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Biomedical subjects

A Russo

Publications and source records attributed to A Russo.

At least 235 records · Page 13Linked to original sources
PubMed1999

Serum levels of ochratoxin A in healthy adults in Tuscany: correlation with individual characteristics and between repeat measurements.

Ochratoxin A (OTA), a mycotoxin widely contaminating staple foods and beverages, has been classified as a "possible human carcinogen (Group 2B)" by the IARC. Serum levels of OTA were measured in a group of 138 healthy adults (age, 35-65 years) living in the area surrounding Florence (Tuscany, central Italy) and detected in all but four samples (97%). After the exclusion of one subject with a peak value of 57.2 ng/ml, OTA levels ranged between 0.12 and 2.84 ng/ml, with mean and median values of 0.56 and 0.48 ng/ml, respectively. OTA levels were significantly higher in men than in women (0.64 versus 0.50) and correlated positively with height. A strong association was found with the season in which blood samples were obtained, with summer values higher than autumn values. On the other hand, OTA levels tended to be negatively associated with blood pressure, either systolic or diastolic; no association was evident with age, weight, body mass index, and smoking history. The associations with height and season persisted in a multivariate regression analysis. A subgroup of subjects provided a repeat blood sample approximately 1 year later. The Spearman correlation coefficient between 68 pairs of original and repeat measurements was practically null (r = 0.05). Only two subjects (2.9%) had OTA levels of >1 ng/ml on both occasions. These results suggest that OTA contamination is widespread in foods consumed by this population, in agreement with previous reports from Italy and other countries. A strong seasonal variation, which possibly differs from year to year, was observed. OTA serum levels are a short-term biomarker with a high within-subject variability; therefore they have limited use at the individual level but can be used to characterize populations or subgroups of subjects. Additional analyses are needed to explore the dietary determinants of OTA levels in this population.

Adult↗
PubMed1999

Antioxidant systems in rat lens as a function of age: effect of chronic administration of vitamin E and ascorbate.

Oxidative damage occurring in the lenses of patients with senile cataract may be due to partially reduced forms of oxygen. We assayed the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSH-Red), and glucose-6-phosphate dehydrogenase (G6PD) in rat lenses at different ages (1, 4, and 24 months), and also evaluated lens glutathione (GSH) levels and the effects of chronic administration of vitamin E and sodium ascorbate. We observed a significant age-related decrease in GSH-Px, GSH-Red and G6PD activities, but no age-related change in SOD activity. Chronic treatment with both vitamin E and sodium ascorbate failed to restore enzymatic activities to the levels of younger rats. An age-related reduction in GSH content was also observed; however, chronic administration of vitamin E, but not of sodium ascorbate, restored GSH levels to those of younger rats.

Aging↗
PubMed1999

[Facial nerve identification in the translabyrinthine approach: an alternative method].

Since the abrupt drop in the mortality rate as a result of the introduction of microsurgical dissection techniques in the treatment of acoustic neuromas, surgeons have concentrated their efforts on preserving hearing and facial nerve function. In the translabyrinthine approach, identification of the facial nerve at the fundus of the internal auditory canal is an important step for subsequent dissection. However, the identification techniques available to date carry with them some potential risk of facial nerve injury when performed by inexperienced surgeons. In addition, they are time-consuming procedures. The authors present an alternative method for identification of the facial nerve at the fundus of the internal auditory canal during the translabyrinthine approach. The superior ampullary nerve is interrupted at the superior cribrosa area where it is not in intimate relationship with the facial nerve. Medial reflection of the superior ampullary nerve and the superior vestibular nerve facilitates identification of the facial nerve and preparation of a vestibulo-facial dissection plane.

Cranial Nerve Neoplasms↗
PubMed1999

[Intrapetrous carotid artery aneurysm].

Intratemporal carotid artery aneurysms are rare lesions, with only 54 cases reported in the literature. Their most common symptoms are pulsatile tinnitus, hearing loss and signs of Eustachian tube obstruction. In case of aneurysm rupture, bleeding may be so profuse as to require emergency legation of the common carotid in the neck. Arteriography is the diagnostic gold standard for this disorder. Successful treatment usually involves selective aneurysm embolization or carotid closure with detachable balloons. The authors report a new case of intratemporal carotid artery aneurysm previously treated with selective embolization. To avoid the risk of aneurysm recanalization and/or infection through the external auditory canal, middle ear obliteration and blind-sac closure of the external canal were performed in this case.

Aged↗
PubMed1999

[The topical therapy of ulcerative colitis. A multicenter study with beclomethasone dipropionate foam].

BACKGROUND AND AIMS: The use of steroids was recently extended to the various forms of ulcerative rectocolitis by the introduction of topical formulations, above all steroids with an hepatic "first pass" devoid of systemic interference. The aim of this study was to evaluate the efficacy and tolerability of Beclomethasone dipropionate (BDP) in a rectal foam formulation, in the treatment of patients suffering from ulcerative colitis. METHODS: The experimental protocol took the form of a 28-day open prospective trial using BDP rectal foam in patients suffering from ulcerative colitis. Endoscopic, histological, clinical and tolerability parameters were evaluated. The centres taking part in the trial collected data for 60 cases out of a total of 80 patients enrolled in the study, of both sexes and aged between 20 and 81 years old, suffering from proctosigmoiditis (46.7%) and ulcerative rectocolitis (53.3%). RESULTS: Endoscopic parameters showed an improvement after 28 days of treatment in 74.5% of patients; a clinical improvement was achieved in 65.2% of cases. In percentage terms of the mean value of all the improved parameters, histological parameters were altered in 56.9% of patients. With regard to tolerability 82% of patients judged the treatment to be good/excellent. CONCLUSIONS: In conclusion, in line with recent reports regarding other pharmaceutical forms of BDP, including the use of rectal foam, these data confirm the efficacy and tolerability of this molecule and emphasise the validity of its use in the treatment of ulcerative colitis and proctosigmoiditis.

Administration, Topical↗
PubMed1999

Principles of chemoradiation: theoretical and practical considerations.

Chemotherapy agents known to enhance the effects of radiation in preclinical studies have been used concurrently with radiotherapy in numerous clinical trials with the prospect of further enhancing radiation-induced local tumor control. While some success in several tumor histologies has been achieved using this approach, a major concern has been enhancement in normal tissue toxicity. This brief review addresses both theoretical and practical issues with respect to chemoradiation clinical trials. Recommendations for clinical trials are provided that, if implemented, can increase our understanding of basic mechanisms (in patients) and provide a more rational approach for future trials.

Animals↗
PubMed1999

[Radiopaque lesions of the jaws].

This paper provides an overview of radiopaque lesions of the jaws after having outlined the various criteria for classification; depending on their etiology. Those lesions are generally separated into lesions with an unknown cause and lesions with a known etiology (phlogistic, dysplastic-dystrophic, tumoral). The authors give a general description of the clinical and radiographic symptoms of the main lesions. In many cases, with the exception of asymptomatic lesions with an unknown etiology, the patient presents a variable swelling that deforms the bone in question, resulting in asymmetry of the face and/or, depending on the site, nasal obstruction, mastication and speech disorders, exophthalmos with or without diplopia. The radiographic aspect of lesions and the associated laboratory and clinical findings often enable a diagnosis to be reached, but in doubtful cases diagnosis can only be confirmed by histological analysis.

Humans↗
PubMed1998

Effects of water deprivation and angiotensin II intracerebroventricular administration on brain nitric oxide synthase activity.

Intracranial administration of L-arginine causes a reduction of the water intake induced by water deprivation or by intracerebroventricular (i.c.v.) injection of angiotensin II (angiotensin II), through the release of nitric oxide (NO) in the central nervous system. We studied the effects of i.c.v. angiotensin II (120 ng/rat) in association with i.c.v. L-arginine (2.5-10 microg/rat) on blood pressure. We also studied the effects of both peripheral and central angiotensin II injection (1.5-6 mg kg(-1) i.p. and 30-120 ng rat(-1) i.c.v., respectively) on NO synthase activity in the cortex, diencephalon and brainstem, after water deprivation (24 h), conditions producing activation of the renin-angiotensin system. L-arginine dose dependently antagonized the increase in blood pressure induced by i.c.v. angiotensin II (P < 0.001). Peripheral administration of angiotensin II produced a dose-dependent reduction of NO synthase activity in the brainstem and cortex (P < 0.001), but not in the diencephalon. Water deprivation produced similar effects on brain NO synthase activity. Angiotensin II i.c.v. injection caused NO synthase activity reduction in all brain regions studied (P < 0.001). Our findings suggest that NO and angiotensin II could play opposite roles in brain regulation of blood pressure and drinking behaviour.

Angiotensin II↗
PubMed1998

Body size and colorectal-cancer risk.

Individuals whose energy intake exceeds expenditure are at increased risk of colorectal cancer. To determine whether body-size measurements at different ages were risk factors for cancer of the colon-rectum, we carried out a hospital-based case-control study in 6 Italian areas, 2 of which were in the South. Interviews were conducted with 1,217 subjects of both genders with incident histologically confirmed cancer of the colon, 726 with cancer of the rectum, and 4,136 controls hospitalized for acute, non-neoplastic, non-digestive conditions. The questionnaire included information on sociodemographic factors, and physical activity, a validated dietary history, height, weight at diagnosis and at 12, 30 and 50 years of age and waist-to-hip ratio (WHR). After allowance for education, physical activity, energy intake, family history of colorectal cancer and recent change in weight, the body-mass index (BMI) was significantly associated with colorectal-cancer-risk in men (odds ratio, OR, in highest vs. lowest quintile = 1.7; 95% confidence interval, CI, 1.3-2.3), but not in women (corresponding OR = 0.9; 95% CI, 0.7-1.2). Cases of both gender tended to have higher BMI than controls in adolescence, young adulthood and middle age. Height appeared unrelated to risk. In women, but not in men, WHR was positively associated with risk, independently of BMI (OR for > or = 0.90 vs. < or = 0.81 = 1.6; 95% CI; 1.2-2.1). Thus, excessive weight predicts colorectal-cancer risk in men, whereas abdominal obesity (i.e., a high WHR) represents a more reliable risk indicator in women.

Adult↗
PubMed1998

Studies of structure-activity relationship of nitroxide free radicals and their precursors as modifiers against oxidative damage.

The protective effects of stable nitroxides, as well as their hydroxylamine and amine precursors, have been tested in Chinese hamster V79 cells subjected to H2O2 exposure at fixed concentration or exposure to ionizing radiation. Cytotoxicity was evaluated by monitoring the viability of the cells assessed by the clonogenic assay. The compounds tested at fixed concentration varied in terms of ring size, oxidation state, and ring substituents. Electrochemical studies were carried out to measure the redox midpoint potentials. The studies show that in the case of protection against H2O2 exposure, the protection was determined by the ring size, oxidation state, and redox midpoint potentials. In general the protection factors followed the order nitroxides > hydroxylamines > amines. Both the six-membered ring nitroxides and substituted five-membered ring nitroxides were efficient protectors. For six-membered ring nitroxides, the compounds exhibiting the lowest midpoint potentials exhibited maximal protection. In the case of X-radiation, nitroxides were the most protective though some hydroxylamines were also efficient. The amines were in some cases found to sensitize the toxicity of aerobic radiation exposure. The protection observed by the nitroxides was not dependent on the ring size. However, the ring substituents had significant influence on the protection. Compounds containing a basic side chain were found to provide enhanced protection. The results in this study suggest that these compounds are novel antioxidants which can provide cytoprotection in mammalian cells against diverse types of oxidative insult and identify structural determinants optimal for protection against individual types of damage.

Animals↗
PubMed1998

Direct identification of each specific mutation in codon 12 and 13 of ci-ki-ras2 by SSCP analysis.

We compared the SSCP behaviour of the DNA fragments containing c-ki-ras 2 wild type 12 and 13 codons or each of the 12 possible point mutated sequences in these two codons. We found that a single electrophoresis condition was sufficient to distinguish each specific mutation from the other 11 and from the wild type sequence. This observation makes it possible to identify each specific mutation directly by SSCP without any need for reamplification and sequencing.

Carcinoma↗
PubMed1998

Macronutrient intake and risk of colorectal cancer in Italy.

To provide further insight on the relationship between macronutrients and colorectal cancer, overall and by specific subsite(s), we carried out between 1992 and 1996 in 6 Italian areas a case-control study on 1,953 individuals of both sexes with incident colorectal cancer (age range 19-74) and 4,154 controls (age range 19-74) in hospital with acute, non-neoplastic diseases. A validated food-frequency questionnaire was used, including questions on 78 foods or recipes and on individual fat-intake pattern. The risk of cancer of the colon and rectum increased with total energy intake (odds ratio in highest vs. lowest quintile 1.43 and 1.50, respectively). The risk also rose significantly with an increase of starch intake, whereas it moderately decreased with an increase of protein intake. Monounsaturated fat intake appeared uninfluential, while saturated fat intake showed a modest direct association with rectal cancer. Polyunsaturated fat intake was inversely associated with colon cancer risk, particularly with the right colon.

Adult↗
PubMed1998

Expression of folate binding protein as a prognostic factor for response to platinum-containing chemotherapy and survival in human ovarian cancer.

Overexpression of the folate binding protein (FBP) is a common feature in epithelial ovarian cancer, but its prognostic significance is not clearly understood. We investigated whether FBP in epithelial ovarian cancer specimens is a predictor of response to chemotherapy and survival. Between 1990 and 1995, 99 patients with epithelial ovarian cancer underwent primary surgery and were treated with chemotherapeutic regimens including platinum derivatives. First-line chemotherapy was performed in 58 patients with residual disease and in 41 patients without residual disease after primary laparotomy. FBP expression level was determined in frozen specimens by cyto-fluorimetric assay using the MOv 18 monoclonal antibody (MAb). Association of FBP fluorescence index (FI) with clinical characteristics, response to chemotherapy, and survival was studied by univariate and multivariate analysis. In the 58 patients with residual disease after primary surgery, failure to respond to chemotherapy (complete or partial remission) was about 15-fold higher (95% confidence interval, 2.96-77.43) when tumors had FBP FI above the median value (FBP FI = 3.25). FBP FI was not a predictor of survival in the entire series of tumors (99 patients). However, in the subgroup of 58 patients with residual disease after primary surgery, survival analysis confirmed the disadvantage observed with respect to response to chemotherapy in patients expressing FBP FI above the median value (hazard ratio 2.01; 95% confidence interval 0.95-4.24). In conclusion, higher levels of FBP expression might be a predictor of chemotherapy response failure in ovarian cancer. In patients with residual disease after primary surgery, FBP FI could represent a valuable prognostic marker for survival.

Adult↗
PubMed1998

Glutamine synthetase activity and HSP70 levels in cultured rat astrocytes: effect of 1-octadecyl-2-methyl-rac-glycero-3-phosphocholine.

The ether lipid 1-octadecyl-2-methyl-rac-glycero-3-phosphocholine (ET-18-OCH3) is a membrane interactive drug selectively cytotoxic toward neoplastic cells compared to normal cells. It induces apoptosis in human leukemic HL-60, T-lymphoid and in U937 myeloid cell lines and stimulates NO biosynthesis in cultured rat astrocytes. We have found a double action of ET-18-OCH3 in astrocytes which, at low doses, promotes a moderate induction of heat shock proteins of 70 kDa (HSP70) and the increase of glutamine synthetase (GS) activity. Conversely, at high doses, the drug shows toxic effects on astrocytes inducing decrease in GS activity, low molecular weight DNA formation, and release of lactic dehydrogenase (LDH) in the culture medium. Its analog compound platelet-activating factor (PAF) shares some of these biological aspects.

Analysis of Variance↗
PubMed1998

Comparison of steerable continuous-wave versus pulsed-wave Doppler ultrasonography to renal artery angiography in diagnosing renal artery stenosis.

Pulsed-wave Doppler ultrasonography is widely used to noninvasively diagnose renal artery stenosis. The use of steerable continuous-wave Doppler has never been tested. We compared pulsed and steerable continuous-wave Doppler ultrasonography, demonstrating that although both methods are highly sensitive for severe stenoses, continuous-wave Doppler shows a better sensitivity for mild to moderate stenoses.

Adult↗
PubMed1998

Micronucleus induction in somatic cells of mice as evaluated after 1,3-butadiene inhalation.

The effect of different 1,3-butadiene (BD) inhalation doses, 130, 250, and 500 ppm, on somatic cells of mice was studied. Two different cell populations with diverse replicative and differentiative activities, namely splenocytes and peripheral blood reticulocytes, were examined and micronucleus (MN) frequencies were estimated. In splenocytes, different postinhalation time intervals were studied with regard to MN induction and characterisation. BD was found to be clastogenic by inducing increased micronucleus frequencies in both cell compartments and also to induce cytotoxicity at the highest level of exposure. In mouse splenocytes, BD has also shown a weak aneugenic effect at a short time interval after the exposure. Postinhalation time influences the induction of chromosome damage in stimulated splenocytes treated in vivo, since MN frequency decreases with time; in addition, BD has shown its aneugenic and cytotoxic potential only at 2 days after exposure.

Animals↗
PubMed1998

Evaluation and characterization of micronuclei in early spermatids of mice exposed to 1,3-butadiene.

The frequency of micronuclei induced in mouse meiotic cells after exposure to 1,3-butadiene has been evaluated in early spermatids. Germ cells were isolated from mice exposed to three butadiene concentrations (130, 250 and 500 ppm), at time intervals allowing to evaluate effects induced in late spermatocytes or at the stage of prelepotene/differentiating spermatogonia. The characterization of the origin of micronuclei, by simultaneous detection of centromeric and telomeric sequences, was also done on spermatid preparations from the 250 ppm concentration. The same analysis was carried out on a group of mice treated with the major butadiene metabolite, 1,2,3,4-diepoxybutane. The results obtained indicate a weak clastogenic effect of butadiene to premeiotic germ cells in the mouse.

Animals↗