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Biomedical subjects

M Bernardi

Publications and source records attributed to M Bernardi.

At least 127 records · Page 7Linked to original sources
PubMed1997

Spectral analysis of intercycle heart fluctuations in Xenopus laevis, conscious or spinalized, treated with calcium channel blockers. Part I.

1. In this study, electrocardiographic second lead tracings were recorded and analyzed online and offline in the conscious and spinalized Xenopus laevis under control conditions and after treatment with at least two effective doses of racemic diltiazem, nifedipine and racemic verapamil hydrochlorides. 2. Heart rates (HR) and intercycle heart rate power spectra (IHRPS) were calculated in the various experimental conditions. 3. Dose-dependent bradycardia was found in most cases, which was associated with dose-related increases in the overall dynamic range of the largest peak of HR variability (increased IHRPS), this being particularly marked at the higher nifedipine dose. The frequency position of the largest peak was unchanged in the spinalized preparation, as well as in the various treatments. 4. These findings may contribute toward a more complete pharmacodynamic definition of calcium channel blockers in their current therapeutic use.

Animals↗
PubMed1997

Proteins but not nucleic acids are molecular targets for the free radical attack during reoxygenation of rat hepatocytes.

Isolated rat hepatocytes generate large amounts of reactive oxygen species and suffer a significant cell injury during postanoxic reoxygenation. The aim of this study was to determine whether oxidation of proteins and nucleic acids occurs during reoxygenation and whether their damage is related to the development of hepatocyte injury. Isolated perfused rat hepatocytes were exposed sequentially to 1 h of aerobic control, 2.5 h of anoxia, and 2 h of reoxygenation. Protein oxidation was determined by measuring the hepatocyte protein carbonyl content. DNA and RNA oxidation was assessed by measuring the 8-hydroxydeoxyguanosine and 8-hydroxyguanosine adducts, respectively. The control preanoxic carbonyl content was 6.48 +/- 1.03 nmol/mg protein. The preanoxic 8-8 hydroxydeoxyguanosine and 8-hydroxyguanosine levels were 4.76 +/- 1.22 pmol/ml and 14.19 +/- 2.17 pmol/ml, respectively. During anoxia, protein and nucleic acid oxidation did not change significantly. With reoxygenation, the protein carbonyl content increased significantly within 30 min, reaching a value of 10.25 +/- 1.58 nmol/mg. The nucleic acid oxidation level remained stable. Perfusion with 100 muM of during reoxygenation abolished protein oxidation. These results indicate that in rat hepatocytes during the early phase of reoxygenation: (1) the protein oxidation level increased significantly above the preanoxic aerobic values; (2) DNA and RNA oxidation does not appear to occur; and (3) free metal-mediated free radical reactions are involved in the oxidative protein damage.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1997

Intermittent anoxia reduces oxygen free radicals formation during reoxygenation in rat hepatocytes.

The sensitivity of liver cells to anoxia is a major problem afflicting liver preservation and transplantation. Intermittent ischemia has been proposed to reduce reperfusion injury. The aim of the study was to assess oxygen free radical formation and cell injury during continuous or intermittent anoxia/reoxygenation in rat hepatocytes. Anion superoxide was measured by lucigenin-enhanced chemiluminescence and cell damage by LDH release and trypan blue uptake. During anoxia, superoxide generation dropped to background level in both groups; trypan blue uptake and LDH release, which increased progressively, were significantly greater in hepatocytes exposed to continuous compared to intermittent anoxia. During reoxygenation, a massive generation of superoxide anion formation, followed by a sharp increase in LDH release, was observed in both groups. However, both oxyradical generation and cell injury were significantly greater in cells exposed to continuous compared to intermittent anoxia. The data, showing that intermittent oxygen deprivation reduce liver cell injury and oxygen free radical formation determined by anoxia/reoxygenation, suggest a novel possible approach to the reduction of reperfusion injury.

Animals↗
PubMed1997

Hyperplasia of the mandibular coronoid process: long-term follow-up after coronoidotomy.

The aim of this study was to evaluate long-term results of treatment by intraoral coronoidotomy and prolonged physiotherapy in five patients with mandibular coronoid process hyperplasia. Five consecutive cases of coronoid process hyperplasia were studied (two unilateral and three bilateral) at the Department of Maxillo-facial Surgery of the University of Turin during the period 1985-1990. All patients were treated by intraoral coronoidotomy and given physiotherapy from the third postoperative day. This continued for an entire year. A clinical and radiological follow-up (average 39.4 months), in three cases over a 5-year period, was completed. Three months after the operation, all patients had achieved satisfactory improvement in mandibular interincisal opening. The mean value for mouth opening at the end of follow-up was 42 mm. Radiographic follow-up showed the presence of a coronoid process almost the size of the original, apparently united with the mandibular ascending ramus, with moderate dislocation and inclination posterior to the body of the zygomatic bone. The results of this study indicate that treatment of coronoid process hyperplasia by intraoral coronoidotomy, when combined with prolonged postoperative physiotherapy, gives satisfactory and stable long-term results in the correction of coronoid-malar interference.

Adolescent↗
PubMed1997

Anthropometric characteristics of healthy Italian nonagenarians and centenarians.

Available anthropometric reference values for elderly people do not include specific norms for over-90-year-old subjects despite their increasing number. In the present study, weight, height and a number of anthropometric variables related to body muscle and fat mass were collected from fifty-seven nonagenarian and forty-one centenarian healthy, non-institutionalized subjects living in an Italian area. Recumbent anthropometry was used to avoid errors associated with impaired mobility. Nonagenarians and centenarian men were taller and heavier than women of corresponding age and had a greater amount of muscle and trunk fat, whereas women showed a marked peripheral adipose distribution. Anthropometric values of both age-groups were generally lower than published norms for 70-89-year-old American and European elderly people. However, differences were less marked when comparing Italian nonagenarians and centenarians with French and British people aged 85 years and over than when comparing Italian subjects with American octogenarians and younger European elderly people. Taken together these findings suggest a dramatic loss of muscle and fat mass in over-90-year-old subjects with respect to younger elderly people. However, changes between successive generations and geographical influences cannot be excluded. The need for local and age-specific norms in nutritional assessment of over-90-year-old people is emphasized. It is also suggested that current anthropometric indices may not be reliable when evaluating the oldest elderly subjects.

Aged↗
PubMed1997

Rehabilitation of walking for paraplegic patients by means of a treadmill.

The present study was aimed at investigating the use of a treadmill for ambulation training of paraplegic subjects. To investigate the likely effectiveness of this modality of rehabilitation, six paraplegic patients (three male and three female) were studied, using new generation reciprocating gait orthoses (RGO and ARGO), in a treadmill training program. Oxygen consumption, heart rate, and pulmonary ventilation were measured when the subjects were walking at their most comfortable speed on the treadmill and on the open field. These measurements were carried out at the beginning of the study and after two and six months of treadmill training. The following findings were significant: the treadmill walking required 30% less energy than open field ambulation prior to training (P < 0.001) and 50% after training (P < 0.05). The most comfortable walking speed was faster on the treadmill than on the open field by 18% prior to training (P < 0.05) and 42% afterwards (P < 0.05). The energy cost was 50% less after 2 months training on the treadmill (P < 0.05) showing that treadmill training can improve the efficiency of over ground ambulation. It can be concluded that the treadmill training improves the RGO/ARGO walking capability, probably both the walking efficiency (short term adaptation) and physical fitness (long term adaptation).

Adult↗
PubMed1997

A randomized controlled study comparing elemental diet and steroid treatment in Crohn's disease.

BACKGROUND: Elemental diet is considered an effective primary treatment for active Crohn's disease, but it is usually given by a feeding tube. METHODS: Twenty-two patients (12 males, median age 30 years, range 18-60) with moderately active Crohn's disease were enrolled in a randomized study in which the efficacy of an elemental diet administered orally was compared to high-dose corticosteroids in achieving clinical and laboratory remission. Ten patients were treated by oral elemental diet (Peptamen, Clintec, USA) and 10 received corticosteroids. Both treatment regimens lasted 2 weeks. The two groups did not differ with respect to age, sex, body weight, location of disease, treatment or disease activity prior to the study. In all patients studied, simple Crohn's disease activity index, nutritional status (expressed as body mass index), percentage of ideal body weight, fat mass, fat free mass, erythrocyte sedimentation rate, interleukin-6, intestinal permeability (expressed as permeability index), prealbumin, retinol binding protein and multiskin test were evaluated before and after treatment. RESULTS: After 2 weeks of treatment, there were significant improvements in simple Crohn's disease activity index, erythrocyte sedimentation rate, permeability index, body mass index, prealbumin, retinol binding protein and multiskin test in the elemental diet group. There were significant improvements in simple Crohn's disease activity index and fat free mass in the corticosteroid group. CONCLUSIONS: These data suggest that, in the short term, an oral elemental diet is at least as effective as steroids in inducing remission of mild-moderately active Crohn's disease, but it may be more effective in improving the nutritional status of these patients, probably through a more rapid restoration of normal intestinal permeability.

Adolescent↗
PubMed1997

Spectral analysis of intercycle heart fluctuations in the diethyl-ether-anaesthetized or pithed rat treated with l-hyoscyamine.

1. Within the context of neural regulation of the activity of sinus node pacemaker cells, the study of heart rate variability, as explored in the frequency domain by spectral analysis, was proposed about 15 years ago as a quantitative tool for the evaluation of short-term autonomic cardiovascular control. It has since been postulated that the two main oscillations observed, one at low and the other at high frequency, may respectively be markers of sympathetic vs. vagal efferent cardiac activity, and that the low- and high-frequency signals may reflect a reciprocal or 'push-pull' relationship between sympathetic and parasympathetic control. 2. In our power spectra assessment, ECG R-R intervals were submitted to fast Fourier transformation analysis in order to study the mechanisms underlying the control of heart beats in rats. Data were acquired in conditions of steady arterial blood pressure and cardiac and respiratory activity (spontaneous or artificially stimulated) in diethyl-ether-anaesthetized and pithed rats, as well as in a group of control rats, all in the presence and absence of l-hyoscyamine. 3. With increasing doses of the parasympathetic antagonist, the fractal dimension of the time-series structure remained stable in most cases. The low-frequency spectral component narrowed with increasing drug doses and the high-frequency band underwent either no, or only very slight, changes. 4. In these rodent assays, the low- and high-frequency signals cannot be interpreted as a push-pull relationship between sympathetic and parasympathetic control.

Anesthetics, Inhalation↗
PubMed1997

Chemoembolization versus chemotherapy in elderly patients with unresectable hepatocellular carcinoma and contrast uptake as prognostic factor.

BACKGROUND: Age is considered one of the important contraindications to surgery for hepatocellular carcinoma (HCC) in cirrhosis patients. We therefore evaluated the safety and prevalence of side effects in endoarterial therapy (EAT) in subjects aged over 65 years compared with younger treated patients. METHODS: Thirty-eight patients with HCC aged 65 years and over underwent transcatheter arterial chemoembolization (TACE) (n = 28) or intraarterial chemotherapy (IAC) (n = 10). The survival rate was calculated using Kaplan-Meier's method with respect to a control group consisting of younger treated subjects (44 TACE; 21 IAC) comparable for stage of HCC and severity of the underlying cirrhosis. RESULTS: The comparison between the two groups regarding side effects, procedure-related death, and survival did not show any difference considering the whole EAT procedure. TACE in elderly subjects reached a statistically lower outcome with respect to younger patients (p < .025) but remained statistically superior in survival versus both older and younger patients treated with IAC (p < .05, respectively). Stratifying the patients following the degree of Lipiodol uptake of tumor mass in the three groups (Group I, > 75%; Group II, 50-75%; Group III, < 50%), in the young subjects a higher probability of survival was strictly correlated to a degree of uptake over 75%, while in the elderly patients an impregnation over 50% was sufficient to obtain a satisfactory survival curve. CONCLUSIONS: EAT is a reliable and safe therapeutic option for the geriatric patient with HCC, with TACE showing a better efficacy than IAC, requiring a lesser degree of Lipiodol uptake to achieve an improvement of outcome.

Adult↗
PubMed1997

Generation of free radicals during anoxia and reoxygenation in perfused osteoblastlike cells.

Sensitivity to ischemia and reperfusion injury is a main problem afflicting tissues exposed to a prolonged period of oxygen deprivation. The generation of oxygen free radicals, in particular, is considered a major cause of postischemic reperfusion injury. However, studies on the mechanisms of production of free radicals are limited by the difficulty to measure in real time their formation and to discriminate between the different oxyradical species. The aim of this study was to determine whether the formation of oxygen free radicals occurs in murine osteoblastlike cells (MC3T3-E1) exposed to anoxia and reoxygenation and to explore its relation to the reoxygenation injury. Cells were cast in agarose and perfused with oxygenated Krebs-Henseleit bicarbonate buffer. Anoxia was obtained by shifting the gas phase of the media to 95% N2-5% CO2. Oxygen free radicals were detected by enhanced chemiluminescence: anion superoxide or hydrogen peroxide was measured by adding lucigenin or luminol plus horseradish peroxidase to the media, respectively. Cell injury was assessed by the rate of lactate dehydrogenase release. During the control period, lucigenin and luminol plus horseradish chemiluminescences were 15 +/- 1 nA per chamber and 20 +/- 2 nA per chamber, respectively. and lactate dehydrogenase release was 10 +/- 1 mU per minute. During anoxia, both chemiluminescences dropped to background levels, although lactate dehydrogenase release increased progressively to 38 +/- 7 mU per minute. During reoxygenation, O2 formation increased sharply to 45 +/- 6 nA and decreased to control levels; H2O2 production increased slowly, reaching 42 +/- 7 nA at the end of the reoxygenation period; lactate dehydrogenase declined progressively to control values. These results show that osteoblastlike cells produce measurable amounts of superoxide and hydrogen peroxide radicals during reoxygenation. Because lactate dehydrogenase release did not appear to relate to chemiluminescence, oxyradical flux may serve as a signal for other events that eventually lead to cell injury.

Animals↗
PubMed1997

Determinants of functional status in healthy Italian nonagenarians and centenarians: a comprehensive functional assessment by the instruments of geriatric practice.

OBJECTIVE: To evaluate the physical ability and psychocognitive status of a population more than 90 years of age with regard to sociodemographic, behavioral, and biomedical variables known to affect functional status in old age. DESIGN: A survey design was used. SETTING: Emilia Romagna, Northern Italy. PARTICIPANTS: Eighty-four healthy community-dwelling subjects aged 90 to 106 years. MEASUREMENTS: Sociodemographic variables, health behavior, anthropometric indices, and serum DHEAS levels were recorded. Functional assessment was performed by instruments currently used in geriatric practice: the Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS), and Activities of Daily Living (ADL) scale. A stepwise multiple regression analysis was performed. RESULTS: GDS scores correlated directly with MMSE scores and inversely with ADL severity scores. Poor education, institutionalization, sensory impairment, muscular mass loss, and lower DHEAS levels were the variables with the highest correlation to functional impairment. Smoking, alcohol consumption, and marital status were relatively unimportant. An inverse association was found between DHEAS levels and dependency scores of single ADLs (continence, mobility). CONCLUSION: Impaired cognitive and physical ability with no increase in depression prevalence was found in a sample of subjects more than 90 years of age free of major age-related disease. Muscular mass and DHEAS levels seem to play a role in maintaining physical independence. In turn, physical independence, as well as social and cultural factors, strongly affect the compliance of long-lived subjects with psychocognitive tests currently used in the clinical evaluation of younger old people, suggesting that these instruments are not reliable for screening for cognitive impairment and depression in the oldest old subjects.

Activities of Daily Living↗
PubMed1997

Ocular naevus and hyperaemia with dilation of the conjunctival vessels: an early manifestation of Crohn's disease?

Two cases of male patients with Crohn's disease showing the same neonatal ocular abnormality, a sector hyperaemia with dilation of the vessels of the bulbar conjunctiva surrounding a naevus close to the limbus, are presented. In both cases, this manifestation worsened when Crohn's disease relapsed, and improved when the disease went into remission with steroid treatment. In Crohn's disease, eye involvement is reported in varying percentages, but the condition discussed here does not fit into any of the ocular patterns previously described in this disease, and could represent an early manifestation of Crohn's disease.

Adult↗
PubMed1996

Clinical and pathologic features of hepatocellular carcinoma in young and older Italian patients.

BACKGROUND: It is not known whether putative etiologic factors and clinical and pathological features of hepatocellular carcinoma (HCC) differ between young adult and older white patients. METHODS: We examined the characteristics of 498 consecutive patients with HCC age < 50 years (Group 1: 54 patients) and age > or = 50 (Group 2: 444 patients), an age beyond which the tumor occurrence rate briskly increases. RESULTS: Demographic characteristics, alcohol and coffee intake, and cigarette smoking did not differ between the two groups. Group 1 had a greater prevalence of the hepatitis B surface antigen (HBsAg) carriers (P = 0.006), while the prevalence of either past hepatitis B virus infection (P = 0.008) or antivirus C antibodies (P = 0.016) was higher in Group 2. The lack of both hepatitis B and C virus serologic markers was more common in Group 1 (P = 0.018). In these patients, HCC was less frequently superimposed on cirrhosis (P = 0.002) and was more advanced at the time of diagnosis. In fact, despite a better histologic differentiation grade (P = 0.019), monofocal (solitary and massive) tumors were larger (P = 0.012), small lesions (< or = 5 cm) less frequent (P = 0.028), and either diffuse (P < 0.001) or massive (P = 0.011) types more common. An elevation of serum alpha-fetoprotein was less frequent in group 1 (P = 0.016), but this difference disappeared when the "diagnostic" cut-off of 400 ng/mL was considered. Albeit the prevalence of presenting symptoms did not significantly differ between the two groups, the clinical stage was more advanced in young patients (P = 0.004). The 9-year cumulative rate of survival was similar in the 2 groups. CONCLUSIONS: An early exposure to the virus and/or an accelerated hepatocarcinogenesis in HBsAg carriers can be inferred. Moreover, in the period of life at low risk for hepatoma: (1) the impact of nonalcoholic chemical carcinogenesis seems to be greater; (2) the tumor occurrence is less dependent on cirrhosis development; (3) although histologically better differentiated, the neoplasm is more advanced at the time of diagnosis; and (4) the long term survival is similar to that of the patients age 50 years or older.

Adolescent↗
PubMed1996

Blockade of the polyamine site of NMDA receptors produces antinociception and enhances the effect of morphine, in mice.

The possible effect of ifenprodil--a potent antagonist at the polyamine site of the NMDA receptor complex--on nociceptive threshold and morphine analgesia was investigated in mice. In the hot plate test, the intraperitoneal (i.p.) injection of ifenprodil significantly prolonged the reaction time of mice at the dose of 30 mg/kg, and increased the analgesic effect of morphine. In the phenylquinone writhing test, ifenprodil reduced the number of abdominal constrictions of mice starting from the dose of 2.5 mg/kg i.p., and increased the effect of morphine. The effect of ifenprodil on pain threshold was prevented by naloxone. Moreover, ifenprodil antagonized the pain threshold-reducing effect of alpha-melanocyte-stimulating hormone (0.05 microgram/mouse, intracerebroventricularly). These data show that blockade of the polyamine site of the NMDA receptor complex produces analgesia and increases the analgesic effect of morphine.

Analgesia↗
PubMed1996

A randomized controlled trial of thymosin-alpha1 versus interferon alfa treatment in patients with hepatitis B e antigen antibody--and hepatitis B virus DNA--positive chronic hepatitis B.

It has recently been shown that thymosin-alpha1(T-alpha1), a synthetic polypeptide of thymic origin, is able to promote disease remission and inhibition of hepatitis B virus (HBV) replication in patients affected by hepatitis B e antigen (HBeAg)-positive chronic active hepatitis. We evaluated the efficacy and safety of T-alpha1 treatment in patients with hepatitis B e antibody (anti-HBe) and HBV-DNA-positive chronic hepatitis. Thirty-three patients were randomly assigned to receive either T-alpha1 900 microg/m2 body surface area twice weekly (17 patients) or 5 MU of interferon alfa (IFN-alpha) three times weekly (16 patients) for 6 months. At baseline, both groups were comparable concerning age, sex, liver histology, and alanine transaminase (ALT) levels. At the end of treatment, complete response (defined as ALT normalization and HBV-DNA loss) occurred in 5 of 17 (29.4%) in the T-alpha1 group and in 7 of 16 (43.8%) in the IFN-alpha group (P = not significant). After a follow-up period of 6 months, a complete response was observed in 7 of 17 (41.2%) in the T-alpha1 group and in 4 of 16 (25%) in the IFN-alpha group (P = n.s.). Compared with the results observed in a group of 15 patients never treated with IFN-alpha and followed for 12 months, the rate of complete response was significantly higher in the IFN-alpha group at the end of therapy (1 of 15 vs. 7 of 16, respectively; P < .05) and in the T-alpha1 group at the end of follow-up (1 of 15 vs. 7 of 17, respectively; P < .05). Unlike IFN-alpha, T-alpha1 was well tolerated by all patients. The only side effect, reported by some, was local discomfort at injection sites. The results of this trial suggest that T-alpha1 is able to reduce HBV replication in patients affected by anti-HBe-positive chronic hepatitis. Furthermore, compared with IFN-alpha, T-alpha1 is better tolerated and seems to induce a gradual and more sustained ALT normalization and HBV-DNA loss. In conclusion, T-alpha1 appears to be a safe and effective alternative treatment for anti-HBe-positive chronic hepatitis. The benefit of this agent in producing long-term inhibition of HBV replication must be confirmed by future trials.

Adult↗
PubMed1996

Motor unit recruitment strategy changes with skill acquisition.

The modifications of motor unit recruitment strategy due to skill acquisition was determined in the elbow flexor-extensor muscles of normal human subjects. The median frequency of the power density spectra of the electromyograms recorded from the biceps and triceps muscles during a 3-s linear increase in flexion force in the range of 0-100% maximal voluntary contraction (MVC) was calculated for each subject, every 2 weeks over a total 6-week period during which subjects practiced linear flexion force increase three times a week. Electromyograms were recorded with two pairs of electrodes of different size and electrode spacing. It was shown that skill acquisition due to the 360 practice trials over the 6-week period caused an increase in the initial motor unit recruitment phase of the agonist's force generation cycle from about 0-65% MVC to about 0-85% MVC. The increase in the recruitment range was gradual and statistically significant for the measurements made every 2 weeks. The recruitment range of the antagonist triceps demonstrated a minor, but statistically insignificant, decrease over the same training period. There was a minor, but statistically insignificant, advantage of using small electrodes and inter-electrode spacing. It was concluded that skill acquisition, due to repeated functional use of a muscle in the same contraction mode, results in a slower, prolonged recruitment of motor units in the initial segment of the force generation cycle, thereby allowing a more precise and accurate control of the increments of force increase. Such conclusions reinforce the concept advocating the plasticity of motor unit control according to the functional demands imposed on the muscle. The results have significant implications in the design of various athletic, occupational and rehabilitation training modalities for optimal performance of various movement functions.

Adult↗