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Biomedical subjects

A Russo

Publications and source records attributed to A Russo.

At least 379 records · Page 21Linked to original sources
PubMed1994

Healing impairment of open wounds by skin irradiation.

BACKGROUND: Ionizing radiation is frequently used for the treatment of malignancy. Sequelae of therapeutic radiation frequently present clinical problems in the form of poor wound healing and easy injury of treated tissue in response to mild trauma. OBJECTIVE: We describe a radiation-impaired wound healing model in guinea pigs, developed to determine the effect of cutaneous irradiation on wound contraction. METHODS: Guinea pigs were anesthetized and a flap of skin was isolated and treated with x-rays to 18 Gy. Circular wounds of identical size were made in irradiated and control skin, and average wound size was recorded. RESULTS: Our results demonstrate that a statistically significant wound healing deficit is produced in open wounds by surface irradiation of skin. CONCLUSION: Radiation of skin results in slower healing of open wounds, and provides an in vivo system for evaluation of topical dressings and growth factors in radiation-impaired wounds.

Animals↗
PubMed1994

Liposomes as in-vivo carriers for citicoline: effects on rat cerebral post-ischaemic reperfusion.

Citicoline is a therapeutic agent widely used in the treatment of brain injury, for example in cerebrovascular disease or traumatic accidents. Unfortunately, the strong polar nature of this drug prevents it crossing the blood-brain barrier. In this paper, the possibility of efficiently trapping citicoline in liposomes to improve its therapeutic effects is reported. The citicoline-encapsulation efficiency, drug leakage and size analysis of various liposome systems were studied. The real therapeutic effectiveness of these citicoline liposome formulations was evaluated by biological assay. The effects of free and liposome encapsulated citicoline on survival rate of ischaemic reperfused male Wistar rats (80-100 g) were investigated. Of the phospholipid mixtures used in citicoline liposome formulation the best in terms of delivery and therapeutic effects was 1,2-dipalmitoyl-sn-glycero-phosphocholine: dipalmitoyl-DL-alpha-phosphatidyl-L-serine:cholesterol (7:4:7 molar ratio). This phospholipid mixture was also assayed for brain conjugated diene levels in rats, since this parameter is an index of lipid peroxidation in rat cerebral cortex during post-ischaemic reperfusion. A citicoline-loaded phospholipid mixture has produced an increase in rat survival rate of about 24% and a reduction in diene levels of 60%, compared to the free drug.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1994

Revision stapes surgery: a critical evaluation.

Fifty-six revision stapes surgeries performed during the last 9 years were evaluated retrospectively for their preoperative symptoms, intraoperative findings, and postoperative results according to the causes of failure, at the Gruppo Otologico, Piacenza, Italy. The most frequent causes of failure were found to be prosthetic misalignments, a reaction to the surgical trauma in the form of excess fibrous tissue reaction or new bony regrowth at the oval window, and ossicular chain problems. The location of the pathology was found to be an important factor in the outcome. Sixty percent of cases resulted in 0- to 20-dB air-bone gap. The causes of these failures, management, and their prevention during primary surgeries are also discussed.

Adult↗
PubMed1994

Surgical anatomy of the petrous apex as it relates to the enlarged middle cranial fossa approaches.

This work was designed to study the surgical anatomy of the petrous apex as it relates to the enlarged middle cranial fossa approaches, on 25 temporal bones. In this study we suggest dividing the petrous apex into two topographic areas: an anterior triangular and a posterior quadrangular area with respect to the posterior border of the Gasserian ganglion. Anatomic descriptions endorsed by relevant measurements of these areas are provided in this study.

Humans↗
PubMed1994

Surgical management of epitympanic cholesteatoma with intact ossicular chain: the modified Bondy technique.

The results of 37 cases surgically treated with the modified Bondy technique during a 6-year period at the Gruppo Otologico-Piacenza, Italy, are reported. This technique, indicated in epitympanic cholesteatoma with good hearing and intact ossicular chain and pars tensa, provides a one-stage mastoid cavity exteriorization with radical removal of cholesteatoma while preserving the preoperative hearing levels. The technique, indications, results, and comparison with other current techniques are discussed in this article.

Adolescent↗
PubMed1994

Histologic patterns of omeprazole and nizatidine-healed duodenal ulcers:accuracy of endoscopic diagnosis.

The mechanisms underlying duodenal ulcer (DU) recurrence after endoscopically confirmed healing are unclear. We sought to examine histologic differences in healing induced by omeprazole and nizatidine. This also entailed assessing interobserver variation in endoscopic diagnosis and the correlation between endoscopic and histomorphologic healing. We treated 31 DU patients for 4 weeks with either omeprazole (20 mg daily a.m.) or nizatidine (300 mg twice daily). The healing rates of both groups showed no significant differences (86.7% versus 81.2%; p = 0.5). Good mucosal repair rates did not differ significantly (38.5% versus 69.2% respectively; p = 0.5). Endoscopists' agreement over scar type was 0.80, with the chance of agreement 0.70 (k = 0.34 +/- -0.08). The correlation between macroscopic and histologic appearance of scars was fair, but fully significant (r = 0.48; p < 0.05). We conclude that the study was too small to detect significant differences in healing patterns between the two drugs. The wide variation in endoscopic diagnosis suggests that mucosal repair is best assessed by histologic examination of biopsy samples.

Adult↗
PubMed1994

Vimentin expression, proliferating cell nuclear antigen and flow cytometric factors. Prognostic role in breast cancer.

A series of 71 patients undergoing surgery for primary breast carcinoma was prospectively studied in order to evaluate the relative weight for four biologic factors (intermediate filament vimentin expression, proliferating cell nuclear antigen [PCNA], flow cytometric DNA ploidy and S-phase fraction) and of several clinicopathologic and biologic features in predicting clinical outcome (disease-free interval). In univariate statistical analysis, positivity of axillary nodes, high number of mitoses, high nuclear grade, high histologic grade, positivity of vimentin, high flow cytometric S-phase fraction (FCM-S) value, high PCNA and high silver-stained nuclear organizer regions scores were significantly related to risk of relapse. In multivariate analysis (Cox's logistic regression) only histologic grade (3) and high FCM-S values (> 10.7) were independently related to risk of relapse, with hazard ratios of 9.84 and 7.98, respectively. The results of our preliminary, prospective study suggest that FCM-S, in addition to morphologic criteria (histologic grade), may be an important biologic indicator in determining breast cancer patients' prognosis.

Analysis of Variance↗
PubMed1994

Lipid peroxidation and survival in rats following cerebral post-ischaemic reperfusion: effect of drugs with different molecular mechanisms.

In the present study the authors investigated the effect of pretreatment with exogenous antioxidants such as deferoxamine (iron chelating drug), allopurinol (competitive inhibitor of xanthine oxidase) and vitamin E (scavenger of oxygen free radicals) on lipid peroxidation in rat cerebral cortex after post-ischaemic reperfusion, and on the survival rate. The effect of pretreatment with two calcium-antagonist drugs (diltiazem and verapamil) was also evaluated under the same experimental conditions. Pretreatment with exogenous antioxidants and with calcium-antagonist drugs significantly decreased cerebral conjugated diene levels (index of lipoperoxidation) with a concomitant increase in survival with respect to untreated ischaemic rats.

Allopurinol↗
PubMed1994

[Incidence of cancer in migrants: data of the Lombardy tumor registry].

Epidemiological studies of migrants have played an important role in evaluating the environmental and genetic components of cancer aetiology. Italian regions were grouped into five areas: North-West, North-East, Central, South and Lombardia. Incidences of cancer in migrants from South and North-East of Italy, in the province of Varese, have been compared with the incidence of Lombardia-born population, using data collected from the Cancer Registry of Lombardia for 12 years (1976-1987). Incidence comparisons were made using the Standardized Incidence Ratio (SIR). Subjects emigrated from the North-East show SIR higher than the Lombardia-born for lung and oesophageal cancer (smoking and alcohol related cancers). SIR for lip and nasopharyngeal cancers were higher in South-born. Cancer of breast, stomach and colon have low SIRs in subjects migrated from the South and, to a even lower extent, in subjects migrated from the North-East. Several others cancers tended, in general, to have lower rates in migrants from South than in native-born in Lombardia.

Cohort Studies↗
PubMed1994

Heat shock proteins following rat cerebral ischemic/reperfusion episode: effect of ketamine.

This paper reports the influence of ketamine on HSP70 expression, during an ischemic/reperfusion episode, in rat cerebral cortex and hippocampus. The results indicate that ketamine, injected 1h before the surgical treatment, increases HSP70 cellular concentration in both ischemic and sham-operated animals. The HSP70 levels, after the transient ischemic episode, are higher in ketamine treated than in urethane-treated animals respect to the control levels. After reperfusion an increase of HSP70 levels is observed; this induction is maintained for at least 22h, irrespective of the anaesthetic drug treatment. Comparing the cerebral areas examined, the hippocampus exhibits higher protein levels than those of the cerebral cortex.

Animals↗
PubMed1993

Interaction between replication forks and topoisomerase I-DNA cleavable complexes: studies in a cell-free SV40 DNA replication system.

The extreme S-phase-specific cytotoxicity of camptothecin has been shown to involve active DNA replication. To investigate the role of DNA replication in camptothecin cytotoxicity, we have studied the interaction between the DNA replication machinery and the topoisomerase I-camptothecin-DNA ternary cleavable complex in a cell-free SV40 DNA replication system. The formation of topoisomerase I-camptothecin-DNA-cleavable complexes on the replication template efficiently and irreversibly inhibited DNA replication. Two aberrant forms of replication products were produced whose abundance varied with the concentrations of exogenously added topoisomerase I and camptothecin. At low concentrations of topoisomerase I and camptothecin, the major aberrant DNA replication product was close-to-unit-length-linear DNA, while at higher concentrations the predominant product was close-to-dimer-size-linear DNA. Analysis of these aberrant replication products has suggested a "collision" model in which the interaction between an advancing replication fork and a topoisomerase I-camptothecin-DNA-cleavable complex results in irreversible arrest of the replication fork and the formation of a double-strand DNA break at the fork. Concomitant with fork arrest and fork breakage, the reversible cleavable complex was converted into a topoisomerase I-linked DNA break. We propose that one or several of these events triggers S-phase-specific cell killing and G2-phase cell cycle arrest.

Camptothecin↗
PubMed1993

The fission yeast cdc18+ gene product couples S phase to START and mitosis.

Commitment to the cell cycle in fission yeast requires the function of the cdc10+ transcriptional activator at START. The product of the cdc18+ gene is a major downstream target of cdc10+, and transcription of cdc18+ is activated by cdc10+ during passage through START. The cdc18+ function is required for entry into S phase. In addition, the product of the cdc18+ gene is part of the checkpoint control that prevents mitosis from occurring until S phase is completed. Thus, cdc18+ plays a key role in coupling S phase to START and mitosis.

Amino Acid Sequence↗
PubMed1993

A retrospective study of the effects of pelvic irradiation for carcinoma of the cervix on gastrointestinal function.

PURPOSE: To evaluate the prevalence of disordered gastrointestinal function following therapeutic irradiation. METHODS AND MATERIALS: Gastrointestinal function was evaluated in 30 randomly selected patients who had received pelvic irradiation for treatment of carcinoma of the cervix between 1 and 6 years previously. Each patient underwent evaluations of (a) gastrointestinal symptoms (b) absorption of bile acid, vitamin B12, lactose and fat (c) gastrointestinal transit: gastric emptying, small intestinal transit and whole gut transit and (d) intestinal permeability. Results were compared with those obtained in 18 normal volunteers. RESULTS: Stool frequency was above the control range in five patients and had increased (p < 0.001) since radiotherapy treatment. Bile acid (p < 0.001) vitamin B12 (p < 0.01) and lactose (p < 0.01) absorption were less in the patients when compared with the control subjects. Bile acid absorption was below the control range in 14 of the 30 patients. Dietary calcium intake was lower (p < 0.05) in those patients with lactose malabsorption. Gastric emptying (p < 0.01) and small intestinal transit (p < 0.01) were more rapid in the patients. Both small intestinal (r = -0.39, p < 0.05) and whole gut (r = -0.45) transit were inversely related to stool frequency. Either bowel frequency, bile acid absorption, vitamin B12 absorption was outside the control range in 19 of the 30 patients. CONCLUSION: Abnormal gastrointestinal function is essentially an inevitable long-term sequel of pelvic irradiation.

Adult↗
PubMed1993

Free radical scavenger depletion in post-ischemic reperfusion brain damage.

In the present study the influence of pretreatment with various GSH depletors such as buthionine sulfoximine (BSO) and diethylmaleate (DEM) was investigated in rats following cerebral post-ischemic reperfusion. Moreover, the effect of diethyldithiocarbamic acid (DDC), inhibitor of endogenous Cu,Zn-SOD, was evaluated. A significant depletion (40% of control value) of GSH levels was observed 24 h after DEM administration; after 48 h the value reached control levels. BSO showed maximal GSH depletion (59%) 24 h after administration and it was constant for almost 48 h. DDC administration caused a marked decrease (60%) of Cu,Zn-SOD activity 4 h after the injection and induced a marked decrease in percentage of survival with respect to control (untreated, ischemic) rats, when administered 4 h before ischemia. BSO and DEM prolonged the survival time of animals when administered 24 h before ischemia. This last paradoxical effect is unclear at present, but it might be due to an influence on glutamate cascade.

Animals↗
PubMed1993

Effect of acetyl-L-carnitine on lipid peroxidation and xanthine oxidase activity in rat skeletal muscle.

It has been reported that acetyl-L-carnitine (AcCn) can reduce the degenerative processes in the central nervous system of rats, modify the fluidity of membranes and decrease the accumulation of lipofuscins in neurones. In light of these considerations we have assayed the in vitro effect of acetyl-L-carnitine on spontaneous and induced lipoperoxidation in rat skeletal muscle; in addition, the effect of AcCn on XD/XO ratio was evaluated. The presence of AcCn (10-40 mM) in incubation medium significantly reduced MDA and conjugated diene formation in rat skeletal muscle; moreover, a significant decrease in induced MDA levels was observed when microsomal preparation where incubated in the presence of 10-40 mM AcCn. Since a significant reduction of XO activity was detected in the presence of 10-80 mM AcCn, the reduced lipid peroxidation by AcCn seems to be due to an inhibition of XO activity.

Acetylcarnitine↗
PubMed1993

Effect of pelvic irradiation on gastrointestinal function: a prospective longitudinal study.

PURPOSE: Although radiation enteritis is a well-recognized sequel of therapeutic irradiation, the effects of abdominal and/or pelvic irradiation on gastrointestinal function are poorly defined and treatment is often unsuccessful. To determine both the short- and long-term effects of therapeutic irradiation on gastrointestinal function, we performed a prospective study. PATIENTS AND METHODS: Various aspects of gastrointestinal function were evaluated in 27 patients with potentially curable malignant disease (23 female, 4 male) before the commencement of, during, and 6 to 8 weeks, 12 to 16 weeks, and 1 to 2 years following completion of radiation therapy. Seventeen patients received pelvic irradiation alone and 10 patients received both abdominal and pelvic irradiation. Gastrointestinal symptoms, absorption of bile acid, vitamin B12, lactose, and fat, gastric emptying, small-intestinal and whole-gut transit, stool weight, and intestinal permeability were measured. Results were compared with those obtained in 18 normal volunteers. RESULTS: All 27 patients completed at least 2 series of measurements and 18 patients completed all 5 series of experiments. During radiation treatment, increased stool frequency (p < 0.001) was associated with decreased bile acid and vitamin B12 absorption (p < 0.001 for both), increased fecal fat excretion (p < 0.05), an increased prevalence of lactose malabsorption (p < 0.01), and more rapid small-intestinal (p < 0.01) and whole-gut (p < 0.05) transit. Although there was improvement in most of these changes with time, at 1 to 2 years after the completion of irradiation, the frequency of bowel actions was greater (p < 0.001), bile acid absorption was less (p < 0.05), and small-intestinal transit was more rapid (p < 0.01) when compared with that of baseline and the normal subjects. At this time, at least 1 parameter of gastrointestinal function was abnormal in 16 of the 18 patients. Stool weight was greater (p < 0.05) and whole-gut transit faster (p < 0.01) in patients who received both pelvic and abdominal irradiation, when compared with those who received pelvic irradiation alone. Stool frequency (p < 0.001) and fecal fat excretion (p < 0.05) were greater in those patients who had surgery before radiation therapy. CONCLUSION: Pelvic irradiation is usually associated with widespread, persistent effects on gastrointestinal function.

Abdominal Neoplasms↗