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Biomedical subjects

A Clerico

Publications and source records attributed to A Clerico.

At least 19 recordsLinked to original sources
PubMed1992

Effects of the administration of thyroid hormone on the plasma levels of atrial natriuretic peptides and on atrial myoendocrine cells in the rat: an immunochemical, ultrastructural, and stereological study.

The effects of an altered thyroidal status on the levels of immunoreactive (ir-) atrial natriuretic peptide (ANP) in serum and in the right and left atria, as well as on the subcellular structures of atrial myoendocrine cells were explored in groups of male Sprague Dawley rats given the vehicle or triiodothyronine in the toxicological dose-range (50 micrograms/100 g bw/day) for 0,5, 1,2,4,7 or 14 days. Plasma levels of ir-ANP were 30% higher in T3-treated rats compared with controls at 0,5 and 1 day after hormone administration and then decreased to levels 30-40% lower than controls at days 2 and 4 to rise again above control values on day 7 and 14. Atrial ir-ANP levels decreased at first both in the right and in the left atria with different latencies (1 and 2 days, respectively) and rose back towards control levels by day 4. Changes in the numerical density of specific granules followed a parallel temporal pattern. An increased in the individual volume of the granules followed was also observed. Investigation into the circulatory effects of T3 administration showed that the heart rate was increased by hour 12 after hormone administration (simultaneously with the early rise in plasma ir-ANP levels) and that blood pressure was increased by day 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Role of endothelin-1 in carrageenin-induced inflammation.

Many vasal factors are produced during an experimental model of inflammation such as rat-paw oedema induced by carrageenin. We investigated whether among the other well-known mediators of inflammation, i.e. serotonin, PAF, eicosanoids and kinins, the peptide endothelin-1 is produced by this kind of inflammatory process caused by carrageenin. Our results indicated that plasma endothelin, and the tissue concentration of endothelin in the oedematous paw, is increased as compared to the control. Consequently, endothelin should also be considered as an important factor in inflammatory processes.

Animals↗
PubMed1992

Endogenous digitalis-like factors in human milk.

We measured the concentration of endogenous digitalis-like factors (EDLFs) in milk or colostrum of women during nursing on different days after delivery. EDLF concentrations were assayed by a solid-phase RIA involving antidigoxin antibodies and by a radioreceptor assay (RRA) involving human placenta Na+/K(+)-ATPase. The mean (SD) EDLF concentrations as measured by RIA were 35.6 (19.4) ng of digoxin equivalents per liter in milk samples (n = 37) and 61.3 (12.5) ng/L in colostrum samples (n = 5); the mean EDLF concentration as measured by RRA in milk samples (n = 11) was 573 (717) ng/L (range 0-2098). EDLF concentration in milk is greater than circulating concentrations in healthy adults but is comparable with serum concentration in the third trimester of pregnancy. In milk and serum samples (n = 8) collected at the same time, heating and (or) extracting with Sep-Pak C18 cartridges before the RIA produced significantly different EDLF values from those in untreated serum (P less than 0.001) and milk (P = 0.035). EDLF in milk appeared to be not bound or weakly bound to milk protein, as indicated by the fact that boiling did not increase the digoxin-like immunoreactivity.

Blood Proteins↗
PubMedDate not supplied

External quality assurance of the carcinoembryonic antigen (CEA) assay: main findings in six years' experience.

In 1984 we initiated a national external quality assessment (EQA) program (supported by the Italian National Research Council, CNR) for the CEA assay; at present, about 200 Italian laboratories are participating in the program. The laboratories assayed the quality control (QC) samples according to their routine procedures and returned the results together with the name of the method/kit they used. The collected results were computer-processed and reports were sent back to the participants. A significant reduction of the CVt (mean between-laboratory agreement) of the CEA assay was observed throughout the EQA survey (from 35% in 1985 to 20-25% in the last cycles). In order to better clarify the differences in variability observed in the first QC cycles against the last ones, we used the ANOVA technique to evaluate the components of variability. The improvement in between-laboratory agreement was mainly due to the reduction of the between-kit component (from 30.5% to 15.2%), rather than to the smaller decrease observed for the within-kit variability (from 18.4% to 14.0%). The results reported for QC samples from different materials showed differences in the between-lab variability and substantial changes of the kit biases, thus suggesting a different specificity of the antibodies used in the various method/kits against different families of CEA molecules. Considerable uncertainty was also encountered in the clinical classification of low pathological samples, which seems mainly due to the variability in cut-off values used by the laboratories for the clinical assessment of the same analytical results. Our data indicate a progressive increase in the reliability of CEA determination during our study and confirm that EQA has improved the reliability of analysis carried out by the participating laboratories, thus stimulating the kit manufacturers to provide more reliable products.

Antibody Specificity↗
PubMedDate not supplied

Endogenous digitalis-like factors (EDLF) in obese individuals: preliminary results.

We measured by RIA the serum and urinary digoxin-like immunoreactivity (EDLF) in 8 subjects with severe obesity and in 10 healthy, non-obese individuals (as a control group), to evidentiate whether circulating and urinary levels of EDLF are increased in obesity. For each individual, we measured the mean EDLF on two sera collected consecutively on two successive mornings, between 8-9 a.m. and the daily urinary EDLF excretion. Every subject collected his/her 24 hour urine in 5 different timed fractions. For each urine fraction, we measured the excretion of EDLF, electrolytes (Na and K), and creatinine. In obese people, the mean serum digoxin-like immunoreactivity (no. 8, 27.3 +/- 8.7 ng/L de) was significantly higher (unpaired t test, p = 0.0002) than in the controls (no. 10, 12.0 +/- 7.3 ng/L de), whereas control and obese subjects had superimposable 24 hour EDLF urinary excretion. Urinary excretion of EDLF significantly changed throughout the day in normals, but not in obese people. In a multiple stepwise regression analysis, urinary K+ and Na+ significantly (p less than 0.01) contributed to the regression with urinary EDLF (EDLF = 76.9 + 0.67 K+ - 0.24 Na+; R = 0.601, no. 40) in obese individuals. The in vivo kinetic and metabolic pathways of EDLF are conceivably different in obese and normal subjects. A difference in the production rate, binding to plasma proteins and/or removal mechanisms could explain the findings of higher circulating levels with normal EDLF urinary excretion in obese persons.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Administration of GSH has no influence on the RBC membrane: oxidative damage to patients on hemodialysis.

In patients on hemodialysis, a metabolic block of the pentose phosphate shunt has been described that impairs the reduction of oxidized glutathione. The block results in lack of detoxication of the free hydroxyl radicals produced inside the red blood cell (RBC) and causes oxidative damage to the polyunsaturated fatty acids of the RBC membrane that results in formation of aldehydes. Malonyldialdehyde has been used as an index of the oxidative damage. In a study group of 13 patients on hemodialysis, the authors have tested whether administering reduced glutathione (GSH) at 1200 mg/day for 1 month could minimize oxidative damage to the RBC membranes and improve the hematologic parameters. Treatment with GSH was followed by significant improvement of hematocrit (P = 0.008), hemoglobin (P = 0.03), and RBC count (P = 0.0037); however, oxidative damage to the membranes was increased (P = 0.0004), which suggests that improvement of the hematologic parameters is not related to reduction of the oxidative damage. This is because oxidized glutathione, formed in the oxidative process, cannot be reduced back to GSH because of alteration of the pentose phosphate shunt.

Adult↗