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P Bartolini

Publications and source records attributed to P Bartolini.

16 recordsLinked to original sources
PubMed1991

New algorithm for the detection of the ECG fiducial point in the averaging technique.

The use of the coherent averaging technique applied to the electrocardiographic signal implies the location of a fiducial point as a synchronisation reference. An algorithm easily adaptable to a personal computer, operable in real time, insensitive to mains and to ECG-baseline fluctuations, with a low jitter value and the capacity to trigger any ECG signal wave or complex, has been developed. The algorithm detects those waveforms which, within certain confidence intervals, are morphologically equal to a reference wave. This wave is chosen by the user as the repetitive waveform within which the fiducial point is to be located. A two-window template and differential parameters are used. The possibility of building the template permits the user to adapt the algorithm to each patient's ECG. To evaluate its accuracy objectively, a software simulation was built of a generator capable of producing test signals as the sum of the 'useful' signal plus 'noise'. A jitter standard deviation of 1.65 ms was obtained in the worst test (SNR = 10 dB; noiseband = 0-50 Hz), which shows the excellent recognition accuracy of the algorithm.

Algorithms↗
PubMed1991

Prosthetic heart valve evaluation in vitro: critical aspects of data comparability.

The technology of heart valve substitution has considerably improved in the last few years, but its reliability after implantation is still not good enough, hence the need to study new valve design and improve quality testing. Different pulse duplicators are used for heart valve testing, but the results depend very much on the system adopted and the measurement protocol. Tests on two pulse duplicators currently used at the Biomedical Engineering Laboratory at the Istituto Superiore di Sanità, Rome, are reported here. The most significant parameters for valve evaluation were measured following each system's own protocol. Attention was focused on vascular load tuning when setting up the system and on the relationship between drive unit flow waveform and valve regurgitation and energy loss measurements. Standardization criteria must be defined in order to ensure the reliable comparability of in vitro testing results.

Coronary Circulation↗
PubMed1989

Ultraviolet scanning densitometry for detection, quantitation, and preparative elution of protein bands from unstained gels.

Ultraviolet scanning of gel rods was used to identify and quantify protein bands in a nondestructive manner with good precision and sensitivity. This same technique, applied on a preparative scale, allowed quantitative protein elution, by reversed electrophoresis, from gel slices completely sealed in a dialysis bag. Protein recovery approached the theoretical yield (93.5 +/- 5%), with practically no interfering substances, and the entire preparative process (first electrophoresis, densitometric scanning, and reversed electrophoresis) could be performed in approximately 6 h. Its application to human growth hormone has shown no alteration in the biological activity of this protein.

Animals↗
PubMed1989

Free tryptophan decrease in jaundiced newborn infants during phototherapy.

Tryptophan and nonesterified fatty acids (NEFA) are bound to serum albumin. NEFA displace tryptophan from their binding sites. Since NEFA decrease during phototherapy, we examined reciprocal variations of NEFA, total and free tryptophan in jaundiced newborn infants during phototherapy. After 24 h of phototherapy, we noticed a significant decrease of both NEFA and free tryptophan (p less than 0.001). Free tryptophan variations might affect the synthesis of cerebral neutrotransmitter 5-hydroxytryptamine, which depends on the passing of free tryptophan through the blood-brain barrier.

Bilirubin↗
PubMed1988

Stokes radius determination of radioiodinated polypeptide hormones by gel filtration.

A simple technique for determination of the molecular (Stokes) radius of radioiodinated proteins was developed using the same column and chromatographic conditions employed in routine radioimmunoassay tracer purification. The calibration curve for five radioiodinated standard proteins presented a highly significant correlation (r = -0.996; P less than 0.001) and allowed precise molecular radius determination for labeled human growth hormone (hGH), luteotropin (hLH), follicle-stimulating hormone (hFSH), thyrotropin (hTSH), prolactin (hPRL), and corticotropin (hACTH), enabling detection of differences of the order of +/- 3%. The validity of the method was verified by determining the molecular radius of hGH in both "cold" (unlabeled standards and unknowns) and "hot" (radioiodinated standards and unknowns) systems. The technique can be applied in a very simple manner, requiring just one simple additional calibration run before Sephadex G-100 tracer purification. Furthermore, it can be applied to any protein, even when only extremely limited amounts are available. Since the standards and unknowns are labeled and chromatographed under identical conditions, potential common alterations of the molecule due to oxidation, iodine incorporation, tracer-carrier interactions, etc., are automatically corrected for.

Chromatography, Gel↗
PubMed1988

Results of a thyroid monitoring survey carried out on workers exposed to 125I in São Paulo, Brazil.

The thyroids of 30 workers performing routine 125I labelling in several laboratories of the city of São Paulo have been monitored about once every 2-3 mo from November 1985 to October 1986. Twenty-five of them presented a significant radioactivity (in our detection system greater than 62 Bq), but none reached the maximum permissible thyroid burden. The maximum measured thyroid contamination is 24 kBq (650 nCi). The uptakes were determined by comparison with a standard curve obtained by placing various calibrated standard sources of 125I in a thyroid neck phantom. The paper also describes the set up of quality controlled counting conditions, with high sensitivity, precision, accuracy and stable detector efficiency, by adaptation of an old equipment to this purpose. Calculated 125I effective half-lives for five individuals ranged between 31.7 and 47.0 d, the average being 39.4 +/- 6.1 d.

Body Burden↗
PubMed1986

Influence of chloramine T iodination on the biological and immunological activity or the molecular radius of the human growth hormone molecule.

Potential alterations of the somatotropic activity of human growth hormone (hGH) resulting from Chloramine T labelling reaction, iodination up to 2.7 atoms/molecule and indirect radiation effects, have been studied. Three 2X2 factorial assays, performed in hypophysectomized rats, failed to reveal any significant difference (P greater than 0.05) in true growth promoting activity between hGH and (127-I)hGH, even after storing the latter with 125-I. Similar results were obtained applying a sensitive and precise gel filtration technique for Stokes Radius determination and radioimmunoassay.

Animals↗
PubMed1977

An accurate determination of human growth hormone content in different pituitary extracts, using a radioimmunoassay with polyacrylamide gel electrophoresis as a bound-free separation system.

Human growth hormone was extrated and purified according to the method of Roos et al. (Roos, P., Fevold, H.R. and Gemzell, C.A. (1963) Biochim. Biophys. Acta 74, 525). A first control of its purification and integrity was performed through molecular weight determination by gel filtration on Sephadex G-100 and on polyacrylamide gel electrophoresis (PAGE). Its biological activity was confirmed by the growth promoted in non-hypophysectomized rats at plateau. The main object, however, was the setting up of accurate, reproducible method tha could furnish the more absolute and comparable values of radioimmunoassayable HGH content in perfect agreement with the results obtained by other laboratories. This was accomplished through a radioimmunoassay system that uses HGH labelled with 125I, where separation of the bound from the free antigen is achieved on polyacrylamide gel electrophoresis, by a modification introduced in the original method of Davis. The resulting values, extremely close to that stated by the KABI-Laboratories (Stockolm), though obtained in quite different conditions of incubation, antibody concentration and with no use of second antibody, represent a confident approach to a comparable measure of this hormone in extracts, which can also be applied to plasma determinations.

Animals↗
PubMedDate not supplied

[Osteomyelitis caused by atypical mycobacteria in multiple colonies].

The authors describe a seven months and a half little girl, A.B., affected by multiple localization osteomyelitis caused by an Atypical Mycobacterium, with the culture identifies as M. Avium, belonging to the third group of Runjon classification. The radiographic tests show a primary pulmonary complex and some osteolytic areas of the seventh right rib and of the bones of the lower legs (femur and tibia). From the beginning a multiple antituberculous chemotherapy against non tuberculous mycobacterial disease has initiated: Streptomycin (for two months) associated with Rifampicin, Isoniazid and Pyridoxine. The patient responds very slowly to the treatment and only three years later the whole radiologic regression of the lesions occurs. The interest of the case comes from the extreme rarity of disseminated bone localization during an atypical mycobacterial infection, and also from the early beginning of the clinical and radiologic manifestations.

Bone and Bones↗