PubMed Health⌕ Search

Biomedical subjects

C Franzini

Publications and source records attributed to C Franzini.

At least 19 recordsLinked to original sources
PubMed1992

Shivering during sleep: relationship between muscle blood flow and fiber type composition.

The present study considers in rabbit: i) the relationship between muscle blood flow (BF) increase and fiber-type composition during shivering; ii) the influence of the vigilance states (Quiet Wakefulness, QW; Synchronized Sleep, SS; Desynchronized Sleep, DS) on this relationship. The results show that muscle BF increase during shivering is proportional to the slow-twitch oxidative (SO) fiber component in QW and SS; in DS the proportionality is lost. This is in accordance with the disappearance of shivering, together with all thermoregulatory effector responses, in this sleep state. Another muscle circulation pattern occurring at low ambient temperature, the relationship between BF increase and muscle depth, also disappears in DS. This confirms that the integrative control of muscle circulation, like other integrative mechanisms, is impaired during DS.

Analysis of Variance↗
PubMed1992

Multicentre clinical placebo-controlled study with buflomedil in the treatment of mild dementia of vascular origin.

A study was carried out in 73 male or female patients suffering from mild vascular dementia. The experimental protocol involved an initial run-in period (14 days) and subsequent double-blind, randomized treatment with 300 mg buflomedil or placebo given orally twice daily for 90 days. At the end of this treatment period, all patients received buflomedil for a further 90 days and, thereafter, patients received buflomedil or no further treatment for another 90 days. The efficacy of buflomedil was monitored using rating scales and neuropsychological tests. The findings of the study indicate that buflomedil improved the symptoms of vascular dementia; the most improvement was recorded in patients who had received buflomedil for the longest period. Inadequacy, cooperation, psycho-affective disorders, self-care and somatic complaints were positively influenced by buflomedil. The efficacy of buflomedil may be due to its effects on platelet aggregation and improvement in blood flow distribution to the ischaemic brain and oxygenation of brain tissue.

Aged↗
PubMed1992

A collaborative trial for the evaluation of blood cholesterol measurement in clinical laboratories in Italy.

A collaborative trial for the evaluation of blood cholesterol measurement in Italy was carried out, with the use of two lyophilized controls, whose target values, respectively 4.42 and 6.21 mmol/l, were established by means of "definitive" methodology (isotope dilution/mass spectrometry). Results from 480 participants showed a somewhat broad dispersion (CV 6.1% and 6.3% respectively), and a definite bias (-0.25 mmol/l and -0.61 mmol/l respectively) with respect to the target values. The different analytical systems were characterized by different combinations of inaccuracy and imprecision; however, the bias observed for the higher concentration sample was a constant finding. The behaviour of the control materials, in comparison with that exhibited by patients' sera, was assessed in a manual enzymatic procedure and in the Kodak Ektachem 700 and Technicon Chem 1 systems. The peculiar property of one control material to behave differently from patients' sera in some analytical systems, i.e. the lack of commutability, was found to be partially responsible for the observed bias in the three methods studied. The importance of testing for commutability of the control materials to be used for the control of accuracy is stressed.

Blood Chemical Analysis↗
PubMed1992

[Acute renal damage caused by ampicillin. Description of a case].

Approximately one week after a cycle of antibiotic therapy using ampicillin for pulmonary inflammation, an 82-year-old woman developed symptoms of acute renal insufficiency reminiscent of nephrotic syndrome. Symptoms were completely reversible and normal renal function was recovered (even after 14 months of follow-up). The Authors conclude by attributing this to acute tubulo-interstitial nephropathy due to hypersensitivity to ampicillin.

Acute Kidney Injury↗
PubMed1991

Loss of integrative control of peripheral circulation during desynchronized sleep.

Regional blood flow (BF) changes during sleep were measured in rabbits at low, neutral, and high ambient temperatures (Ta) with radioactive microspheres. At both low and high Ta, peripheral vasomotor changes at the onset of desynchronized sleep (DS) were incompatible with thermoregulatory homeostasis. At low Ta, BF decreased in muscle (with the disappearance of shivering), whereas it increased in the arteriovenous anastomoses (AVA) and in the splanchnic bed. At high Ta, BF decreased in muscle (with the disappearance of panting) and in the AVA, whereas it increased in the splanchnic bed. An impaired central nervous regulation underlies the disruption of peripheral circulation patterns in this sleep stage. The lack of adaptive vasomotor adjustments in DS, which has little consequence in normal conditions, may become relevant in cardiovascular pathophysiology when BF redistribution through increased neurogenic vasomotor activity becomes a major compensating mechanism.

Animals↗
PubMed1991

Measurement of alkaline phosphatase activity in serum with N-methyl-D-glucamine as a buffer: evaluation of the method for routine use.

Some aspects of the measurement of alkaline phosphatase activity concentration in human serum, using N-methyl-D-glucamine as a buffer, were evaluated with a view to the possible routine use of the method. The evaluated characteristics included: the temperature-dependence of the pH of the buffer; the effect of adding the magnesium/zinc ions buffer; the effect of the serum volume fraction; the substrate-starter versus the serum-starter mode; the effect of modifying the formulation of reagents; the within-run and the between laboratory imprecision; the correlation with an alternative routine method. Also, sex- and age-related reference values were produced, based on 2968 values from selected reference sample groups in 7 laboratories. In general, the results demonstrate the robustness of the method, its adaptability to a variety of mechanized analysers, and hence its feasibility as a routine measurement method.

Adolescent↗
PubMed1991

The reference method value.

The basis for the achievement and the control of accuracy in routine testing is represented by a hierarchy of methods. Different materials are used for transferring accuracy and for monitoring traceability. In these two operations, unreliable results may be obtained by using different materials (e.g. clinical specimens and reference materials) when matrix-sensitive methods are being used, as is frequently the case with routine methods. Intermediate-level (reference) methods may help to bridge the gap between the highest and the lowest levels, by using clinical specimens for method comparisons. If non-commutable materials are used for calibration and control of routine methods, these should have system specific values, assigned with an appropriate experimental design, including appropriate use of clinical specimens. Setting up networks of reference laboratories to implement and run reference systems on an ongoing basis, appears to be the practical pathway to accuracy. Improvements should be directed to lowering the matrix-sensitivity of routine methods and increasing the commutability of reference materials.

Calibration↗
PubMed1991

Use of a synthetic soluble bilirubin derivative to assess interference in creatinine measurements.

In assessing interference from bilirubin, the use of a synthetic soluble derivative (ditaurobilirubin, DTB) is recommended as a surrogate for the natural conjugates (Bc). We compared the interference effect of unconjugated bilirubin (Bu), Bc, and DTB, using six mechanized methods for serum creatinine measurement. No significant interference was noted in methods that include removal of proteins or in an enzymatic method involving NADH oxidation. Heavy (negative) interference was observed in an alkaline picrate method, and in direct enzymatic methods based on hydrogen peroxide measurement: interference was always more pronounced in the presence of the two soluble derivatives (Bc and DTB), whose interference was of the same magnitude. These results point out the utility of testing for bilirubin interference by using soluble derivatives, in addition to Bu, and suggest the feasibility of using DTB as a surrogate for Bc for this purpose.

Bilirubin↗
PubMed1990

Regional splanchnic blood flow during sleep in the rabbit.

Regional splanchnic blood flow (rSBF) was measured in rabbits with the radioactive microsphere technique. No statistically significant changes occurred in rSBF or vascular conductances in relation to the different states of the sleep-waking cycle (quiet-wakefulness, synchronized sleep, and desynchronized sleep).

Animals↗
PubMed1990

An extraction/enzymatic procedure for serum cholesterol measurement: evaluation of performance characteristics.

The performance characteristics of an extraction/enzymatic procedure for serum cholesterol measurement were evaluated. The procedure is substantially derived from the accepted reference method as standardized by the Centers for Disease Control, substituting the enzymatic reaction for the Liebermann-Burchard reaction. Imprecision (CV) was consistently less than 1.5%, and accuracy was comparable to that of the definitive isotope dilution mass spectrometry method and the accepted reference method. Direct comparison of the enzymatic with the Liebermann-Burchard reaction, using a set of 50 human sera, revealed about -0.05 mmol/l constant bias of the former versus the latter, this being possibly due to higher specificity of the enzymatic reaction. As compared with the accepted reference method, the method described is characterized by higher practicability, the reagent being easier to prepare and to handle, and generating a more stable, chemically defined end-product.

Blood Chemical Analysis↗
PubMed1990

Importance of using soluble derivatives in assessing bilirubin interference: the example of gamma-glutamyltransferase.

In assessing possible in vitro interference from bilirubin on analytical methods, different results are to be expected from using either unconjugated (uB) or conjugated (cB) bilirubin as test materials, because of their different solubilities. In vitro interference of a synthetic soluble bilirubin derivative (ditauro-bilirubin, dtB) on gamma-glutamyltransferase activity measurement has been studied, in comparison with uB. In three out of five analytical methods/systems for the measurement of the enzyme activity, significantly higher (negative) interference was observed in the presence of the soluble derivative. Whichever the mechanism for the observed effect, the opportuneness of using soluble derivatives in order to assess bilirubin interference is pointed out: pathological serum specimens, submitted for laboratory investigations, are indeed frequently loaded with soluble bilirubin conjugates.

Bilirubin↗
PubMed1990

[Renovascular hypertension: a clinical dilemma].

The case of a 63-year-old patient in whom serious hypertension of recent onset was recalcitrant to conventional anti-hypertensive therapy is reported. Clinical and biohumoral data suggested a form of nephro-vascular hypertension. This clinical case led to a review of the clinical and diagnostic criteria of this by means rare form of secondary hypertension. The correctness of the diagnostic and therapeutic approach was confirmed by the normalisation of plasma renin levels and by the good control of arterial pressure after right nephrectomy (rendered indispensable after the angiographic finding of complete stenosis of the right renal artery).

Female↗
PubMed1989

Muscle blood flow changes during sleep as a function of fibre type composition.

In rabbits blood flow was measured in 19 muscles with the radioactive microsphere technique. Fibre type composition (SO, slow-twitch oxidative; FOG, fast-twitch oxidative-glycolytic; FG, fast-twitch glycolytic) was determined histochemically for the same muscles. While no significant changes occur in the transition from quiet wakefulness (QW) to synchronized sleep (SS), in desynchronized sleep (DS) blood flow decreases in SO and increases in FOG and FG fibres. These changes may be related to the changes in motor activity characteristic of DS: muscle atonia and twitches, respectively.

Animals↗