PubMed Health⌕ Search

Biomedical subjects

V Russo

Publications and source records attributed to V Russo.

At least 127 records · Page 7Linked to original sources
PubMed1991

Determination of zeranol and beta-zearalanol in calf urine by immunoaffinity extraction and gas chromatography-mass spectrometry after repeated administration of zeranol.

A method for the determination of zeranol and its metabolite beta-zearalanol in bovine urine is described. It has been applied to samples from calves given multiple subcutaneous doses of zeranol. Samples were extracted with immunoaffinity columns containing antibodies raised against zeranol and were analysed by gas chromatography-mass spectrometry. The immunoaffinity columns were prepared by coupling immunoglobulin G fractions obtained from rabbit antisera with a Sepharose matrix. The immunizing agent was carboxybutylzeranol coupled to bovine serum albumin. Gas chromatography-mass spectrometry was performed in the negative-ion chemical ionization mode, after derivatization of the compounds to their pentafluorobenzyl ethers, and allowed detection of analytes with a sensitivity of 0.01 ppb in spiked urine. The derivatization method and the gas chromatographic determination were also applied to the similar compounds zearalanone, zearalenone and beta-zearalenol. A synthesis of dideuterated zeranol and beta-zearalanol by isotopic exchange is described. These deuterated analogues had an isotopic purity of more than 99% and were used for quantitation of zeranol and beta-zearalanol by isotope dilution mass spectrometry. The recoveries of zeranol and beta-zearalanol, using the immunoaffinity columns, were determined after extraction from spiked urine and were 84 and 64%, respectively. The urines of treated calves were collected for several days after treatments and were analysed after hydrolysis with beta-glucuronidase and arylsulphatase. The samples showed variable but generally decreasing concentrations of zeranol and beta-zearalanol. The levels of beta-zearalanol ranged from less than 0.01 to 98 ppb and were 1.2-3.2 times higher than those of zeranol.

Animals↗
PubMed1991

Clinical utility of fractionating erythrocytes into "Percoll" density gradients.

Two rapid methods for fractionating the RBC into five or nine layers of increasing density are reported. These procedures have been used to monitor the decline of glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) activity during the process of red cell aging in normal subjects and in beta-thal carriers, to study transfused patients with G6PD and pyruvate kinase (PK) deficiency and to test the effects of inositol hexaphosphate (IHP) encapsulation on RBC subpopulations.

Adult↗
PubMed1991

Erythrocyte glucose, ATP, lactate concentrations and their modifications induced by isologous plasma in non-insulin-dependent diabetes mellitus.

We determined erythrocyte glucose, ATP and lactate contents in diabetic subjects using an experimental design in which red blood cells (RBCs) were incubated over four hours in their own plasma and in plasma from normal subjects. The results indicated that baseline RBC glucose and lactate concentrations were higher in diabetic RBCs than in the controls, while ATP content was similar. After incubation, in diabetic RBCs glucose decreased significantly but more markedly when RBCs were incubated in normal plasma; lactate increased markedly in diabetic erythrocytes in their own plasma, but increased to the same extent as controls when incubated in normal plasma. ATP levels were similar to baseline values in diabetic RBCs in their own plasma, but decreased significantly when incubated in normal plasma. Since we found such a different metabolic behaviour in diabetic RBCs changing from diabetic to normal plasma, the important role of blood glucose in regulating RBC glycolysis is again confirmed.

Adenosine Triphosphate↗
PubMed1991

Stepwise increase in plasma insulin and C-peptide concentrations in obese, in obese hypertensive, and in obese hypertensive diabetic subjects.

Several clinical and epidemiological evidences support the increased risk of cardiovascular disease (CVD) in pathological conditions as obesity, hypertension, non-insulin-dependent diabetes mellitus, which have hyperinsulinemia as a common feature. In this study, we assessed basal plasma insulin (IRI) and C-peptide (CPR) concentrations in 297 volunteers who participated in a survey concerning risk factors of CVD. We found a stepwise increase in fasting insulin and C-peptide levels in normal subjects (IRI 9.10 +/- 0.41 microU/ml; CPR 1.79 +/- 0.08 ng/ml), in obese subjects (IRI 11.31 +/- 0.38 microU/ml; CPR 2.54 +/- 0.07 ng/ml) in obese hypertensive subjects (IRI 14.17 +/- 0.72 microU/ml; CPR 2.64 +/- 0.09 ng/ml), in obese hypertensive diabetic subjects (IRI 22.57 +/- 2.62 microU/ml; CPR 3.33 +/- 0.27 ng/ml). Thus, we found increasing levels of IRI and CPR as normal conditions changed towards progressively more severe pathological conditions. Although several other factors contribute to determine CVD, we conclude that increasing levels of insulin and C-peptide could play an important role in causing CVD.

Adult↗
PubMed1991

The Takagi Automatic Tangent Screen ATS-85 analyzer for the detection of glaucomatous patients.

The effectiveness of a new visual field analyzer, the Takagi Automatic Tangent Screen ATS-85, in detecting glaucomatous patients was studied. The study population consisted of three groups of subjects: normal healthy volunteers, glaucomatous patients with defective visual fields, and glaucomatous patients with early visual-field defects. Our results indicated that the screening program of the ATS-85 could be a useful instrument particularly for epidemiologic investigations.

Glaucoma↗
PubMed1991

[Plasma levels of beta-endorphin in obese subjects with normal glucose tolerance test and in diabetics].

Forty obese subjects with normal glucose tolerance test (NGTT) thirteen diabetic obese subjects and sixteen normal subjects were studied to evaluate the possible interactions between beta-endorphin (B-Ep) and glucose homeostasis. On the basis of baseline B-Ep levels, two subgroups were selected: one group with normal mean values of B-Ep (7.02 +/- 0.59 pmol/l); another group with elevated mean values of B-Ep (18.95 +/- 1.52 pmol/l). No differences between these subgroups were found as regards body mass index (BMI), insulin and glucagon levels. Normal B-Ep values were found in diabetic obese subjects. No significant correlation was found between B-Ep and BMI, insulin or glucagon. Considering that B-Ep is involved in eating behavior and on the basis of our results, we suggest that elevated B-Ep levels can be found only in those obese NGTT subjects whose obesity is probably related to an abnormal modulation of food intake, such as hyperphagia.

Adult↗
PubMed1990

Structural and functional features of the alpha 3 chain indicate a bridging role for chicken collagen VI in connective tissues.

Type VI collagen is a component of 100 nm long periodic filaments with a widespread distribution around collagen fibers and on the surface of cells. It is an unusual collagen constituted by three distinct chains, one of which (alpha 3) is much larger than the others and is encoded by a 9-kb mRNA. The amino acid sequence of the alpha 3(VI) deduced from the present cDNA clones specifies for a multidomain protein of at least 2648 residues made of a short collagenous sequence (336 residues), flanked at the N-terminus by nine 200 residue long repeating motifs and at the C-terminus by two similar motifs that share extensive identities with the collagen-binding type A repeats of von Willebrand factor. Type VI collagen and alpha 3(VI) fusion proteins bound to insolubilized type I collagen in a specific, time-dependent, and saturable manner. The alpha 3(VI) chain has three Arg-Gly-Asp sequences in the collagenous domain, and cell attachment was stimulated by the triple helix of type VI collagen and by alpha 3(VI) fusion proteins containing Arg-Gly-Asp sequences. This function was specifically inhibited by the Arg-Gly-Asp-Ser synthetic peptide. The type I collagen-binding and the cell-attachment properties of the alpha 3(VI) chain provide direct information for the role of type VI collagen in connective tissues.

Amino Acid Sequence↗
PubMed1990

Early assessment of coronary reserve after bypass surgery by dipyridamole transesophageal echocardiographic stress test.

The evaluation of coronary reserve within a few hours of aortocoronary bypass surgery could be of extreme utility for the follow-up or therapeutical management of these patients. In 11 men patients who underwent aortocoronary bypass surgery, a dipyridamole echocardiography stress test was carried out before (1 to 3 days), early after (68 to 130 minutes), and 1 week after surgery. The first and third tests were performed using a standard transthoracic approach, while the second was performed by a transesophageal approach. Dipyridamole was administered intravenously at a dose of 0.56 mg/kg body weight (low dose) and eventually adding 0.28 mg/kg body weight (high dose), always in the absence of antiischemic therapy. An arbitrary wall motion score (0 = eukinesia; 1 = hypokinesia; 2 = akinesia; 3 = dyskinesia) was assigned to the seven different myocardial regions in which the left ventricle was divided in order to have a semiquantitative score. Under basal conditions wall motion score per patient in the three series of tests did not change significantly (1.6, 1.4, and 1.5, respectively), while the mean score during dipyridamole administration showed significant differences (3.6, 1.9, and 1.9, respectively), indicative of the results obtained by surgical repair. The test, positive in all patients before surgery, showed wall motion abnormalities and ischemic ECG changes in two patients immediately after surgery by the transesophageal approach. One patient who had a normal basal contraction pattern and an abnormal response after the test developed in the following days a perioperative myocardial infarction, while a second patient in the follow-up period developed low-level effort angina.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Increase in red cell lactate concentration and its reduction by isologous plasma in NIDDM subjects.

We determined red blood cell (RBC) lactate concentrations in NIDDM subjects using an experimental protocol in which diabetic RBCs were incubated over 8 hours both with own plasma and with normal plasma. Furthermore, normal RBCs were incubated both with own plasma and with diabetic plasma. The results indicate that the increased lactate concentrations in RBCs from NIDDM subjects decreased significantly when the same RBCs were incubated in normal plasma. Conversely, lactate concentrations in normal RBCs increased significantly when RBCs were incubated in diabetic plasma. Thus, other than muscle and adipose tissue, RBCs may contribute to increase lactate release for hepatic gluconeogenesis in NIDDM and we suggest that there may be extrinsic plasmatic factor(s) capable of stimulatory effect on diabetic RBC glycolytic pathway.

Adult↗
PubMed1990

[Oxygen affinity of mouflon blood].

Hemoglobin phenotypes of European mouflon and sheep were analyzed by isoelectric focusing; the results show that the sheep HbA migrated faster than that of other animals, while the mouflon HbA was more anodic than the sheep HbB. The oxygen dissociation curve of blood from mouflon is similar to that of sheep with HbA. The authors suggest that the mouflon should not be considered a direct ancestor of the Sardinian breed of sheep.

Animals↗
PubMed1989

Alpha 1 chain of chick type VI collagen. The complete cDNA sequence reveals a hybrid molecule made of one short collagen and three von Willebrand factor type A-like domains.

A cDNA library constructed from chick aorta poly(A+) RNA in the expression vector pEX1 was screened with rabbit polyclonal antisera. Additional clones were obtained by DNA-DNA hybridization with subclones from the most 5'- and 3'-ends. The overlapping clones span 4.6 kilobases and code for the entire alpha 1 (VI) chain. The nucleotide sequence reveals a 3057-base pair open reading frame that codes for 1019 amino acids. Analysis of the deduced amino acid sequence predicts that alpha 1 (VI) has one collagenous domain (COL) of 336 residues flanked by three repeated domains of about 200 residues each, one at the amino (A'3) and two at the carboxyl ends (A'2 and A'1), respectively, that are similar to the type A repeats of von Willebrand Factor. The COL domain presents two short interruptions near the carboxyl end of the triple helix and three of the six potential N-asparaginyl-linked carbohydrate attachment sites (Asn-Xaa-Ser/Thr). Furthermore, it contains 1 cysteine at position 89 that could participate in the formation of dimers and 3 Arg-Gly-Asp sequences that might be potential sites for cell adhesion. The COL domain shows an extended region, starting from position 40, within the triple helix, made of 14 Gly-Xaa-Yaa triplets that lack proline in the Y position, suggesting that it might be more flexible than the rest of the domain. At the junction of the COL with the N- and C-terminal domains, there are several cysteines that could confer the well known resistance of type VI collagen to pepsin and collagenase digestion under nonreducing conditions. The present sequence data allow a structural model for type VI collagen assembly to be proposed that is consistent with the structure implied from previous electron microscopic observation by Furthmayr et al. (Furthmayr, H., Wiedemann, H., Timpl, R., Odermatt, R., and Engel, J. (1983) Biochem. J. 221, 303-311).

Amino Acid Sequence↗
PubMed1989

In vivo measurement of human lens aging using the lens opacity meter.

Lens aging has been measured in vivo using a new instrument: the lens opacity meter 701 (Interzeag, Schlieren, Switzerland). Statistical analyses have been performed to verify the occurrence of the phenomenon, the sex differences and the reproducibility of the obtained results. The findings demonstrate an increase in the light scattering in the normal lens with aging, which is similar in both sexes. The instrument detects this process and the measurements have a high degree of reproducibility.

Adolescent↗