Search PubMed⌕ Search

Biomedical subjects

A Alfano

Publications and source records attributed to A Alfano.

11 recordsLinked to original sources
PubMed1993

Prognostic value of triple phase bone scanning for reflex sympathetic dystrophy in hemiplegia.

Twenty-two patients with cerebral vascular accident (CVA), clinically confirmed by head computed tomography, were observed for symptoms of the reflex sympathetic dystrophy syndrome (RSDS). All patients received triple phase bone scans; 16 scans were positive for RSDS. Patients with negative scans had no symptoms of RSDS. Five patients with positive scans had RSDS symptoms at the time of bone scanning. Seven of 11 patients with positive scans but no symptoms of RSDS at the time of bone scan developed symptoms of RSDS within six months. We found a significant relationship between positive bone scans and the subsequent development of RSDS (p < 0.01). Considering only those patients who were asymptomatic for RSDS at the time of bone scanning, we found bone scanning to be a good predictor for the future development of clinical RSDS. We found the correlation between positive bone scans and the subsequent development of clinical RSDS in previously asymptomatic individuals to be statistically significant (p < 0.05). We conclude that bone scans may be a good predictor of patients at risk for developing clinical RSDS after CVA.

Bone and Bones↗
PubMed1991

Spectroscopic characteristics and site I/site II classification of cis and trans benzo[a]pyrene diolepoxide enantiomer-guanosine adducts in oligonucleotides and polynucleotides.

The highly tumorigenic isomer (+)-7,8-dihydroxy-anti-9, 10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene [(+)-anti-BPDE] and its non-tumorigenic enantiomer (-)-anti-BPDE are known to react predominantly with the exocyclic amino group (N2) of deoxyguanine in DNA and to form adducts of different conformations. The spectroscopic characteristics (UV absorbance, fluorescence and circular dichroism) of stereochemically defined (+)-trans, (-)-trans, (+)-cis and (-)-cis d(5'-CACATGBPDETACAC) adducts in the single-stranded form, or complexed with the complementary strand d(5'-GTGTACATGTG) in aqueous solution, were investigated. The spectroscopic characteristics of the double-stranded d(5'-CACATGBPDETACAC).d(5'-GTGTACATGTG) adducts can be interpreted in terms of two types of conformations. In site I-type conformations, there is an approximately 10 nm red shift in the absorption maxima, which is attributed to significant pyrenyl residue-base interactions; in site II-type adducts, the red shift is only approximately 2-3 nm, and the pyrene ring system is located at external, solvent-exposed binding sites. The spectroscopic characteristics of the BPDE-modified duplexes are of the site II type for the (+)- and (-)-trans, and of the site I type for the (+)- and (-)-cis adducts. In adducts derived from the binding of (+)-anti-BPDE to poly(dG-dC).(dG-dC) and poly(dG).(dC), the trans/cis BPDE-N2-dG adduct ratio is 6 +/- 1; in the case of (-)-anti-BPDE this ratio is only 0.4 +/- 0.1 and 0.6 +/- 0.15 in poly(dG-dC).(dG-dC) and poly(dG).(dC) respectively. The spectroscopic properties of these BPDE-modified polynucleotide adducts are consistent with those of the BPDE-modified oligonucleotide complexes; the cis adducts are correlated with site I adduct conformations, while the trans adducts are of the site II type. The correlations between adduct characteristics and biological activities of the two BPDE enantiomers are discussed.

Base Sequence↗
PubMed1989

[Programming VTIM physiologic pacemakers (evoked QT)].

Seventeen VTIM pacers were implanted in seventeen patients. Average follow up were 16.7 months. This paper concerns TX track and TX on modes only. Sensing window period and slope, which determine the rate response, must be programmed carefully. Potential competitive rhythms, severe ventricular arrhythmias or inadequate rate response to physical stress may potentially develop under inadequate programming. Consequently, it is advisable to program the sensing window 20-25 ms longer than the QTE max (at LRL) and the slope at 100% of the whole value. No complications were detected. Figures 1, 2 and 3 show examples of competitive rhythms without heart stimulation and unsensed beats by abnormally long programmed SW values. When properly shortened, this interval allows proper measurement of the Stim.-T and no competitive rhythm, during almost the same spontaneous rhythm. This system fulfills the major conditions for pacing the heart: rate adaptation to neurohormonal release, to physical stress and operative mode as a close-loop system during the recovery period.

Adaptation, Physiological↗
PubMed1981

[Practical method for morphometric reliefs].

This morphometric method consists in: - to photograph, during culture's period, with constant magnification, the organ rudiment explanted in vitro; - to place on the single images, in printing, a transparent squared reticle with size unit known; - to compute the size values of the considered image counting the number of reticle's squares comprised in the image.

Animals↗
PubMedDate not supplied

Dependence of conformations of benzo[a]pyrene diol epoxide-DNA adducts derived from stereoisomers of different tumorigenicities on base sequence.

The conformations of covalent adducts derived from the binding of the highly tumorigenic stereoisomer (+)-trans-7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyren e [(+)-anti-BPDE] and its nontumorigenic (-)-anti-BPDE isomer with poly[(dG).(dC)], poly[(dG-dC).(dG-dC)], poly[(dT-dC).(dG-dA)], and poly[(dA-dC).(dG-dT)] were investigated by employing UV absorbance and linear dichroism methods. The degrees of orientation of the BPDE residues (bound covalently to N2 of deoxyguanosine), relative to the DNA bases, are most pronounced in the alternating and nonalternating (dG).(dC) polymers and decrease in polymers with neighboring dA.dT base pairs. The tumorigenic (+)-anti-BPDE isomer gives rise predominantly to external (solvent-exposed) site II adducts, while the (-)-enantiomer gives rise predominantly to site I adducts with significant carcinogen-nucleoside interactions. In the mixed (dA-dC).(dG-dT) and (dT-dC).(dG-dA) copolymers, the (+)-anti-BPDE isomer also binds predominantly to N2 of deoxyguanosine, but the adducts are weakly oriented with respect to the DNA bases. The incidence of site II adducts is considerably reduced as compared to the (dG).(dC) and (dG-dC).(dG-dC) polymers, and there is a greater proportion of site I adducts; the presence of a significant proportion of unordered adduct forms is also suggested from the diffuseness and broadness of the absorption spectra in the dA.dT base pair containing polymers. The preference of formation of site II adducts in dG-rich sequences in the case of the biologically highly active (+)-anti-BPDE isomer is discussed in terms of the known binding and mutation spectra.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗