Parallel optical trap assisted nanopatterning on rough surfaces.

There exist many optical lithography techniques for generating nanostructures on hard, flat surfaces over large areas. However, few techniques are able to create such patterns on soft materials or surfaces with pre-existing structure. To address this need, we demonstrate the use of parallel optical trap assisted nanopatterning (OTAN) to provide an efficient and robust direct-write method of producing nanoscale features without the need for focal plane adjustment. Parallel patterning on model surfaces of polyimide with vertical steps greater than 1.5 µm shows a feature size uncertainty better than 4% across the step and lateral positional accuracy of 25 nm. A Brownian motion model is used to describe the positional accuracy enabling one to predict how variation in system parameters will affect the nanopatterning results. These combined results suggest that OTAN is a viable technique for massively parallel direct-write nanolithography on non-traditional surfaces.

[Dilated coronary sinus. A preoperative transesophageal echocardiographic diagnosis]. / Koronarsinusdilatation.Eine präoperative transösophageale echokardiographische Diagnose.

A 36-year old woman was presented to our hospital with congenital ventricular septal defect and one-vessel coronary artery disease (75% proximal left main coronary artery) for CABG and repair of the VSD. After induction, a transesophageal echocardiographic (TEE) baseline examination was performed, showing a severely dilated coronary sinus (CS) measuring approximately 3 cm (abnormal >1 cm). We suggested a persistent left superior vena cava (PLSVC) draining into the CS. PLSVC is a common venous congenital anomaly, with a reported incidence of 0.5% in general population and in 3-5 % of patients with congenital heart defect. Injection of echo-contrast solution in a left arm vein, visualizing microbubbles passing through the PLSVC into the CS confirmed our suspicion. The diagnosis of a PLSVC and dilated CS is a contraindication for retrograde cardioplegia because of the loss of cardioplegia into the PLSVC resulting in a inadequate myocardial protection. It may be difficult to pass a pulmonary artery catheter (PAC) through a left internal or left subclavian vein and it may be associated with arrhythmias. A chest radiograph shows the anomalous course of the PAC along the left heart.

[Perspectives in applying guidelines]. / Perspektiven im Umgang mit Leitlinien.

Definition, purpose and future fate of guidelines are presented. Special stress is placed on the fact that guidelines represent a tool for rationalization by which economical capacities are activated and rationing is prevented.

Characteristics of repeat trauma patients, San Diego County.

Data on 22,312 admissions to the San Diego County Trauma System were used to identify 185 trauma patients admitted repeatedly to trauma units. These patients were compared with the entire group of nonrepeating trauma patients admitted during the 80-month period of the study. In comparison with nonrepeaters, the repeaters were younger, were more often men, were more often Black, and were much more frequently victims of assault. Forty-eight percent of the repeaters were injured by the same general mechanism on both admissions.

[Results of immediate and delayed bypass operation in PTCA emergencies]. / Ergebnisse der sofortigen und der verzögerten Bypass-Operation beim PTCA-Notfall.

UNLABELLED: The therapeutic strategy for irreversible coronary occlusion as a complication of PTCA is influenced by the rate of myocardial infarctions and mortality after emergency bypass surgery. If immediate bypass operation cannot prevent myocardial infarction, medication will be the treatment of choice. Since the duration of ischemia is of critical importance for the preservation of myocardium, we analyzed our results with respect to the time interval from the onset of ischemia to surgery. From 12/84 to 12/93 there were 49 emergency operations for 4,478 PTCAs. In 38 patients acute closure occurred in the cath lab; because of very strict standby arrangements these patients could be brought to the operating rooms without delay (group A). In 11 patients acute closure occurred during the following 24 hours in the intermediate care unit (group B); attempts of catheter recanalisation and/or preparation for surgery accounted for an additional time delay until surgery of 79 minutes. RESULTS: In the 38 patients of group A there were only one small transmural (CKmax 533/U/l) and four non-Q wave (CK-max 322 U/l) myocardial infarctions. Of the 11 patients in group B only two did not suffer any loss of myocardium. In seven cases there were transmural (CKmax 1,296 U/l) and in two cases non-Q wave (CKmax 721 U/l) myocardial infarctions. Two patients of group B died on the second and third postoperative day. Thus the results of emergency bypass operations were excellent if surgery could be performed immediately after failure of catheter interventions (all survived, no transmural M.I. in 97%).(ABSTRACT TRUNCATED AT 250 WORDS)

A new sternal retraction device for the dissection of the internal mammary artery.

For the dissection of the internal mammary artery (IMA), we use a new sternal retraction technique. The retractor is an angled stainless steel device with a slotted face and two sternal arresting hooks. The method is simple and the device acts as a unit with a standard sternal spreader. The time period between mounting and the exposure of the IMA is only a few seconds. The entire procedure takes place in the sterile operative field. By utilizing this method, we dissected nearly 300 IMAs without any complications or serious sternal injuries.

Converting enzyme inhibition and blood pressure reactivity to psychological stressors.

There is considerable interest in blood pressure reactivity to psychological stressors. Because the sympathetic nervous system and the renin-angiotensin system are so responsive to stressors and are themselves the targets of many antihypertensive medications, many investigators have wondered if such medications decrease the blood pressure response to stressful stimuli. We studied 25 normotensive and 21 hypertensive men in a double-blind crossover study during which they received either placebo for 4 days or captopril (25 mg b.i.d.) for 4 days while they were hospitalized in a clinical research center. Patients were studied at resting baseline, while performing a mathematics task, and while reading out loud a disturbing newspaper article. Although captopril lowered the resting blood pressure levels, it had no effect on the amplitude of reactivity to stressors.

[Acute pulmonary embolism--are vena cava interruption procedures and extracorporeal circulation always necessary?]. / Die akute Lungenarterienembolie--sind Cavasperroperationen und extrakorporale Zirkulation immer notwendig?

Between 1983 und 1991, emergency pulmonary embolectomy with the aid of extracorporeal circulation was performed in 13 patients. Ten patients were in class IV according to Greenfield, seven came into the operating theater with external cardiac massage. The 30-day mortality was 46%. In the same period, 15 venous interruption procedures were performed (three Adams de Weese Clip, ten Greenfield-Filter, and two femoral vein ligations). Eight times the venous interruption procedure was done prophylactically. The acute pulmonary embolism of class III and IV according to Greenfield is an indication for lytic therapy. We operate only if there is a contraindication to lytic therapy or if there is deterioration of the clinical state.

[Immediate bypass operation prevents heart infarct in PTCA emergencies]. / Die sofortige Bypass-Operation verhindert den Herzinfarkt beim PTCA-Notfall.

UNLABELLED: Between December 1984 and June 30, 1989, we performed PTCAs on 1438 patients. The procedures were performed with strict cardiosurgical standby. In 24 patients (22 X LAD, 2 X RCA), abrupt coronary occlusion necessitated immediate bypass surgery. In 19 cases, abrupt coronary closure occurred during PTCA in the cath lab; in five patients, during the following 24 h on the intermediate care ward. No patient died. Immediate bypass surgery prevented myocardial infarction (MI) in 79.2% of the cases. None of the 19 patients with abrupt coronary closure in the cath lab had a Q-wave myocardial infarction postoperatively. One of these 19 patients had an R-wave reduction (non-Q-MI) and one patient had a new terminally negative T-wave in the postoperative ECG. Two of the five patients with evidence of acute coronary occlusion on the intermediate care ward had small Q-wave MIs and one had a non-Q-wave MI postoperatively. Time of ischemia (defined als time interval between the end of PTCA and the beginning of extracorporal circulation) was 65 +/- 28 min in the former group and 122 +/- 30 min in the latter. CONCLUSION: Because immediate bypass surgery prevents Q-wave MI after abrupt closure during PTCA, strict temporal and spatial cooperation with the cardiac surgeon is mandatory.

[A drowning accident of long duration with deep hypothermia and rewarming with extracorporeal circulation. A report of 2 patients]. / Lang dauernder Ertrinkungsunfall mit tiefer Hypothermie und Aufwärmung mittels extrakorporaler Zirkulation. Bericht über 2 Patienten.

Two nearly drowned, 2 9/12 and 3 6/12 years old boys with profound hypothermia were admitted to our pediatric intensive care unit with all signs of clinical death. Both patients could be rewarmed and oxygenated by extracorporeal circulation. One of them died 36 hours after the accident with severe brain edema. The second one survived without any defect. Rewarming of cold-water nearly-drowned patients by extra-corporeal circulation seems to be a very effective way of treatment.

[Accidental drowning with extreme hypothermia--rewarming with extracorporeal circulation]. / Unfall durch Ertrinken mit extremer Unterkühlung--Wiedererwärmung mittels extracorporaler Zirkulation.

A 3 1/2 year old boy had fallen into a fishpond. After about one hour the boy was brought to our hospital. He was cyanotic and bloated, the rectal temperature was 18.4 degrees C. There was no heart beat, the pupils were wide without reaction to light. Via a sternotomy the heart lung machine was connected and core rewarming was achieved. After 7 days of artificial respiration the boy could be extubated, after 16 days the boy left our hospital without neurological consequences.

[Coronary spasm immediately following coronary revascularization]. / Koronarspasmus unmittelbar nach Koronarrevaskularisation.

Of 2,600 coronary operations performed from August 1983, to December 1988, two ischemic reactions of the inferior wall immediately after operation were observed. In both patients the right coronary artery was either dissected or revascularized intraoperatively. Under the diagnosis of postoperative spasm both patients had reangiography three hours after surgery. Right coronary artery spasm was demonstrated in both patients. After intracoronary injection of calcium channelblockers the spasm resolved completely. Patient 1 demonstrated a small inferior infarction during control angiography, patient 2 remained free of a myocardial infarction. The possible causes of coronary spasm during or after surgery are discussed. The diagnosis and an approach to therapy are outlined.

Use of the left internal thoracic artery to correct a left main coronary atresia.

Dyspnea with a slightly enlarged heart was noticed in a five year old girl at a checkup. The cardiological investigation revealed an enlarged left ventricle with slight mitral regurgitation. The right coronary artery was enlarged and filled the entire left arterial system via collaterals. The left main coronary artery could not be detected. In addition, outflow of contrast medium into the large vessels was absent. With the diagnosis of left main coronary atresia, the left internal thoracic artery was implanted on to the proximal left anterior descendent in October 1985. In the control angiogram, the anastomosis conditions were normal, the left ventricle had decreased in size and contracted almost normally. The collaterals from the right could no longer be demonstrated. The child (now six years old) has full exercise tolerance today. In the ultrasonogram, the ventricle shows normal contraction behavior. Up to know, four cases with congenital main coronary atresia have been reported in the literature.

[Use of the mammary artery in coronary revascularization]. / Verwendung der Arteria mammaria zur Coronarrevascularisation.

From August 1983 through December 1985 1088 patients underwent coronary surgery. 406 (37%) received a single or bilateral internal mammary artery (IMA) graft with single or sequential anastomoses. The youngest patient was 6 years old, the oldest 75, with a mean age of 55.7 years. A total of 672 IMA anastomoses was constructed. In addition 348 patients received 610 saphenous vein grafts. 83% of the IMA were anastomosed to the LAD and its branches, 12% to the circumflex and 5% to the right coronary artery. 4 patients (0.98%) died postoperatively, 402 survived and are free of angina. In our experience the IMA can be used routinely with low operative risk and good results.

A new technique for measuring oxygen saturations of hemoglobin and myoglobin and its application in open heart surgery.

Light reflected from the human heart surface was used to determine mixed hemoglobin and myoglobin oxygen saturations (O2SAT) in the cardiac tissue. The measurements were performed in 8 patients with coronary heart disease including stenosis of left anterior descending coronary artery (LAD) who underwent aorto-coronary bypass surgery. At the end of the operation the O2SAT was measured in the supply area of the LAD either with patent or occluded coronary bypass. In 13 experiments occlusion of the bypass resulted in a decrease of O2SAT from 74 +/- 16% to 61 +/- 24% (p less than 0.02). A new technique is introduced and its limitations are discussed. Preliminary results of application in coronary bypass surgery demonstrate an increase in tissue oxygenation following myocardial revascularization.

[Ventricular septal defect as a complication of myocardial infarct]. / Der Ventrikelseptumdefekt als Komplikation des Myokardinfarkts.

Between 1978 and 1982 emergency closure of postinfarction ventricular septal defect was performed in 4 patients (51--74 years) on the 3rd-7th day after acute myocardial infarction. All patients had a large left-to-right shunt and were in intractable acute heart failure; all of them survived the operation (3 patients had additional aortocoronary bypass grafts), and follow-up (0.5--4.5 years) was uncomplicated. The favorable clinical and functional results of surgical therapy indicate that postinfarction ventricular septal defects should be operated on even in patients over 70 years of age.

Thermographic evaluation of myocardial temperature during infusion of cold cardioplegia.

Delay in myocardial cooling during an infusion of cold cardioplegic solution may occur in patients with coronary artery disease. Forty patients with significant stenosis of the left anterior descending coronary artery (LAD) were divided into 3 groups according to the extent of the LAD stenosis. Group A consisted of 12 patients with 70% stenosis. Group B included 23 patients with 90% stenosis, and in group C there were 5 patients with LAD occlusion. Myocardial temperature was measured with a thermocamera during infusion of 2000 ml 8 to 10 degrees C cold Bretschneider's cardioplegic solution and compared to 10 other patients without coronary artery disease undergoing mitral valve replacement (group D). In group A the myocardium cooled to 15 degrees C after 4 1/2 minutes and to 12 degrees C after 10 minutes. In group B the myocardial temperature was 15 degrees C after 5 minutes and 12 degrees C after 10 minutes. In group C the temperature reached 18 degrees C after 5 minutes and 14 degrees C after 10 minutes. In group D the myocardial temperature was 12 degrees C after 3 minutes and 10 degrees C after 7 minutes. This study shows far better myocardial cooling rates in patients with unobstructed coronary arteries.

[Whole body oxygen uptake in coronary artery bypass surgery (author's transl)]. / Uberwachung der Gesamtsauerstoffaufnahme bei koronarchirurgischen Eingriffen.

In 10 patients who underwent aorto-coronary bypass operations haemodynamic parameters and whole body oxygen uptake were monitored, beginning after induction of anaesthesia, during extracorporeal circulation and the postoperative period up to 5 h. In the intensive care unit a new device for the continuous measurement of whole body oxygen uptake from expired gases was used. For anaesthesia constant doses of fentanyl (10 micrograms/kg/h) and nitrous oxide were given. These were supplemented by low concentrations of halothane and nitroglycerine if hypertension occurred. Before extracorporeal circulation hypertensive states were observed in 8 cases and were effectively controlled without compromising tissue oxygenation. During extracorporeal circulation oxygen consumption was reduced more than could be explained only by the effects of hypothermia, indicating a limited shock state. Within the first postoperative hour the total peripheral resistance increased more than during the whole operation, impairing cardiac function at low levels of oxygen uptake. Thereafter a rise in metabolism was seen, partially induced by shivering which led to a marked (235% of control) increase in whole body oxygen uptake. This was accompanied by a reduction of the total peripheral resistance and an improvement of cardiac function. No acidosis was observed. Artificial ventilation is mandatory until metabolic demands have normalized. Noninvasive continuous monitoring of whole body oxygen uptake was useful for the assessment of cardiovascular function, increased postoperative metabolic demands, early detection of hypovolaemia and weaning from artificial ventilation.