Subclavian artery laceration and acute hemothorax on attempted internal jugular vein cannulation.
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Biomedical subjects
Publications and source records attributed to A Montoya.
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High yields of human hepatocytes (up to 23 X 10(6) viable cells/g) were obtained from small surgical liver biopsies (1 to 3 g) by a two-step collagenase microperfusion method. Cell viability was about 95%, attachment efficiency of hepatocytes seeded on fibronectin-coated plates was 80% within 1 h after plating, and cells survived for about 2 wk in serum-free Ham's F12 containing 0.2% bovine serum albumin, 10(-8) M insulin, and 10(-8) M dexamethasone. To evaluate the metabolism of human hepatocytes in serum-free conditions, we measured their most characteristic biochemical functions and compared them to those reported for human liver. After 24 h in culture, glycogen content was 1250 +/- 177 nmol glucose/mg cell protein and remained stable for several days. Gluconeogenesis from lactate in hormone-free media was (3.50 +/- 0.17 nmol glucose.mg-1.min-1) similar to that reported for human liver. Insulin at 10(-8) M activated glycolysis (X1.40) and glycogenesis (X1.34), and glucagon at 10(-9) M stimulated gluconeogenesis (X1.35) and glycogenolysis (X2.18). Human hepatocytes synthesized albumin, transferrin, fibrinogen, alpha 1-antitrypsin, alpha 1-antichymotrypsin, alpha 1-acid glycoprotein, haptoglobin, alpha 2-macroglobulin, and plasma fibronectin and excreted them to the culture medium. Maximum protein synthesis was stimulated by 10(-9) M dexamethasone. Basal urea synthesis oscillated between 2.5 and 3.5 nmol.mg-1 cell protein.min-1, about 5 times the value estimated for human liver. Cytochrome P-450 decreased in culture but it was still 20% of freshly isolated hepatocytes by Day 5 in culture. In addition, ethoxycumarin-O-deethylase and aryl hydrocarbon hydroxylase could be induced in vitro by treatment with methyl cholanthrene. Glutathione levels were similar to those reported for human liver (35 nmol.mg-1). The results of our work show that adult human hepatocytes obtained from small surgical biopsies and cultured in chemically defined conditions express their most important metabolic functions to an extent that is similar to that reported for adult human liver.
Cardiovascular collapse due to pulmonary hyperinflation was noted in a patient with chronic obstructive pulmonary disease following median sternotomy for cardiac surgery. Treatment included bronchodilator therapy to reduce airway obstruction, limitation of minute ventilation, and increasing time available for exhalation. High inspiratory flow rates and expiratory retard may be beneficial.
The proliferation of transplantation programs has not been paralleled by a similar increase in the availability of organ donors. Between 1984 and 1987, 104 orthotopic heart transplantations were performed at Loyola University Medical Center. During the same period, 25 patients died while awaiting a donor organ. To reduce the mortality, we began using the total artificial heart (TAH) and a ventricular assist device (VAD) as a bridge to transplantation in 1988. Of 29 patients who underwent transplantation, 15 patients required a TAH and three patients required a VAD as a bridge. The underlying heart conditions were ischemic cardiomyopathy (11 patients), dilated cardiomyopathy (5 patients), giant cell myocarditis (1 patient), and allograft failure (1 patient). The average duration of mechanical support was 10 days (range, 1 to 35 days). Of the 17 patients who successfully underwent transplantation, 1 patient died at 17 days because of acute rejection of the transplanted heart, and another patient died at 14 days because of a cerebral vascular event. Fifteen patients (83%) were long-term survivors. Nine patients required reoperation for bleeding. While the mechanical device was in place, the activated clotting time was maintained between 170 and 200 seconds with heparin. Dipyridamole was given. We conclude that the TAH and VAD are excellent mechanical bridges to transplantation.
Supplementation of Ham's F12 culture medium with essential amino acids (EAA) up to the rat plasma levels increased the rates of synthesis of albumin and transferrin by cultured rat hepatocytes by 1.3 and 1.7, respectively. Fifty percent of this increase could be attributed to three of the EAA: the branched-chain amino acids (BCAA: Leu Ile and Val). Non-branched-chain essential amino acids (non-BC-EAA) stimulated only 25% of the increase produced by the whole EAA mixture. When each EAA was tested individually, none of them caused an appreciable increase in albumin and transferrin in culture medium. When the concentrations of all EAA were raised to rat postprandial portal levels, albumin and transferrin synthesis rates reached a maximum, increasing by 3.2 and 3.5, respectively. Supplementation with BCAA at postprandial portal concentrations increased albumin and transferrin synthesis rates by 2.2 and 2.0, respectively, and had no noteworthy effect on the synthesis of cellular proteins. Non-BC-EAA at their postprandial portal concentrations increased albumin and transferrin synthesis rates by 1.7 and 1.9, respectively. Supplementation with alanine to reach a nitrogen content equal to that of the modified EAA-enriched medium had no stimulatory effect. Our results show that EAA have a specific effect on the synthesis of plasma proteins by cultured hepatocytes, and that BCAA at physiologic concentrations account for the major part of this stimulatory effect. Consequently, EAA and particularly BCAA concentration should be elevated in serum-free nutrient media to sustain maximum plasma protein synthesis.
A left ventricular aneurysm developed in 3 patients sustaining blunt chest injury. Evidence of an acute myocardial infarction on the electrocardiogram and enzyme analysis prompted cardiac catheterization, which revealed total occlusion of the left anterior descending coronary artery in 2 of the 3 patients. Ventricular aneurysmectomy was performed in each patient. A review of the literature revealed 32 previously reported patients with left ventricular aneurysm caused by blunt trauma. Clinical features, catheterization or autopsy findings, and outcome are examined.
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Twenty-two open-heart operations have been performed on 21 patients receiving chronic renal dialysis. These cases include 16 aortocoronary bypasses and six valve replacements. The average time on dialysis prior to surgery was 26 months; 18 of 21 patients were in NYHA grade 3 or 4. Twenty-seven postoperative complications occurred, with six requiring further surgery and 21 treated nonsurgically. Two perioperative deaths occurred, both due to sepsis. Long-term follow-up was achieved on all hospital survivors. Ten patients remain alive with a mean follow-up of 21 months. At a mean of 16.5 months after surgery, nine deaths occurred, with only two due to known cardiac problems. In summary, indicated cardiac surgery can be performed on chronic renal dialysis patients with a reasonable morbidity and mortality; however, the long-term survival of our patients has not been assured by a successful cardiac operation.
Cardiac transplantation is now an accepted therapeutic procedure in the management of patients suffering from end-stage congestive heart failure. The advances in myocardial preservation, long-distance procurement, immunosuppression, improvement in the treatment of infectious diseases, and utilization of endomyocardial biopsy in the diagnosis of rejection have made its application widespread and resulted in improved survival.
Iatrogenic aortic injury occurring during either coronary bypass grafting or valve replacement is a well-recognized complication of cardiac surgery. We retrospectively reviewed our experience and found 11 cases occurring in a case load of 8,945 hearts (incidence of 0.12%). All 11 cases were repaired, with 10 patients surviving. The type of repair used usually was determined by when the diagnosis was made. When an intraoperative diagnosis was made, a local repair was done in four of six cases. If a postoperative diagnosis was made, then all five patients needed the ascending aorta replaced. With early diagnosis and rapid repair, good surgical results can be achieved.
1. A protocol is proposed for screening for hepatotoxicity of xenobiotics in vitro in which hepatocytes exposed to the compounds are evaluated for both cytotoxic and metabolic effects. Four established hepatotoxins have been studied. 2. alpha-Amanitin at 1.5 pg/mg cell protein inhibited RNA synthesis by 93% and reduced albumin synthesis to 56% of the control after 13 h treatment. 3. D-Galactosamine at 40 microM inhibited glycogen synthesis by 31%, glucuronidation of p-nitrophenol by 13% and albumin synthesis by 10%, and produced an increase in cytosolic enzyme leakage. 4. Thioacetamide decreased ureogenesis after 24 h of treatment at 230 microM (31% inhibition) and after 48 h at 2.3 microM (25% inhibition). 5. Ultrastructural alterations of hepatocytes were found after 48 h exposure to 1 mM acetaminophen and were preceded by extensive leakage of the enzymes GOT and LDH. Membrane damage was observed after 24 h exposure to 0.1 mM acetaminophen.
Optimal conditions for long-term storage of peroxidase-labelled immunoglobulins for use in enzyme immunoassays have been investigated with particular emphasis on the preservation of the immunological and enzyme activity. Immunoglobulin G preparations from different animal species were purified according to conventional methods and labelled with horseradish peroxidase. Conjugates were stored at different temperatures either in liquid form with 50% glycerol, after lyophilization or as ammonium sulphate precipitates. In addition, the conjugates were also frozen and stored at -40 degrees C. The immunological and enzymatic activity of the conjugates was evaluated at regular intervals throughout storage. The best results were obtained with conjugates stored as ammonium sulphate precipitates at 4 degrees C. Under these conditions, the complexes retained after 2 years of storage 92 and 91% of their enzymatic and immunological activity respectively and gave excellent reproducibility in ELISA. The conjugates exhibited a very low degree of self-aggregation. The ammonium sulphate did not interfere in the ELISA. Storage at elevated temperatures resulted in a greater decrease in enzymatic than immunological activity but the results obtained with the ammonium sulphate precipitates were clearly superior to those obtained with alternative storage procedures. The estimated half life of the whole enzymatic-immunological activity of conjugates at 4 degrees C was 9 years. The stability of both activities at 25 degrees C was also reasonably good for short periods. Conjugates stored for 40 days at 37 degrees C lost 60% enzyme activity but retained unaltered their immunological activity and gave rise to high blanks in the ELISA, due to auto-aggregation.
In 1983 and 1984, coronary artery bypass grafting (CABG) was performed on 107 consecutive patients for postinfarction angina. In each instance, CABG was done within 30 days of infarction. Sixty-three patients (59%) required intravenous administration of nitroglycerin and/or the intraaortic balloon pump (IABP) for relief of angina. Oral medications relieved angina in the remaining 44 patients. Thirty-eight patients underwent CABG 7 days or less after the infarction (Group 1), 25 received it between 8 and 15 days later (Group 2), and 44 had CABG between 16 and 30 days later (Group 3). There were 9 in-hospital deaths: 4 in Group 1, 2 in Group 2, and 3 in Group 3. Thirteen patients needed the IABP for hemodynamic stability as well as relief of angina. Even when the patient was stable hemodynamically, death was more likely to occur among these 13 patients if CABG was conducted within 7 days of infarction. Follow-up was 94% complete at 29.4 months. Eighty-six percent of patients were asymptomatic or in New York Heart Association Functional Class I, and 6% were in Class II. There were 2 late deaths. CABG for angina can be accomplished within 30 days of an acute infarction with good results. The exception to this rule is the patient in whom shock develops after a myocardial infarction and who, despite stabilization, receives CABG within 7 days of the infarction.
A consecutive group of 100 patients in the eighth decade of life who had aortic valve replacement (AVR) from 1975 through 1986 were retrospectively studied. Eighty-five of them were in New York Heart Association (NYHA) Functional Class III or IV. Isolated AVR was performed in 44 patients and AVR with concomitant procedures, in 56. Perioperative mortality (30 days) was 3%, and perioperative morbidity included 83 complications in 60 patients. Long-term follow-up was available on 93 patients, 71 of whom were alive and 22 of whom were dead. Sixty-eight of the 71 long-term survivors are now in NYHA Class I or II. The low rate of perioperative mortality and the improved quality of life after AVR support the performance of this procedure in this older population.
The Loyola Open-Heart Registry is a fully operational database that contains detailed data on approximately 9,000 patients who have undergone coronary bypass or cardiac valve replacement from January 1970 to December 1984. We analyzed the registry data using multivariate discriminant analysis to identify and quantitate those factors that might predict operative mortality (OM) for patients undergoing coronary artery bypass grafts at Loyola University Medical Center: Operative mortality was defined as death within 30 days following surgery. A total of 50 clinical and angiographic variables were analyzed for possible univariate association with operative mortality. Twenty-two variables were found to have significant univariate association with OM, and these 22 variables were subjected to multivariate discriminant analysis. For patients undergoing isolated, elective coronary artery bypass, the factors found to be predictive of OM are age (greater than 70) (F = 11.57), severe (more than six stenoses) coronary artery disease (F = 5.81), diffuse disease (F = 5.54), positive family history (F = 5.17), and number of coronary arteries bypassed (F = 4.78).
The DNA sequences of the promoter and 5' upstream regions of six Agrobacterium tumefaciens Ti-plasmid encoded virulence (vir) genes were determined. The transcription initiation sites were mapped by the S1 nuclease protection assay. In the -10 region, the vir promoters share a consensus sequence that is homologous to a DNA sequence found in the same region of E. coli promoters. In contrast, the -35 region sequences are variable. Several vir genes contain two common hexanucleotide sequences, 5'CGAGTA3' and 5'GCAATT3'. Translation initiation codons for all vir genes, except virG, are preceded by sequences homologous to the ribosome binding site sequences found in E. coli.
Qualitative distribution of coronary flow using thallium-201 perfusion scans immediately postintubation was studied in 22 patients scheduled for elective coronary artery bypass surgery. Ten patients received a thiopental (4 mg/kg) and halothane induction. Twelve patients received a fentanyl (100 micrograms/kg) induction. Baseline thallium-201 perfusion scans were performed 24 h prior to surgery. These scans were compared with the scans performed postintubation. A thallium-positive scan was accepted as evidence of relative hypoperfusion. Baseline hemodynamic and ECG data were obtained prior to induction of anesthesia. These data were compared with the data obtained postintubation. Ten patients developed postintubation thallium-perfusion scan defects (thallium-positive scan), even though there was no statistical difference between their baseline hemodynamics and hemodynamics at the time of intubation. There was no difference in the incidence of thallium-positive scans between those patients anesthetized by fentanyl and those patients anesthetized with thiopental-halothane. The authors conclude that relative hypoperfusion, and possibly ischemia, occurred in 45% of patients studied, despite stable hemodynamics, and that the incidence of these events was the same with two different anesthetic techniques.
Subspeciation of penicillin susceptible alpha-hemolytic streptococci is not routinely performed. However, Streptococcus MG-intermedius is an extremely virulent organism in this strep subgroup and is associated with abscess formation. Our patient, who had endocarditis due to this organism, remained chronically ill despite appropriate antibiotic therapy, and had a perforated aneurysm of the sinus of Valsalva with a myocardial abscess that required extensive surgical debridement. Persistent fever in patients with S MG-intermedius endocarditis should warrant further work-up for metastatic or myocardial abscess formation.