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Biomedical subjects

A Colombo

Publications and source records attributed to A Colombo.

At least 469 records · Page 26Linked to original sources
PubMed1977

[Precordial ST segment elevation mapping: a new method for a technically easier recording (author's transl)].

Precordial ST segment maps are currently recorded using a 35 electrode blanket connected to an electrocardiograph through a switch box. Problems in adjustment to patients' chests and artifacts are frequently encountered. Other techniques using a single suction electrode placed on different reference points are time wasting. The authors suggest the use of 35 self-adhesive electrodes (3M "Red Dot" chloride free gel pediatric electrodes--cat N. 2243) connected by a press button to a multichannel EKG recorder. This technique prevents artifacts, assures constant arrangement of the electrodes, is suitable for different thoracic structures and does not need any additional device. The authors consider that such a practical method should make precordial ST mapping a more widespread clinical procedure.

Coronary Disease↗
PubMed1977

[Sublingual isosorbide dinitrate-induced severe hypotension, bradycardia and prelypothymia in patients with acute myocardial infarction (author's transl)].

100 patients with acute myocardial infarction were given 5 mg of sublingual isosorbide dinitrate within 36 hours by the onset of their symptoms. 86 patients did not show any unusual effect after the administration of the drug; their heart rate was only slightly increased and their arterial pressure slightly reduced. 14 patients developed severe systemic arterial hypotension, associated with absolute or relative bradycardia, within 30 minutes of receiving the drug. All the patients complained of fainting and sweating, 1 patient developed a syncope. Symptoms were relieved by raising patients legs in 10 cases, by 0.5 mg Atropina e.v. in 4 cases, 1 case required also external cardiac massage. There was no significant difference between the two groups as regard to the location of myocardial infarction nor to the functional class (according to Killip classification). Possible mechanism producing bradycardia, hypotension and lipothymia after nitrates administration are considered. A vagally mediate reflex possibly elicited by a fall in venous return is the most acceptable hypothesis. The study emphasizes the importance of carefull observation of patients receiving sublingual nitrates during acute myocardial infarction, and the rapid response of bradycardia, hypotension and lipothymia following nitrates administration, to a simple therapy, which avoids other potentially hazardous treatments.

Aged↗
PubMed1976

The occurrence of visual neglect in patients with unilateral cerebral disease.

Visual neglect for the contralateral space has been reported to occur more frequently and more severely following right than left brain damage. The present study sought to determine whether this hemispheric difference is task dependent, i.e. is maximal for tests demanding a thorough exploration and minimal for tests leaving space scanning to the patient's initiative. The findings supported this hypothesis. When the occurrence of neglect was assessed by means of a copying drawings test omissions of details contralateral to the involved hemisphere were found only in the right brain-damaged patient. When the patient was required to bisect a line or to choose the correct response among the alternatives of the Raven test, a tendency for preferring the homolateral hemi-space was also shown by left brain-damaged patients, although it was much more marked in the right-sided group. When patients were asked to insert balls in the holes of a board, both hemispheric groups showed a preference for the homolateral space. The incidence of constructional apraxia was evaluation in the same hemispheric groups and found not to be significantly different.

Brain Damage, Chronic↗
PubMed1976

[Intraligamentary anesthesia with the "Peripress" syringe].

The authors have been using for some time the intraligamentary anaesthesia with the Peripress syringe in their own practices. They consider this syringe as an instrument for efficient and rational working and as an improvement of the local anaesthesia techniques. After specifying the instruments they describe in all detail the injection technique which allows all current work on teeth like extractions, cavity preparation and stumps for crowns, endodontic treatments requiring anaesthesia, all this without loss of waiting time. The intraligamentary anaesthesia does not cause any secondary troubles if carefully applied. It causes very little pain if at all. It allows to start dental work immediately after infiltration and avoids block anaesthesia for current dental work. Patients are favourable to the method. They prefer this type of anaesthesia.

Anesthesia, Dental↗
PubMed1976

Halving a horizontal segment: a study on hemisphere-damaged patients with cerebral focal lesions.

The aim of this study was to point out a hemisphere asymmetry in focal brain-damaged patients and a hand asymmetry in normals on halving binocularly a horizontal line. 50 left hemisphere and 53 right hemisphere patients (both subdivided by presence/absence of visual field defect) and 50 controls (divided by the hand they used to carry out the task) were employed. 4 differently long segments made up the test material and the error scores with respect to the geometric midpoint were worked out by means of parametric statistical procedures. It turned out that: (i) healthy subjects committed a mean leftward displacement, regardless of the hand they used. All the same, only the halving error committed by the right hand is significant keeping as reference the geometric midpoint of the segment; (ii) left and right hemisphere-damaged patients committed halving errors, that are opposite in direction, leftward for the former and rightward for the latter; (iii) the behaviour of right patients with visual field defects is the only to be significantly different from that of the corresponding controls. Our findings point to prevailing importance of the right hemisphere mainly of its posterior areas, in the halving task.

Brain Damage, Chronic↗
PubMed1975

DNA polymerases of rat liver. Partial characterization and effect of various inhibitors.

Three distinct DNA-dependent DNA polymerase activities have been partially purified from normal rat liver. Soluble activities are separable into two distinct fractions (P1 and P2) by phosphocellulose chromatography. A low-molecular-weight DNA polymerase was isolated from purified nuclei. The enzymes were characterized according to chromatographic and sedimentation behavior, enzymological properties, and response to various inhibitors. The results indicate that fraction P1 corresponds to the high-molecular-weight enzyme and suggest that polymerase P2 may be derived from partial dissociation of the high-molecular-weight enzyme. The molecular weight of polymerase P1 was estimated to be about 250 000 by Sephadex column chromatography. Both fraction P2 and nuclear DNA polymerase appeared to be low-molecular-weight enzymes. However, the molecular size of these activities was apparently different. The estimated molecular weights of nuclear and P2 enzyme are about 40 000 and 25 000, respectively. As with the nuclear enzyme, polymerase P2 (but not P1) appeared to be free of detectable exonuclease activity. All of these polymerases showed a marked preference for initiated polydeoxyribonucleotide templates. The rat liver polymerases differed in their ability to use poly[d(A-T)-A1 primer-template, as is shown by the ratios of their activity with this synthetic polymer to that with activated DNA: 0.5, 2.75, and 1.34 for P1, P2, and nuclear polymerase, respectively. Denatured DNA was a poor template for both enzymes P1 and P2, but it was inert as template for the nuclear enzyme. Although each of these polymerases required all four deoxynucleoside triphosphates for maximal activity, they catalyzed a high rate of synthesis in the absence of one or more deoxynucleoside triphosphates. Such a 'limited' synthesis was much more extensive for polymerase P2 and nuclear enzyme than for P1 was the most sensitive of the three to sulphydryl reagents, ehtidium bromide, heparin, and single-stranded DNA. The responses of P2 and nuclear enzymes to various inhibitors were very similar. However, these two enzymes respond differently to heat and high ionic strength.

Animals↗