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Biomedical subjects

E Romano

Publications and source records attributed to E Romano.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Sulfonylurea resistance in type II diabetes mellitus. Assessment of metabolic and hormonal aspects].

Sensitivity tests to SU allow two populations to be distinguished. One contains severely diabetic subjects in a continuous state of metabolic precariousness with reduced alkaline reserves, hyperinsulinemia and insulin resistance; the other contains mildly diabetic subjects who are normoinsulemic and show no insulin-resistance to i.v. tests irrespective of the presence of a similar level of SU resistance. While the first group may be more readily interpreted, especially with reference to the dualism between the alterations of insulin synthesis and resistance of peripheral tissues, with special reference to the function of receptors and post-receptors, the second group raises numerous questions of interpretation. The test becomes important to identify those subjects who right from the start show a reduced insulin secretion to drug stimulation and the possibility of obtaining euglycemia with high doses of SU. This finding suggests the existence of a genetically determined mechanism for SU resistance: in addition to the population who show marked SU resistance from the onset of diabetic symptoms, there is also a group of subjects in whom this resistance is less evident and may be provoked only by certain stimuli or spontaneously under stress, or by the appearance of the triggering metabolic factor. It is clearly important to identify the latter population before the clinical manifestation of symptoms so as to establish the correct therapy or combined therapy. This led us to consider the SU-resistant cases in the series of patients studied as being two clinical stages of the same condition rather than two separate populations with different pathogenesis.

Aged↗
PubMed1990

A new hemolytic assay for bovine serum complement and its application during experimental bovine anaplasmosis.

A new hemolytic assay for bovine complement is presented. Using this assay we found a significant reduction in bovine serum complement activity during the acute phase of anaplasmosis, and an increase in the sensitivity of the red blood cells (RBC) to bovine complement lysis in vitro. The new hemolytic test is performed with bovine RBC, rabbit anti-bovine RBC serum and bovine serum complement. An isotonic sucrose Tris-buffered saline solution of ionic strength 0.094 and pH 7.2 was found to be adequate for this test. The titres obtained with this new assay, which uses autologous RBC, are comparable with those obtained using the guinea pig RBC assay. The finding of a reduction in bovine serum complement during anaplasmosis may be suggestive of a mechanism responsible for the pathology of this disease.

Anaplasmosis↗
PubMed1989

[Comparison of 2 exchangers of heat and humidity in anesthesia (Hygrobac vs Ultipor BB50)].

Comparison between Hygrobac and Ultipor BB50, two commercially available heat and moisture exchangers, shows that the former is more efficient: temperature (T degrees C) and water content (absolute humidity, AH) of the inspired gas is greater with Hygrobac than Ultipor BB50. However, both HMEs work at the low limit of the normally accepted range of T degrees C and AH for intubated patients.

Anesthesiology↗
PubMed1989

Functional characterization of mononuclear cells of normal and hypercholesterolemic rabbits.

Cholesterol-fed rabbits are more susceptible to respiratory and skin infections, and show a higher index of mortality than rabbits given a normal diet. Several tests were employed to estimate the proportion of T and B lymphocytes (L-T and L-B) and aspects of their physiology in rabbits with hypercholesterolemia. The proportion of L-T and L-B in hypercholesterolemic rabbits (HChR) was found to be similar to that of normal rabbits (NR). The proliferative response of mononuclear cells (MNC) from peripheral blood stimulated with mitogens in HChR decreased during the first ten days of the cholesterol rich-diet, being variable afterwards. The addition of HChR serum to the culture media decreased the proliferative response of MNC isolated from both HChR and NR and stimulated by Con A and PWM. A similar antibody response to sheep red blood cells (SRBC) and bovine serum albumin (BSA) antigens was found in HChR and NR.

Animals↗
PubMed1988

Iron and transferrin uptake by phytohemagglutinin-stimulated human peripheral blood lymphocytes.

Iron (Fe) and transferrin (TF) uptake by human peripheral blood lymphocytes stimulated in vitro with phytohemagglutinin was measured. Pulses of 59FeTF or 125I-TF were added to the cultures either at time 0 or 8 hr before the end of a 72-hr incubation. In time-course experiments, peak iron and transferrin uptake coincided with the peak of tritiated thymidine uptake taken as a measure of cellular activation. Iron, but not transferrin, was accumulated by the cells. Non-linear relationships existed between both iron and transferrin uptake and the degree of activation. Both rose markedly above basal levels only at a level of activation at least 50% of the maximum observed. The results suggest that although iron utilization is related to cellular activity, the uptake mechanism is only activated when an increased iron metabolism has exhausted internal stores.

Biological Transport, Active↗
PubMed1988

Lymphocyte activation, iron uptake and release by human mononuclear leukocytes in the presence of desferrioxamine.

Desferrioxamine (DFO), an iron chelating drug, has been shown to inhibit the proliferative response of leukocytes to mitogen. In the present study we investigated the effect of DFO on different aspects of human mononuclear leukocyte (MNL) function in vitro. DFO, added at the beginning of the culture period, inhibited both tritiated thymidine and radioiron uptake by phytohemagglutinin-stimulated MNL and the degree of inhibition correlated with the degree of cellular activation, to the extent that in the absence of mitogen a significant stimulatory effect of DFO was observed, especially when iron supplement was present in the culture medium. However DFO was not found to inhibit iron uptake directly, and relatively low concentrations of iron as iron-transferrin totally reversed the inhibitory action of DFO on thymidine uptake. Although the release of iron from preloaded MNL in the presence of DFO was only 15% greater than the spontaneous release of control cultures, we conclude that the site of action of DFO is an intracellular iron pool, that increases in importance when the supply of iron to the cellular iron metabolism become limiting as in optimally activated MNL.

Deferoxamine↗
PubMed1988

The induction phase of neuromuscular block after suxamethonium and pancuronium: analysis of the time constant of single-twitch decay (tau T1).

The T1% (first unconditioned stimulus of train-of-four) decay was analysed in 55 patients paralysed with different doses of suxamethonium and pancuronium during minor elective ear and nose surgery. In patients given pancuronium, T1% decay is well described by a mono-exponential function: a semi-log plot of ln(T1%) versus time is in fact a straight line. Predicted values are quite comparable with mean and individual values recorded in patients. From these equations the time-constant of single-twitch decay, or tau T1, may be calculated easily: it is a good dynamic descriptor of the speed of onset of neuromuscular block. In patients paralysed with suxamethonium, the rapidly developing block makes it difficult to acquire a sufficient number of data for computation of regression lines: while T1% seems to decrease exponentially, as in the pancuronium groups, no definite conclusions are possible at present. The authors conclude that tau T1 may be a useful dynamic descriptor of neuromuscular block induced by non-depolarizing muscular blocking drugs. Two new concepts are introduced: (i) the time spent to overcome the 'margin of safety' of neuromuscular transmission, or T MOS; and (ii) the speed index, as a measure of the relative speed of the onset of block.

Action Potentials↗
PubMed1987

The AluI-induced bands in great apes and man: implication for heterochromatin characterization and satellite DNA distribution.

Restriction endonucleases have recently been proved to be active on fixed chromatin, producing differences in staining of metaphase chromosomes. In this paper we show the results obtained by treating the metaphase chromosomes of Pan troglodytes, Pan paniscus, and Gorilla gorilla with the restriction enzyme AluI. These results demonstrate qualitative differences in the telomeric heterochromatin between Pan and Gorilla despite the fact that these areas appear homogeneous in the two genera by the C-banding method. The results found with individual chromosomes in the different species also appear relevant, in the light of the evolutionary relationships between these nonhuman primates and man. Lastly, the results suggest the presence, in great apes, of some highly repetitive DNA sequences different from the human satellites I-IV.

Animals↗
PubMed1987

Physiological and non-physiological forms of iron affect differently proliferation and ferritin synthesis in human mononuclear cells in vitro.

The effect of iron in different forms on the proliferative response to mitogen and ferritin content of human mononuclear leukocytes (MNL) was studied in vitro. Iron-loaded transferrin (FeTF) but not apotransferrin (apoTF) significantly enhanced the mitogenic response of MNL in serum-free culture. Removal of TF from serum markedly reduced its effectiveness as a serum supplement. This effect could be almost totally reversed when the serum was reconstituted with both iron and apoTF. Four forms of iron showed a stimulatory effect on ferritin synthesis in MNL in the increasing order: FeTF less than iron nitrilotriacetate less than iron citrate (molar ratio 1:20) less than iron citrate (1:1). The effect appeared to be correlated with their susceptibility to polymerization in aqueous solution. It is proposed that iron may a) enhance the mitogenic response of MNL, due probably to the physiological form of iron, FeTF, and b) stimulate ferritin synthesis, a protective reaction of the cell to toxic polymerized forms of the metal.

Cell Division↗
PubMed1987

Effects of a heat and moisture exchanger on carbon dioxide equilibrium during mechanical ventilation with the Bain circuit.

The introduction of a heat and moisture exchanger (HME) into the anaesthetic circuit may cause a rise in carbon dioxide (CO2) tension through an increase in dead space. We studied the effects of the Ultipor Pall BB50 filter included 'in series' in the Bain circuit on CO2 equilibrium. Arterial carbon dioxide tension (PaCO2) was measured in 81 patients scheduled for elective surgery before and after the insertion of the filter. Results showed that: females were always more hyperventilated than males when fresh gas flow was set at 70 ml kg-1 ideal body weight; the inclusion of the filter increased the PaCO2 in the group as a whole (the difference was statistically, but not clinically, significant); PaCO2 increased after the application of the filter only in females; the effects of the filter were completely independent of the patient's age. It is concluded that the use of the Ultipor Pall BB50 filter is a safe procedure during mechanical ventilation with the Bain breathing system and there is no need to modify ventilation.

Adult↗
PubMed1987

Time constant of single-twitch decay during the induction phase of neuromuscular block: a clinical study with atracurium besylate.

Visual inspection of several records of the onset of neuromuscular block due to atracurium suggested that the temporal decay in the response to the first stimulus (T1) of train-of-four could be regarded as an exponential process, analogous to the distribution (alpha) phase of the drug. Retrospective analysis of 69 train-of-four tracings recorded in patients of both sexes scheduled for minor elective surgery confirmed that T1% decay is best described by an exponential function, theoretical values correlating well with the recorded values (r greater than 0.9, P less than 0.01).

Adult↗
PubMed1986

The Alu I-induced bands in metaphase chromosomes of orangutan (Pongo pygmaeus). Implications for the distribution pattern of highly repetitive DNA sequences.

Restriction endonucleases have been recently proved to be active on fixed chromosomes, thus they are useful in chromatin structure studies. Within this class of enzymes, Alu I is able to detect the presence and localization of highly repetitive DNA sequences in human and in other mammalian and dipteran species. In this paper the pattern obtained on fixed metaphase chromosomes of orangutan (Pongo pygmaeus) by Alu I digestion and Giemsa staining is shown. The results are discussed in the light of the distribution, in this species, of the I-IV human satellite DNAs. It is also suggested that in Pongo some highly repetitive sequences, different from the major human satellites, are present.

Animals↗
PubMed1985

[Clinical course and histopathology of acute oliguric and non-oliguric renal insufficiency].

A retrospective analysis of clinical course and hystopathologic lesions of 23 patients with multiple system organ failure (MSOF) showed that: non-oliguric acute renal failure is more frequent than the oliguric one; the prognosis is severe in both forms; hystopathologic findings are similar. Since acute tubular necrosis during sepsis is characterized by an high incidence of microthrombosis, the prophylactic use of heparin could be justified.

Acute Kidney Injury↗
PubMed1985

Synergistic effect of albumin and transferrin on the mitogen stimulation of human mononuclear leukocytes in serum-free medium.

It is well known that optimal lymphocyte proliferation in vitro requires the supplementation of the culture medium with serum, the usual concentration varying between 5% and 20%. In an attempt to reduce the serum requirement of lymphocytes in culture, we have found that supplementation of RPMI 1640 medium with as low as 1% human serum allows an adequate proliferation of human peripheral blood lymphocytes cultured in microtiter plates in a CO2 atmosphere and stimulated by phytohemagglutinin. In serum-free cultures, the addition of albumin (4 mg/ml) or transferrin (10 micrograms/ml) allows a significant proliferation of lymphocytes. This permissive effect was cell concentration-dependent, being maximal at 2 X 10(5) cells/well. The simultaneous addition of albumin and transferrin produced a synergistic effect, the phytohemagglutinin-induced proliferation being higher than expected from the addition of the two proteins separately. This synergistic effect was observed in 89% of the subjects studied (8 out of 9). These results suggest that albumin and transferrin are required for optimal lymphocyte proliferation and that the serum can be partially substituted by these two proteins.

Animals↗