Plasmatic fibronectin in malignancies

Plasmatic fibronectin has been studied in tumor patients on the basis of the role that unspecific opsonin may play in tumor growth and spreading. Alterations in fibronectin levels might be used as a biological marker and our purpose has been to evaluate the significance of this test in the biological diagnosis of cancer. When comparing the levels found in the control group (22.86 +/- 1.40 mg/dl) and in tumor patients (23.80 +/- 1.90 mg/dl), we observed no difference in the overall group. However, in relation to the localization of tumors, a significant increase was found in breast cancer (31.83 +/- 3.83 mg/dl) and a significant decrease in squamous cell carcinoma of the head and neck (9.56 +/- 1.68 mg/dl). These results suggest that plasmatic fibronectin could be useful as a biomarker in some types of tumors. Our conclusion was confirmed by analysis of ROC curves related to every one of the studied tumors.

Time lapse study of neurite growth in hypothalamic dissociated neurons in culture: sex differences and estrogen effects

Cultures of dissociated hypothalamic cells taken from rat fetuses of 19 days of gestation were studied using time-lapse recording and sequential microphotography from 1 to 5 days in vitro (DIV) and at 7 and 21 DIV. Cultures were seeded with cells taken from fetuses grouped by sex or sexually mixed; experimental cultures were raised in medium containing 17-beta-estradiol 100 nM (E2). Cells were plated on poly-D-lysine-coated coverslips at a culture density of approximately 4,000 cells/cm2. Immunocytochemistry of cell cultures was performed using a Tau monoclonal antibody (clone Tau-1 PC1C6) and a monoclonal antibody against MAP-2 (clone AP-20). Cells started to produce lamellipodia and neuritic processes approximately 4 hr after plating. Forty-eight hours later a few neurons had defined their morphological polarity by the differentiation of an axon-like process that grows faster than the others; at 5 DIV almost all neurons had defined their axons. At this time, monoclonal antibody against MAP-2 clearly stained soma and dendrites, but not axons. Tau immunoreactivity (lots CCA101 and CCA101N from Boeringher Mannheim) was differentially distributed, with a clear predominance in axon and soma. Results on the morphometric analysis of control and E2 treated neurons provide direct evidence for the existence of sex related differences in the neurite outgrowth response of hypothalamic neurons, since cultured neurons taken from female fetuses differentiated axons later and had fewer primary neurites and shorter dendrites than neurons taken from male fetuses or sexually mixed cultures. Also, it was demonstrated in living neurons that E2 effectively enhances outgrowth and elongation in axons. The frequency distribution curves of axonal length for control and E2 treated cultures was unimodal, suggesting that the effect of E2 was a uniform increase in the axonal length of all neurons. The structural differences between neurons from both sexes and the changes induced by E2 may contribute to explain the differences in brain function found between the sexes.

Methodological variables in the assessment of beta amyloid neurotoxicity

Cell culture systems for evaluating the biological effects of the beta-amyloid protein are potentially important tools in the study of the pathogenesis of Alzheimer's disease. In this report, methodological considerations in the assessment of beta-amyloid neurotoxicity are discussed. Chronic incubation of beta 1-40 in primary human cortical cultures results in progressive neuronal degeneration. The neurodegenerative process occurs in association with localized deposition of beta-amyloid on the neuronal soma ultimately resulting in the formation of compact beta-amyloid deposits. A beta 1-40 preparation from another laboratory was tested that did not form neuronal beta-amyloid deposits and was not neurotoxic. Thus, the conformational state of the beta 1-40 peptide leading to the formation of neuronal amyloid deposits is an important determinant of neurotoxicity. Variables in peptide preparation that influence this property may account for variation in neurotoxic potency.

[Beta-thromboglobulin levels and atherosclerosis. Its relationship with the presence of risk factors]

In order to evaluate whether plasma beta-thromboglobulin (as a marker of the degree of platelet function) in patients presenting clinically evident atherosclerosis is related to the presence or absence of different risk factors (smoking habit, arterial hypertension, hypercholesterolemia, diabetes, hypertriglyceridemia, obesity, hyperuricemia, alcoholism), 40 patients have been studied in whom mean beta-thromboglobulin levels was 54 +/- 25.56 ng/ml, which is very superior to levels considered normal. However, the presence of one or more risk factors did not lead to significant variations in b-thromboglobulin concentrations, and no differences were found either when each risk factor was considered separately. The positive correlation (r = 0.98; p less than 0.01) between beta-thromboglobulin and apo B levels is highlighted. The results suggest that platelet hyperfunction seems to be due to a greater extent to the atherosclerotic process rather than to the existence of a particular risk factor.

[Ceruloplasmin levels in patients with chronic obstructive bronchopneumopathy]

The seric levels of ceruloplasmin in a group of 20 patients suffering of chronic obstructive lung disease were studied. Levels in this group of patients (51.42 +/- 11.15 mg/dl) (p less than 0.005) were significantly higher than those of the control group (36.59 +/- 13.37 mg/dl). There was no correlation between ceruloplasmin levels and PaO2, PaCO2, SaO2, HCO3- measurements. Results show a possible oxidation reaction; owing to the fact that ceruloplasmin is a general oxidase which, combined with an antioxidant stimulus of patients with chronic respiratory insufficiency, can produce this reaction.

[Results of the functional tests using calcitonin in patients with chronic diffuse hepatopathy]

A group of ten patients suffering cirrhosis who were treated with 100 U/l of calcitonin was studied with the aim of knowing whether in patients with cirrhosis the calcitonin is able to provoke the usual characteristic biologic modifications on the basis of the knowledge of their hormonal high levels accompanied of oesteopenia. Regarding their baseline determinations, no statistically significant modifications have been observed in calcium, phosphorous, alkaline phosphatase or its thermostable and thermolabile fractions, magnesium, uric acid and creatinine plasma concentrations respectively. This absence of a biological response to calcitonin could be due either to a numeric or functional damage of the hormone receptors or a diminished biodisponibility, although there are facts suggesting a lesser hormone biopotenciality in these patients.

Rat blood and brain amino acid pattern in short term experimental diabetes

Some serum and brain amino acid variations occurring in animals with short term streptozotocin-diabetes (24 h) are studied in this work. Diabetic animals showed an increase in serum of the three branched-chain amino acids as well as an increase in free tryptophan, besides a decrease in total serum tryptophan and in the tryptophan/competitor amino acids ratio. In brain, the three branched-chain amino acids increased, but there were no variation in whole brain tryptophan. Nevertheless, by studying levels of tryptophan in different brain regions, an increase in medulla-pons was recorded. This circumstance could be explained by the increase in free serum tryptophan levels, in agreement with several authors who assign this reason for brain tryptophan.

Electrical properties and fluxes of Na+ and Cl- across lizard intestine

Electrical parameters and unidirectional Na+ and Cl- fluxes were determined in vitro across the duodenum, ileum and colon of lizard (Gallotia galloti). Electrical potential difference (PD) and short circuit current (Isc) were low in the three segments studied, whilst tissue conductance (Gt) was high. A net active transport of Na+ and Cl- was observed in the three segments. Net Na+ absorption was higher across duodenum and ileum than across the colon, while net Cl- absorption was similar in duodenum, ileum and colon. Ouabain virtually abolished Isc, PD and net Na+ and Cl- fluxes in all the segments. Amiloride abolished net Cl- flux in duodenum, ileum and colon, whereas net Na+ flux was abolished in colon but decreased in duodenum and ileum. PD and Isc were not affected by the presence of the diuretic.

Verapamil injections in the peripeduncular nucleus suppress multiunit evoked activity and sexual receptivity in female rats

Using a combination of injection cannula and recording electrode, the effect of 1 microliter of 3 mM verapamil upon the multiunit responses evoked in the peripeduncular nucleus (PPN) by electric stimuli applied to the pudendal nerves in urethane anesthetized proestrous female rats was studied in 9 experiments. It was observed that in 6 cases responses were suppressed after the injection and in 2 other cases there was a marked decrease, whereas no change was observed in 1 case. Similar injections of vehicle (saline) produced no change (7 rats) or small and short lasting depression of evoked activity (4 rats). Similar injections of verapamil applied to a region of the mesencephalic reticular formation caudal to the PPN, presumably containing fibers that carry evoked activity towards the PPN, had no effect on evoked multiunit activity in the PPN. Injection of 2% Xylocaine in the same site in the same animal eliminated the evoked responses. These experiments support our hypothesis that verapamil suppressed evoked responses in the PPN blocking Ca++-dependent release of neurotransmitter at local synapsis, without interfering with fiber conduction of neural activity. Based on this assumption we used identical injections to test the hypothesis that activation of neurons in the PPN is necessary for the performance of lordotic behavior in ovariectomized rats primed with estradiol benzoate. Guide cannulae aimed at the PPN were implanted in castrated females which were then primed with enough estradiol benzoate to induce sexual receptivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological changes in serum antiproteases as related to tumor progression

The two major antiproteases (alpha-1-antitrypsin and alpha-2-macroglobulin) were studied in the serum of cancer patients (273 and 103 subjects, respectively) and in a control group. In cancer patients, the values were stratified by clinical stage (local, loco-regional and metastatic disease). Serum alpha-1-antitrypsin was different in normal people (341 +/- 110.7 mg/dl) than in every cancer group (p less than 0.0005). The behavior of alpha-2-macroglobulin was similar, with significant differences (p less than 0.0005) between normal people (317.6 +/- 105.4 mg/dl) and the cancer groups. Serum alpha-1-antitrypsin was different in local, loco-regional and metastatic disease; however, alpha-2-macroglobulin did not show these differences. In metastatic disease, sensitivity was 96.66% for alpha-1-antitrypsin and 94.79% for alpha-2-macroglobulin.

The role of aldosterone in water and electrolyte transport across the colonic epithelium of the lizard, Gallotia galloti

1. The effects of D-aldosterone on the electrical properties and ionic transport have been analysed (in vitro) in the colonic epithelium of the lizard, Gallotia galloti. 2. The injection of 30 g of D-aldosterone induced a significant rise of plasma aldosterone concentration, sustained for 4 hr after administration. 3. Intraperitoneal injections of D-aldosterone caused a slight reduction of transmural potential difference (PD) and short-circuit current (Isc). 4. Net absorption of Na+ across the colon from aldosterone-treated lizards did not increase when compared to colon from normal lizards. Cl- absorption was increased in treated lizards. 5. Addition of mucosal barium to treated tissues brought about a sustained increase of PD and Isc. 6. The absorption of fluid in normal lizards was reversed to fluid secretion in treated lizards. 7. The effects of D-aldosterone on lizard colon are compared with those reported for the colon of mammals and birds.