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Showing papers by "University of Perugia published in 1984"


Journal ArticleDOI
TL;DR: Expectations for coronary death from the experience in the United States and northern Europe greatly exceeded observed deaths in southern Europe for men of their age, serum cholesterol, blood pressure, smoking habits, physical activity, and relative weight.

518 citations


Journal ArticleDOI
01 Dec 1984-Diabetes
TL;DR: Early morning increases in plasma glucose concentrations and insulin requirements observed in IDDM and NIDDM may be an exaggeration of a physiologic circadian variation in hepatic insulin sensitivity induced by antecedent changes in catecholamine and/or growth hormone secretion.
Abstract: To ascertain whether the dawn phenomenon occurs in nondiabetic individuals and, if so, whether it is due to an increase in glucose production or a decrease in glucose utilization, we determined plasma concentrations of glucose, insulin, C-peptide, and counterregulatory hormones, as well as rates of glucose production, glucose utilization, and insulin secretion at one-half-hourly intervals between 1:00 and 9:00 a.m. in eight normal volunteers. After 5:30 a.m., plasma glucose, insulin, and C-peptide concentrations all increased significantly; rates of glucose production, glucose utilization, and insulin secretion also increased (all P less than 0.05). Plasma cortisol, epinephrine, and norepinephrine increased significantly from nocturnal nadirs between 4:00 and 6:30 a.m. Plasma growth hormone, which had increased episodically between 1:00 and 4:30 a.m., decreased thereafter nearly 50% (P less than 0.05). Plasma glucagon did not change significantly throughout the period of observation. These results indicate that a dawn-like phenomenon, initiated by an increase in glucose production, occurs in nondiabetic individuals. Thus, early morning increases in plasma glucose concentrations and insulin requirements observed in IDDM and NIDDM may be an exaggeration of a physiologic circadian variation in hepatic insulin sensitivity induced by antecedent changes in catecholamine and/or growth hormone secretion.

186 citations


Journal ArticleDOI
TL;DR: In this article, a one-dimensional bistable flow driven by additive, exponentially correlated Gaussian noise is considered and the small relaxation time Fokker-Planck approximations, widely used in the recent literature, are derived and possible shortcomings of those approximation schemes are discussed.
Abstract: A one-dimensional bistable flow driven by additive, exponentially correlated Gaussian noise is considered. The small relaxation time Fokker-Planck approximations, widely used in the recent literature, are derived and possible shortcomings of those approximation schemes are discussed. In particular, it is pointed out that higher order non-Fokker-Planck type contributions are generally of the same order as the Fokker-Planck terms. In principle, those contributions cannot be neglected if the global behavior of the probability solutions is to be described accurately. The result for the activation rate (Arrhenius factor), as evaluated from the approximative Fokker-Planck schemes, does not coincide in leading order in the correlation time τ of the noise with a computer simulation of the rate at low noise level. This result indicates that the wings of the stationary probability\(\bar p(x)\) are in leading order in τ not recovered correctly from the approximative Fokker-Planck schemes. Some implications of our study for adiabatic elimination procedures are also discussed.

142 citations


Journal ArticleDOI
TL;DR: In this article, a serie de theoremes qui generalise le theoreme du col are presented, i.e. theorem 1 : I:X→R ou X est un espace de Banach reel et ou I satisfait la condition de compacite de Palais-Smale.

115 citations


Journal ArticleDOI
01 Aug 1984-Diabetes
TL;DR: It is concluded that this test, when performed in standardized conditions, is safe and reproducible and can reliably predict those patients with type I diabetes who are at risk of developing severe hypoglycemia during intensive insulin therapy.
Abstract: The safety, reproducibility, and reliability of an insulin infusion test for assessment of adequate glucose counterregulation were evaluated in 18 patients with type I (insulin-dependent) diabetes mellitus. When the test (a 60-min, 30-mU/m 2 /min insulin infusion) was administered on three separate occasions at 3–4-wk intervals, coefficients of variation for plasma glucose and counterregulatory hormone (glucagon, epinephrine, cortisol, and growth hormone) responses averaged less than 8%. No patient experienced symptoms requiring discontinuation of the test and plasma glucose concentrations increased spontaneously after stopping the insulin infusion. Using objective criteria based on plasma glucose nadirs or postnadir rates of plasma glucose recovery, no patient judged to have adequate glucose counterregulation by the test (post-nadir rates of plasma glucose recovery or plasma glucose nadir above 0.4 mg/dl/min and 45 mg/dl) developed severe hypoglycemia (plasma glucose

114 citations


Journal ArticleDOI
TL;DR: In this paper, a brief discussion of the present status of knowledge of the mechanism of intercalation processes in α-zirconium phosphate, recent developments particularly in the synthesis of new layered materials with α-structures are examined.

108 citations



Journal ArticleDOI
TL;DR: In this paper, a study of the production characteristics of W and Z bosons produced at the CERN p p p Collider has been made, where W→ev decays and 39 Z→e + e − decays were identified by the UA2 detector.

85 citations


Journal ArticleDOI
TL;DR: The results indicate that the glucagon response to insulin-induced hypoglycemia is independent of the level of both endogenous intraislet and exogenous arterial insulin concentration in normal man, and that this response may be normal in the absence of endogenous insulin secretion, in contrast to earlier reports.
Abstract: To elucidate the mechanisms controlling the response of glucagon to hypoglycemia, a vital component of the counterregulatory hormonal response, the role of intraislet insulin was studied in seven normal subjects and five subjects with insulin-dependent diabetes mellitus (IDDM) (of less than 15-mo duration). In the normal subjects, hypoglycemia (arterial plasma glucose [PG] 53 +/- 3 mg/dl) induced by an intravenous insulin infusion (30 mU/m2 X min for 1 h, free immunoreactive insulin [FIRI] 58 +/- 2 microU/ml) elicited a 100% fall in insulin secretion and an integrated rise in glucagon of 7.5 ng/ml per 120 min. When endogenous insulin secretion was suppressed by congruent to 50 or congruent to 85% by a hyperinsulinemic-euglycemic clamp (FIRI 63 +/- 1.5 or 147 +/- 0.3 microU/ml, respectively) before hypoglycemia, the alpha cell responses to hypoglycemia were identical to those of the control study. When the endogenous insulin secretion was stimulated by congruent to 100% (hyperinsulinemic-hyperglycemic clamp, FIRI 145 +/- 1.5 microU/ml, PG 132 +/- 2 mg/dl) before hypoglycemia, the alpha cell responses to the hypoglycemia were also superimposable on those of the control study. Finally, in C-peptide negative diabetic subjects made euglycemic by a continuous overnight intravenous insulin infusion, the alpha cell responses to hypoglycemia were comparable to those of normal subjects despite absent beta cell secretion, and were not affected by antecedent hyperinsulinemia (hyperinsulinemic-euglycemic clamp for 2 h, FIRI 61 +/- 2 microU/ml). These results indicate that the glucagon response to insulin-induced hypoglycemia is independent of the level of both endogenous intraislet and exogenous arterial insulin concentration in normal man, and that this response may be normal in the absence of endogenous insulin secretion, in contrast to earlier reports. Thus, loss of beta cell function is not responsible for alpha cell failure during insulin-induced hypoglycemia in IDDM.

67 citations


Journal ArticleDOI
TL;DR: Aqueous suspensions of delaminated zirconium phosphate have been recently obtained in this article by a suitable intercalation-deintercalation of alkylamines.

65 citations


Journal ArticleDOI
TL;DR: In this article, a 275.5 m thick section of white, pelagic limestones occupying the valley of the Fonte del Giordano river on the southern slope of Mt. Montagnola has yielded a biostratigraphically controlled clear magnetic reversal pattern after thermal cleaning.

Journal ArticleDOI
TL;DR: It is shown that the strong immunodepression provoked by Cy does not modify significantly the susceptibility of the animal to those species of Candida which were endowed with low or no pathogenicity for normal mice, but it greatly increases the susceptibility to thosespecies ofcandida that are already pathogenic for unmodified host.
Abstract: The experimental pathogenicity of Candida albicans, C. krusei, C. guilliermondii, C. parapsilosis, C. tropicalis and C. viswanathii was tested in normal and in cyclophosphamide-(Cy) immunodepressed mice. In unpretreated CD1 mice only C. albicans, C. tropicalis and C. viswanathii were pathogenic on intravenous challenge, with LD50 of 1.0 X 10(6), 4.8 X 10(6), 7.2 X 10(8) cells, respectively, per kg. Three days after a single intraperitoneal injection of Cy (150 mg kg-1) mice had a marked decrease in spleen weight and cellularity as well as reduced numbers of circulating leukocytes. Under these conditions, there was a significant, proportional increase in pathogenicity of C. albicans, C. tropicalis and C. viswanathii but the animals were still resistant to challenge with C. krusei, C. guilliermondii and C. parapsilosis. This pattern of susceptibility was not influenced by higher doses of Cy. Only C. albicans and C. tropicalis were capable of rapid and extensive multiplication in target organs such as kidney and brain in normal and Cy-treated mice and for both these species of Candida, there was a 'rebound' effect of increased resistance to experimental infection after 12 days from Cy administration. This study shows that the strong immunodepression provoked by Cy does not modify significantly the susceptibility of the animal to those species of Candida which were endowed with low or no pathogenicity for normal mice, but it greatly increases the susceptibility to those species of Candida that are already pathogenic for unmodified host.

Journal ArticleDOI
TL;DR: It was shown that the source of the Saccharomyces flora of fermenting musts was the winery itself and that a selected yeast starter added initially is able to impose itself on the spontaneous grape juice flora naturally.
Abstract: The source of Saccharomyces cerevisiae responsible for the natural fermentation of grape must and the dominance of added yeast in wine fermentations have been studied using a strain of Saccharomyces cerevisiae selected for wine-making and labelled for not producing hydrogen sulphide (H2S-) as fermentation starter.It was shown that the source of the Saccharomyces flora of fermenting musts was the winery itself and that a selected yeast starter added initially is able to impose itself on the spontaneous grape juice flora naturally.

Journal ArticleDOI
TL;DR: Alkyl and aryl selenide anions react with unactivated vinyl halides, in dipolar aprotic solvents, to give alkyl or aryal vinyl selenides in good yields as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this paper, a new way of fitting ab initio values of the electronic energy of reactive systems is discussed, and the potential energy surface of the Li + HF reaction is built up by matching the functional forms fitted to the different regions of the interaction.
Abstract: A new way of fitting ab initio values of the electronic energy of reactive systems is discussed. Following this scheme, the potential energy surface of the Li + HF reaction is built up by matching the functional forms fitted to the different regions of the interaction.

Journal ArticleDOI
TL;DR: It is suggested that NE might be associated with pressure factors in regulating LVhypertrophy development only in a subgroup of hypertensive patients characterized by echocardiographic LV hypertrophy and abnormally elevated circulating NE levels.
Abstract: The relations between some pressure and humoral factors, and some echocardiographic indexes of left ventricular (LV) hypertrophy were studied in 64 patients with essential hypertension. Fifty-seven percent of these patients showed echocardiographic evidence of LV hypertrophy (LV mass > 215 g). Multivariate stepwise regression analysis showed that only mean blood pressure (BP) and circulating norepinephrine (NE) levels were significantly related to LV mass index in the group of patients with LV hypertrophy. However, mean BP was the only factor related to LV mass index in the subgroup of patients with LV hypertrophy and plasma NE within the normal laboratory range, whereas NE was the sole factor related to LV mass index in the subgroup with LV hypertrophy and abnormally elevated NE levels (greater than mean + 2 standard deviations of the normal laboratory range). Correlation of LV mass index vs NE was −0.35 (not significant) in the former group of patients and 0.89 (p

Journal ArticleDOI
TL;DR: The geomagnetic field at this time was characterized by two intervals of mixed polarity, separated by an interval of predominantly normal polarity corresponding to the Jurassic "quiet-zone" in the oceanic magnetic anomaly record as mentioned in this paper.

Journal ArticleDOI
TL;DR: Two alternatives were considered feasible in improving prophylaxis for rotavirus infections: the continuous feeding of calves with 1st day colostrum as part of the ration throughout the period of greatest risk (first week of life), or enhancing the efficacy of the vaccine in pregnant cows to the point where antibody concentration in the milk would remain at a protective level.
Abstract: Calves which were continuously fed colostrum from vaccinated cows for the first ten days of life, were fully refractory to experimental infection with strain 81/36 F of bovine rotavirus. By contrast, the response to virus exposure of calves which were treated with normal colostrum was identical to that of the control calves, in that they underwent severe diarrhea and a significant slowing of the growth rate. The antibody titer in the milk of vaccinated cows tends to decline rapidly so that it no longer provides any protective effect. Two alternatives were considered feasible in improving prophylaxis for rotavirus infections: (a) the continuous feeding of calves with 1st day colostrum as part of the ration throughout the period of greatest risk (first week of life), or (b) enhancing the efficacy of the vaccine in pregnant cows to the point where antibody concentration in the milk would remain at a protective level.

Journal ArticleDOI
TL;DR: In this article, a finite element model of the ground deformations observed at Phlegraean Fields is proposed, which assumes an oblate-spheroid magma chamber at the depth of 5.4 km with major semiaxis of 1.5 km.
Abstract: A preliminary finite elements model of the ground deformations observed at Phlegraean Fields is proposed. The model assumes an oblate-spheroid magma chamber at the depth of 5.4 km with major semiaxis of 1.5 km and minor semiaxis of 0.75 km. The dimensions of the magma chamber have been evaluated by using a thermal model based on the assumptions that a progressively cooling huge magmatic body is responsible for the volcanic activity at Phlegraean Fields in the last 35,000 years. Surface deformations caused by an over-pressure of 30 MPa in the magma chamber have been calculated. Constant, and temperature-dependent elastic parameters of the surrounding medium have been considered. Vertical displacements of the order of those presently observed at Phlegraean Fields can be obtained only with temperature-dependent elastic properties of the medium.

Journal ArticleDOI
TL;DR: In this article, the role played by tunnelling, resonance and interference effects in determining the reactivity of the Li + FH reaction has been investigated using a surface moulded on ab initio values of the electronic energy.


Journal ArticleDOI
TL;DR: As the enzyme activities were positively correlated to each other, a common source of the enzymes is suggested even though the coefficients of correlation demonstrate that only a low percentage of the variability can be ascribed to the interactions among enzyme activities.
Abstract: Amylase, dehydrogenase, arylsulphatase and phosphatases activities were measured in a clay-loam soil amended with seven different crop residues. All enzyme activities, except phosphomonoesterase, were generally higher in the derived soil samples than in the original soil. Addition of tobacco and sunflower residues caused an increase on most of the enzyme activities while tomato residues increased only the amylase and phosphodiesterase activities.

Journal ArticleDOI
TL;DR: T Tone-pip ABR morphology does not show the conventional seven peaks but a single large vertex-positive wave that probably corresponds to the Jewett V wave, and it is possible to obtain ABRs to middle- and low-frequency stimuli.
Abstract: Auditory brainstem responses (ABR) evoked by clicks allow a threshold evaluation for the high-frequency range (2-4 kHz) but not for middle and low frequencies (0.5-1 kHz). In 19 normally hearing subjects aged between 24 and 40 years. ABRs have been recorded using clicks and 0.5- and 1-kHz tone pips, with durations of 6 and 3 ms, respectively, and rise-decay times of 3 and 1.5 ms. The input signal was filtered by a passband filter of 20-5 000 Hz. Parameters of tracings elicited by the different kinds of stimuli are compared. Tone-pip ABR morphology does not show the conventional seven peaks but a single large vertex-positive wave. On the ascending branch high-frequency potentials, probably corresponding to the I, II, III and IV-V click-evoked peaks, were visible in some cases, but they rapidly disappeared as the stimulus intensity was decreased. Their 2.3-3 ms greater mean latency values are presumably related to the rise times of the stimuli employed. In terms of bioelectric generators, this large vertex-positive peak probably corresponds to the Jewett V wave. It probably represents a generalized asynchronous dendritic activity. Thus it is possible to obtain ABRs to middle- and low-frequency stimuli. Mean amplitude values of the slow wave are considerably higher than those of the Jewett V wave, but standard deviations are also larger. The positive wave has been identified in response to 1-kHz tone pips in 100% of cases at 30 dB nHL and in 52% of cases at 20 dB, while for 0.5-kHz tone pips in 73.7% of cases at 30 dB and in 57% at 20 dB. On the whole the threshold is located between 15 and 30 dB nHL.

Journal ArticleDOI
M. Maurizi1, F. Ottaviani1, G. Paludetti1, M. Rosignoli1, G. Almadori1, A Tassoni1 
TL;DR: The morphology of MLC elicited by tone pips is less affected by changes in stimulus frequency than that of corresponding auditory brainstem responses, thus, MLC are a reliable indicator for defining low- and middle-frequency auditory thresholds.
Abstract: Middle-latency auditory components (MLC) in response to clicks and tone pips have been recorded in 20 normal subjects, aged between 26 and 32 years, in order to verify their reliability in response to frequency-specific stimuli (0.5 and 1kHz). The results indicate a good reliability of MLC obtained when using tone pips. The responses show the conventionally labeled Po, Na, Nb, Pb waves. The latencies of these waves tend to be greater than those of the corresponding waves elicited by clicks and their amplitudes are smaller. This is probably due to an asynchrony of the responses. The Po and Pa waves are the most resistant to decreasing stimulus intensity, as both are clearly detectable down to 20 dB nHL, but Po is the best threshold index because at 20 dB it has a more clear-cut shape than Pa. According to the latency values obtained for MLC elicited by both clicks and tone pips, the Po wave is probably generated at the inferior colliculus level. The latency shift towards the click-elicited Jewett wave V is mainly due to the different filter settings employed. The morphology of MLC elicited by tone pips is less affected by changes in stimulus frequency than that of corresponding auditory brainstem responses. Thus, MLC are a reliable indicator for defining low- and middle-frequency auditory thresholds.

Journal ArticleDOI
TL;DR: Studies on the effect of high doses of AA and DHA added to the culture medium in single or fractionated doses revealed that fractionated administration is more efficient in inhibiting cell multiplication than single administration.
Abstract: The effects of AA and DHA on ATP C+ cell multiplication in vitro were studied by measuring incorporation of 3H thymidine into DNA. The results obtained demonstrate that both AA and DHA have the same effects: they favor cell multiplication at low doses and inhibit it at high doses. Experiments carried out with serial doses of both these substances revealed that AA is more efficient in determining both stimulating and inhibiting effects. The lesser efficiency of DHA may be attributed to its limited stability in culture medium. Studies on the effect of high doses of AA and DHA added to the culture medium in single or fractionated doses revealed that fractionated administration is more efficient in inhibiting cell multiplication than single administration.

Journal ArticleDOI
M. Maurizi1, F. Ottaviani1, G. Paludetti1, G. Almadori1, C. Zappone1 
TL;DR: The data obtained show that the nasal mucociliary function is generally reduced in children but, while in the group with poorly developed adenoids an early and progressive improvement can be observed, the children with severely hypertrophied adenoid show an impaired function up to 10 years, without age-related improvements.

Journal ArticleDOI
TL;DR: Comparisons between worm cast, substrate and soil IR and NMR spectra demonstrated the humifying capacity of worms.
Abstract: An investigation was carried out to analyze the chemical composition and enzymatic activity of five worm casts obtained from various animal dungs and municipal waste. The E4/E6 values for humic and fulvic acids were higher in all worm casts than in a typical Umbrian soil. Comparisons between worm cast, substrate and soil IR and NMR spectra demonstrated the humifying capacity of worms. Enzyme activity was high in all casts and only dehydrogenase seemed to be affected by lead concentration.

Journal ArticleDOI
TL;DR: Fibrochondrogenesis is a distinct, neonatally lethal, short-limb skeletal dysplasia which was first described in a single patient in 1978 and now has distinct radiographic and chondro-osseous morphologic defects different from those seen in the other known skeletal Dysplasias.
Abstract: Fibrochondrogenesis is a distinct, neonatally lethal, short-limb skeletal dysplasia which was first described in a single patient in 1978. We report the radiographic and morphologic studies of 2 additional unrelated stillborn infants with fibrochondrogenesis. This syndrome has distinct radiographic and chondro-osseous morphologic defects different from those seen in the other known skeletal dysplasias. The long bones are short and dumbbell-shaped with metaphyseal flare. The spine is platyspondylic with superior-inferior clefting defects, and the ribs are short and distally cupped. The growth-plate cartilage is grossly disorganized and has a densely fibrous collagenous matrix when examined by light and electron microscopy. Light, transmission, and scanning electron microscopy shows diaphyseal and metaphyseal trabecular bone to be normal.

Journal ArticleDOI
01 Apr 1984-Diabetes
TL;DR: It is concluded that near-normalization of glycemic control for up to 9 mo is insufficient to reverse the impairment in glucose counterregulation found in long-term IDDM.
Abstract: To assess the effects of glycemic control on glucose counterregulation, rates of plasma glucose recovery from hypoglycemia and counterregulatory hormonal responses were studied in 18 C-peptide-negative patients with insulin-dependent diabetes mellitus (IDDM) before and after either improvement, no change, or deterioration in glycemic control. Hypoglycemia was induced by an i.v. insulin infusion (30 mU/m2 X min for 1 h) after maintenance of euglycemia overnight with i.v. insulin. In 13 patients with long duration of IDDM (9 +/- 0.5 yr, mean +/- SEM) and initially poor glycemic control (mean diurnal blood glucose, MBG 199 +/- 8 mg/dl, ketoamine-HbA1 12.4 +/- 0.2%; nondiabetic subjects 104 +/- 4 mg/dl and 6.8 +/- 0.09%, respectively), rates of plasma glucose recovery from hypoglycemia (0.30 +/- 0.01 versus 0.60 +/- 0.01 mg/dl X min in nondiabetic subjects, P less than 0.001) and plasma glucagon (AUC 0.56 +/- 0.09 versus 6.3 +/- 0.50 ng/ml X 150 min in nondiabetic subjects, P less than 0.01) and epinephrine (AUC 16.9 +/- 0.2 versus 25.7 +/- 0.2 ng/ml X 150 min in nondiabetic subjects, P less than 0.001) responses to hypoglycemia were impaired. Intensive therapy (three daily injections of insulin) instituted in 7 out of 13 IDDM patients for up to 9 mo improved MBG (124 +/- 6 mg/dl, P less than 0.01) and ketoamine-HbA1 (7.9 +/- 0.02%, P less than 0.01) but not rates of plasma glucose recovery (0.31 +/- 0.01 mg/dl X min) and plasma glucagon (AUC 0.69 +/- 0.07 ng/ml X 150 min) and epinephrine (AUC 14.9 +/- 0.17 ng/ml X 150 min) responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Journal ArticleDOI
TL;DR: The beta-hexosaminidase (EC 3.2.1.30) isoenzymes were separated on the basis of their carbohydrate moieties by an affinity chromatography using immobilized phenylboronate to find an extra isoenzyme that may be a marker for the leukemic conversion of hematopoietic tissue.