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Biomedical subjects

S Rossi

Publications and source records attributed to S Rossi.

At least 145 records · Page 8Linked to original sources
PubMed2000

Effects of vitamin E on clinic and ambulatory blood pressure in treated hypertensive patients. Collaborative Group of the Primary Prevention Project (PPP)--Hypertension study.

A randomized controlled open trial studied the effect of vitamin E supplementation (300 mg/day) on clinic and 24-h ambulatory blood pressure (BP) in 142 treated hypertensive patients. After 12 weeks, clinic BP decreased whether or not patients were randomized to vitamin E. Ambulatory BP showed no change in systolic BP and a small decrease in diastolic BP (-1.6 mm Hg, 95% confidence intervals from -2.8 to -0.4 mm Hg), approaching statistical significance in comparison to the control group (P = .06). Vitamin E supplementation thus seems to have no clinically relevant effect on BP in hypertensive patients already under controlled treatment.

Antihypertensive Agents↗
PubMed2000

Characterization of chitosan hydrochloride-mucin interaction by means of viscosimetric and turbidimetric measurements.

In the present work the interaction between chitosan hydrochloride (HCS) and two different types of mucin - one obtained from bovine submaxillary glands and the other from porcine stomach - was investigated. Two hydration media were tested: distilled water and 0. 1 M HCl. Intrinsic viscosity, which provides information about polymeric chain conformation, was assessed in both media for HCS and bovine submaxillary mucin. Changes in the specific viscosity of HCS-mucin mixtures were observed as a function of the polymer:mucin weight ratio. The formation of interaction products was indicated by a minimum in the specific viscosity. Such a minimum occurred at different polymer:mucin weight ratios depending on the hydration medium and mucin type. This suggested a different stoichiometry of interaction. Turbidimetric measurements were also effected in order to evidentiate the eventual precipitation of the polymer-mucin interaction products. While in distilled water the precipitation of the interaction product did occur, in acidic medium, although a minimum in specific viscosity was observed, no precipitate was formed. The two techniques employed, viscosimetric and turbidimetric, allowed us to investigate for both mucins the influence of hydration medium on the formation of the HCS-mucin interaction products and to conclude that a slightly acid-neutral pH favours the interaction between HCS and mucins.

Animals↗
PubMed2000

Effects of repetitive transcranial magnetic stimulation on movement-related cortical activity in humans.

Several lines of evidence suggest that low-rate repetitive transcranial magnetic stimulation (rTMS) of the motor cortex at 1 Hz reduces the excitability of the motor cortex and produces metabolic changes under and at a distance from the stimulated side. Therefore, it has been suggested that rTMS may have beneficial effects on motor performance in patients with movement disorders. However, it is still unknown in what way these effects can be produced. The aim of the present study is to investigate whether rTMS of the motor cortex (15 min at 1 Hz) is able to modify the voluntary movement related cortical activity, as reflected in the Beretischaftspotential (BP), and if these changes are functionally relevant for the final motor performance. The cortical movement-related activity in a typical BP paradigm of five healthy volunteers has been recorded using 61 scalp electrodes, while subjects performed self-paced right thumb oppositions every 8-20 s. After a basal recording, the BP was recorded in three different conditions, counterbalanced across subjects: after rTMS stimulation of the left primary motor area (M1) (15 min, 1 Hz, 10% above motor threshold), after 15 min of sham rTMS stimulation and following 15 min of voluntary movements performed with spatio-temporal characteristics similar to those induced by TMS. The tapping test was used to assess motor performance before and after each condition. Only movement-related trials with similar electromyographic (onset from muscular 'silence') and accelerometric patterns (same initial direction and similar amplitudes) were selected for computing BP waveforms. TMS- evoked and self-paced thumb movements had the same directional accelerometric pattern but different amplitudes. In all subjects, the real rTMS, but neither sham stimulation nor prolonged voluntary movements, produced a significant amplitude decrement of the negative slope of the BP; there was also a shortening of the BP onset time in four subjects. The effect was topographically restricted to cortical areas which were active in the basal condition, irrespective of the basal degree of activation at every single electrode. No changes in the tapping test occurred. These findings suggest that rTMS of the motor cortex at 1 Hz may interfere with the movement related brain activity, probably through influence on cortical inhibitory networks.

Adult↗
PubMed2000

Fertility and obstetric outcome after laparoscopic myomectomy of large myomata: a randomized comparison with abdominal myomectomy.

The purpose of this study was to compare, in infertile patients, the efficacy of laparoscopic myomectomy versus abdominal myomectomy, in restoring fertility and to evaluate the obstetric outcomes. Between January 1993 and January 1998, 131 patients of reproductive age, with anamnesis of infertility, underwent myomectomy because of the presence of at least one large myoma (diameter greater than or = 5 cm). Patients were randomly selected for treatment by laparotomy (n = 65) or laparoscopy (n = 66). The two groups were homogeneous for number, size and position of large myomata. Significant differences were found in the post-operative outcome: febrile morbidity (> 38 degrees C) was more frequent in the abdominal than in the laparoscopic group (26.2 versus 12.1%; P < 0.05). Laparotomy caused a more pronounced haemoglobin drop (2.17 +/- 1.57 versus 1.33 +/- 1.23; P < 0.001); three patients received a blood transfusion after laparotomy and none after laparoscopy. The post-operative hospital stay was shorter in the laparoscopic group (142.80 +/- 34.60 versus 75.61 +/- 37.09 h; P < 0.001). No significant differences were found between the two groups as concerns pregnancy rate (55.9% after laparotomy, 53.6% after laparoscopy), abortion rate (12.1 versus 20%), preterm delivery (7.4 versus 5%) and the use of Caesarean section (77.8 versus 65%). No case of uterine rupture during pregnancy or labour was observed.

Abortion, Spontaneous↗
PubMed2000

Percutaneous radio-frequency thermal ablation of nonresectable hepatocellular carcinoma after occlusion of tumor blood supply.

PURPOSE: To evaluate the usefulness of percutaneous radio-frequency (RF) thermal ablation of nonresectable hepatocellular carcinoma (HCC) after occlusion of the tumor arterial supply. MATERIALS AND METHODS: Sixty-two patients with cirrhosis and biopsy-proved HCC underwent RF ablation after interruption of the tumor arterial supply by means of occlusion of either the hepatic artery with a balloon catheter (40 patients) or the feeding arteries with gelatin sponge particles (22 patients). RESULTS: After a single RF procedure in 56 patients and after two procedures in six patients, spiral computed tomography (CT) demonstrated a nonenhancing area corresponding in shape to the previously identified HCC, which was suggestive of complete necrosis. No major complications occurred. Two patients subsequently underwent surgical resection; the remaining 60 patients were followed up with spiral CT. During a mean follow-up of 12.1 months, 11 HCC nodules showed areas of local progression; 49 were identified as nonenhancing areas with a 40%-75% reduction in maximum diameter. The 1-year estimate of failure risk was 19% for local recurrence and 45% for overall intrahepatic recurrence. The estimated 1-year survival was 87%. Histopathologic analysis of one autopsy and two surgical specimens revealed more than 90% necrosis in one specimen and 100% necrosis in two. CONCLUSION: HCC nodules 3.5-8.5 cm in diameter can be ablated in one or two RF sessions after occlusion of the tumor arterial supply.

Aged↗
PubMed2000

Volumetric bone mineral density in young women with Turner's syndrome treated with estrogens or estrogens plus growth hormone.

To explore the effects of estrogen replacement therapy (ERT) and recombinant growth hormone (GH) treatment on bone mineral density (BMD) in Turner's syndrome, we assessed volumetric BMD (vBMD), which is less dependent on body and bone sizes, in these patients at final height. The areal BMD (aBMD) was measured in 26 young women with Turner's syndrome (age range 17.5-25.0 years) by dual-energy X-ray absorptiometry, and vBMD was calculated. Patients were subdivided as group 1 (n = 12; ERT alone) and group 2 (n = 14; GH + ERT). Years of estrogen exposure were not different between the groups (group 1: 6. 4 +/- 1.5 years; group 2: 5.3 +/- 1.7 years); in group 2, GH therapy was 5.3 +/- 1.4 years. Final heights were significantly higher in group 2 than in group 1 (148.1 +/- 3.0 vs. 142.0 +/- 2.8 cm; p < 0. 0001) as well as aBMD (1.073 +/- 0.118 vs. 0.968 +/- 0.122 g/cm(2); p < 0.04). vBMD was higher in group 2 but not significantly different from group 1 (0.374 +/- 0.030 vs. 0.358 +/- 0.027 g/cm(3); p = 0.169). aBMD was reduced with respect to the normative values in both groups (group 1: -1.97 +/- 1.04 SDS, p < 0.0001 vs. 0; group 2: -0.93 +/- 1.01 SDS, p < 0.005 vs. 0), whereas vBMD was not (group 1: -0.07 +/- 0.79 SDS; group 2: 0.42 +/- 0.82 SDS). Our data suggest that: in Turner's syndrome GH administration improves final height and aBMD, but it does not significantly increase vBMD; aBMD reduction in Turner's syndrome is likely due to the impaired growth and reduced bone size; Turner's patients on ERT from adolescence show vBMD values in the normal range in young adulthood.

Adolescent↗
PubMed2000

Antibiotic drug prescription in respiratory tract infections: a pharmacoepidemiological survey among general practitioners in a region of Italy.

Data concerning patients undergoing antibiotic treatment for upper (URTI) or lower (LRTI) respiratory tract infections were collected from 23 General Practitioners (GPs) in the Campania Region of Italy from November 15, 1997 to March 15, 1998. The objectives of the study were: a) to assess the occurrence of URTIs and LRTIs; b) to document the factors that influence GPs' choice of therapy; c) to correlate antibiotic choice with duration and outcome of treatment; d) to assess the incidence of unwanted effects. 2198 questionnaires were collected. Patients were +/-43.9 of age. URTIs were diagnosed in 65.4% and 34.6% LRTIs. The mean duration of antibiotic treatment was 4.5 days in URTIs and 5.6 days in LRTIs. The choice of antibiotic treatment was influenced by clinical assessment of infections (67.1%). The most commonly used antibiotic categories in URTIs were macrolides (39.3%), penicillins (27.4%) and cephalosporins (23.8%) whereas for LRTIs mainly cephalosporins (63.8%), penicillins (9.2%) and fluoroquinolones (7.4%) were used. Adverse events were experienced by 3.9% of patients.

Adolescent↗
PubMed2000

Correlation of tumor size and survival in patients with stage IA non-small cell lung cancer.

OBJECTIVE: The purpose of this study was to determine the relationship between tumor size and survival in patients with stage IA non-small cell lung cancer (non-small cell lung cancer; ie, lesions < 3 cm). METHOD: Five hundred ten patients with pathologic stage IA (T1N0M0) non-small cell lung cancer were identified from our tumor registry over an 18-year period (from 1981 to 1999). There were 285 men and 225 women, with a mean age of 63 years (range, 31 to 90 years). The Cox proportional model was used to examine the effect on survival. Tumor size was incorporated into the model as a linear effect and as categorical variables. The Kaplan-Meier product limit estimator was used to graphically display the relationship between the tumor size and survival. RESULTS: The Cox proportional hazards model did not show a statistically significant relationship between tumor size and survival (p = 0.701) as a linear effect. Tumor size was then categorized into quartiles, and again there was no statistically significant difference in survival between groups (p = 0.597). Tumor size was also categorized into deciles, and there was no statistical relationship between tumor size and survival (p = 0.674). CONCLUSIONS: This study confirms stratifying patients with stage IA non-small cell lung cancer in the same TNM classification, given no apparent difference in survival. Unfortunately, these data caution that improved small nodule detection with screening CT may not significantly improve lung cancer mortality. The appropriate prospective randomized trial appears warranted.

Adult↗
PubMed2000

Inhibitory action on GHRH-induced GH secretion of chronic tamoxifen treatment in breast cancer.

OBJECTIVE: Previous in vitro and in vivo studies on animal models have demonstrated that tamoxifen (TAM) inhibits GH secretion. Studies in humans are conflicting. The aim of this study was to evaluate the effect of chronic TAM treatment on GH secretory dynamics in the presence of negligible endogenous oestrogens, in postmenopausal women with breast cancer. PATIENTS: Ten female patients were studied over a 6-12-month period after surgical therapy, before medical therapy, and during chronic treatment with TAM (20 mg/day p.o.). MEASUREMENTS: In all subjects we performed a standard GHRH-test (50 mg i.v. as a bolus) and compared the single time points, the peak response and the areas under the curves (AUC), before and during treatment. In basal samples, we evaluated the circulating levels of IGF-1, IGF-BP3 and their ratio, SHBG, FSH, LH, Oestradiol (E2) and PRL. GH was assayed by Immunoradiometric assay (IRMA). Insulin-like growth factor type I (IGF-I), Insulin-like growth factor-binding protein-3 (IGF-BP3), FSH, LH and PRL were measured by Radioimmunoassay (RIA). SHBG was measured by a noncompetitive liquid phase immunoradiometric assay, while E2 was measured directly in plasma by a liquid phase technique. RESULTS: TAM chronic treatment significantly reduced GH response to GHRH at single time point evaluations, GH peak response (mean decrease: 59.8 +/- 7.3%) and GH-AUC (mean decrease 53.8 +/- 8.9%). TAM also significantly reduced plasma IGF-1 levels. No significant variations were found in IGF-BP3 levels or in the IGF-1/IGF-BP3 ratio. A significant inverse correlation between SHBG and IGF-1 circulating levels was noticed during TAM treatment. CONCLUSIONS: Our data show that long-term tamoxifen treatment blocks the response of GH to exogenous GHRH and reduces IGF-1 levels, possibly by a central mechanism other than the demonstrated peripheral action. The results of this study, keeping in mind the demonstrated mitogenic role of IGF-1 in cancer proliferation, can contribute to clarify the mechanism by which TAM exerts its antiproliferative effect.

Aged↗
PubMed2000

Anti-Ro(SS-A) 52 kDa and 60 kDa specificities in undifferentiated connective tissue disease.

UNLABELLED: Autoantibodies to Ro(SS-A) may recognize two different polypeptides, of 52 kDa and 60 kDa, respectively. We used an ELISA with purified human recombinant antigens to conduct a detailed analysis of the specificities of anti-Ro(SS-A) antibodies from 170 patients with definite diagnoses (systemic lupus erythematosus [SLE], n = 55; primary Sjögren's syndrome [PSS], n = 39; systemic sclerosis, n = 9; rheumatoid arthritis [RA], n = 10) or undifferentiated connective tissue disease (UCTD, n = 57). Most of the patients with SLE or PSS had both anti-52 kDa and -60 antibodies; isolated anti-60 kDa antibodies were found in 13% of the SLE patients and in none of the PSS patients, whereas high titers of anti-52 kDa were more common in the PSS than in the SLE patients. In the UCTD patients, the anti-Ro(SS-A) profile showed no significant correlations with clinical features but was associated with the clinical outcome. Over the mean follow-up of five years, definite SLE developed in four of the five UCTD patients with isolated anti-60 kDa vs only one of the remaining 52 patients (P < 0.0001); progression to PSS was seen in seven of the 34 patients with both anti-52 kDa and anti-60 kDa vs none of the remaining 23 patients (P = 0.03); none of the 12 patients with isolated anti-52 kDa developed a definite connective tissue disease. CONCLUSION: Our study suggests that analysis of anti-Ro(SS-A) specificity may provide useful information for predicting the course of UCTD.

Antibody Specificity↗
PubMed2000

[Food additives: effects on pregnancy and lactation].

Exposure to several substances in a critical period of life, as in perinatal age, could cause long-term effects. Among these agents we can consider food additives, defined as "substances used to conserve, colour or flavour ailments without nutritional effects". Food additives utilisation by women during pregnancy and breastfeeding has not to be considered completely safe; actually, current evidence suggests that these substances induce alterations of the differentiation of several cell-types, resulting in development of disease during the adult age. During pregnancy, for instance, E100 color additive, is suspected to be embryotossic, amaranth causes a reduced olfactory orientation in F1 generation mice and beta-cyclodextrin produces a transient neonatal growth retardation in rodents. The food additive methylmercury is excreted in human milk and causes neurotoxicity in breastfed babies. Steroids pass in human milk, too: they can inhibit lactation and cause newborn breast ipertrophy. Regulations to avoid these early exposures may contribute to an important improvement of health conditions of humankind.

Female↗
PubMed1999

Time course of frontal somatosensory evoked potentials. Relation to L-dopa plasma levels and motor performance in PD.

OBJECTIVE: To verify whether the change in L-dopa plasma levels after a single dose of carbidopa/L-dopa 50/200 (controlled-release) transiently modifies frontal components of somatosensory evoked potentials (SEPs) in patients with PD in parallel with improvement of motor performance. BACKGROUND: Apomorphine, a potent dopamine-agonist drug, transiently increases frontal SEP components, which may be depressed in PD; however, relationships between clinical status, frontal SEPs, and therapy are still unclear. METHODS: Nineteen PD patients (mean age 65.9 years, range 52 to 77, responders to L-dopa therapy, were studied in the same day at times T0 (baseline predose level), T1 (presumed L-dopa peak time), and T2 (end of dose-induced motor response). The following were monitored: L-dopa plasma concentration, tapping test, reaction times, peak latency (with central conduction times), and amplitude of cervical, subcortical, as well as cortical parietal and frontal SEP components elicited by median nerve stimulation of the more clinically affected arm. RESULTS: The average amplitude of frontal components of PD patients was significantly reduced at T0 with respect to control subjects. A significant and transient amplitude increase of frontal SEPs was found at T1, in parallel with the L-dopa peak concentration and improvement in motor performance (tapping and reaction times), without significant changes in amplitude of parietal SEP waves. No latency shifts were observed in brain and spinal waves. CONCLUSIONS: L-Dopa may influence the responsiveness of the parkinsonian brain as assessed by frontal somatosensory evoked potentials. The time course of these modifications coincides with that of the clinical response in the motor performance.

Aged↗
PubMed1999

Nitroxides and malignant human tissues: electron spin resonance in colorectal neoplastic and healthy tissues.

Healthy and neoplastic colorectal human tissues of as many as 12 patients have been studied, immediately after surgery, by electron spin resonance (ESR) of stable nitroxides at physiological temperature. Cells were maintained in a living state using the McCoy's 5A culture medium. The very low concentration changes of hydrophilic and lipophilic nitroxides allowed us to establish that the response to the oxidative stress induced by the occurrence of nitroxides in healthy and tumor cells was very weak, thus suggesting these compounds are good candidates for contrast enhancement agents in magnetic resonance imaging of colorectal tumor. The analysis of the computed ESR line shape of lipophilic nitroxides in both healthy and malignant cells of the same patient agreed for an unmodified physical status of the membranes where they were mainly localized. The results reported here proved that the comparison between ESR results must be made in tissues from the same patient and that the physical status of the membranes depended more on the patient history than on changes in the colorectal cell membrane fluidity induced by the neoplastic process.

Aged↗
PubMed1999

DNA damage by hydroquinone in human white blood cells: analysis by alkaline single-cell gel electrophoresis.

The genotoxicity of hydroquinone (HQ) in human white blood cells was investigated by means of alkaline single-cell gel electrophoresis (SCGE). The exposure of purified lymphocytes to HQ (0.5-50 microg/ml) produced significant and dose-related increases in DNA migration; conversely, no induction of DNA damage was observed in leukocytes after in vitro treatment of whole blood samples (100-500 microg/ml). Similar differences in DNA damage between whole blood samples and purified lymphocytes were observed after treatments with hydrogen peroxide (H2O2, 50 microM). The DNA damaging activity of HQ was significantly (p<0.001, U-test) inhibited by exogenous catalase (250 U/ml), indicating the generation of peroxides in the mechanism of genotoxicity of HQ. Parallel experiments using the standard SCGE protocol, and an acellular method entailing the lysis of cells before HQ treatment, provided fairly similar results, indicating that HQ oxidation does not require endogenous metabolism. Experiments to compare the effectiveness of HQ in the induction of single-strand breaks and alkali-labile sites in resting cells and micronuclei in cytokinesis-blocked cells indicate that despite the extensive DNA damage detected by SCGE immediately after treatment, a significant excess of micronuclei is not observed after stimulation and in vitro cultivation. These data explain the apparent discrepancy between the high DNA damaging potential of HQ in human lymphocytes, as revealed by SCGE, and the relatively low activity reported in most cytogenetic assays with HQ on the same cell type.

Adult↗
PubMed1999

CSF and ECF glutamate concentrations in head injured patients.

Excitatory Amino Acids (EAAs) release has been considered to be neurotoxic in traumatic brain injury patients. Microdialysis samples of extracellular space (ECS) and high glutamate concentrations in cerebrospinal fluid (CSF) following Traumatic Brain Injury (TBI) have been documented. The objective of this study was to determine the correlation between EAA release in ECS and CSF in focal and diffuse injury. Head injury patients (GCS < or = 8, n = 16) admitted to Medical College of Virginia Hospital were instrumented for microdialysis collection of ECS samples. CSF samples were collected through the external ventricular drainage catheter at four hour intervals for the first four days following injury. As a control group, CSF was collected from normal pressure hydrocephalus patients (n = 6). Elevated glutamate levels were observed in both CSF and ECS following head injury. The average glutamate concentration in CSF (3.20 +/- 3.62 mumol/l) was significantly increased from control levels (1.13 +/- 0.49 mumol/l, p < 0.05). Comparison of CSF and extracellular fluid (ECF) samples showed that the glutamate concentrations were maximal on the first and second days and gradually decreased on days 3 and 4. On days 4, the level of the glutamate had remained elevated above the normal level.

Adult↗
PubMed1999

Intracranial hypertension in head injury: management and results.

OBJECTIVE: (1) To describe the pattern of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in a group of severe head-injured patients, (2) to quantify complications of ICP monitoring, and (3) to describe a management protocol and its results. DESIGN: Prospective observational study. SETTING: General intensive care unit in a teaching hospital. PATIENTS: 138 comatose patients, selected according to the following criteria: age > 16 years, coma [Glasgow Coma Scale (GCS) < or = 8] with at least one pupil reactive after resuscitation, digital recording of intracranial and arterial pressure, and jugular saturation measurements. MEASUREMENTS AND RESULTS: Median GCS was 5, and 62 patients had significant extracranial injuries; 71 had intracranial hematomas, which were urgently evacuated. Mean ICP was 20.5 mmHg (SD 8.34), mean CPP was 71.86 mmHg (SD 11.22); cerebral extraction of oxygen averaged 29 %. Medical therapy was used to control ICP in 130 cases; 93 patients required hyperventilation. Vasopressors were infused in 16 cases; in 14 cases a barbiturate infusion was started. In 6 patients all pharmacological treatments failed and surgical decompression was done. The only complication of ICP monitoring was meningitis in 3 patients. Outcome at 6 months was a good recovery and moderate disability for 82 patients (59.4%), severe disability and vegetative status for 37 (26.8%), and 19 patients died (13.7%). The severity of intracranial hypertension was related to poorer results at 6 months. CONCLUSIONS: Intracranial hypertension is very frequent in severe head injury but can be reasonably well controlled by combined surgical and medical therapy.

Adolescent↗