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Biomedical subjects

F Corsi

Publications and source records attributed to F Corsi.

17 recordsLinked to original sources
PubMed2002

The mechanisms of blood vessel closure in humans by the application of ultrasonic energy.

BACKGROUND: The use of the ultrasonically activated scalpel (UAS) for vessel closure has attained widespread acceptance in many surgical fields. The aim of our study was to investigate the electron microscopic changes to the blood vessels after the application of UAS. METHODS: We collected 10 arterial and 10 venous segments from vessels that had previously been closed by UAS during abdominal operations. The samples were then prepared for ultramicroscopic analysis. Pathological changes in the lumen and the three wall layers of the blood vessel were examined under scanning and transmission electron microscopy. RESULTS: All of the vessel segments showed similar changes: the presence of a blood clot, endothelial cell condensation, coagulative necrosis of the wall, and charring of the vessel at its tip. The edge of the cut vessel were closed by the coagulation bond, which was tied up by collagen fibrils escaped from denaturation. CONCLUSION: When ultrasonic energy is applied to tissues, it changes their structure so as to make a new extracellular matrix.

Cystic Duct↗
PubMed2002

Low molecular weight hyaluronic acid prevents oxygen free radical damage to granulation tissue during wound healing.

Hyaluronic acid protects granulation tissue from oxygen free radical damage and stimulates wound healing, but its molecular weight prevents it from permeating the epidermal barrier A low molecular weight hyaluronic acid preparation is able to permeate the skin, but it is unknown whether or not it retains the scavenging effects of oxygen free radicals in granulation tissue. Our experiments were conducted in rats with excisional or incisional wounds. Wound contraction over 11 days and breaking strength on the fifth day were measured. Oxygen free radical production was induced by intraperitoneal administration of two different xenobiotics: phenazine methosulfate and zymosan. The wounds were treated topically with low molecular weight hyaluronic acid (0.2%) cream or placebo. In the incisional wound group, the effects of superoxide dismutase were also determined. Absolute controls received wounds and placebo but no xenobiotics. Wound healing was significantly slower in the xenobiotic group than in the control groups. These effects were strongly reduced by topical administration of low molecular weight hyaluronic acid (0.2%) cream and in incisional wounds by topically injected superoxide dismutase. Low molecular weight hyaluronic acid is effective as the native compound against oxygen free radicals. Its pharmacological effects through transdermal administration should be tested in appropriate models.

Granulation Tissue↗
PubMed2001

Effects of surgical stress and nitrous oxide anaesthesia on peri-operative plasma levels of total homocysteine. A randomised, controlled study in general surgery.

Previous studies of patients have shown that anaesthesia with nitrous oxide (N2O) increases the plasma levels of total homocysteine. In a randomised, controlled trial we measured the plasma total homocysteine levels in patients undergoing general surgery before and after anaesthesia with and without N2O. Plasma total homocysteine levels were measured before anaesthesia and 1, 3-5 and 24 h after incision in 24 patients randomly allocated to anaesthesia with N2O (n = 12) and without N2O (n = 12). Total homocysteine levels significantly decreased from 10.4 +/- 2.7 to 8.2 +/- 2.9 micromol x l(-1) in the non-N2O group 24 h after incision (p < 0.02), while they tended to increase slightly in the N2O group from 10.5 +/- 4.5 to 10.9 +/- 4.3 micromol x l(-1) (p > 0.05). Our randomised controlled study indicates that total homocysteine decreases after general surgery in patients in whom anaesthesia is maintained without N2O, but not in patients in whom anaesthesia is maintained with N2O.

Adolescent↗
PubMed2001

Angiogenic effects of suture biomaterials. An experimental study in rats.

Angiogenesis is a limiting step of inflammation and wound healing. Although laboratory tests for the evaluation of the angiogenetic effects of biomaterials are available, no investigations have been performed. In this study we examine the angiogenetic effect of suture biomaterials in the rat mesenteric window model. Absolute controls had laparotomy only, controls had mesenteric window wounding, test groups had the insertion of either a thread of collagen, polyglactin 910, polyglycolic acid salt, silk or of a titanium clip. We considered the percentage area of the mesenteric window covered by neovessels. After 7 days, negligible angiogenesis was found in absolute controls, significant angiogenesis in controls, collagen, polyglactin 910 and polyglycolic acid salt treated rats, without differences between treatments. A significant increase of angiogenesis in comparison to the control group was found in rats treated with silk and titanium. Ultramicroscopy of the neovessels showed specific changes of their architecture in titanium-treated rats. In conclusion, angiogenesis during wound healing is differently influenced by the suture material used. Silk and titanium stimulated angiogenesis in a different way.

Animals↗
PubMed2001

Molecular epidemiology of TT virus in Italy and phylogenesis of viral isolates from subjects at different risk for parenteral exposure.

The prevalence and genotype distribution of human TT virus (TTV) in Italy were analysed in 593 subjects at different risk of parenteral infection who included blood donors, patients with chronic type C hepatitis (HCV), thalassemic patients, patients on haemodialysis, human immunodeficiency virus type 1 (HIV-1)-negative intravenous drug users (IVDUs), and HIV-1-infected subjects (IVDUs, heterosexual contacts and homosexual males). Plasma TTV-DNA was detected using nested PCR with primers deduced from the N22 region of the open reading frame 1 (ORF-1) and from the untranslated region (UTR) of the viral genome. Phylogenetic analysis of the sequences obtained from ORF-1 was also undertaken. A high prevalence of plasma TTV-DNA was observed using the UTR primers, with rates varying from 83-100% in the study groups. Using the N22 primers, HIV-1 positive IVDUs and homosexual males, haemodialysed patients and thalassemic patients had a significantly higher TTV prevalence (range: 23.0-86.1%) than blood donors, who displayed a high frequency of positivity (10.6%). Sequence analysis of 127 N22-positive isolates revealed that 42.5% were of type 1, 53.5% of type 2, 2.4% of type 3, and that two isolates (1.6%) were closely related to genotypes 1-2 but distinct from the other major genotypes. TTV-2 was significantly more prevalent in patients at high risk for parenteral infection and in HIV-1 positive homosexuals. In sequential samples from 15 TTV-infected subjects, N22 sequences were detectable persistently in 12 (80.0%) and UTR sequences persisted in all 15 patients over a mean period of 29.6 months. This data indicates that TTV is widespread in Italy in parenterally exposed subjects, and that the infection frequently persists.

Adult↗
PubMed2000

Metastatic melanoma of the gallbladder.

A 38-year-old man arrived at our clinic with symptoms and investigation results (U.S. scan and MR) suggestive of acute calculous cholecystitis. He gave a past history of excision of a stage I melanoma of the shoulder. Metastatic disease was suspected following measurement of CA 19.9 levels and the CT scan. The patient underwent laparotomy and cholecystectomy; pathological examination confirmed the presence of a malignant melanoma metastatic lesion of the gallbladder.

Adult↗
PubMed1999

Estimating temporal independence of radio-telemetry data on animal activity

Radio-telemetry is an excellent tool for gathering data on the biology of animals and their interactions with the environment they inhabit. Many methods have been developed for analyses of spatial information, on home range size and utilization density. Activity patterns are often described using radio-tracking data, but no generally accepted method is currently available specifically for determining the temporal independence of this type of data for statistical inference. Activity rhythms have generally been analysed by ecologists with the assumption that data are temporally independent, or by subjectively fixing an independence interval, based on attributes of their ranging behaviour. Although some good approximations of activity patterns can be obtained in these ways, we underline the need for a functionally correct method of estimating independence interval. Here we use semi-variograms to estimate the minimum interval required for the readings to be sequentially independent. This geostatistical tool is applied to the analysis of data on activity of Chilean foxes (Pseudalopex culpaeus) and Chacoan peccaries (Catagonus wagneri). Data were collected in the field by radio-tracking over 24-hr periods, with readings on activity state taken every 15 min. The spatial dimension in which the theory of geostatistics lies has been transferred into the time dimension, so that the correlation interval is expressed in time units (min). Time of independence as estimated by the variogram was 110 min for foxes, while data on peccaries indicated that they have long periods of activity, more suitable for time-series analysis. Copyright 1999 Academic Press.

Journal Article↗
PubMed1998

Late rejection of the mesh after laparoscopic hernia repair.

We report the first case of late rejection of a mesh after laparoscopic hernia repair. It occurred in a 48-year-old man who had had a laparoscopic hernia repair by transabdominal preperitoneal approach 3 years earlier. The most characteristic finding was the slow development of a firm mass in the right groin, without pain or fistula. At admission 3 months later, US and CT scans demonstrated a necrotic mass extending into both iliac fossa. The mass was approached through a midline incision. Pus was taken for microscopic examination (negative), and the mesh was removed, along with several staples. Ultramicroscopic examination of the mesh showed breakdown of the fibers, collagen reduction, and no chronic inflammatory cells. No infectious cause of inflammation was identified.

Foreign-Body Reaction↗
PubMed1997

Paradoxical effects of intra-arterial administration of basic fibroblast growth factor on inflammatory angiogenesis in rats.

The authors studied the effects of basic fibroblast growth factor (b-FGF) on inflammatory angiogenesis in rats. In the corneal cauterization model b-FGF was given intra-arterially (i.a.) (carotid) and in the mesenteric window angiogenesis model, topically (i.e., intraperitoneally (i.p.)). The corneal cauterization was done under anaesthesia by topical application of silver nitrate. Mesenteric window angiogenesis was induced by injection of saline or b-FGF for four days. There were the same two groups of treatment in both models b-FGF 2.5 micrograms/kg/day or saline 1.2-5 ml/kg/day. The area of neovessels and the number of polymorphonuclear cells/field were considered for the corneal angiogenesis, the total length of neovessels was measured for the mesenteric window angiogenesis. The results were expressed as mean values (s.d.). When given i.a., b-FGF significantly reduced the number of polymorphonuclear cells three days after corneal cauterization (from 107 +/- 27 to 41.8 +/- 26, p < 0.01) and inhibited the area covered by neovessels (30 +/- 7.7% vs 51 +/- 20%, p < 0.01) after five days. In contrast, given through the extracellular space, it significantly stimulated the length of mesenteric window microvessels (169 +/- 60 mm vs 90 +/- 31 mm, p < 0.05). These results suggest that b-FGF stimulates inflammatory angiogenesis through interaction with extracellular matrix components, but inhibits it directly when given intra-arterially.

Administration, Topical↗
PubMed1995

[Osteoporosis and densitometry screening: preliminary results].

We have examined the bone densitometry with osteoradiometer (ORM) of 355 patients who came to the "Centre for Prevention, Diagnosis and Therapy of Osteoporosis" at the Israelitic Hospital of Rome. 144 patients, 141 females and 3 males, will be studied in the future because their densitometric values are lower than the values considered normal for age and sex. We have valued anamnestic data (age, menopause, pregnancies, excessive use of alcohol and smoke, sedentary habits), medical data hyperthyroidism, OCB, chronic diarrhoea) and surgical data (ovariectomy, thyroidectomy, gastro-duodenal resection, mastectomy) to have the correct outline of the patient situation before further researches and beginning the best medical therapy. For the prevention and screening of people "at risk" densitometry is irreplaceable both pre-clinical osteopeny, and for checking the effects of the therapy.

Adult↗
PubMed1995

Diffuse leptomeningeal gliomatosis with osteoblastic metastases and no evidence of intraaxial lesions.

An autopsy-proved case of cerebral and medullary leptomeningeal gliomatosis and diffuse osteoblastic metastases without evidence of intraaxial tumor is described. MR findings included diffuse thickening of the cerebral and medullary leptomeninges on T1-weighted, proton density-weighted, and T2-weighted images and abnormal enhancement of the sulci and cisterns of the cerebrum, brain stem, cerebellum, and medulla on postcontrast T1-weighted images. MR also showed several areas of replacement of the normal bone marrow of the skull. No intraaxial lesion was seen.

Adult↗
PubMed1994

Inhibition of inflammatory angiogenesis in rats by loco-regional administration of hydrocortisone and protamine.

We have studied the antiangiogenetic effects of hydrocortisone and protamine given intra-arterially. The cornea of male, Sprague-Dawley rats were cauterized with silver nitrate. The following treatments were given: 30 micrograms hydrocortisone topical (t.p.), b.i.d., 50 mg/kg/day intraperitoneally (i.p.) or intra-arterially (i.a.), 10 mg/kg/day protamine i.p. or i.a. Saline was administered to the control groups. In separate experiments we also evaluated the anti-inflammatory effects of hydrocortisone, i.p., on the cauterized corneas. Five days after cauterization, the animals were killed, exsanguinated and India ink was injected to show the network of neovessels. The percentage area of the cornea covered by neovessels was measured morphometrically and evaluated statistically. Hydrocortisone t.p. (-84%), i.a. (-60%) and protamine i.a. (-44%) significantly inhibited angiogenesis in the cauterized cornea. Either drugs, i.p., had any antiangiogenetic effects, but hydrocortisone significantly reduced cell infiltration of the corneas. The results suggest that locoregional administration of antiangiogenetic drugs might be clinically useful.

Animals↗
PubMed1977

[Methods for the sampling and tracing of caprolactam monomer dispersed in the air].

The problem of hygiene in the production of epsilon-caprolactam is very important; pollution of work room air is possible when the substance is stored, transported or packed in bags. In this work toxic and irritant properties of epsilon-caprolactam are described. Infrared spectroscopic, gas chromatrographic and spectrophotometric methods used by us, for the determination of epsilon-caprolactam traces, are also described.

Air Pollutants↗