PubMed Health⌕ Search

Biomedical subjects

L Pennacchietti

Publications and source records attributed to L Pennacchietti.

8 recordsLinked to original sources
PubMed1997

1H NMR spectra of normal urines: reference ranges of the major metabolites.

Serial urine samples from 50 normal subjects were studied by 1H NMR spectroscopy operating at 300 MHz. Analyses of the spectra have shown the presence of the following metabolites in 100% of the normal subjects: Creatinine, lactate, alanine, citrate, dimethylamine, trimethylamine-N-oxide, glycine and hippurate. Other analytes, such as creatine, valine, betaine, leucine and isoleucine, were sometimes found. All metabolites were quantified on the basis of peak heights and were expressed as mmol/mol of creatinine. The study of metabolic profiles in serial samples allowed us to evaluate intra-individual variability and physiological changes due to feeding. The aim of our report is to define standard conditions for this analytical technique and to calculate confidence intervals for the major metabolites in normal urine samples, such as preliminary and mandatory stages for clinical diagnostic 1H NMR utilization.

Adult↗
PubMed1997

Resting and stimulated human polymorphonuclear leucocytes from type-2 diabetic patients: change in purine nucleotide pattern.

It is known that polymorphonuclear leucocytes are deeply involved in the inflammatory complications of diabetes mellitus, showing many functional and biochemical abnormalities. Because adenine and guanine metabolites exert an important role in many metabolic aspects of phagocytic cells, we have investigated the pattern of purine metabolites during the respiratory burst of polymorphonuclear leucocytes in order to characterize any difference that may be significantly correlated with the abnormal neutrophil function of diabetic patients. The results obtained show clearly that polymorphonuclear leucocytes from diabetic patients are characterized by an abnormal pattern of purine nucleotides and their metabolites. In particular, the concentration of adenine and guanine triphosphates and the net amount of adenosine triphosphate hydrolysed during neutrophil stimulation by phorbol ester is higher in diabetic than in control cells. Moreover, higher values of adenosine monophosphate, inosine monophosphate and inosine have been found in diabetic cells. The behaviour of guanosine triphosphate is highly interesting. In fact, in addition to the higher concentration found in diabetic polymorphonuclear leucocytes, stimulation by phorbol ester induces a net decrease in guanosine triphosphate whereas control neutrophils show a slight increase. These findings have been associated with the ease with which diabetic neutrophils undergo metabolic activation and sustain an inflammatory response.

Adenine Nucleotides↗
PubMed1996

Human erythrocyte metabolism is modulated by the O2-linked transition of hemoglobin.

The metabolic behaviour of human erythrocytes has been investigated with particular regard to the effect of their oxygenation state. Experiments performed at high phosphate concentration (80 mM) within the pH range 7.0-7.8 on erythrocytes at high (HOS) and low (LOS) oxygen saturation showed that at any pH value: (1) glucose consumption was independent of the oxygenation state; (2) pentose phosphate pathway (PPP) flux was about 2 times higher in the HOS than in the LOS state. At low phosphate concentration (1.0 mM) the PPP flux doubled in HOS as well as in LOS erythrocytes, whereas the decrease in glucose consumption was more marked in the HOS state. Metabolism of LOS erythrocytes approached that of HOS erythrocytes under the following conditions: (1) erythrocytes having band 3 modified by 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid; (2) CO-saturated erythrocytes. These data support the hypothesis of a modulation of the relative rates of PPP and glycolysis achieved through competition between deoxy-hemoglobin (deoxy-Hb) and glycolytic enzymes for the cytoplasmic domain of band 3.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1996

Determination of peptide dissociation constants and Stokes radius at different protonation stages by capillary electrophoresis.

Peptide electrophoretic mobility measured by capillary zone electrophoresis can be regarded as deriving from the mean of mobilities of different protonated forms, each one participating according to its charge. Stokes radius and relative percentage. The percentage is a function of the peptide dissociation constant and solution pH. Therefore, mobility modifications due to pH variations can be related to peptide dissociation constant, charge, and Stokes radius throughout general binding equations. Thus, not only can peptide dissociation constants be measured, but information about Stokes radius modifications linked to proton loss can also be obtained with picomoles of peptide.

Adrenocorticotropic Hormone↗
PubMed1995

[Transesophageal echocardiography in patients with chronic atrial fibrillation and cerebral ischemia].

The authors wanted to verify the possibility of discovering, by means of transesophageal echocardiography, cardiac causes that can't be clearly shown with 2D echocardiography, in patients who suffered a cerebral ischaemic pathology and who had a cronic atrial fibrillation. The left atrial appendage is not well visualized by the 2D echocardiographic approach. Transesophageal echocardiography has been shown to be superior to transthoracic imaging in the evaluation of the mass lesions in the left atrium and his appendage and often the best visualization of the mitral valve leaflets and aortic semilunar cusps.

Age Factors↗
PubMed1993

Non invasive evaluation in cerebrovascular study: possibility and prospects.

The authors outline the importance of the global investigation of the cerebrovascular system in order to obtain more exact information about the ethiopathology of vascular ischaemic brain disease. Each patient is always submitted to the following investigations: Duplex scanner of epiaortic vessels, Transcranial doppler and echocardiographic screening in our vascular laboratory; moreover, when haemodynamic carotid artery stenosis is present, duplex scanner of femoro-popliteal vessels and microcirculatory study of the brain with Zenon133, via inhalation, were undertaken. In the second part of the study the authors refer a relationship between the instrumental doppler signal and the real risk evidenced by techniques which can provide information on the composition, structure and stability of the plaques and correlate this information with the data from the doppler analysis. Instrumental techniques such as thermal analysis, atomic absorption spectroscopy, ICP analysis and IR spectroscopy were used to carry out this study.

Cerebrovascular Circulation↗
PubMedDate not supplied

Stroke unit: a cardio-cerebral approach.

Stroke units are special units where stroke patients receive, simultaneously, medical and physical treatment. Compared to general neurological and medical wards, stroke units show a significant reduction of short- and long-time mortality, and an improvement of long-term quality of life. Nevertheless, mortality in these units is still high (1-year mortality approximately 32%; 5-year mortality degrees 60%), and consequently, new approaches are needed to control stroke parameters during the acute phase, with the goal to reduce mortality rates. The philosophy of our stroke unit in Fermo (Italy), is to establish a strong association between heart and brain care by approaching each stroke patient as a cardiocerebral patient. In particular, we perform 12-lead Holter ECG monitoring, to prevent the vicious cycle affecting correct cerebral and cardiac functions, and to react to cardiac complications, mostly arrhythmias, that can worsen cerebral damage. Holter ECG monitoring allows a fast physiotherapeutic approach, a better evaluation of metabolic parameters, and collectively, a better global evaluation of the patient during the acute phase of disease. In two years of activity, 80 patients that were admitted to our stroke unit during 1998, and treated as cardio-cerebral patients, were followed-up. This combined treatment decreased the 1-year mortality rate by about 30%, in comparison with the 22% mortality rate reported in the literature. These results confirm the validity of stroke units, as well as of our approach based on cardio-cerebral control of each stroke patient.

Adult↗