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Biomedical subjects

G Grassi

Publications and source records attributed to G Grassi.

At least 37 records · Page 2Linked to original sources
PubMed2002

Lifestyle intervention by group care prevents deterioration of Type II diabetes: a 4-year randomized controlled clinical trial.

AIMS/HYPOTHESIS: Metabolic control worsens progressively in Type II (non-insulin-dependent) diabetes mellitus despite intensified pharmacological treatment and lifestyle intervention, when these are implemented on a one-to-one basis. We compared traditional individual diabetes care with a model in which routine follow-up is managed by interactive group visits while individual consultations are reserved for emerging medical problems and yearly checks for complications. METHODS: A randomized controlled clinical trial of 56 patients with non-insulin-treated Type II diabetes managed by systemic group education and 56 control patients managed by individual consultations and education. RESULTS: Observation times were 51.2+/-2.1 months for group care and 51.2+/-1.8 for control subjects. Glycated haemoglobin increased in the control group but not in the group of patients ( p<0.001), in whom BMI decreased ( p<0.001) and HDL-cholesterol increased ( p<0.001). Quality of life, knowledge of diabetes and health behaviours improved with group care ( p<0.001, all) and worsened among the control patients ( p=0.004 to p<0.001). Dosage of hypoglycaemic agents decreased ( p<0.001) and retinopathy progressed less ( p<0.009) among the group care patients than the control subjects. Diastolic blood pressure ( p<0.001) and relative cardiovascular risk ( p<0.05) decreased from baseline in group patients and control patients alike. Over the study period, group care required 196 min and 756.54 US dollars per patient, compared with 150 min and 665.77 US dollars for the control patients, resulting in an additional 2.12 US dollars spent per point gained in the quality of life score. CONCLUSION/INTERPRETATION: Group care by systemic education is feasible in an ordinary diabetes clinic and cost-effective in preventing the deterioration of metabolic control and quality of life in Type II diabetes without increasing pharmacological treatment.

Adult↗
PubMed2001

Participation of the hypothalamus-hypophysis axis in the sympathetic activation of human obesity.

Previous studies have shown that hypothalamic and hypophyseal factors are involved in the acute sympathoexcitation induced by a variety of laboratory stimuli. Whether a chronic condition of sympathetic activation, such as that characterizing human obesity, is also dependent on these factors has never been investigated. In 40 normotensive obese subjects ([mean+/-SEM] age, 39.1+/-0.8 years) we measured blood pressure (Finapres), heart rate (ECG), and postganglionic muscle sympathetic nerve activity (MSNA) (microneurography). In 20 subjects measurements were repeated, according to a double-blind randomized sequence, after a midnight oral dose of dexamethasone (1 mg) (n=10) or placebo (n=10), while in the remaining subjects they were performed again after 1 week of a daily evening oral administration of 1 mg of dexamethasone (n=10) or placebo (n=10). The same protocol was performed in 16 age-matched lean normotensives. In both groups acute dexamethasone administration markedly reduced plasma cortisol (radioimmunoassay), without affecting hemodynamic and neural variables. In contrast to the acute administration, in obese subjects prolonged dexamethasone administration, although not affecting blood pressure and heart rate, significantly reduced both plasma cortisol (from 16.0+/-1.3 to 0.7+/-0.1 microg/dL; P<0.01) and MSNA (from 59.5+/-2.8 to 39.6+/-2.9 bursts per 100 heartbeats; P<0.02; -33.1+/-4.1%). This was not the case in lean subjects, in which the dexamethasone-induced reduction in plasma cortisol was associated with a slight and nonsignificant MSNA decrease. In both lean and obese subjects, placebo administration caused no change in any variable. Thus, prolonged dexamethasone administration exerts in obese subjects marked sympathoinhibitory effects that are not detectable in lean individuals. This suggests that hypothalamic and hypophyseal factors substantially contribute to the sympathoexcitation of obesity.

Adult↗
PubMed2001

The influence of different jaw positions on the endurance and electromyographic pattern of the biceps brachii muscle in young adults with different occlusal characteristics.

To investigate the hypothesis of a functional coupling between the stomatognathic motor apparatus and the muscles of other body districts, as well as between occlusal conditions and neuromuscular performance, two groups of men (age range 20-26 years), with either normal occlusion (14 men) or malocclusion (15 men), sustained with their dominant arm a dumbbell weighing 80% of their maximum while maintaining different jaw positions: mouth open, without dental contact; mouth close, with light dental contact; maximum voluntary clench; maximum voluntary clench on two cotton rolls positioned on the posterior mandibular teeth; maximum voluntary clench on one cotton roll positioned on the right/left-side posterior mandibular teeth. Surface electromyography (EMG) of the biceps brachii muscle was performed, and the endurance time, mean root mean square (rms) potential, and mean median power frequency were computed. The mean potential and median power frequency were also computed for 2-s windows, and values as a function of time were interpolated by a linear regression analysis. Data were compared between groups and trials by using a factorial analysis of variance. The malocclusion group subjects could perform the exercise for a longer time span than the normal occlusion individuals (P < 0.005). During this endurance time their biceps brachii muscles contracted with different patterns: on average, in the malocclusion group they had a larger EMG amplitude (P < 0.005), and a shift of the power spectrum toward lower frequencies (P < 0.005). The factor 'jaw position' was significant only for the endurance time (P < 0.005). In both groups, the longest endurance time was found in the 'clench' trial, while the shortest in the 'right-side bite' trial. In conclusion, a morphologically altered occlusion does not always worsen the muscular performance of other body districts, and the use of occlusal supports (cotton rolls) is not always beneficial.

Adult↗
PubMed2001

Patterns of regional sympathetic nerve traffic in preascitic and ascitic cirrhosis.

Overactivity of the sympathetic nervous system and portal hypertension are key factors in the development of ascites in cirrhosis. The sympathoexcitation that characterizes the more advanced stages of liver diseases is less clearly defined in preascitic cirrhosis. We measured sympathetic nerve traffic to skeletal muscle (peroneal nerve) and to skin districts by microneurography in (1) 12 Child class A cirrhotic patients with clinically significant portal hypertension (portal pressure gradient > 10 mm Hg, 14.8 +/- 1.2 mm Hg, mean +/- SEM) but without actual or previous ascites, (2) 16 Child class C cirrhotic patients with tense ascites, and (3) 10 patients with mild congestive heart failure, a condition paradigmatic of a marked sympathetic activation. Muscle sympathetic nerve traffic was markedly increased in Child class C subjects as compared with controls (23.9 +/- 1.6 bursts/min, P <.01) and superimposable to that recorded in heart failure patients (52.9 +/- 4.7 vs. 60.3 +/- 2 bursts/min, P = not significant). Muscle sympathetic nerve traffic was also increased in Child class A subjects (41.6 +/- 2 bursts/min, P <.01 vs. controls) although to a lesser extent (P <.05 vs. Child class C patients). Skin sympathetic nerve traffic was within the normal range in all patients. Neurohormones were all markedly increased in Child class C subjects. Only norepinephrine was increased in Child class A patients. Our data show that sympathetic nerve traffic activation (1) is already detectable in Child class A cirrhosis when clinically significant portal hypertension is present but ascites never developed and (2) is not generalized because although muscle traffic is increased, skin traffic is within normal range. The role of drugs modulating sympathoactivation should be investigated in preascitic cirrhosis.

Aged↗
PubMed2001

Selection and characterization of active hammerhead ribozymes targeted against cyclin E and E2F1 full-length mRNA.

Proliferation of vascular smooth muscle cells is generally accepted as a key event in the development of restenosis following percutaneous transluminal angioplasty. To prevent human restenosis, we have designed a molecular strategy based on hammerhead ribozymes targeted against the mRNA of cyclin E and E2F1, two proteins relevant in cell cycle progression whose regulation is interconnected by a positive feedback loop. Following the identification of accessible ribozyme target sites by RNase H mapping, several hammerhead ribozymes were generated that cleave with comparable efficiency two different splice forms of cyclin E mRNA and the full-length and a truncated form of E2F1 RNA, respectively. The most active ribozymes were tested in vitro under single-turnover conditions yielding k(react)/K(m) ratios between 36 and 73 x 10(4) M(-1) min(-1), which places them in the top range ribozymes targeted against long and structured substrates. In addition, we show that the most active ribozyme selected in vitro reduces specifically and significantly (p < 0.0028) proliferation of cultured human vascular smooth muscle cells (VSMC).

Base Sequence↗
PubMed2001

Foliar morphological and physiological plasticity in Picea abies and Abies alba saplings along a natural light gradient.

The role of morphological versus physiological foliar plasticity in the capacity for, and mechanisms of, photosynthetic acclimation was assessed in Picea abies (L.) Karst. and Abies alba Mill. saplings in a forest gap-understory light gradient (relative irradiance, RI, ranging from 0.02 to 0.32). The species investigated showed a similar foliar morphological plasticity along the light gradient, at both the needle level (through alteration in leaf dry mass per area) and the shoot level (through alteration in the silhouette area ratio, e.g., shoot silhouette to projected needle area ratio). In both species chlorophyll (Chl) concentration on a mass basis decreased at increasing RI, but was independent of RI when expressed on an area basis. In contrast, leaf N concentration on a mass basis was independent of RI, but was positively influenced by RI when expressed on an area basis. The parameters describing photosynthetic performance at low light (dark respiration rate, apparent quantum yield and light compensation point) suggest that Abies alba was better suited to maintain a positive carbon balance in shaded conditions. By contrast, parameters describing biochemical capacity at high light (maximum electron transport rate, Jmax and maximum ribulose-1,5-biphosphate carboxylation capacity, Vcmax) indicate that only Picea abies was capable of acclimating physiologically to high photosynthetic photon flux densities (PPFDs) by increasing nitrogen partitioning to Rubisco and Vcmax/mass by increasing RI. These results support the hypothesis that interspecific differences in nitrogen partitioning within the photosynthetic apparatus may provide a mechanistic basis for species separation along a light gradient. The differences in photosynthetic plasticity observed are likely to influence regeneration patterns and habitat breadth of the species investigated. The limited ability of Abies alba saplings to exploit high-light conditions may be a competitive disadvantage in large canopy gaps and thus limit recruitment of this species to small gaps.

Abies↗
PubMed2001

3-Phenyl-4H-furo[3,2-C]chromen-4-one.

The crystal structure of the title compound, C(17)H(10)O(3), is the first example of a furocoumarin containing three fused rings. The tricyclic furocoumarin fragment is perfectly planar. The phenyl substituent forms a dihedral angle of 39.52 (8) degrees with the plane of the tricyclic system. The crystal packing involves centrosymmetric dimers interconnected by strong pi-interactions between their furo[3,2-c]coumarin fragments [at distances of 3.42 (4) A].

Journal Article↗
PubMed2001

Effects of chronic clonidine administration on sympathetic nerve traffic and baroreflex function in heart failure.

Congestive heart failure is characterized by a sympathetic activation that is coupled with a baroreflex impairment. Whether these alterations are affected by clonidine is unknown. In 26 normotensive patients age 58.0+/-1.1 years (mean+/-SEM) affected by congestive heart failure (New York Heart Association functional class II or III) and treated with furosemide and enalapril, we measured mean arterial pressure, heart rate, venous plasma norepinephrine, and muscle sympathetic nerve traffic (microneurography) at rest and during baroreceptor stimulation and deactivation caused by stepwise intravenous infusions of phenylephrine and nitroprusside, respectively. Measurements were repeated after a 2-month administration of transdermal clonidine patch (14 patients) or placebo (12 patients) according to a double-blind, randomized sequence. Clonidine caused a slight, nonsignificant reduction in mean arterial pressure and heart rate without affecting exercise capacity and echocardiographically determined left ventricular ejection fraction. In contrast, both plasma norepinephrine and sympathetic nerve traffic were significantly reduced (-46.8% and -26.7%, respectively; P<0.01 for both). This reduction was coupled with no change in cardiac and sympathetic baroreflex responses. Transdermal placebo administration for a 2-month period did not affect any of the above-mentioned variables. Thus, in congestive heart failure patients who are undergoing conventional drug treatment, chronic clonidine administration exerts marked sympathoinhibitory effects without adversely affecting cardiac functions and clinical state. Whether this leads to further therapeutic benefits remains to be tested.

Baroreflex↗
PubMed2001

[Saphenous vein graft bypass from the external carotid artery to the supraclinoid internal carotid artery to treat a giant aneurysm of the cavernous internal carotid: case report].

Alternative surgical procedures to treat unclippable aneurysms of the intracavernous carotid artery include proximal vessel occlusion and trapping. Those techniques, even in patients with rich collateral vessels, are associated with risk of hemodynamic compromise and ischemic complications. Therefore, a safe treatment requires revascularization to maintain blood flow to the involved territories. We report the case of a 47-year-old female, with ischemic signs and symptoms and a right third nerve palsy caused by a giant aneurysm, partially trombosed, of the intracavernous carotid artery. The patient was submitted to trapping after a saphenous vein graft bypass from the external carotid artery to the supraclinoid internal carotid artery. The surgical result was good without complications.

Anastomosis, Surgical↗
PubMed2001

[Monitoring of primary cerebral injury due to trauma].

The author analyses and synthetizes the standard parameters of monitoring the evolutive cerebral injury after cranial trauma. This study presents the main criteria and the reciprocal relation between parameters in the prognostic function.

Brain Injuries↗
PubMed2001

Sympathetic and reflex abnormalities in heart failure secondary to ischaemic or idiopathic dilated cardiomyopathy.

Congestive heart failure (CHF) is characterized by a sympathetic activation and a baroreflex impairment whose degree is directly related to the clinical severity of the disease. However, whether these abnormalities vary according to the ischaemic or idiopathic dilated nature of the CHF state has not been conclusively documented. In patients with a clinically stable, chronic CHF state in New York Heart Association functional class II and III, due either to ischaemic heart disease (IHD; n=22, age 60.3+/-2.4 years, means+/-S.E.M.) or to idiopathic dilated cardiomyopathy (IDC; n=20, age 58.9+/-2.8 years), and in 30 age-matched controls, we measured arterial blood pressure (using a Finapres device), heart rate (by electrocardiogram) and postganglionic muscle sympathetic nerve traffic (by microneurography) at rest and during baroreceptor manipulation induced by the vasoactive drug-infusion technique. Blood pressure values were not significantly different in CHF patients and controls. Compared with controls, heart rate was similarly increased and left ventricular ejection fraction (by echocardiography) similarly reduced in CHF patients with IHD or IDC. Muscle sympathetic nerve traffic was significantly greater in CHF patients than in controls, and did not differ between patients with IHD or IDC (67.3+/-4.2 and 67.8+/-3.8 bursts/100 heart beats respectively). This was also the case for the degree of baroreflex impairment. These data show that CHF states due to IHD or to IDC are characterized by a similar degree of peripheral sympathetic activation and by a similar impairment of the baroreflex function. Thus the neuroadrenergic and reflex abnormalities characterizing CHF are independent of its aetiology.

Adult↗
PubMed2001

[Autonomic nervous system in arterial hypertension].

In several experimental animal models of hypertension, alterations in the autonomic cardiovascular drive have been shown to participate in the development and/or in the maintenance of high blood pressure. This has been shown to be true also in case of hypertension occurring in humans in whom a reduction in the parasympathetic influences to the heart is paralleled by an increase in the cardiac and vascular adrenergic tone. Several factors have been claimed to favor the hyperadrenergic state of essential hypertension. These include 1) a dysfunction in the central mechanisms physiologically inhibiting adrenergic outflow, 2) a sympathoexcitation induced by humoral factors (hyperinsulinemia, activation of the renin-angiotensin system, etc.), and 3) a functional alteration in arterial baroreceptors and in cardiopulmonary receptors which restrains in normal conditions adrenergic activity. Evidence has been provided indicating that the autonomic derangement occurring in hypertension contributes to the development of the target organ damage associated with the hypertensive state. This represents the rationale for employing, in the treatment of high blood pressure states, drugs exerting sympathoinhibitory effects.

Autonomic Nervous System↗
PubMed2001

Thyroid autoimmunity and infertility.

We aimed to study the prevalence of thyroid autoimmunity in infertile women; to assess whether thyroid autoantibodies were associated with non-organ-specific autoantibodies; and to investigate the influence of this dysfunction on the couples' chances of pregnancy. We assayed serum levels of thyroid stimulating hormone (TSH), free thyroxine, and microsomal and thyroglobulin autoantibodies in 149 infertile women. In patients with serum TSH levels in the hypothyroid or hyperthyroid range and/or with thyroid autoantibodies, we performed thyroid ultrasound examinations and assayed some non-organ-specific autoantibodies. We compared the duration of infertility in infertile patients with normal thyroid (control group), with thyroid abnormalities, and with thyroid autoantibodies in euthyroidism. Thirty infertile patients (20.1%) had thyroid abnormalities. The prevalence of thyroid autoantibodies was 17.4%. In infertile patients with thyroid autoantibodies, we found a poor association with non-organ-specific autoantibodies. Only the women with thyroid abnormalities and ovulatory dysfunction had a mean duration of infertility significantly longer than that of the control group. When the data were analyzed for euthyroid women with thyroid autoantibodies, we found no significant variation in the duration of infertility. Although we found a high prevalence of thyroid autoantibodies in infertile patients, the presence of these autoantibodies per se did not reduce the chance of pregnancy.

Adult↗