underwent wedge resection of a pulmonary lesion (benign granuloma) 4 days before CABG. Eighteen patients underwent concomitant pulmonary resection and CABG through the median sternotomy (7 benign, 11 malignant). A delayed pneumonectomy was performed 17 days after CABG in another patient. Three of 40 patients died during the perioperative period without pathologic diagnosis. The remaining 17 were followed with serial roentgenograms. Three of 17 (18%) had lesional enlargement in the follow-up period their lesions were found to be malignant. The remaining 14 patients have been observed without surgical intervention now with a mean follow-up of 5.7 years (range, 20 months to 13 years). The prevalence of malignancy in lesions found on CABG preoperative chest roentgenograms was 15 out of 191 (7.8%); however, among patients with NCL the prevalence of malignancy was 15 out of 40 (37%), and malignancy was present in 12/13 (92%) of patients with NCLs that were >/= 2 cm in diameter. When malignancy is diagnosed in an NCL before CABG surgery, the decision to proceed with CABG should be based upon the coronary pathophysiology and the stage and cell type of the malignancy. Concomitant CABG and pulmonary resection is possible in most cases; however, we prefer a staged resection of all newly diagnosed NCLs when these are identified in patients requiring emergent revascularization or when these lesions are difficult to access through sternotomy. The mortality rate may be slightly increased in patients having concomitant procedures (5.47%) versus isolated CABG (3%). The incidence of malignancy in these NCLs is related to size. If a staged resection is not undertaken after CABG, careful observation of NCLs is important, as 18 per cent of these so managed were ultimately found to be malignant.

Adult↗
PubMed1996

Cyclosporine bioavailability: dosing implications and impact on clinical outcomes in select transplantation subpopulations.

Reports in the literature indicate that clinical outcomes in select patient subpopulations have been inferior to those in the general transplantation population. Of potential interest in this regard is the finding that lower cyclosporine bioavailability correlates with a higher incidence of acute rejection and graft loss. To gain insights into these issues, we examined data from renal transplant recipients at our own centers and in one large data base. Our experience revealed that cyclosporine bioavailability was markedly lower in patients who developed acute or chronic rejection than in those with stable graft function. An analysis by demographic or clinical factors showed that cyclosporine bioavailability was lower in diabetics and black patients. In one study, diabetics required much higher daily doses of cyclosporine to achieve outcomes comparable to those in non-diabetics; even then, diabetics attained lower cyclosporine blood levels. Other work found that long-term graft survival rates were poorer in blacks, even though cyclosporine dosages and blood levels were comparable to those in whites. A case-controlled study from the pregnancy registry found that cyclosporine dosages were consistently higher in pregnant patients who maintained good graft function than in those who experienced graft dysfunction. These results suggest that the subpopulations examined should receive immunosuppression with higher cyclosporine dosages than those used in the general transplantation population. These subpopulations may also benefit from a cyclosporine formulation that provides better absorption, resulting in more consistent and predictable cyclosporine bioavailability.

Biological Availability↗
PubMed1996

Possible mediators in hypertension: renal factors.

Hypertension is more prevalent and more severe in African Americans compared with whites. Evidence is presented that support an important role of the kidney in the excess incidence of hypertension in this population group. There are quantitative differences in renal physiology between hypertensive African Americans and whites, the most dominant of which is an increased renal vascular resistance in African Americans that might be structural or functional. This increased renal vascular resistance might represent an underlying primary renal disease that has remained concealed among the spectrum of diseases referred to as benign nephrosclerosis. The answer(s) to this intriguing question will provide a better understanding of the kidney as a mediator and/or target of hypertension.

Black People↗
PubMed1996

A calf model for left ventricular centrifugal mechanical assist.

The increased use of centrifugal mechanical assist (CMA) for treatment of refractory postcardiotomy cardiogenic shock highlights the need for experimental testing to improve clinical results. This report describes the preoperative conditioning, anesthetic and surgical technique, and postoperative management of a reliable calf model refined in this laboratory for in vivo subchronic (96 h) testing of CMA. Holstein bull calves (2 to 3 months old; mean body weight, 78 kg; n = 35) were instrumented for left ventricular CMA; 4 of these calves were sham-operated controls. Anesthetic recovery and postoperative restraint were accomplished in a specially designed crate to which each calf was preconditioned extensively. Younger calves were more readily conditioned and more tolerant of postoperative restraint than older calves. One calf died of ventricular fibrillation intraoperatively. One calf that had been heparinized developed uncontrollable hemothorax and died 12 h postoperatively. One calf prematurely dislodged his aortic cannula 15 h postoperatively and exsanguinated. Six calves developed pelvic limb paresis or paralysis because of lumbar spinal cord thromboembolism by 36 h postoperatively, and 3 of these calves were sacrificed by 42 h postoperatively. Fifteen calves required sedation in the first 12 h after the operation. Tachycardia associated with bottle feeding occurred in 15 calves. Second-degree atrioventricular block was noted frequently during deep relaxation. Postmortem examination demonstrated the absence of surgical wound and distant infection, security of cannulae in all but the calf that prematurely dislodged the aortic cannula, absence of thrombus formation at cannulation sites, and presence of thromboembolism in 51% of the calves. The incidence of thromboembolic lesions was not influenced by the need for chemical restraint, by the occurrence of feeding-associated tachycardia, or by the presence of atrioventricular block. There were no thromboembolic lesions in any of the sham-operated controls.

Anesthesia↗
PubMed1996

Improved method for deep thoracoscopic lung nodule excision.

Minimally invasive excision of deep lung nodules can be difficult partly because endoscopic staplers do not open wide enough. We describe a method in which a standard atraumatic straight clamp compresses the lung to allow placement of the stapler without difficulty.

Humans↗
PubMed1995

Progress in renal transplantation. A single center study of 3359 patients over 25 years.

OBJECTIVE: The study analyzed 3359 consecutive renal transplant operations for patient and graft survival, including living related, cadaveric, and living unrelated patients. The analysis was separated into three groups according to immunosuppression and date of transplant. SUMMARY BACKGROUND DATA: Improvements in renal transplantation in the past 25 years have been the result of better immunosuppression, organ preservation, and patient selection. METHODS: A single transplant center's experience over a 25-year period was analyzed regarding patient and graft survival. Potential risk factors included patient demographics, tissue typing, donor characteristics, number of transplants, acute and chronic rejection, acute tubular necrosis, primary disease, and malignancy. RESULTS: The primary cause of graft loss was rejection. Improvement in cadaveric graft survival since 1987 with quadruple therapy was not apparent in living donor patients. Race continued to be a negative factor in graft survival. Avoiding previous mismatched antigens and the use of flow cytometry improved allograft survival. The leading cause of death in the past 7 years in cadaveric recipients was cardiac (52%). CONCLUSIONS: Improved graft survival in the past 25 years was related to 1) advances in immunosuppression, 2) better methods of cytotoxic antibody detection, and 3) human lymphocyte antigen match.

Adolescent↗
PubMed1995

Improving clinical outcome with centrifugal mechanical assist for postcardiotomy ventricular failure.

Between October 1986 and May 1994, 65 patients undergoing cardiac surgery required centrifugal mechanical assist devices to separate from cardiopulmonary bypass. This experience was arbitrarily divided into early (n = 33) and recent (n = 32) groups for the purpose of comparing trends in morbidity and mortality. The incidence of mechanical assist application decreased from 2.19% in the early group to 0.96% in the recent group (p < 0.0001). Ability to wean patients from centrifugal assist increased from 33% in the early group to 53% in the more recent group, and hospital survival increased from 15 to 28%. The median chest tube drainage during the first 24 h decreased from 3,245 ml to 1,535 ml, and the incidence of renal failure decreased from 39.4% and 18.8% in the more recent group. Clinically relevant improvement in patient outcome following application of centrifugal mechanical assist for postcardiotomy ventricular failure is being observed.

Adult↗
PubMed1995

Cyclosporine inhibits the renal response to L-arginine in human kidney transplant recipients.

To evaluate the association of cyclosporine (CsA)-related nephrotoxicity with nitric oxide (NO) and endothelin, the effects of L-arginine (LA) and branched-chain amino acid (BCAA) infusions on renal hemodynamics in 5 normal volunteers and 12 renal transplant recipients were assessed. In normal humans, LA, but not BCAA, reduced mean arterial pressure and renal vascular resistance while increasing RPF and urinary nitrate (NO3-) excretion. Group 1 included six transplant recipients not on CsA; Group 2 subjects (N = 6) were receiving CsA. In both groups, mean arterial pressure declined during the infusion of LA (116 +/- 4 to 109 +/- 4 mm Hg; P < 0.001) but not BCAA (116 +/- 3 to 115 +/- 3; P = not significant). In Group 1, LA increased RPF 33 +/- 13% (329 +/- 48 to 436 +/- 77 mL/min per 1.73 m2; P = 0.01) and GFR 37 +/- 16% (95 +/- 7 to 130 +/- 18 mL/min per 1.73 m2; P = 0.01); renal vascular resistance declined 27 +/- 6%. In Group 2, LA did not affect renal hemodynamics. No changes occurred with BCAA in either group. LA increased urinary NO3-excretion by 27 +/- 17% in Group 1 (P < 0.05), but only by 16 +/- 13% in Group 2 (P = not significant). Urinary endothelin excretion was higher in Group 2 subjects (10.1 +/- 1.3 versus 5.3 +/- 0.8 pg/mL of GFR, P < 0.01). LA-induced renal vasodilation is associated with the increased urinary excretion of NO3-.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Role of hypertension in chronic renal allograft dysfunction.

The damaging effects of essential hypertension and the central role of the kidney in its pathogenesis have long been recognized. Essential hypertension is the second leading cause of end-stage renal disease in the United States, with its prevalence increasing dramatically over the last decade. Similarly, the role of the transplanted kidney in the pathogenesis of hypertension has been demonstrated in animals and humans. Concerns over the inability of immunologic advancements to improve long-term allograft survival have focused attention on nonimmunologic factors, such as hypertension, and its contribution to chronic renal allograft injury. However, the complex nature of post-transplant hypertension has made it difficult to discern if its occurrence is the cause or the consequence of chronic allograft dysfunction. The possibility remains that, in many patients, the two processes are not mutually exclusive and coexist. Regardless, post-transplant hypertension negatively impacts long-term allograft and patient survival. Many questions regarding the etiology, optimal therapy and role of various growth factors in mediating the damaging effects of post-transplant hypertension remain unanswered and should serve as the focus for future studies.

Animals↗
PubMed1994

Severe dysphagia from an Angelchik prosthesis: futility of routine esophageal testing.

A 33-year-old woman presented with progressive dysphagia 3 years after implantation of an Angelchik prosthesis for esophageal reflux disease. Routine esophageal testing was normal. Esophagogastroduodenoscopy and computed tomography suggested migration of the prosthesis. Because of the persistent and progressive dysphagia, the device was removed. All symptoms of dysphagia or reflux have since resolved. Routine esophageal testing may not be helpful in the evaluation of dysphagia associated with the Angelchik prosthesis.

Adult↗
PubMed1994

Coronary revascularization in the elderly: determinants of operative mortality.

Over a 13-year period, 668 patients 70 years of age or older underwent isolated primary coronary artery bypass grafting at our institution. There were 472 men and 196 women, ranging from 70 to 90 years of age (median age, 74 years). Hospital mortality was 5.2% (35/668). In patients 70 to 79 years of age, hospital mortality was 4.2% (25/600), whereas in patients 80 years of age or older, mortality was 14.7% (10/68; p < 0.001). Twenty-seven clinical or hemodynamic variables hypothesized as predictors of operative mortality were examined. Mortality was higher in women than in men (9% versus 3.6%; p = 0.006). Those who died were a mean of 3 years older (77 versus 74 years old; p < 0.05) and were more likely to have unstable angina or Canadian class III or IV angina (p < 0.01). Patients requiring urgent operations, preoperative intraaortic balloon assist, intravenous nitroglycerin, or inotropic agents, and those with preoperative hypotension or cardiac arrest were most likely to die in the hospital (p < 0.001). Multivariate logistic regression analysis revealed advancing age, female sex, bypass time, urgency of operation, preoperative cardiac arrest, and unstable angina as primary determinants of mortality (p < 0.05). Although mortality after coronary artery bypass grafting increases with age, the greatest risk of death is in the acutely ill patient with few options for management other than surgical intervention.

Age Factors↗
PubMed1994

Lack of cardioplegia uniformity in clinical myocardial preservation.

Advances in myocardial preservation have led to improved patient survival after open heart operations. However, few studies have detailed the nature of national or regional patterns of cardioplegia use. To determine the regional pattern, all open heart surgery programs in Missouri were surveyed. During 1 year, it was found that cardioplegia was administered to 8,382 patients by 61 cardiothoracic surgeons at ten academic affiliated hospitals and 16 nonteaching hospitals. All cardioplegic solutions were hospital produced. Of 13 crystalloid solutions, 11 differed from one another and eight were intracellular formulations. Of 28 multidose blood-based cardioplegic solutions, there were 23 different mixtures. Most crystalloid (69%) and blood-based (89%) solutions differed substantially from commonly reported formulations. The incidences of the various additives to crystalloid solutions were as follows: bicarbonate, 92%; glucose, 69%; lidocaine, 54%; mannitol, 46%; magnesium, 31%; calcium, 23%; methylprednisolone, 15%; heparin, 8%; and acetate, 8%. Of the common blood-based cardioplegic solution additives, the following incidences were observed: glucose, 79%; bicarbonate, 43%; trishydroxyaminomethane, 36%; acetate, 29%; magnesium, 29%; procaine (or lidocaine), 25%; citrate-phosphate-dextrose, 18%; mannitol/albumin, 14%; nitroglycerin, 11%; glutamate/aspartate, 11%; calcium, 7%; insulin, 3%; and methylprednisolone, 3%. No calcium channel blocker or high-energy phosphate additives were reported. We conclude that many different cardioplegic admixtures that have not been tested experimentally are used routinely in clinical practice, presumably with acceptable results. Because the salutary effects of induced cardiac arrest and hypothermia may mask suboptimal solutions, further study of customized cardioplegia should be considered, particularly with regard to high-risk patients.

Blood↗