Biomedical subjects
Publications and source records attributed to C M Burnett.
Pleurodesis is a commonly used option in the management of malignant pleural effusion. Although several chemical agents are used talc has only recently been advocated as the sclerosing agent of choice. Talc can be administered via open thoracotomy or tube thoracostomy, but thoracoscopy offers an excellent alternative to these approaches. We describe a new technique of thoracoscopically applied talc pleurodesis that is easy, inexpensive, and reliable.
BACKGROUND: Pulmonary dirofilariasis is a rare entity caused by Dirofilaria immitis, the dog heartworm that is transmitted to humans by mosquitos. This filarial nematode enters the subcutaneous tissue, travels to the right ventricle where it dies, and then embolizes the pulmonary vasculature, causing a small pulmonary infarction, which subsequently appears as a solitary nodule. Although these nodules are usually identified incidentally by chest radiography in asymptomatic patients, the lesion is generally presumed to be neoplastic. Diagnosis is made by surgical excision. METHODS: We reviewed the pathology reports at Memorial Medical Center, Savannah, GA since 1990. RESULTS: There have been approximately 150 cases reported in the literature worldwide. We found 4 patients with pulmonary dirofilariasis diagnosed at our hospital since 1992. A review of the pathogenesis of the disease and clinical manifestations, diagnosis, and treatment of this entity are presented. CONCLUSIONS: Pulmonary dirofilariasis is a benign condition, transmitted by mosquitos to humans that results in peripheral pulmonary nodules. Awareness of this entity is important in the differential diagnosis of pulmonary coin lesions.
Lung hernia is a distinctly rare event, regardless of its location and cause. Most lung hernias are acquired traumatic thoracic hernias. All previously reported cases of acquired spontaneous lung hernia involve some aspect of trauma, most commonly caused by vigorous coughing with a subsequent rib fracture. We report a case of totally atraumatic, acquired spontaneous lung hernia.
Eleven cardiac transplant candidates (all male; mean age, 43.3 years) with multiorgan (hepatic, pulmonary, and/or renal) dysfunction were sustained for prolonged periods (> 30 days) with the HeartMate (Thermo Cardiosystems, Inc, Woburn, MA) left ventricular assist device. We evaluated the effect of extended support on end-organ recovery and on the ultimate outcome of cardiac transplantation. In addition to cardiac failure, 9 patients had hepatic dysfunction, 8 had pulmonary dysfunction, and 6 had renal dysfunction (4 of whom required hemodialysis before left ventricular assist device support). Mean duration of support was 115 days (range, 31 to 233 days). All patients underwent successful transplantation; 10 of these patients survived a mean of 24 months. One patient, who had required hemodialysis and ventilatory support during and after support, experienced progressive multiorgan failure and died 7 weeks after transplantation. Two late deaths after transplantation were unrelated to the device. Overall, patients experienced improvement in cardiac functional class status, and most participated in cardiac rehabilitation programs before transplantation. During left ventricular assist device support, hepatic function returned to normal in 8 patients, pulmonary function recovered in 7, and renal function returned to normal in 4. One patient who required hemodialysis underwent renal transplantation after cardiac transplantation and had complete recovery of renal function. In the current era of donor shortages, gravely ill patients can benefit from a strategy of prolonged left ventricular assist device support. This strategy has proved safe, has allowed for reversal of multiorgan dysfunction, and has produced healthier transplant candidates.
Stretching of suture material is an infrequent cause of delayed mediastinal hemorrhage after lateral repair of the aorta. In contrast to end-to-end reconstructions, lateral patch repairs of the aorta present unusual stress on the anastomotic suture line. We describe a simple technique for repair of loosened suture lines, with suggestions for preventing this complication in cases of lateral aortic reconstruction.
We describe a 54-year-old man who had an ascending aortic prosthetic graft and a porcine aortic valve prosthesis that were infected by Candida albicans. This infection led to the formation of a dissecting false aneurysm of the remaining transverse and entire descending thoracic aorta, and the man was admitted to our hospital for surgical treatment in February of 1991. Staged in situ graft replacement was performed using Borst's "elephant trunk" repair for the proximal aortic reconstruction and an open distal anastomosis technique for the distal repair. Candida albicans in the residual prosthetic graft was identified, and therapy with high-dose liposomal amphotericin B was initiated. The use of liposomal amphotericin B reduces the incidence of adverse effects and allows administration of higher doses than those possible with conventional amphotericin B therapy. Lifelong antifungal therapy is recommended for patients with C. albicans infection of prosthetic aortic grafts.
The excimer laser underwent phase I clinical trials at three centers to determine its safety for intraoperative coronary laser angioplasty as an adjunct to coronary artery bypass grafting. A 308-nm Xenon-Chloride, pulsed-wave excimer laser was used to perform angioplasty in 30 patients undergoing coronary artery bypass surgery. Forty vessels (30 patients) were treated, in which the extent of occlusion ranged from 30% to 100%, with complete occlusion in 40% of all vessels. Improvement in vessel luminal caliber was achieved in 33 (79%) vessels, with perforations occurring in 4 (12%) vessels, 2 of which required surgical repair. The lumens of the remaining 8 (19%) vessels were not enlarged, and 2 (5%) of these vessels were perforated. Luminal enlargement was most often achieved in totalled occluded vessels in which 16/17 (94%) were recanalized. No patients died within 30 days postoperatively. Five patients demonstrated biochemical and electrocardiographic evidence of myocardial injury 48 hr postoperatively, and one patient died of cardiac arrest 139 days postoperatively. On the basis of these results, we believe that excimer laser angioplasty can be performed safely to improve coronary luminal patency, even in totally occluded vessels, in an operative setting. The long-term value of this procedure remains to be elucidated.
OBJECTIVE: To determine whether the iv infusion of prostaglandin E1 (PGE1) could modify the early influx of neutrophils into bleomycin-injured lungs and if that would affect subsequent development of inflammation and fibrosis. BACKGROUND AND METHODS: In vivo controlled animal study performed in a university hospital pulmonary research laboratory. Male Syrian golden hamsters (100- to 110-g body weight) were divided into four treatment groups: a) No treatment; b) intratracheal bleomycin plus PGE1 infusion; c) bleomycin plus saline infusion; d) PGE1 infusion only. PGE1 (180 ng/hr.100 g) or saline were infused iv 3 to 25 hr after intratracheal instillation of bleomycin sulfate (0.5 U/0.5 mL.100 g). Total and differential counts of cells recovered by lavage, lavage fluid protein, and lung total protein and hydroxyproline levels were measured from 6 hr to 30 days later. RESULTS: PGE1 infusion reduced the influx of neutrophils 6 hr after bleomycin injury by 53% compared with saline infusion (p less than .0001), but increased inflammatory cell traffic after 24 hr for 15 days. At 4 days, protein recovered in lung lavage fluid was also decreased in PGE1-treated, bleomycin-injured animals, reflecting reduced injury to lung permeability barriers. Accumulation of lung collagen in the PGE1-treated, bleomycin-instilled hamsters tended to be lower than in the bleomycin-injured, saline-infused group at 15 and 30 days, although these differences did not achieve statistical significance. Despite this fact, greater than 33% of the animals in the PGE1-treated group died, possibly indicating an increased risk of sepsis in these animals. CONCLUSIONS: PGE1 infusion can decrease early neutrophil traffic and reduce injury to the lung permeability barriers. However, this treatment augments late inflammatory events and does not significantly alter the development of fibrosis.
More than 25 years of experience performing heart surgery on Jehovah's Witnesses has culminated in successful cardiac transplantation without administering blood products in five patients (mean age, 44.4 +/- 8.3 years) of this faith. The use of blood-conserving methods, iron supplementation, bone marrow-sparing maintenance immunotherapy, and brisk postoperative diuresis has added to the efficacy of cardiac transplantation in these patients. No perioperative deaths occurred, and early follow-up studies have shown that these patients have not been more susceptible to higher graft rejection rates due to the lack of pretransplant blood transfusions. As more Jehovah's Witnesses undergo heart transplantation in the future, comparison with other recipients who allow pretransplant blood transfusions may lead to a better understanding of rejection immunobiology. We conclude that cardiac transplants may be safely offered to Jehovah's Witnesses without fear of a uniformly poor outcome.
To combat the continuing shortage of ideal donor hearts, we have used cardiac allografts from high-risk donors for critically ill recipients. We defined high-risk donor variables as age greater than 40 years, systemic (noncardiac) infection, cardiopulmonary resuscitation greater than 3 minutes, ischemic time longer than 5 hours, weight more than 20% less than that of the recipient, and requirements for high doses of inotropes. Of the 305 donors we have used, 73 (23.9%) have been high-risk, with 59/73 (80.8%) exhibiting one variable, 12/73 (16.4%) exhibiting two variables, and 2/73 (2.7%) exhibiting three variables. No correlation was found between the number of donor variables and a poor postoperative result. No infectious complications occurred in 17 patients receiving hearts from potentially infected donors. Hospital mortality rates (30 day) for recipients of high-risk donor versus non-high-risk donor hearts were 8.2% and 6.9%, respectively (not significant). The 1-, 6-, and 12-month actuarial survival rates were 91.7%, 81.2%, and 75.9% for the high-risk donor group and 93.5%, 80.3%, and 77.8% for the non-high-risk donor group (not significant). Among survivors with high-risk donor hearts, mean left ventricular ejection fractions were 0.54 +/- 0.08 at 3 months, 0.55 +/- 0.08 at 1 year, and 0.54 +/- 0.09 at 2 years after transplantation. These results suggest that accepting less than ideal donor hearts can be safe and might be considered when better options are not available.
Hypervolemia, a potential complication in patients on ventricular assist device support, can be managed by use of continuous arteriovenous hemofiltration. The Hemopump, a new catheter-mounted, transaortic axial-flow ventricular assist device, and the vascular access catheter for the Diafilter-30 Hemofilter system, used in continuous arteriovenous hemofiltration, are both usually inserted by way of the femoral artery. Because placing two large catheters in the femoral artery of a patient with peripheral vascular disease can compromise circulation, a technique for placing them in the abdominal aorta was developed. Two patients have undergone combined Hemopump and hemofiltration treatment, and neither experienced complications. Such techniques may benefit more patients in the future, as the usefulness of the Hemopump is proved.
We analyzed the treatment of a recent group of patients with life-threatening acute posterior mediastinitis due to esophageal perforation to elucidate common factors in successful treatment. Life-threatening acute posterior mediastinitis due to esophageal perforation was diagnosed in 16 patients over the past 12 years. Esophageal perforation resulted from endoscopy in 11 patients, retching in 4, and blunt trauma in 1 patient. Preoperative serum albumin levels were higher in patients who survived. Fourteen of 16 patients (88%) underwent exploration: mediastinal drainage in 14 (10 survived), esophageal repair in 9 (7 survived) with diversion in 3 (3 survived), and stent placement in 2 (1 survived). Six of 16 patients (38%) died, always of polymicrobial sepsis. Female patients and those with cancer, endoscopic perforations, delayed diagnosis, persistent mediastinal contamination, mediastinal suppuration or necrotizing cellulitis, and postoperative complications did poorly. Antibiotics must be effective against both gram-positive and gram-negative bacteria, and against both anaerobic and aerobic bacteria. Early surgical intervention is key, particularly elimination of ongoing mediastinal soilage. Thorough mediastinal debridement and wide mediastinal drainage appear to be important in improving survival of patients with life-threatening acute posterior mediastinitis due to esophageal perforation.
Allograft coronary artery disease (CAD) is the major determinant of long-term survival following heart transplantation (HTx). In a group of 210 heart transplant recipients, we diagnosed CAD in 54 (27.1%) by coronary angiography, postmortem examination or examination of the transplanted heart at the time of retransplantation. Retrospective analysis of potential risk factors for the development of CAD was performed for both immunological (rejection pattern, immunosuppressive therapy, cytomegalovirus [CMV] infection), and nonimmunological (hyperlipidemia, smoking, hypertension, diabetes mellitus, obesity) risk factors. The total number of rejection episodes correlated significantly with the occurrence of CAD (P less than 0.05), showing that patients who experienced two or more rejection episodes had an incidence of CAD of 40%, as opposed to a 23% incidence in patients who experienced no rejection. A composite rejection score derived from multivariate regression analysis of the severity, frequency, and timing of acute cardiac rejection episodes was found to correlate with the development of CAD (P less than 0.05). Postoperative arterial hypertension also correlated significantly with the onset of CAD (P less than 0.01), with a 92.6% incidence of hypertension in the group with CAD versus 76.3% in the group without CAD. Smoking after transplantation correlated significantly with the occurrence of CAD (P less than 0.05). There was no significant correlation with other analyzed factors in this group of patients. In this review, the development of CAD after heart transplantation correlated with treated allograft rejection. Aggressive treatment of hypertension and cessation of smoking may contribute to alleviation of this serious complication.
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p-Aminophenol (p-AP) was fed in the diet to groups of 40 male and 45 female Sprague-Dawley rats at levels of 0.07, 0.2 or 0.7% for up to 6 months. Methaemoglobin levels were determined after 6 wk. During wk 12, urine was collected from ten rats/sex/group for evaluation of mutagenicity in the Ames test. Clinical chemistry, haematology and histopathology studies were performed in subgroups after 13 and 27 wk. In addition, after 13 wk, 25 females/group were mated to untreated males in a teratology study. After 20 wk, 20 males/group were removed from the test diets and mated to untreated virgin females in a dominant lethal mutagenicity study. These males remained untreated until they were killed at 27 wk. Rats that had been maintained on the test diets throughout the study were also killed at wk 27. The high dose level of 0.7% p-AP resulted in a significant (10-15%) reduction in body-weight gain in both sexes. There was no increase in the level of methaemoglobin and, other than slight reductions in total erythrocytes and haemoglobin in female rats at 13 wk, there were no toxicologically important differences between groups in haematology or clinical chemistry values at any time during the 27 wk of treatment. Dose-related nephrosis was seen in both sexes after 13 and 27 wk and in the high-dose males that were removed from the test diet for a 7-wk recovery period. The compound was not teratogenic, but an increase in developmental variations associated with maternal toxicity was noted at the mid- and high-dose levels. In the dominant lethal study, an increase in the total number of resorptions (but not litters with resorptions) was observed in the high-dose group in the first of two matings but this observation was not confirmed in a follow-up study. Mutagenic activity was not detected in the urine of rats fed p-AP.
Debate concerning the superiority of cholecystoenteric bypass (CCEB) vs. choledochoenteric bypass (CDEB) in patients with pancreatic cancer and biliary obstruction prompted this review. Thirty-six patients with biliary duct obstruction due to pancreatic cancer underwent 37 operations for biliary decompression between 1976 and 1986: 22 CCEB, 15 CDEB. Age, sex, race, preoperative health, and preoperative symptoms and signs were similar for both groups. Seven CDEB patients had previous cholecystectomy (n = 5) and failed CCEB (n = 2). Twenty CCEB patients and 13 CDEB patients had elevated preoperative total bilirubin with an average abnormal bilirubin of 15.3 mg per cent and 12.0 mg per cent, respectively. Perioperative significant morbidity/mortality was seen in 59.1 per cent and 22.7 per cent, respectively, in CCEB and 53.3 per cent and 6.7 per cent in CDEB. Twenty (90.9%) CCEB patients and 15 (100%) CDEB eventually succumbed to either their operation or pancreatic cancer: average survival was 7.5 months (range, 2-41 months) and 10.4 months (range, 2-30 months), respectively. Two CCEB patients were alive at 15 and 41 months. Eleven out of 22 CCEB patients (50%) experienced short term (within 2 months of surgery) absence of jaundice, icterus, pruritus, and biliary tract disease symptoms or signs, and six out of 12 experienced long term (more than 3 months after surgery) absence of these problems; with CDEB, 14 patients out of 15 (93%) experienced short term and 10 out of 12 patients (83%) experienced long term absence of these problems. Cholecystoenteric bypass is a significantly morbid procedure and yet does not reliably palliate biliary obstruction due to pancreatic cancer; it is not preferred.
Two-generation reproduction and chronic toxicity-carcinogenicity studies were conducted in Sprague-Dawley rats receiving topical applications of six oxidative hair-colouring formulations. These formulations were prepared as prototypes of permanent hair colourings using the base ingredients and primary intermediates and couplers most often used in this kind of product. Among the dyes included in the various formulations were p-phenylenediamine, p-toluenediamine, p-aminophenol, resorcinol, m-aminophenol, 1-naphthol, 2-amino-4-nitrophenol, 4-chlororesorcinol, p-aminodiphenylamine hydrochloride and N-methyl-p-aminophenol sulphate. The dye solutions were mixed with an equal volume of 6% hydrogen peroxide prior to application. In the reproduction study the samples were applied topically twice weekly throughout the growth, mating, gestation and lactation phases of the F0 parents to the weaning of the F1a and F2b litters. Fertility, gestation and foetal viability indices and body weights were evaluated for the six treatment groups and these were compared with the values for the three concurrent control groups. Weanlings selected from the F1a litters were the subjects for the lifetime carcinogenesis study. For 24 months they received twice-weekly topical applications of the same dyes as were administered to their parents. Clinical chemistry, haematological and urinalysis studies were performed at months 3, 12, 18 and 24, and five animals/sex/group were killed at month 12 and autopsied for histological examination of the rat tissues. All animals in the chronic study were evaluated for incidence of neoplastic and non-neoplastic lesions. In the reproduction phase the application of hair dyes had no adverse effect on the fertility of the males or females, or on gestation, lactation and weaning indices. The average number weaned per litter and the mean body weights of the weanlings were comparable among the treated and control groups. No treatment-related gross lesions were observed in any animals necropsied at month 12 or at study termination, or in any rats that died during the course of the carcinogenicity study. Comparison of the tumour incidences among the six treated and three control groups showed some significant variations among those tumours occurring most frequently in this strain of rats, and pituitary adenomas were also increased significantly (P less than 0.05) in the females of one of the treated groups. The incidence of this tumour is known to be high and variable in untreated female Sprague-Dawley rats.(ABSTRACT TRUNCATED AT 400 WORDS)
A number of hair-dye chemicals that have given positive results in various short-term mutagenicity tests have shown no clear evidence of carcinogenicity in animal bioassays. Commercial HC Blue No. 1 and its analogues HC Red No. 3 and HC Blue No. 2 are all mutagenic in the Ames test but only the HC Blue No. 1 is carcinogenic in animals. A carcinogenicity study in mice was carried out on both a commercial sample of HC Blue No. 1 and a highly purified sample which was negative in a battery of short-term tests for mutagenic activity. Both samples, administered at 0.3% in the diet for up to 24 months, were carcinogenic to mice, inducing hepatocellular carcinomas in greater than or equal to 89% of the mice examined. Therefore the presence of mutagenic impurities is not responsible for the carcinogenicity of commercial HC Blue No. 1. Discrepancies between the results of mutagenicity and carcinogenicity tests on hair dyes and other chemicals are discussed, and the value of short-term mutagenicity tests for assessing chemical safety is questioned.