Respiratory Profile in Patients After Liver Transplantation.

BACKGROUND: Patients in the immediate post-operative liver transplantation (LxT) period can develop respiratory and functional complications. In the postoperative months, these functions tend to improve. Nevertheless, there are few studies that evaluate precisely and specifically respiratory function in post-LxT long-term after surgery. The objective of the study was to describe the respiratory profile of patients 1 to 6 months after LxT, accompanied by LxT outpatients. METHODS: We included patients between 25 and 60 years old. We excluded patients with chronic renal or cerebrovascular impairment, severe heart disease, and history of lung surgery or liver re-transplantation. Evaluations were carried out on 3 occasions: 1 month, 3 months, and 6 months after LxT. The following evaluations were submitted: respiratory muscle strength (manuvacuometer), value flows and lung volumes (spirometer), and surface electromyography analyzing root mean square in the right (RMS-R) and left (RMS-L) diaphragm. We analyzed MELD (Model for End-Stage Liver Disease). After normality tests, we used the Friedman test (non-parametric values) and ANOVA (parametric values), P ≥ .5 with the use of SPSS 21.0. RESULTS: Patients (n = 15) had a mean age of 53.0 ± 7.5 years and 25.9 ± 4.6 MELD score. The statistically significant value obtained at the 3 occasions of evaluation was RMS-R, with a decline during periods of evaluation. This can be caused by removal of the liver, resulting in a denervation and reduction in compliance of this portion of the muscle. CONCLUSIONS: Patients between 1 and 6 months after transplantation have a specific respiratory profile, close to normal values. However, there are few studies on this subject, and we suggest that more research be done.

Studies on the specificity of CNF, a phospholipase A2 inhibitor isolated from the blood plasma of the South American rattlesnake (Crotalus durissus terrificus). I. Interaction with PLA2 from Lachesis muta muta snake venom.

A phospholipase A2 inhibitor has been previously purified and cloned from the blood plasma of the South American rattlesnake, Crotalus durissus terrificus. This inhibitor, named CNF for Crotalus neutralizing factor, interacts with crotoxin, the main neurotoxin from C. d. terrificus venom, abolishing its phospholipase A2 activity. Crotoxin is a heterodimer of an acidic subunit (CA) and a basic phospholipase A2 (CB). CNF acts by forming a stable non-toxic complex with CB, replacing CA in the toxic CA-CB of crotoxin. In the present investigation, we have shown that CNF has a broader specificity. It is able to inhibit the PLA2 activity of the whole venom from the bushmaster snake (Lachesis muta muta), a species evolutionary related to Crotalus. Inhibition experiments have been carried out with four PLA2 active components isolated from L. m. muta venom, one basic and three acidic ones. CNF inhibition is not restricted to the basic PLA2, but extended to the three acidic forms as well.

Thymosin alpha 1 is a native peptide in several tissues.

Failure to detect thymosin alpha 1 (T alpha 1) in tissue extracts prepared by procedures that prevent proteolytic activity has hitherto supported the suggestion that T alpha 1 is not a natural peptide, but the product of uncontrolled proteolysis of prothymosin alpha (ProT alpha), a polypeptide that includes T alpha 1 at its NH2 terminus. In this work, purification by isoelectric focusing of a product with the same isoelectric point as synthetic T alpha 1, and its further characterization, demonstrated that T alpha 1 is present as a native peptide in calf thymus and in several lymphoid and non-lymphoid rat tissues. T alpha 1 shows abnormal chromatographic behaviour which appears to be due to association with other components in tissue extracts. In all the tissues studied, T alpha 1 was present in higher concentration than ProT alpha (80-183 and 44-123 micrograms per gram of tissue, respectively). The ProT alpha/T alpha 1 ratio did not change when no measures were taken to prevent proteolysis during tissue homogenization.

Synthesis and apparent secretion of prothymosin alpha by different subpopulations of calf and rat thymocytes.

Prothymosin alpha (ProT alpha), a polypeptide containing the sequence of thymosin alpha 1 (T alpha 1) at its NH2-terminus, has been isolated from calf thymocytes in a concentration in the order of that found in the whole thymic gland. As deduced from the analysis of their tryptic peptides, calf ProT alpha differs from the rat polypeptide at least in an alanine residue replacing valine at position 92. Thymocytes cultured in a radioactive medium exhibit an important secretory activity, ProT alpha being one of the products synthesized and exported to the culture medium. Large and small thymocyte subpopulations from calf and rat differ in their capacity to synthesize ProT alpha. The polypeptide is produced in a major concentration by large thymocytes. However, all the calf and rat thymocyte subpopulations show a similar capacity to secrete ProT alpha, the amount of the newly synthesized polypeptide recovered from cell culture supernatants being 80-90% of that found in thymocyte extracts.