Reduction of bacteria on pork carcasses associated with chilling method.

In addition to reducing the temperature of pork carcasses immediately after slaughter and before fabrication, blast chilling (snap chill) or conventional chilling can reduce bacterial populations associated with fresh meats. However, there is little information on bacteria survival resulting from the freeze or chill injury of meat products. In this study, porcine fecal slurries with and without pathogens (Listeria monocytogenes, Salmonella Typhimurium, and Campylobacter coli) were inoculated onto skin-on and skin-off pork surfaces and subjected to industry-specific blast or conventional chilling conditions. A thin agar layer method was used for the recovery of freeze- or chill-injured cells. Test results indicated that there were no statistically significant (P > 0.05) differences between blast and conventional chilling treatments with respect to the reduction of high and low inoculation levels of mesophilic aerobic bacteria, total coliforms, or Escherichia coli on either skin-on or skin-off surfaces. Chilling treatments did not differ significantly (P > 0.05) with respect to their ability to reduce low (3 log10 CFU/cm2) levels of L. monocytogenes and Salmonella Typhimurium. However, C. coli was reduced to undetectable levels, even after enrichment, on pork surfaces inoculated with low levels (3 log10 CFU/cm2) and subjected to blast chilling. Blast and conventional chilling treatments were more effective against all pathogenic bacterial populations when pork surfaces where inoculated at high levels (5 log10 CFU/cm2). The effects of chilling techniques on microbial populations could provide pork processors with an additional intervention for pork slaughter or information to modify and/or improve the chilling process. The information obtained from this study has the potential to serve as a means of producing a microbiologically safer product.

Comparison of recovery methods for freeze-injured Listeria monocytogenes, Salmonella Typhimurium, and Campylobacter coli in cell suspensions and associated with pork surfaces.

Cells injured as a result of freezing, heating, and acidification treatments may not grow during conventional microbiological procedures owing to the presence of selective agents, compounds, or dyes in the media, impairing the cell's ability to repair itself and grow. Injured cells can be recovered by combining selective and nonselective media into a single system. With such combinations, the diffusion of the selective compounds or dyes is controlled, allowing for the resuscitation of injured cells of interest while also inhibiting the growth of undesirable background microflora. In this study, Listeria monocytogenes, Salmonella Typhimurium, and Campylobacter coli suspended in buffer or associated with pork surfaces were subjected to a freeze-thaw cycle (-15 degrees C for 24 h, 4 degrees C for 4 h). Following treatments, freeze-injured cells were plated on appropriate media for the overlay (OV), thin agar layer (TAL), and Lutri plate (LP) recovery methods. The levels of L. monocytogenes and Salmonella Typhimurium recovered from cell suspensions and pork surfaces by the TAL, OV, and LP methods following freeze treatments were not statistically different (P > 0.05) from recovery levels associated with nonselective media. Conversely, levels of pathogens on selective media were significantly reduced compared with those for the other methods employed. The TAL method's recovery of C. coli was not significantly different from that achieved with the nonselective media. Overall, the results presented in this study demonstrate that the TAL method not only was easier to perform, but also allowed improved isolation of single colonies for further characterization. This study may provide researchers with better methods to determine the effectiveness of industry-employed chilling processes in reducing pathogenic bacteria associated with red meat surfaces.

A prospective randomized study of prophylactic OKT3 versus equine antithymocyte globulin after heart transplantation--increased morbidity with OKT3.

The aim of this study was to compare the efficacy and toxicity of prophylactic OKT3 and equine antithymocyte globulin when each drug was administered for a similar duration after heart transplantation. Forty-one patients (35 males, 6 females; mean age 46 +/- 2 years) were randomized to receive either OKT3 for 10 days (20 patients) commencing within 24-48 hr of transplantation or ATGAM for 8 days (21 patients) commencing on the day of transplantation. All patients were maintained on triple-agent immunosuppression with prednisolone, azathioprine, and cyclosporine. The two groups were well matched with respect to age, sex distribution, pretransplant cardiac diagnosis, and donor heart ischemic time. Mean duration of follow-up was 14 months (range 9-19 months): Actuarial survival at 12 months was 83 +/- 9 in the OKT3 group and 81 +/- 9 in the ATG group (P = NS). Mean time to first cardiac rejection was 33 +/- 8 days in the OKT3 group compared with 27 +/- 5 days in the ATG group (P = NS). Linearized rejection rate did not differ between the two groups at any time point up to 12 months posttransplant. Viral infections were significantly more common in the OKT3 group: 1.6 +/- 0.3 vs. 0.8 +/- 0.2 infections per patient (P < 0.05). Adverse reactions were more common in patients who received OKT3 prophylaxis and included three patients who developed acute respiratory distress, two of whom required assisted ventilation. In conclusion, prophylactic OKT3 and ATGAM result in comparable rejection rates and survival when administered for a similar duration after cardiac transplantation. OKT3, however, is associated with increased morbidity due to a higher incidence of adverse reactions and of viral infections. These findings suggest that ATGAM is the more suitable cytolytic agent for rejection prophylaxis after heart transplantation.

In vitro and in vivo evaluations of the antithrombogenic properties of the spiral vortex pump for temporary left heart bypass.

From conception to realization, the design emphasis of the spiral vortex diaphragm pump has been on promoting efficient blood flow patterns in order to lower thrombogenicity. The tracer method was used to visualize flow patterns in this pump and the results were compared with those of a conventional diaphragm pump with paraxial inlet and outlet ports. During diastole, the flow through a 45 degrees angled inlet is tangential to the axis of the pump forming a continuous vortex central along the pump axis. During systole, the vortex converges to pass through the apically located outlet. No areas of turbulence or stasis could be found, whilst in the conventional pump only random flow with recirculation could be demonstrated. Dye washout tests confirmed good washout at the periphery of this pump with no signs of stasis. However, large areas of stagnation with incomplete washout at diaphragm-housing (D-H) junctions were observed in the conventional pump. The comparative in vitro haemolysis test revealed that the level of free plasma haemoglobin was doubled in a commercially available pump compared with that of the spiral vortex pump. No thrombus formed within the pump housing after up to 50 hours of pumping in five acute animal experiments without postoperative anticoagulants. However, thrombi were found at the D-H junction of this pump due to imperfect fabrication techniques in one of the four sheep that survived 14-21 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Quality of life after heart transplantation in patients assigned to double- or triple-drug therapy.

The purpose of this study was to compare the quality of life after heart transplantation for patients treated with cyclosporine and azathioprine (double therapy) versus cyclosporine, azathioprine, and corticosteroids (triple therapy). This study was based on a randomized, prospective trial and was focused on patients from ages 17 to 57 years at 1-year after transplantation. Patients who received double therapy showed advantages on 10 of 11 measures of quality of life. Significant differences were found on measures of anxiety, sexual activity, physical well-being, and financial well-being. Patients who received double-drug therapy reported a lower frequency and less distress from the side effects of immunosuppression; a higher proportion of double-drug therapy patients had returned to full-time employment. In addition double-therapy patients were better able to control body mass. These features may explain why double-drug therapy patients reported a higher quality of life, and in the long term, could be important from a cost benefit analysis.

Right ventricular assist and prostacyclin infusion for allograft failure in the presence of high pulmonary vascular resistance.

The presence of high pulmonary vascular resistance (PVR) greater than 4 Wood units contributes to significant early posttransplant mortality, and remains a negative predictor of long-term survival. Current trends have been toward exclusion of the recipient with high PVR from the orthotopic procedure; elective heterotopic allograft placement is increasingly advocated. A patient with a PVR of 6 Wood units underwent orthotopic transplantation; the cardiac allograft from a 12 kg heavier donor was implanted after an ischemic time of 115 minutes. Early graft failure at 4 hours and subsequent cardiac arrest were followed by reinstitution of cardiopulmonary bypass, during which time optimal pharmacologic manipulation of the pulmonary vasculature was undertaken, including the use of high-dose prostacyclin. Refractory right heart failure indicated the requirement for right ventricular assistance (RVA) for patient survival. RVA with a Bio-Medicus pump was instituted in association with high-dose prostacyclin; an intraaortic balloon pump was inserted 12 hours later. Maintenance immunosuppression consisted of cyclosporine and azathioprine alone. RVA was maintained for 3 days; during this time the patient was totally pump dependent. Over an 18-hour period the patient was weaned and successfully withdrawn from RVA. Intraaortic balloon pump counterpulsation and the prostacyclin infusion were continued for 6 and 10 days, respectively. The clinical implications of the various interventions that resulted in the patient's survival are discussed.

Reproducibility of radionuclide left ventricular ejection fraction in patients awaiting cardiac transplantation.

Radionuclide-derived left ventricular ejection fraction (LVEF) is used to assess LV systolic function, to follow trends in the natural history of dilated cardiomyopathy, and to prioritize patients waiting for cardiac transplantation. Reproducibility of LVEF at extremely low levels has not, however, been reported. To assess the reproducibility of radionuclide LVEF at levels below 0.30 EF U, 17 highly symptomatic patients (NYHA Class III/IV) with dilated cardiomyopathy were studied on two occasions, 72 hours apart. Sequential scans were analyzed by two independent observers. Mean LVEF was 0.18 +/- 0.06 U (scan 1) and 0.17 +/- 0.06 U (scan 2). Interoperator reproducibility (SD) was 0.03 U (R = 0.76), interscan reproducibility (SD) was 0.03 U (R = 0.62), and overall reproducibility (SD) was 0.04 U (R = 0.50). The interobserver variation of 0.03 (actually 0.027) was just over one half that seen in normal volunteers (variation 0.05, n = 29) studied previously in this department. A change of greater than or equal to 0.08 U (2SD) in either direction is highly likely to represent a real change in LV function in those with LVEF less than or equal to 0.30 units, compared with the change of at least 0.10 units required in those with normal LV function. Lower interobserver and interscan reproducibility should be taken into account when interpreting sequential scans in patients with severe LV dysfunction.

Coronary artery surgery in Asian patients.

We studied retrospectively, 412 consecutive Asian patients undergoing coronary artery bypass grafting between January 1st, 1982 and June 30th, 1987. The mean age was 55 +/- 9 years at operation with a 70.5% male predominance. Patients of Chinese origin accounted for 60.9%, Indonesian for 26.4%, Indian 9.9% and Malaysian 2.6%. Chronic stable angina was the most consistent presenting symptom in 71% and 49% had at least one myocardial infarction in the past. Fifty percent were hypertensive and 26% diabetic. Left main stem coronary artery obstruction was evident in 21.6% and the coronary arteries diffusely diseased in 53%. An average of 3.8 +/- 0.4 grafts were performed per patient using reversed saphenous vein, and endarterectomies were necessitated in 27.1%. The small calibre of coronary arteries in Asian patients was reflected by 54% of grafted vessels having a luminal diameter of 1.5 mm. The early mortality rate and the peri-operative myocardial infarction rate was 1.2% in each instance. A mean follow-up of 30 months revealed a late mortality of 1.9% and 76% of patients were in NYHA Functional Class I. This study suggests that despite a high incidence of hypertension, diabetes and diffuse coronary artery disease Asian patients tolerate coronary artery bypass graft surgery well and obtain significant benefit from it.

Ascending aortic aneurysms associated with aortic valve regurgitation: St Vincent's Hospital's experience.

This report represents a retrospective analysis of the St Vincent's Hospital experience with combined replacement of the aortic valve and ascending aorta using a composite conduit and coronary artery reimplantation, in 44 patients, from 1 January 1981 to 30 June 1988. The mean age at operation was 48 years. Annuloaortic ectasia was the most common indication for operation in 24 patients (54%). There were three hospital deaths (7%). Forty-one patients were discharged from hospital and were followed up for a total of 1,106 patient months (mean = 26.5 months). There were three late deaths (7%). One death was due to a new dissection, one to a cerebrovascular accident and one to a drug overdose. So far, no patients have required reoperation. Of the 36 surviving patients available for follow-up, 28 are in New York Heart Association class I, seven patients are in class II and one in class III. Composite graft replacement reduces the risk of recurrent dissection and aneurysm formation and of periprosthetic leak. In the present experience, it is the method of choice in patients with degenerative lesions in the ascending aorta and aortic valve and particularly for annuloaortic ectasia. The exact surgical technique currently used has been the result of an evolution of different techniques.

Repeat myocardial revascularization surgery: an analysis of 169 cases.

One hundred and sixty-nine patients who underwent repeated myocardial revascularization surgery between 1982 and 1987 were studied. The mean interval between operations was 91.6 +/- 7.3 months. The indications for repeated surgery were graft failure in 37.2% of patients, progressive coronary atherosclerosis in 40.2% of patients and a combination of the two causes in 22.5% of patients. The mean number of grafts that were inserted was 2.74 +/- 0.61 grafts per patient at the second operation. Coronary endarterectomy as an adjunctive procedure was necessary in 17.1% of patients. The hospital mortality rate was 4.1%, with a 1.8% incidence of perioperative myocardial infarctions. Of the surviving patients, 96.3% were available for follow-up at a mean of 19 +/- 6.4 months. Of these patients, 68.5% were well and could be categorized into the New York Heart Association's functional class I. We conclude that both progression of coronary atherosclerosis in native vessels and obstruction of venous grafts cause recurrent angina and that repeated myocardial revascularization surgery is a feasible treatment option in these patients.

Open cardiac compression in the postoperative cardiac intensive care unit.

Thirty-nine patients required heroic resuscitative measures for sudden hypotension and cardiac arrest in the first 72 hours following cardiac surgery between January 1, 1984 and May 31, 1988. Emergency sternotomy with open cardiac compression was performed in twenty-four of these patients when external cardiac compression failed. These were categorised as Group A. Group B comprised the fifteen patients in whom resuscitation was entirely by means of external compression and adjuvant measures. Survival with NYHA Functional Class I and II status was noted in 75% of patients in Group A, compared with 20% in Group B (P less than 0.002). Emergency sternotomy with open cardiac compression is an effective way of resuscitating patients in the intensive care unit in the first few days following open heart surgery.

Cyclosporine and azathioprine immunosuppression without maintenance steroids: a prospective randomized trial.

Since the commencement of the St. Vincent's Transplant Programme, 41 patients have undergone orthotopic heart transplantation, with low-dose cyclosporine and prednisolone as maintenance immunosuppression. An actuarial survival rate of 75% at 1 year resulted. To reduce early rejection-related death, azathioprine was chosen as an augmenting immunosuppressive agent to be administered as a prospective randomized trial. Sixty patients were randomized; 29 received low-dose cyclosporine plus azathioprine plus prednisolone (group A). Thirty-one patients received cyclosporine and azathioprine alone (group B). Both groups received a 7-day course of antithymocyte gamma globulin. One group B patient who underwent retransplantation was not analyzed. Actuarial survival for group A was 92% and group B 93%. The overall incidence of rejection for group A was 1.1 per patient and group B, overall, 2.3 episodes per patient. Group B patients who had persistent rejections were converted to group A protocol. Nine group B patients (30%) required conversion to maintenance steroids (group C). The overall incidence of infection was 1.6 episodes per patient and 1.3 episodes per patient for group A and group B, respectively. Two early deaths in group B and one in group A were unrelated to immunosuppressive protocol. One group A patient died at day 280 of multiorgan failure. There were no rejection- or infection-related deaths in the series. Hypertension occurred with equal frequency in both study groups. The cyclosporine and azathioprine protocol produces actuarial survival and morbidity rates comparable to those of a matched triple-therapy group. Thirty percent of patients in this protocol, however, will require maintenance steroids.

Myocardial revascularisation in patients over seventy five years.

A consecutive series of 73 patients aged 75 years and above underwent coronary artery bypass graft surgery during a 6 year period. Pre-operatively unstable angina (61.6%) and congestive heart failure (10.9%) were significant presenting features. Triple vessel disease accounted for 61.6% of cases while 26% had left main coronary obstruction. The mean number of grafts per patient was 3.2 +/- 0.9. Combined procedures such as valve replacement were done in 16.2% of patients. The hospital mortality rate was 2.7% and there was not a single recordable case of peri-operative myocardial infarction. Significant complications post-operatively were atrial arrhythmias (43.8%), segmental pulmonary atelectasis (43.8%) and renal problems (15%). Of the sixty patients followed up at an average of 27.7 months, 58 were in NYHA Functional Class I. Good patient selection and careful monitoring leads to encouraging results with coronary artery bypass grafting in the elderly.

The Bentall procedure: a surgical option in Ehlers-Danlos syndrome.

The Ehlers-Danlos syndrome (EDs) is one of the most frequently encountered inherited disorders of connective tissue. The arterial-ecchymotic type IV is notorious for large vessel involvement associated with spontaneous catastrophic bleeding. Most of these patients who require cardiovascular surgical procedures have a poor prognosis. Our experience of two patients, with aneurysmal dilatation of the ascending aorta is presented. The first patient presented with an aortic dissection extending from the ascending aorta to the common iliac arteries. The second patient presented with asymptomatic but progressive aneurysmal dilatation of the aortic root. Both patients underwent the Bentall procedure using a 25 mm St. Jude composite valved conduit. Despite increased vascular friability, both of these patients tolerated the operative procedure without complication and are doing well on early follow-up. This experience suggests that the Bentall procedure may be used to decrease the risks of dissection and rupture of the ascending aorta in patients with Ehlers-Danlos syndrome.

Rehabilitation after heart transplantation: the Australian experience.

This study was designed to assess aspects of the quality of life and rehabilitation of heart transplant recipients who had transplantations at St. Vincent's Hospital, New South Wales, Australia, between February 1984 and March 1987. Factors determining return to full-time employment were delineated. A questionnaire was sent to 51 recipients. The response rate was 92%. The questionnaire measured employment status and satisfaction with family, social, marital, and sexual life. Financial status, exercise ability, and participation in daily activities were also assessed. Analysis showed that 53% of recipients had returned to either full-time or part-time employment, home duties, or full-time study. A further 28% were receiving a pension, 9% had chosen voluntary retirement, 6% were receiving unemployment benefits, and 4% were getting paid leave. Ability to exercise was improved for 77% of recipients and remained the same for another 14%. Financial status was unchanged for 45% and improved for 17%. Thirty-eight percent believed that they were worse off financially. Ratings of social, family, and marital life showed nearly complete or complete satisfaction in most cases. Satisfaction with sex life was less favorable. Comparison of the group who had returned to full-time employment with the group receiving a pension identified two variables of work status--length of time since transplantation and employment status before transplantation. There were also some differences between the two groups on quality of life ratings.

Psychological adjustment after cardiac transplantation.

Cardiac transplantation is viable therapeutic alternative for patients with end-stage heart disease, which offers a favourable short- and medium-term prognosis. The survival has improved from 20% of patients who survived at one year after transplantation in the 1960s to the present figures of 80%-85% of patients who are alive at one year, and 50%-70% of patients who are alive at five years, after transplantation. Therefore, it seems timely to focus attention on the psychological well-being of cardiac-transplant recipients. The medical literature is scant in regard to the psychiatric and the psychosocial impact of cardiac transplantation on recipients, and a systematic and prospective study of the psychosocial adaptation of recipients is lacking. Since 1984, we have been studying the emotional impact of cardiac transplantation on recipients and their families. This article presents the results for a group of recipients who have been assessed before transplantation, then followed-up at discharge from hospital and at four, eight and 12 months after transplantation. The study attempted to quantitate the recipients' anxiety, depression, body image and subjective quality of life by way of standardized self-assessment questionnaires. The recipients' satisfaction with relationships or their marital situation also was reported, as were their degree of rehabilitation at 12 months and their attitudes to various aspects of treatment after the transplantation. Before the transplantation, 53% of patients reported an increase in anxiety and 34% of patients recorded scores that indicated mild-to-moderate levels of depression. Thirty-seven per cent of patients showed a deterioration in the quality of their lives and 34% of patients had a negative body image. After the transplantation, significant improvements occurred in all parameters, which were maintained at follow-up.

Effects of low-dose cyclosporine A on toxicity and rejection in cardiac transplantation.

In conclusion, the low doses of CsA have significantly reduced nephrotoxicity and infectious complications. The patient survival has been acceptable, but there has been a disappointing incidence of rejection and graft loss in patients who have survived the first 3 months. We feel our experience would indicate that by targeting our CsA dosages to such low serum levels some of our patients receive suboptimal immunosuppression. Perhaps the best way of overcoming this is add a third maintenance immunosuppressive agent such as azathioprine to supplement immunosuppression. In fact, we have now changed our immunosuppressive protocol to include azathioprine while maintaining our CsA therapy at its current level.

The social and emotional impact of cardiac transplantation.

To date, there has been limited systematic research in the area of the emotional impact of cardiac transplantation. Since September 1984, a prospective study addressing this issue has been in progress at St. Vincent's Hospital, Sydney, Australia. Initial results suggest that anxiety, associated with declining health and adjustment to the prospect of transplantation, was the major issue at pre-transplantation. Follow-up at the time of their first hospital discharge after transplantation and again at 3 months showed improvement in all psychological measures and did not identify any psychological morbidity.

Effectiveness of minimal dosage cyclosporine in limiting toxicity and rejection.

The optimal dose of cyclosporine to achieve minimal toxicity and adequate control of rejection remains undetermined. We initiated our program with an immunosuppressive protocol designed to reduce drug toxicity, to reduce early severe rejection, and to provide adequate long-term immunosuppression. Because of increasing reports of nephrotoxicity associated with cyclosporine, we adopted a protocol of low-dose cyclosporine combined with steroids and equine antithymocyte globulin. The mean preoperative creatinine was 0.12 +/- 0.08 mmol/L and by 1 year after transplant was 0.13 +/- 0.04 mmol/L. Cyclosporine dose at 1 year was 5 +/- 2 mg/kg/day, and the serum cyclosporine level was 120 +/- 40 ng/ml. However, at 1 year 85% of the patients were hypertensive. The incidence of rejection in the first year after transplantation was 1.46 episodes per patient. Incidence of infection was 0.85 episodes per patient. The 3-month survival was 91%, and the actuarial 1-year survival was 76%. Seventy percent of our mortality was due to rejection, and four patients suffered significant graft damage in the period 3 months to 1 year, two requiring retransplantation. Although these low doses of cyclosporine have reduced nephrotoxicity and infectious complications, hypertension remains a significant problem. Moreover, although survival is acceptable, the incidence of graft rejection causing death or loss of function is of concern. This may indicate that cyclosporine at this dosage needs supplementation by a third immunosuppressive agent such as azathioprine.