Cardiac output assessed by arterial thermodilution during exsanguination and fluid resuscitation: experimental validation against a reference technique.

BACKGROUND AND OBJECTIVE: The arterial thermodilution technique offers the ability to measure cardiac output using only central venous and arterial catheters. However, the technique has been reported to overestimate cardiac output because of a higher loss of cold indicator due to the increased distance between the sites of injection and measurement. In this study, the two techniques were compared with respect to conditions of low cardiac output in which a longer passage time may further increase loss of indicator. METHODS: Seventeen anaesthetized dogs were studied during hypovolaemic shock and fluid resuscitation. Cardiac output measurements were carried out simultaneously by arterial and pulmonary artery thermodilution techniques. RESULTS: One-hundred-and-two measurements were performed. The mean cardiac output was 2.28 +/- 1.4Lmin(-1) by the pulmonary arterial technique and 2.29 +/- 1.56Lmin(-1) by the arterial thermodilution technique. The correlation coefficient between the two measurements was 0.95, the precision -0.04 +/- 0.41 Lmin(-1) and the limits of agreement from -0.86 to 0.78Lmin(-1). The agreement was also consistent at low cardiac outputs. CONCLUSIONS: The arterial thermodilution technique may serve as a less invasive cardiac output monitor in conditions of severe bleeding and shock.

Evaluation of carcinoembryonic antigen levels in gastric juice, stomach mucosa and plasma in high-risk and gastric cancer patients.

The aim of this study is to compare the levels of carcinoembryonic antigen (CEA) in the gastric juice, stomach mucosa and plasma of gastrectomy patients at risk of developing cancer with those in normal controls and gastric cancer subjects. Blood samples, gastric juices and biopsy material were taken from 52 patients (8 normal, 10 gastric carcinomas, 24 gastroresected according to Billroth II and 10 according to Billroth I). No significant correlation was found between age, sex or smoking habits and CEA levels in plasma, gastric juice or stomach mucosa. A significant correlation between CEA levels in gastric secretion and those in tissue emerged from out data (n = 52; r = 0.67; p less than 0.01). A minor correlation was found between tissue and plasma CEA values (r = 0.34; p less than 0.05). The mean levels of CEA in plasma did not show significant differences between controls and neoplastic risk subjects. The average level of CEA in gastric secretions and in tissue were significantly lower in normal controls than in neoplastic and gastroresected patients; in this latter group, we have observed a correlation between the severity of the histological lesions and the levels of CEA in the biopsy specimens; no correlation was found with the type of operation (Billroth I or Billroth II). The level of CEA in gastric juices and in biopsy material, therefore, appears to be more useful than in plasma in recognizing cancer risk subjects.

The biological and clinical significance of tumor markers in tissue extracts.

A quantitative study of carcinoembryonic antigen (CEA) activity was made in plasma and in 25 colorectal tumors, 30 lung tumors, 20 breast tumors, and 20 fibrocystic dysplasias of the breast. The CEA content was detected by enzyme assays (EIA) in solid phase. In colorectal cancer the amount of CEA ranged from 40 to 800 ng/mg protein. In lung cancer, values ranged from 5 to 130 ng/mg protein. Differences in mean content of CEA between normal and cancer yielded the highest significant value of P less than 0.001. In 54 of 95 of cases, high concentrations of CEA in tissues were associated with high values in plasma. In fibrocystic dysplasia of the breast, the CEA concentration levels were lower than in cases of breast carcinoma. The CEA concentration values in fibrocystic dysplasia were associated with the epithelial proliferation and the degree of dysplasia. Therefore, the presence of elevated CEA tissues values may be indicative of patients with higher risk of malignant transformation.

Specific blastogenic response of peripheral blood lymphocytes from lung cancer patients to a fetal lung antigen.

A human lung tumor fetal-associated antigen (LTFA) has been purified from lung tumor tissue by a combination of salt precipitation and ion-exchange chromatography. The purification steps were monitored by double immunodiffusion with the use of a rabbit anti-LTFA-specific antiserum. The isolated protein was tested for its blastogenic properties toward peripheral blood lymphocytes (PBL) by [3H]thymidine incorporation. PBL obtained from 25 healthy individuals, 34 patients with tumors other than lung tumors, 13 patients with lung diseases other than lung tumors, and 51 lung tumor-bearing patients were tested. Only PBL with an in vitro positive response to phytohemagglutinin were employed. Whereas PBL of lung tumor patients showed a significant blastogenic response to the purified antigen in 14 of 22 patients tested (60%), PBL of other patients were completely unreactive (P less than 0.005). The present data suggested that a specific immune response toward an LTFA was present in patients with lung cancers.

Specific and aspecific immune responsiveness in lung cancer patients: cutaneous delayed hypersensitivity reactions to a lung cancer-associated antigen.

The ability of a lung cancer-associated antigen (LCAA) to provoke specific cutaneous delayed-hypersensitivity reactions has been studied on a group of 59 lung cancer patients. Biological activity of LCAA, monitored by skin testing, was demonstrated in 32% (17 of 53) of lung cancer patients, in 48.0% with limited disease, and in 17.2% with extensive disease. All the responders were in the group of normal reactors to standard recall antigens, if three antigens were used (PPDSK-SD, candida). No correlation was found between biological activity of LCAA and level of immunocompetence evaluated by lymphocyte-blastic transformation with PHA and count of rosette E-forming cells. These studies on the capacity to evoke specific DTH reactions in lung-cancer patients will be extended to the use of assays in vitro in the perspective of a more significant evaluation of immunocompetence levels.

Immunologic monitoring during combined radiochemoimmunotherapy in inoperable lung cancer.

49 patients with advanced lung cancer underwent a combined treatment including radiochemoimmunotherapy. Before and at the end of the combined treatment, the immune status of the patients has been evaluated by testing the immunoreactivity to PPD in vivo and the phytohemagglutinin lymphocyte response and the rosette-forming cells in vitro. While the in vitro tests were not significantly modified by immunostimulation, as regards the immunoreactivity to PPD, we observed a positive conversion at the end of the treatment in 11 out of 25 patients who showed a negative reaction before therapy. All the patients who converted from negative to positive showed also a good response to therapy with regression or no progression of the tumor. Survival curves confirmed the prognostic value of PPD reactivity.

Partial characterization of a fetal lung antigen associated with human bronchogenic carcinoma.

A human lung tumor-associated fetal antigen (LTFA) has been partially isolated and characterized. The antigen that differs in several immunochemical parameters from previously described lung cancer antigens was shared by fetal lung and liver tissue. The neoantigen migrated in immunoelectrophoresis as an alpha2-beta globulin, had an average molecular size of 7S, and was soluble in 50% saturated ammonium sulfate. Whereas LTFA was insensitive to both DNase and RNase treatment, its antigenicity was completely abolished by pronase. The biologic significance of this antigen and its possible clinical use were discussed.

Short-term results of combined radioimmunotherapy in inoperable lung cancer.

Fifty-three inoperable lung cancer patients were treated with radiotherapy combined with immunostimulation with BCG. A good response was obtained in 30 patients (56%); the results were not significantly different than those obtained with a control group of 50 lung cancer patients matched by age, sex and stage of the disease (24 out of 50 equals 46%). These short-term results were compared with the immunologic "status" of patients evaluated before treatment by the parameters monitoring in vivo and in vitro delayed type hypersensitivity. The good response to therapy was documented in a higher percentage of patients with positive skin tests to recall and standard antigens and with normal values of lymphocyte transformation with PHA and Rosette E-forming cells, in comparison with patients with low levels of immunocompetence. An impairment of the cell-mediated immune response was found after combined therapy, presumably due to radiotherapy. BCG was not able to restore the patient's immunocompetence, no effect on host's immune reactivity was demonstrated. As regards humoral immunity, the patients with low levels of IgG before treatment (12/14) showed a good response.

Quantitation of estradiol receptors employing a sensitive radioimmunoassay.

A method aimed at the identification and quantitation of estradiol receptors has been developed. The test is based on competitive binding reaction between solubilized cell receptors and anti-estradiol antibodies bound to acrylamide beads, for 3H-estradiol. The technique can be employed both for estradiol radioimmunoassay and quantitation of specific receptors in tissues and appears to be a sensitive, specific and reproducible method which can be applied to the evaluation of any hormone and its receptor.