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Biomedical subjects

C Buonomo

Publications and source records attributed to C Buonomo.

8 recordsLinked to original sources
PubMed1990

Vasovagal reactions induced by head-up tilt and tests of vagal cardiac function.

The vagal cardiac activity was compared in two groups of patients with a history of syncope. Sixty-one patients (Group A) experienced vasovagal reactions induced by head-up tilt, 61 sex and age-matched patients (Group B) did not. No significant differences in vagal cardiac activity between two groups were found. Group A was further subdivided into two subgroups: A1 (14 patients) with stronger, and A2 (47 patients) with smaller cardioinhibition. Again, vagal cardiac activity was not different between two subgroups. Thus, the baseline vagal cardiac activity ('tone') seemed not to be helpful in predicting the susceptibility to vasovagal orthostatic syncope and in discriminating the patients with stronger cardioinhibition.

Adult↗
PubMed1988

In vivo and in vitro 31P-NMR preliminary studies of the VX-2 carcinoma in rabbits.

In vivo and in vitro 31P-NMR spectroscopy was used to study the high energy phosphate metabolism of VX-2 tumors implanted into rabbit liver, kidney, and hind-limb muscle. Tumors, at various stages of growth, were first examined by in vivo 31P-NMR spectroscopy, then they were excised and underwent histologic examination and biochemical analysis; both in vitro 31P-NMR and standard enzymatic techniques were used. There was good correlation among the in vivo NMR spectra, the in vitro NMR data, and the biochemical analyses. Although the tumor spectra showed characteristics similar to those reported in the other tumor models, there was a striking variability in the spectra obtained from tumors implanted in the same site and from different sites. There was poor correlation between the degree of necrosis in the tumor and the tumor pH and between the Pi:ATP ratio and necrosis. This variability has important implications for the potential value of using 31P-NMR spectroscopy to monitor tumor growth and therapy in vivo.

Adenosine Triphosphate↗
PubMed1988

Labeled plasma metabolites of L-methyl-hydrogen-3-methionine and L-methyl-carbon-14-methionine in the dog.

The validity of the mathematical models that attempt to describe positron emission tomography (PET) images produced with [11CH3] methionine in terms of rates of local cerebral protein synthesis has yet to be established. A major objection to current models is that the use of methionine labeled at the methyl position results in the dispersal of the label among various methyl-accepting compounds that appear in the plasma and may then enter the brain. One approach to overcoming this problem has been the use of "standard" corrections for the activity contributed to plasma by labeled plasma protein and labeled serine. In order to determine the validity of this approach, the metabolic fate of labeled methionine was studied in six dogs. After injection with either [C3H3] methionine or [14CH3] methionine arterial blood was sampled. Plasma fractions containing protein were separated by fast gel filtration, counted with standard scintillation techniques, and their radioactivity was compared with total plasma radioactivity. Plasma was also separated by high-pressure liquid chromatography into methionine, serine, and nonmethionine or serine-containing fractions. These fractions were counted, and their radioactivity was compared with total plasma radioactivity. Labeled protein appeared in plasma about 20 minutes postinjection and then increased steadily. Labeled serine also appeared and reached a peak value of 9.4 +/- 2.1% of plasma activity at 40 minutes. Of greatest interest was the appearance in later plasma samples of increasing amounts of activity contained in nonserine low molecular weight metabolites of methionine. At 40 minutes, those metabolites made up 27 +/- 6.9% of total plasma activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Micturition syncopes.

Micturition syncope accounts for 8.39% of the total number of syncopes and is prevalent among men in the 50 and 60 year age groups. The cardiovascular vegetative nervous system is unaffected in patients with micturition syncope. Sixty-one percent of patients with micturition syncope also exhibit other kinds of syncope. These patients experience vasovagal reaction during the vegetative activation tests more often than patients exclusively with micturition syncope.

Adolescent↗
PubMedDate not supplied

Syncopes with reference to sex and age.

The incidence of different types of syncopes and their relationship to sex and age were studied. In agreement with previous findings in the literature, a cause of syncopes in a large proportion of patients could not be determined. Vasovagal syncopes clearly prevailed among diagnosed syncopes with a female prevalence. Other syncopes (due to orthostatic hypotension, carotid-sinus syndrome etc.) had a male preponderance. Syncopes with poor prognosis prevailed in elderly patients.

Adolescent↗
PubMedDate not supplied

Electroencephalographic and electrocardiographic features of vasovagal syncope induced by head-up tilt.

Two hundred and seventy-nine consecutive patients referred for transient loss of consciousness, compatible with syncope, underwent head-up tilt to 70 degrees during polygraphic (EEG, ECG, pneumographic) and blood pressure monitorings. Vasovagal syncopes occurred in 28 patients with the following EEG changes: progressive slowing until the appearance of middle or high amplitude delta waves generalized and synchronous in 9 patients; delta waves suddenly followed by transient flattening of EEG activity in 16 patients. In 2 patients EEG could not be interpreted because of muscle and/or movement artifacts. Fifteen out of 28 patients exhibited a marked cardioinhibition, expressed by long-lasting cardiac pauses; a relationship between duration of EEG flat and duration of asystole was not found.

Adolescent↗