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Biomedical subjects

F B Cerra

Publications and source records attributed to F B Cerra.

At least 217 records · Page 12Linked to original sources
PubMed1975

Hemorrhagic infarction: A reperfusion injury following prolonged myocardial ischemic anoxia.

Sixteen canine myocardial pedicle preparations were divided into four groups. Group I received 60 minutes of reversible ischemic anoxia, Group II 90 minutes, Group III 120 minutes, and Group IV 180 minutes. Transmural ischemic infarction was present in Group I. With longer periods of anoxia, capillary disruption occurred, first in the subendocardium (90 minutes) and then transmurally (180 minutes). Reperfusion after ischemic, anoxic time periods of 90 minutes or greater produced hemorrhagic necrosis, the extent of which was directly proportional to the duration of the preceding ischemic, anoxic period. One hundred and twenty patients with aortic valve replacement surgery then were analyzed retrospectively. Of the 25 deaths, seven were due to immediate postinfarction, five from subendocardial hemorrhagic necrosis. The common factor in the patients with hemorrhagic infarction was a markedly reduced coronary flow (45 to 55 ml. per minute) for more than 70 minutes during the interval of cardiopulmonary bypass. Although other factors may be involved, it is hypothesized that the main cause is a degree of localized ischemia of sufficient duration to induce capillary disruption and subsequent postbypass hemorrhagic necrosis when normal coronary artery perfusion is resumed.

Animals↗
PubMedDate not supplied

Immunoprotection of xenocytes in a hollow fiber bioartificial liver.

A new, hollow fiber bioartificial liver (BAL) was tested in an anhepatic rabbit model to assess the hollow fiber membrane as an immunologic barrier. The extracorporeal BAL contained rat hepatocytes (xenocytes) entrapped in collagen gel inside the lumen of hollow fibers with 100 kd nominal molecular weight cut-off. Blood from the anhepatic rabbit flowed in the extracapillary compartment. After 4 h of BAL hemoperfusion, the hepatocyte gels were tested for evidence of rabbit immunoglobulin and complement. Samples of the gels were stained with fluorescein isothiocyanate (FITC)-labeled antibodies directed against rabbit IgM, rabbit IgG (Fc and F[ab]2), and rabbit complement (C3) and studied by immunofluorescence microscopy. Enzyme-linked immunosorbent assay and Western blotting were used, respectively, to quantify and identify proteins inside the BAL and in the rabbit blood. These studies suggest that very little rabbit IgG (primarily fragments of IgG) and no IgM or C3 crossed the hollow fibers during hemoperfusion. Rat albumin steadily accumulated in the rabbit blood during hemoperfusion, which indicated membrane permeability to molecules of that size and stable hepatocyte function by the BAL. The authors conclude that hollow fibers with 100 kd nominal molecular weight cut-off provide immunoprotection for xenocytes in an extracorporeal BAL.

Animals↗
PubMedDate not supplied

Inaccuracy of nitrogen balance determinations in thermal injury with calculated total urinary nitrogen.

Many burn centers use nitrogen balance studies to estimate the adequacy of nutritional support. Nitrogen loss includes the sum of urinary urea nitrogen, nonurea urinary nitrogen, and losses from skin, wound, and stool. Urinary urea nitrogen is often used to calculate total urinary nitrogen by multiplying the urinary urea nitrogen by a factor of 1.25 to account for nonurea urinary nitrogen. This formula is appropriate when applied to a nonstressed individual who has fasted overnight but is not appropriate for patients who have undergone surgery or experienced trauma. We have undertaken this study to assess the predictability of this formula in patients with thermal injuries. Twenty-seven patients with major thermal injuries had random 24-hour urine collections, which were analyzed for both urinary urea nitrogen and total urinary nitrogen. In these patients with burns we found that urinary urea nitrogen represented approximately 65% of the directly measured total urinary nitrogen rather than 80% as assumed by the formula. This increase in the nonurea nitrogen loss is greater than that found after surgery or trauma. Individual measurements may underestimate losses by 20% to 60%. Directly measured total urinary nitrogen should replace calculated total urinary nitrogen as the index of urine nitrogen losses for nitrogen balance studies in patients with burns.

Burns↗
PubMedDate not supplied

Amino acid abnormalities in infants with extrahepatic biliary atresia and cirrhosis.

We measured fasting plasma amino acids in 26 children aged 6 months to 5 years with extrahepatic biliary atresia and cirrhosis and compared them with fasting values in 95 normal control children aged 4 months to 12 years. We found that the cirrhotic children had elevations of total free plasma amino acids implying reduced hepatic metabolism of amino acids and that the molar ratio of the branched chain amino acids (isoleucine, leucine, and valine) to the aromatic amino acids (phenylalanine and tyrosine) was significantly depressed. Methionine was also markedly elevated, and taurine concentrations were significantly decreased. Manipulation of the amino acid distribution in dietary protein to normalize plasma amino acids prior to orthotopic hepatic transplantation may be helpful in improving amino acid utilization.

Amino Acids↗
PubMedDate not supplied

Review of support systems used in the management of fulminant hepatic failure.

Fulminant hepatic failure has an exceedingly high mortality. Liver transplantation is the treatment option of choice. Unfortunately, one-third of patients with fulminant hepatic failure die awaiting a donor liver. For over 35 years attempts to remove or dilute putative toxins in the blood have been unsuccessful in improving survival rates. The use of biocompatible interfaces with blood or plasma and current hepatocyte culture techniques have led to the development of new support systems. This generation of bioartificial livers will hopefully provide the necessary hepatic functions and prevent many of the complications associated with fulminant hepatic failure. This paper will review the support systems tried and currently under investigation, with an emphasis on bioartificial livers.

Cells, Cultured↗
PubMedDate not supplied

Home parenteral nutrition with full-time home care nurses.

A group of patients exists who cannot manage home parenteral nutrition (HPN) due to debilitating conditions and/or lack of family resources. They are limited to either nursing home placement or extended hospitalization unless home nursing care is provided. A 58-year-old single female with malabsorption secondary to scleroderma was sent home on cyclic HPN under the supervision of full-time home care nurses. A comprehensive patient-centered nurse training program was designed to teach nursing personnel from a private nursing service the theory and practice of HPN. Each nurse must achieve at least 80% in the theory posttest and demonstrate the competent performance of central venous catheter care, mixing of parenteral nutrition solutions, use of infusion pump, and application of the heparin lock. The results of the pre- and posttests have shown that the home care nurses have been able to learn the theory necessary for implementing HPN. The mean pretest value was 46% while the mean posttest value was 90% (n = 12, p = 0.01). The patient has been doing very well at home for 5 months in this psychologically, medically, and financially effective program covered by third party payers. To the best of our knowledge, this program has never before been accomplished.

Education, Nursing↗
PubMedDate not supplied

Does modified amino acid total parenteral nutrition alter immune-response in high level surgical stress.

A randomized prospective double-blinded study was conducted in patients in moderate to high level surgical stress to ascertain the effect of high dose branched-chain (BcAA) hyperalimentation on skin test reactivity and lymphocyte count. Isocaloric, isonitrogenous balanced total parenteral nutrition solutions were administered to two treatment groups. The study group received the high dose (45% BcAA) solution while the control group received a standard amino acid solution (24.2% BcAA). All patients received 1 to 1.5 g/kg/day of amino acids and 30 nonprotein cal/kg/day, with 30% of them as fat. Immune function was assessed by absolute lymphocyte count and delayed cutaneous hypersensitivity on days 0 and 7 of therapy. Absolute lymphocyte count showed a marked improvement in patients receiving high dose aBcAA (p less than 0.03). All patients were anergic at baseline; a much greater percentage of skin test reactivity was observed in the BcAA group on day 7 (p less than 0.03). They were also in positive nitrogen balance. The data suggest that improved nitrogen retention and immune-competence is possible with branched-chain-enriched hyperalimentation in high level surgical stress.

Adult↗