Purification and crystallization of the endoglycosidase PNGase F, a peptide:N-glycosidase from Flavobacterium meningosepticum.

The endoglycosidase peptide: N-glycosidase, secreted by the Gram-negative bacterium Flavobacterium meningosepticum (PNGase F), has been isolated, purified to homogeneity and crystallized from polyethylene glycol solutions using vapour diffusion and seeding techniques. The crystals are orthorhombic, space group P2(1)2(1)2, with unit cell dimensions a = 85.07 A, b = 85.14 A, c = 48.50 A, and are suitable for high resolution X-ray structure analysis.

Reconstruction of right ventricular outflow tract with a valved conduit in 75 cases of congenital heart disease.

Reconstruction of the right ventricular outflow tract with an aortic homograft conduit was performed in 75 patients from 1966 to 1974. The types of congenital heart disease were as follows: pulmonary atresia, 35 cases; severe tetralogy of Fallot, 22 cases; truncus arteriosus, 6 cases; transposition of the great arteries (TGA), 3 cases; single ventricle, 2 cases; and tricuspid atresia, 7 cases. Ninety per cent of the patients had one or more previous shunts, and this was a factor affecting the mortality rate. Other factors included age, pulmonary vascular resistance, surgical anatomy, and technical problems such as bleeding, prolonged bypass, coronary artery injury, and compression of the conduit by the sternum. Our present approach is to avoid shunts, define the anatomy precisely by angiography, and to attempt total correction when severe hypoxia or effort intolerance occurs or before increased pulmonary vascular resistance develops.

Preoperative and postoperative comparison of patients with univentricular and biventricular support with the thoratec ventricular assist device as a bridge to cardiac transplantation.

OBJECTIVES: The goal of this study was to determine whether there are differences in populations of patients with heart failure who require univentricular or biventricular circulatory support. METHODS: Two hundred thirteen patients who were in imminent risk of dying before donor heart procurement and who received Thoratec left (LVAD) and right (RVAD) ventricular assist devices at 35 hospitals were divided into three groups: group 1 (n = 74), patients adequately supported with isolated LVADs; group 2 (n = 37), patients initially receiving an LVAD and later requiring an RVAD; and group 3 (n = 102), patients who received biventricular assistance (BiVAD) from the beginning. RESULTS: There were no significant differences in any preoperative factors between the two BiVAD groups. In the combined BiVAD groups, pre-VAD cardiac index (BiVAD, 1.4 +/- 0.6 L/min per square meter, vs LVAD, 1.6 +/- 0.6 L/min per square meter) and pulmonary capillary wedge pressure (BiVAD, 27 +/- 8 mm Hg, vs LVAD, 30 +/- 8 mm Hg) were significantly lower than those in the LVAD group, and pre-VAD creatinine levels were significantly higher (BiVAD, 1.9 +/- 1.1 mg/dl, vs LVAD, 1.4 +/- 0.6 mg/dl). In addition, greater proportions of patients in the BiVAD groups required mechanical ventilation before VAD placement (60% vs 35%) and were implanted under emergency conditions than in the LVAD group (22% vs 9%). The survival of patients through heart transplantation was significantly better in patients who had an LVAD (74%) than in those who had BiVADs (58%). However, there were no significant differences in posttransplantation survival through hospital discharge (LVAD, 89%; BiVAD, 81%). CONCLUSION: Patients who received LVADs were less severely ill before the operation and consequently were more likely to survive after the operation. As the severity of illness increases, patients are more likely to require biventricular support.

Successful mechanical circulatory support for noncoronary shock.

Mechanically assisted recovery from shock and long-term survival of nontransplant patients with acute noncoronary myocardial decompensation have not been previously reported. We treated nine patients (aged 8 to 53 years) who were referred with acute nonischemic cardiogenic shock (pulmonary capillary wedge greater than 20, cardiac index less than 1.5 L/min/m2, mean blood pressure less than 60 mm Hg, ejection fraction less than 0.3%). Eight patients had viral prodromes, and one patient was peripartum. All patients' lungs were mechanically ventilated, and pharmacologic support failed in all patients. Two patients received steroids. All received mechanical circulatory support. Seven were initially supported with intraaortic balloon counterpulsation pumps. Two patients recovered with intraaortic balloon counterpulsation pumps alone (3 days and 4 days). Four patients received left ventricular assist devices (3, 7, 10, and 79 days), and two received biventricular support devices (10 days and 14 days). One patient was supported with extracorporeal femoral vein-to-femoral artery bypass for 6 days. Four patients required dialysis (4 days to 5 weeks). Seven patients underwent myocardial biopsies, of which three demonstrated acute myocarditis. All patients recovered ventricular function (ejection fraction greater than 0.55%), and all are New York Heart Association functional class I, 7 months to 4 1/2 years after support. Mechanical circulatory assist devices may be lifesaving for patients with acute nonischemic myocardial decompensation. Patients should be supported for at least 2 weeks before transplantation is considered.

Analysis of homograft valve failure in 311 patients followed up to 10 years.

Homograft aortic valve replacement was performed in 311 patients at the tnational Heart thospital, London, between 1964 and 1973. Valve failure has occurred in 61 patients (20%), 32 of whom survived reoperation. From 1963 through 1967, 156 valves were freeze-dried and account for 56 of the valve failures. From 1968 to 1973, 118 fresh or fresh-frozen valves resulted in only 5 failures. Six general types of failure have been identified: calcification (13), dehiscence (15), infective endocarditis (17), prolapse (6), cusp degeneration (5), and tear or perforation (5). Valve failure may be due to surgical technical error resulting in dehiscence or valve incompetence, or it may be related to degenerative changes in the homograft. The clinical results, supported by gross and histological examination and viability testing, enable us to conclude that fresh or fresh-frozen valves are superior to freeze-dried valves, having resulted in only 4% valve failure over the past five years.

Left main coronary artery stenosis: hemodynamic monitoring to reduce mortality.

A review of 20 consecutive patients with left main coronary artery stenosis operated on in 1976 indicated a general hemodynamic pattern characterized by systolic hypertension and an increase in heart rate that occurred early during the induction phase of anesthesia. From January through August, 1977, 28 patients with this stenotic condition were operated on with hemodynamic monitoring of left ventricular pressure and cardiac output by a Swan-Ganz catheter inserted before induction of anesthesia. Pharmacological interventions to optimize preload with volume, reduce afterload with nitroprusside or nitroglycerine, control heart rate with propranolol, and improve contractility with dopamine resulted in a decrease in mortality from 20% in Group 1 (1976) to 3.5% in Group 2 (1977). We conclude that control of systemic blood pressure, heart rate, and preload has notably reduced the mortality in this group of patients and that hemodynamic monitoring provides precise guidelines for therapeutic interventions.

Diagnosis of perioperative myocardial infarction after coronary artery bypass.

The diagnosis of perioperative myocardial infarction (POMI) in patients undergoing coronary artery bypass is uncertain because the criteria of infarction are unclear. Fifty patients who underwent coronary artery bypass were evaluated preoperatively and postoperatively with serial ECGs, creatine phosphokinase (CPK), isoenzyme determinations, and technetium pyrophosphate myocardial scans. Clinical evaluation correlated with exercise testing and postoperative angiography supported the diagnosis in questionable cases. Thirty-five patients (70%) had no evidence of POMI by any criteria, and 2 patients (4%) had unequivocal evidence of infarction by all criteria. Our studies indicate the complexities of diagnosing POMI. We believe that the serially recorded ECG is the most useful diagnostic technique. CPK isoenzyme determinations may be useful but are difficult to interpret in the operative setting. Preoperative cardiac scans are necessary so as to avoid a high incidence of false-positive scans postoperatively. In doubtful cases, postoperative coronary arteriography and left ventricular angiography may provide the most definitive information.

Care plans for marketing and sales opportunities.

Similarities exist between marketing/sales behaviors and the skills dietitians practice in the development and implementation of nutrition care plans. A parallel process can be followed throughout the nutrition care plan and the sales call. Market research is completed prior to the sales call with the client. The product or service and the desired outcome are identified. Sales strategies make up the interactive skills used to accomplish the marketing plan.

Task force: a management technique that produces quality decisions and employee commitment.

A task force is a technique that can be used by the dietitian-manager to develop solutions for specific, identified problems. Because employees are directly involved in the decision-making process, better solutions--ones that are also more acceptable to the work group--result. To implement a task force, management must plan the strategy: Select a facilitator, explain the concept and problem to the work group, select task force participants, and make meeting arrangements. The task force meetings should be structured to maximize efficiency and productivity. The plan of action is developed by the task force members; all decisions are based upon input from the work group. Successful implementation of the solutions is the responsibility of the task force. Applications for task forces in both the clinical and food management areas are numerous and result in both tangible and intangible benefits.

Antisense oligodeoxynucleotides to the kappa1 receptor enhance delta9-THC-induced antinociceptive tolerance.

Delta-9-tetrahydrocannabinol produces potent antinociceptive effects in mice and rats. Evidence exists for an interaction between the cannabinoids and the kappa receptor subtype, kappa1, in the production of antinociception. Data indicate that delta9-THC induces the release of endogenous dynorphins, the ligand(s) for the kappa receptor. It has been demonstrated that antisense oligodeoxynucleotides directed against the kappa1 receptor attenuate the antinociceptive effects of delta9-THC. The exact mechanism for the expression of cannabinoid tolerance is unknown. Bidirectional cross-tolerance between the kappa opioids and delta9-THC implies that a common mechanism may be responsible for tolerance expression. We tested the hypothesis that the kappa1 receptor is involved in tolerance to delta9-THC. Antisense to the kappa1 receptor has been shown to downregulate the kappa receptor. We observed a significant increase in the ED50 for delta9-THC in antisense-, but not mismatch-treated mice, indicating an increase in tolerance to delta9-THC. Such data indicate that a decrease in kappa receptor number may accompany tolerance to delta9-THC.

Non-pulsatile circulatory support in 90 cases.

Survival after cardiac arrest is reportably less than 10%; after cardiogenic shock it is less than 50%; and in failure to wean post-cardiotomy (even with centrifugal pumps in several large series) it is only 11-21%. The authors' experience with non-pulsatile circulatory support in 90 consecutive cases from 1986-91 has shown improved survival. The emergent cardiopulmonary bypass system (CPS) was used in 67 of the 90 patients, with 65 patients resuscitated, 34 (51%) weaned, and 19 (28%) transferred to other cardiovascular support therapies. Of the patients weaned or transferred, 34 (51%) survived > 24 hr, and 21 (31%) survived > 30 days. In the current series, 108 major cardiovascular procedures were done during or after CPS implementation. An in-house trained nursing team working with surgeons and perfusionists contributed to early implementation of the CPS and the subsequent improved survival. The BioMedicus centrifugal pump (VAD) was used predominantly for post-cardiotomy failure to wean in 16 patients and as a bridge to transplant in 7 patients. Fourteen patients (61%) were weaned or transplanted. Of these 14 patients, 11 (48%) survived > 30 days. Non-pulsatile circulatory support devices are relatively inexpensive and available to most hospitals. With careful patient selection and early implementation, one can expect survival of 37% of patients who would otherwise not survive.

Experimental design in health care.

Design of experiments (DOE) is a collection of statistically based methods for testing multiple process improvement ideas after a quality improvement team has made initial improvements to remove defects and stabilize the process. Although experimental design techniques are not new, their use in improving administrative processes has not been fully exploited. Anderson Area Medical Center, located in Anderson, South Carolina, used classical quality improvement methods and DOE to significantly decrease patient dissatisfaction with emergency room services from an average of 27 percent to 6 percent.

Comparing the efficacy of prophylactic metoclopramide, ondansetron, and placebo in cesarean section patients given epidural anesthesia.

STUDY OBJECTIVE: To compare the relative efficacy of prophylactic metoclopramide, ondansetron, and placebo in nonemergent cesarean section patients given epidural anesthesia intraoperatively and for the first 24-hour period after delivery. DESIGN: Randomized, double blind, placebo-controlled study. SETTING: Inpatient obstetric unit at a university hospital center. PATIENTS: 164 nonemergent cesarean section patients given epidural anesthesia. INTERVENTION: At time of umbilical cord clamp, patients received intravenously (IV) either 4 mg ondansetron (Group O) or 10 mg metoclopramide (Group M) or 10 mL normal saline (Group P). MEASUREMENTS AND MAIN RESULTS: Episodes and severity of nausea and vomiting, rescue antiemetic requirement, patient satisfaction, and side effects were recorded. The frequency of intraoperative nausea were 24%, 43%, and 57% for Group O, Group M, and Group P, respectively (p < 0.03). The frequency of nausea for the 24-hour study period were 26%, 51% and 71% for Groups O, M, and P respectively (p < 0.03). The frequency of intraoperative and postoperative vomiting were similar between Group O and Group M, but significantly higher in Group P (p < 0.05). Overall patient satisfaction was highest in Group O compared with Groups P and M (p < 0.05). Maximum analog sedation score was higher in Group M compared to Groups O and P (p < 0.05). CONCLUSIONS: In cesarean section patients given epidural anesthesia, prophylactic ondansetron, 4 mg IV, is more efficacious and has a higher patient satisfaction than that with metoclopramide, 10 mg IV, or placebo in preventing nausea and achieving complete responses during intraoperative period and the first 24-hour postdelivery period. However, there is no difference between ondansetron and metoclopramide in reducing frequency of vomiting. Prophylactic ondansetron 4 mg IV is more effective in preventing nausea than vomiting.