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Biomedical subjects

G Cavallaro

Publications and source records attributed to G Cavallaro.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Internal abdominal hernia. Unusual cause of intestinal occlusion].

Internal abdominal hernias are an unusual cause of intestinal occlusion. They are responsible for 2% of all the intestinal obstructions. Various types of hernia have been described. The diagnosis is difficult, but should be suspected in patients suffering from intestinal obstruction who have undergone earlier laparotomy. Diagnosis is even more difficult in cases of congenital internal hernia. The authors report a case of left paraduodenal hernia (congenital), and a case of transmesenteric hernia (acquired). Both patients complained of a short history of abdominal pain and characteristic symptoms of acute abdomen (nausea, vomit, cramps and obstipation). Emergency surgery using laparotomy enabled diagnosis and treatment. The authors underline the difficulty of diagnosing these hernias and emphasise the diagnostic and therapeutic importance of emergency surgery.

Adult↗
PubMed2000

[Malignant nodular hidradenoma. A clinical case].

Malignant clear cell hidradenoma is an uncommon tumor of eccrine sweat gland origin. In contrast to the benign form, malignant clear cell hidradenoma tends to invade the surrounding tissue and has a high incidence of distant metastases. For these reasons a wide surgical excision associated to a locoregional lymph node dissection should be performed alter the initial diagnosis. The case of a 17 year old female with this rare lesion is reported; the literature is reviewed and surgical treatment discussed.

Adenoma, Sweat Gland↗
PubMed1999

Studies of macromolecular prodrugs of zidovudine.

The current problems in controlling severe viral infections such as AIDS as well as the lack of effective and safe therapeutic measures for such diseases have caused interest in systems such as macromolecular prodrugs potentially able to solve heavier drawbacks of conventional antiviral therapy. This review focuses on various approaches proposed in the literature in this field. Neoglycoproteins and synthetic protein-like structure polymers have been mainly proposed. In the first group, the possibility of incorporating into the polymeric structures a determined amount of sugar molecules make them interesting candidates for targeting of infected blood cells. The conjugate of zidovudine (AZT) and an anti-transferrin receptor antibody OX-26 has been proposed for brain targeting. The conjugate of AZT with alpha,beta-poly(N-hydroxyethyl)-DL-aspartamide (PHEA) showed good release properties in a prolonged time.

Journal Article↗
PubMed1999

New biodegradable hydrogels based on a photocrosslinkable modified polyaspartamide: synthesis and characterization.

alpha,beta-Poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA), a synthetic water-soluble biocompatible polymer, was derivatized with glycidyl methacrylate (GMA), in order to introduce in its structure chemical residues having double bonds and ester groups. The obtained copolymer (PHG) contained 29 mol% of GMA residues. PHG aqueous solutions at various concentrations ranging from 30 to 70 mg/ml were exposed to a source of UV rays at lambda 254 nm in the presence or in the absence of N,N'-methylenebisacrylamide (BIS); the formation of compact gel phases was observed beginning from 50 mg/ml. The obtained networks were characterized by FT-IR spectrophotometry and swelling measurements which evidenced the high affinity of PHG hydrogels towards aqueous media at different pH values. In vitro chemical or enzymatic hydrolysis studies suggested that the prepared samples undergo a partial degradation both at pH 1 and pH 10 and after incubation with enzymes such as esterase, pepsin and alpha-chymotrypsin. Finally, the effect of irradiation time on the yield and the properties of these hydrogels was investigated and the sol fractions coming from irradiated samples, properly purified, were characterized by FT-IR and 1H-NMR analyses.

Acrylamides↗
PubMed1999

Basic fibroblast growth factor and myointimal hyperplasia after experimental polytetrafluoroethylene arterial grafting.

OBJECTIVE: To assess the role of polyclonal antibodies to basic fibroblast growth factor (bFGF) in inhibiting myointimal hyperplasia after insertion of polytetrafluoroethylene (PTFE) grafts in rats. DESIGN: Experimental study. SETTING: University laboratory, Italy. ANIMALS: 24 inbred Lewis rats. INTERVENTIONS: A segment of PTFE I cm long was interposed in the abdominal aorta. The animals were randomised in two groups, n = 12 in each. The first were given polyclonal antibodies to bFGF at the time of operation, and for the first two postoperative days; and the second were given non-specific IgG at the same time periods. MAIN OUTCOME AND MEASURES: Two animals died during the immediate postoperative period of anaesthetic complications. 12 animals (6 in each group) were killed 7 days postoperatively (24 hours after injection of 5-bromo-deoxyuridine BrdU) to assess smooth muscle cell proliferation. The remaining 10 animals (5 in each group) were killed after 1 month to assess the degree of anastomotic myointimal hyperplasia. RESULTS: Antibodies to bFGF resulted in less smooth muscle cell proliferation at the anastomoses as well as anastomotic myointimal hyperplasia. Smooth muscle cell proliferation was reduced to about half in animals treated with anti-bFGF antibodies. Neointimal thickness was reduced in treated animals. CONCLUSIONS: We conclude that after PTFE arterial grafting there is increased production of bFGF at the anastomotic regions that leads to smooth muscle cell proliferation and formation of myointimal hyperplasia. Agents that reduce the production of bFGF may also reduce the development of myointimal hyperplasia after PTFE arterial grafting.

Analysis of Variance↗
PubMed1999

New biodegradable hydrogels based on an acryloylated polyaspartamide cross-linked by gamma irradiation.

Alpha, beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA), a synthetic biocompatible macromolecule, was functionalized with glycidyl methacrylate (GMA) in order to introduce in its side chains residues having double bonds and ester groups. The copolymer (PHG), obtained from PHEA and GMA, had a degree of derivatization of 29 mol%. PHG aqueous solutions are cross-linked by gamma radiation at 0 degrees C either in the presence or absence of N,N'-methylenebisacrylamide (BIS) giving rise to new hydrogel systems. In both cases gelation occurs at quite low doses (0.26 and 0.4 kGy, respectively). The obtained networks were characterized by FT-IR spectrophotometry which confirmed that the cross-linking process involves the vinyl groups of the polymer chains. Swelling measurements evidenced the high affinity of aqueous media at different pH-values towards PHG hydrogels. The sol fractions of the irradiated samples, properly purified, were characterized by FT-IR and 1H-NMR analyses and reduced viscosity measurements. Finally, in vitro chemical or enzymatic hydrolysis studies suggested that the prepared samples undergo a partial degradation at pH 1 and 10 or after incubation with enzymes such as esterase, pepsin, and alpha-chymotrypsin.

Biocompatible Materials↗
PubMed1999

[Isolated mesenteric fibromatosis. A clinical case].

The authors report a case of isolated mesenteric fibromatosis un associated with familial adenomatous polyposis or Gardner's syndrome or prior abdominal surgery. These neoplasms are usually asymptomatic until when the compression of the small or large bowel or the ureter causes symptoms; although they are benign lesions without metastases, local recurrences are very frequent. Surgical removal is the primary treatment; until now no satisfactory results have been obtained with other therapeutic modalities.

Adult↗
PubMed1999

Isolated true atherosclerotic aneurysm of the profunda femoris artery. Case report.

The authors report a case of true isolated atherosclerotic aneurysm of the profunda femoris artery. On the basis of a careful search of the literature some aspects of this rare disease are illuminated in terms of its low incidence, pathologic background and treatment; the last should always be aggressive due to the high possibility (about 50%) of major complications mainly represented by rupture. Simple aneurysmectomy without flow re-establishment may be allowed only if the femoropopliteal tract is normal

Aged↗
PubMed1998

Coupling of the antiviral agent zidovudine to polyaspartamide and in vitro drug release studies.

A macromolecular prodrug of the known antiretroviral agent zidovudine and alpha, beta-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) was synthesized. A succinic spacer was present between the polymer and the drug, and 1,1'-carbonyldiimidazole was used as the coupling agent. In vitro drug release studies at pH 1.1, 5.5 and 7.4 indicated that limited amounts of intact drug were released from the conjugate. At pH 1.1 and 7.4 succinylzidovudine was released, and this was hydrolysed to give free zidovudine. In the presence of alpha-chymotrypsin, zidovudine was released preferentially in comparison with the succinyl derivative. The amounts of released zidovudine and succinylzidovudine were greater in plasma than in aqueous buffer solutions. These results show that after i.v. administration this drug-polymer conjugate can release zidovudine into the blood circulation for prolonged periods.

Anti-HIV Agents↗
PubMed1998

Usefulness of microsurgery to isolation of recurrent laryngeal nerve and parathyroid during thyroidectomy operations.

The authors report their experience of the application of microsurgical techniques in total and subtotal thyroidectomy operations from January 1984-January 1997. Four hundred and eighty-six patients with thyroid diseases were operated upon with both traditional and microsurgical techniques. The comparison of results shows that microsurgical skills are effective in reducing the dangers and important complications in both laryngeal nerves and parathyroids.

Adolescent↗
PubMed1998

Iliac-to-isolated hepatic artery bypass in the treatment of intestinal angina: two cases.

Two cases in which a severe form of intestinal angina was cured by revascularization of an isolated hepatic artery were studied. The collateral pathways to the hepatic artery may serve, in a retrograde fashion, to assure an acceptable blood supply to the splanchnic organs, even when the disease of the 3 main vessels is so extensive that the commonly used techniques of revascularization cannot be applied.

Abdominal Pain↗
PubMed1998

Suppression of smooth muscle cell proliferation after experimental PTFE arterial grafting: a role for polyclonal anti-basic fibroblast growth factor (bFGF) antibody.

OBJECTIVES: To determine the role of polyclonal anti-basic Fibroblast Growth Factor (bFGF) antibody in inhibiting the proliferation of smooth muscle cells after experimental polytetrafluorethilene (PTFE) arterial grafting. MATERIALS: In 14 male inbred Lewis rats (weight 250 mg) a 1 cm long segment of PTFE was interposed at the level of abdominal aorta. Animals were randomised to receive polyclonal anti-bFGF antibody (group A: n = seven animals) or aspecific immunoglobulin (group B: n = seven animals). Anti-bFGF antibody or aspecific immunoglublin were given intraperitoneally at the end of operation, and for the first 2 postoperative days. Animals were sacrificed 7 days after surgery, 24 h after intraperitoneal injection of BromodeoxyUridin (BrdU) to label proliferating smooth muscle cells. RESULTS: One animal in each group died in the immediate postoperative period due to anaesthetic problems. All grafts were patent at the time of sacrifice. BrdU labelling index was statistically higher in the control group B animals at the level of the anastomotic regions (proximal anastomosis: group B 7.9% vs. group A 4.1%. Distal anastomosis: group B 5.1% vs. group A 2.6% p = 0.009) and at the level of PTFE graft (group B 3.8% vs. group A 2.6% p = 0.002), while there was no statistical difference between the control thoracic aorta of the two groups. MAIN CONCLUSIONS: bFGF plays a major role in the proliferation of smooth muscle cells at the level of the anastomoses after arterial PTFE grafting. Agents able to block the action of bFGF may be useful in inhibiting the formation of myointimal hyperplasia.

Anastomosis, Surgical↗
PubMed1998

[Microsurgical approach to epididymal neoplasms. Our experience].

In the period from January 1st 1988 to January 15th 1994 inclusive, we observed 36 patients with epididymal neoformations. In patients with a considerable oligospermia, we associated microsurgical extirpation of neoformations, with the "testis biopsy" operation, to assess eventual histologic alterations of the interstice and seminiferous tubulus. The authors show as the application of microsurgical techniques with the help of magnifying optical instruments, permits to remove these neoformations with respect to near by structures besides consenting the accurate reconstruction of structures operated and maintenance or recovery of functionality mostly in young people, where fertility recovery is obligatory.

Adult↗
PubMed1996

Preparation and characterization of polyethyl-2-cyanoacrylate nanocapsules containing antiepileptic drugs.

Biocompatible and biodegradable colloidal drug delivery systems can be obtained by means of in situ polymerization of alkylcyanoacrylate. In particular, nanocapsules of polyethylcyanoacrylate (PECA) were prepared by adding the monomer to an organic phase, consisting of Miglyol 812 and an organic solvent (ethanol, acetone or acetonitrile), and subsequently mixing the organic phase with an aqueous phase containing Pluronic F68 at different concentrations. The possible mechanism of formation and the influence of preparation conditions on the quality of nanocapsule formulations were investigated by freeze-fracture electron microscopy and laser light scattering using both the inverse Laplace transform and the standard cumulant analysis for data fitting. High-quality nanocapsule systems were obtained using an aprotic fully water-miscible organic solvent such as acetone. The presence of ethanol led to the formation of both nanospheres and nanocapsules. The concentrations of nonionic surfactant in the aqueous phase of monomer in the organic phase did not influence the kind of colloidal suspension obtained. The oil simply plays the role of monomer support. The diameter of PECA nanoparticles (nanospheres and nanocapsules) ranged from 100 to 400 nm. Three antiepileptic drugs (Ethosuximide, 5,5-diphenyl hydantoin and carbamazepine) were entrapped in PECA nanocapsules. The loading capacity of PECA nanocapsules, prepared using acetone as organic solvent, varied from 1% to 11% (drug/dried material) as a function of the solubility (affinity) of the different drugs with the oil core. This parameter also influenced the release from PECA nanocapsules, which was slower for drugs with a higher affinity for Miglyol 812. By encapsulating the three antiepileptic drugs in the PECA nanocapsules, it was possible to achieve controlled drug release. The mechanism of drug release from PECA nanocapsules was mainly diffusion from the oil core through the intact polymer barrier.

Acetone↗
PubMed1996

Cytarabine release from alpha, beta-poly (N-hydroxyethyl)-DL-aspartamide matrices cross-linked through gamma-radiation.

alpha, beta-Poly (N-hydroxyethyl)-DL-aspartamide solutions were cross-linked through gamma-radiation and the systems obtained were tested as matrices for drug sustained release, using cytarabine as model drug. We performed the characterization of the cross-linked polymer, both drug-loaded and unloaded. through water swelling measurements, scanning electron microscopy and X-ray analysis. Finally, we investigated the in vitro release behaviour of cytarabine.

Chemistry, Pharmaceutical↗