Appropriate dose of parenteral arginine enhances immunity of peripheral blood cells and splenocytes in rats with subacute peritonitis.

BACKGROUND: Arginine deficiency and chronic inflammation may cause immune dysfunction. The authors previously showed that a pharmacological dose of parenteral arginine facilitates ornithine rather than nitric oxide production in subacute peritonitis. Herein, they investigated the effects of different doses of parenteral arginine supplementation on immunocytic subpopulation distribution and function. MATERIALS: Male Wistar rats that underwent cecal punctures for induction of subacute peritonitis were infused with conventional parenteral nutrition solution (1.61% of total calories as arginine) or solutions supplemented with low-, medium-, or high-dose arginine (2.85%, 4.08%, and 6.54% of total calories, respectively) for 7 days. Distributions of T cells, B cells, and monocytes/macrophages and cytokine productions of peripheral blood lymphocytes (PBLs) and splenocytes were analyzed. RESULTS: There were no significant differences in circulating white blood cell numbers and serum tumor necrosis factor (TNF)-α and interferon (IFN)-γ concentrations among groups. Serum nitrate/nitrite (NOx) and interleukin (IL)-2 levels were significantly decreased by arginine in a dose-dependent manner. Animals supplemented with parenteral arginine had significantly decreased productions of concanavalin (Con) A- and lipopolysaccharide (LPS)-stimulated TNF-α in PBLs and splenocytes, spontaneous IL-6 and LPS-stimulated IFN-γ in PBLs, and LPS-stimulated IL-6 in splenocytes. In addition, low-dose arginine significantly increased production of spontaneous IFN-γ in PBLs and splenocytes. High-dose arginine significantly increased spontaneous TNF-α, and Con A stimulated IL-4 and IL-6 in PBLs. CONCLUSION: Parenteral arginine administration at approximately 4% of total calories may alter PBLs and splenocytic immunity, and >6% of total calories might not be of benefit in rats with subacute peritonitis.

Immune status of free-ranging green turtles with fibropapillomatosis from Hawaii.

Cell-mediated and humoral immune status of free-ranging green turtles (Chelonia mydas) in Hawaii (USA) with and without fibropapillornatosis (FP) were assessed. Tumored and non-tumored turtles from Kaneohe Bay (KB) on the island of Oahu and from FP-free areas on the west (Kona/Kohala) coast of the island of Hawaii were sampled from April 1998 through February 1999. Turtles on Oahu were grouped (0-3) for severity of tumors with 0 for absence of tumors, 1 for light, 2 for moderate, and 3 for most severe. Turtles were weighed, straight carapace length measured and the regression slope of weight to straight carapace length compared between groups (KB0, KB1, KB2, KB3, Kona). Blood was assayed for differential white blood cell count, hematocrit, in vitro peripheral blood mononuclear cell (PBMC) proliferation in the presence of concanavalin A (ConA) and phytohaemagglutinin (PHA), and protein electrophoresis. On Oahu, heterophil/lymphocyte ratio increased while eosinophil/monocyte ratio decreased with increasing tumors score. Peripheral blood mononuclear cell proliferation indices for ConA and PHA were significantly lower for turtles with tumor scores 2 and 3. Tumor score 3 turtles (KB3) had significantly lower hematocrit, total protein, alpha 1, alpha 2, and gamma globulins than the other four groups. No significant differences in immune status were seen between non-tumored (or KB1) turtles from Oahu and Hawaii. There was no significant difference between groups in regression slopes of body condition to carapace length. We conclude that turtles with severe FP are imunosuppressed. Furthermore, the lack of significant difference in immune status between non-tumored (and KB1) turtles from Oahu and Kona/Kohala indicates that immunosuppression may not be a prerequisite for development of FP.

[Activity of membrane-bound acetylcholinesterases in the presence of benzene alcohol and concanavalin A]. / Aktyvnost' membranosviazannoi atsetylkholyniesterazy v prysutstvyy benzylovoho spyrta i konkanavalyna A.

UV-sensitivity of membrane-bound acetylcholinesterases in the presence of agents, which selectively modify lipid phase and integral proteins of erythrocytic membranes (benzene alcohol and concanavalin A), has been studied. It has been determined, that UV-irradiation of human erythrocytic membranes within the range of wavelengths 240-390 and 300-400 nm leads to differently directed changes of enzymatic activity, which are caused by different number of membranous chromophores of UV-light and by their different nature. The scheme of process, causing the photomodification of membranous acetylcholinesterases, has been suggested. It takes into consideration a contribution of several structural components of membranes in these processes. Authors have made the conclusion about the important role of microenvironment in processes of acetylcholinesterases functioning and about the possibility of purposeful regulation of its UV-sensitivity by introduction of exogenous agents, which modify structural state of closest "neighbours" of enzyme.

Measurements of haptoglobin by the reaction with concanavalin A in sera of patients with ovarian tumours.

The concentration of haptoglobin in sera of healthy women and patients with non-malignant and malignant ovarian tumours was measured by two methods, i.e. complex formation with haemoglobin and complex formation with concanavalin A. High correlation (r = 0.74) between both the methods was found in the group of healthy women, but correlation coefficients were much lower in the group of non-malignant and malignant tumours (r = 0.42 and 0.37, respectively). Direct determinations of haptoglobin, and calculation of the ratio of haptoglobin bound to concanavalin A to haptoglobin bound to haemoglobin revealed statistically significant differences among the examined groups. Comparison of two methods of haptoglobin quantitation suggest that processes connected with ovarian disorders may alter the glycosylation of haptoglobin oligosaccharide chains.

Clinical relevance of alphafetoprotein microheterogeneity in alphafetoprotein-secreting tumors.

The importance of the oncofetal glycoprotein antigen alphafetoprotein (AFP) as a tumor marker is well documented. Structural heterogeneity of AFP molecules due to its associated carbohydrate moieties has also been demonstrated. In the present study, molecular variants of AFP, Concanavalin A reactive (R Con A) and Concanavalin A nonreactive (NR Con A) were quantified in five cases of hepatocellular carcinoma (HCC), three cases of hepatoblastoma, five gonadal and two extragonadal germ cell tumors, and two suspected liver secondaries by employing crossed immunoaffino electrophoresis (CIAE). AFP peaks were localized using anti-AFP antibodies conjugated to alkaline phosphatase. Characteristic patterns of AFP R Con A and NR Con A fractions were obtained in different AFP-secreting malignancies. Serum samples of HCC and hepatoblastoma were predominantly composed of R Con A AFP, while gonadal and extragonadal germ cell tumors showed significant reduction of R Con A AFP and elevation of NR Con A AFP. Analysis of AFP variants in sera from two patients of suspected liver metastasis with elevated AFP confirmed liver secondaries arising from germ cell tumor in one patient and HCC in the other patient. The present study highlights the importance of AFP microheterogeneity analysis not only as diagnostic aid for the differential diagnosis of AFP-secreting tumors, but also in providing better management and prognosis.

Biphasic reduction and concanavalin A binding properties of serum alpha-fetoprotein in preterm and term infants.

Reference values for postnatal serum alpha-fetoprotein (AFP) and concanavalin A (ConA) binding subfractions of AFP in preterm and term infants are presented. Preterm infants had 10-fold higher serum concentrations of AFP than did term infants at birth. The reduction of serum values of AFP was biphasic in both groups and differed significantly between the two groups. The first declining phase continued for approximately 4 months in preterm and for 2 months in term infants, and was related to the degree of prematurity. The AFP values reached adult levels by 12 months in preterm and by 9 months in term infants. The developmental pattern of the carbohydrate moiety of AFP was determined by ConA fractioning. The proportion of the ConA nonreactive subfraction of AFP in preterm and term infants at birth was 6% and 13%, respectively; it increased more rapidly in term than in preterm infants but reached 85% to 95% by the age of 6 months in both infant groups. Our results indicate that the postnatal maturation of AFP synthesis is dependent on gestational age. Malignant recurrences of neonatal sacrococcygeal teratomas were associated with an increase in serum concentration of AFP and a decrease in the proportion of the ConA nonreactive subfraction of AFP.

Binding of serum ferritin to concanavalin A in patients with malignancy.

The percentage non-glycosylated, tissue type ferritin was measured in the serum of 30 cancer patients and 11 normal subjects, as well as in 10 tumour cytosols. As expected, in normal subjects the larger part of serum ferritin corresponded to glycosylated ferritin, and in tumour cytosols the larger part corresponded to non-glycosylated ferritin (tissue ferritin). In all but one cancer patients a significant part of the protein did not bind to Con A, thus behaving as tissue ferritin. The findings obtained suggest release of tissue type, non-glycosylated, ferritin by damaged cells or through abnormal secretion. This relative increase of the non-glycosylated ferritin fraction appears to be very frequently present in cancer, although not specific for it. Assaying for Con A binding may prove to be valuable in the study of malignant disease, and therefore deserves further investigation.

Impairment of early ovarian growth in landlocked Atlantic salmon by an antibody to carbohydrate-rich gonadotropin.

The role of the carbohydrate-rich gonadotropin (Con AII GtH) in an early phase of ovarian growth in landlocked Atlantic salmon (Salmo salar) was investigated by treating in vivo with an antibody to chum salmon (Oncorhynchus keta) Con AII GtH (anti-Con AII). Anti-Con AII treatment significantly inhibited ovarian growth but did not consistently lower serum levels of vitellogenin. This suggests that Con AII GtH is necessary for early ovarian growth and, has one or more functions in early ovarian growth in addition to stimulation, via estrogen, of vitellogenin production.

[Availability of erythrocyte phosphatidylethanolamine for labelling by trinitrobenzenesulfonic acid at different stages of radiation sickness in rats]. / Dostupnost' fosfatidilétanolamina éritrotsitov dlia mecheniia trinitrobenzolsul'foksilotoi na raznykh étapakh luchevoi bolezni u krys.

It has been found that 1 h after rats' irradiation (dose 800 rad) the incorporation of the label 2, 4, 6-trinitrobenzenesulpho-acid into phosphatidylethanolamine of erythrocyte membranes increases and 3 h and 72 h after irradiation it decreases. Concanavalin and calcium ions modify the incorporation of the label into phosphatidylethanolamine.

Concanavalin A binding of pregnancy-specific beta-1-glycoprotein in normal pregnancy and trophoblastic disease.

The binding of pregnancy-specific beta-1-glycoprotein (SP1) to Concanavalin A (Con A) has been studied in serum samples from 34 pregnant women and 13 patients with trophoblastic diseases. In normal pregnancy and in hydatidiform moles, the fraction that did not bind to Con A accounted for 0.5--4.3% of the total SP1 concentration whereas, in 5 out of 6 patients with choriocarcinoma, the fraction was 4.8--30%. The secretion of Con A non-binding SP1 appears to be an inherent characteristic of some malignant trophoblast tissues and may result from its altered glycosylation.

Metabolism of concanavalin A-affinity molecular variants of alpha-fetoprotein in rats.

Serum half-lives of unfractionated rat alpha-fetoprotein (AFP), concanavalin A (Con A)-nonreactive AFP, and Con A-reactive AFP in normal 45- to 55-day-old male and female F344 rats were determined to be 19 hours. No significant differences were seen between the half-lives of unfractionated AFP and either of the two Con A-affinity molecular variants of AFP studied. No evidence of interconversion of the Con A-affinity AFP variants during 24 hours in the circulation was found. These results supported the conclusion that the proportions of Con A-affinity molecular variants of AFP in the sera of fetal, newborn, and hematoma-bearing rats result from differences in the relative synthesis rates of the two variants.