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Biomedical subjects

G Lombardo

Publications and source records attributed to G Lombardo.

At least 19 recordsLinked to original sources
PubMed2004

Time resolved experimental analysis of the electric field induced biaxial order reconstruction in nematics.

We present the time resolved experimental characterization of the biaxial switching between two topologically distinct textures of a nematic liquid crystal cell submitted to a strong electric field. This fast electro-optical effect is governed by the electric induced order reconstruction in the nematic bulk, which is an actual challenge for a complete theoretical description of the nematodynamics. The electric measurements across the cell are suitable to this purpose since they well discriminate among the dielectric, the ionic, and the order reconstruction contributions. A phenomenological model describes the experimental data, allowing the measurements of the order reconstruction characteristic time.

Journal Article↗
PubMed2004

Protective effects of estradiol on TRAIL-induced apoptosis in a human oligodendrocytic cell line: evidence for multiple sites of interactions.

Demyelinating diseases are high impact neurological disorders. Steroids are regarded as protective molecules in the susceptibility to these diseases. Here, we studied the interactions between tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), a potent proapoptotic molecule toxic to oligodendrocytes, and 17-beta-estradiol (E-17-beta), in human oligodendrocytic MO3.13 cells. Exposure of cells to TRAIL resulted in the upregulation of both death receptors DR4 and DR5 and apoptosis, as well as the activation of caspase-8 and -3, increased phosphorylation of Jun-N-terminal kinase and p38 kinase, and the reduction of bcl-2 and bcl-xL proteins. TRAIL-mediated MO3.13 cell apoptosis was abrogated by the dominant-negative form of the adaptor protein FADD and by caspase inhibitors. Preincubation with E-17-beta completely prevented both TRAIL-induced DR4 and DR5 upregulation and apoptosis. Estrogen-induced cytoprotection was time and concentration dependent and reverted by antiestrogens. Estrogen treatment per se reduced kinase phosphorylation, and upregulated bcl-2 and bcl-xL proteins. In conclusion, our data show that the detrimental role of TRAIL on oligodendrocytes can be effectively counteracted by estrogens, thus suggesting that the underlying molecular interactions can be of potential relevance in characterizing novel targets for therapy of demyelinating disorders.

Apoptosis↗
PubMed2003

Heme oxygenase-1 expression levels are cell cycle dependent.

Heme oxygenase-1 (HO-1) is a stress protein, which has been suggested to participate in defense mechanisms against agents that may induce oxidative injury, such as angiotensin II (Ang II). The purpose of the present study was to examine the role of human HO-1 in cell-cycle progression. We investigated the effect of Ang II on HO-1 gene expression in serum-deprived media to drive human endothelial cells into G(0)/G(1) (1% FBS) compared to exponentially grown cells (10% FBS). The addition of Ang II (100 ng/ml) to endothelial cells increased HO-1 protein and activity in G(0)/G(1) in a time-dependent manner, reaching a maximum HO-1 level at 16 h. Real-time RT-PCR demonstrated that Ang II increased the levels of HO-1 mRNA in G(0)/G(1) as early as 1 h. The rate of HO-1 induction in response to Ang II was several-fold higher in serum-starved cells compared to cells cultured in continuous 10% FBS. The addition of Ang II increased the generation of 8-epi-isoprostane PGF(2 alpha). Inhibition of HO-1, by Stannis mesoporphyrin (SnMP), potentiated Ang II-mediated DNA damage and generation of 8-epi-isoprostane PGF(2 alpha). These results imply that expression of HO-1 in G(0)/G(1), in the presence of Ang II, may be a key player in attenuating DNA damage during cell-cycle progression. Thus, exposure of endothelial cells to Ang II causes a complex response involving generation of superoxide anion, which may be involved in DNA damage. Upregulation of HO-1 ensures the generation of bilirubin and carbon monoxide (CO) in G(0)/G(1) phase to counteract Ang II-mediated oxidative DNA damage. Inducibility of HO-1 in G(0)/G(1) phase is essential and probably regulated by a complex system involving oxygen species to assure controlled cell growth.

Anions↗
PubMed2003

Neutralization of TRAIL death pathway protects human neuronal cell line from beta-amyloid toxicity.

Here we report that a novel member of the TNF-alpha family, TNF-related apoptosis-inducing ligand (TRAIL), contributes substantially to amyloid-induced neurotoxicity in human SH-SY5Y neuronal cell line. Involvement of TRAIL in the amyloid-induced cell death is supported by cDNA array, Northern blot, and Western blot data, demonstrating increased TRAIL expression after treatment of the cells with a neurotoxic fragment of amyloid protein (betaAP). TRAIL was also found to be released in the culture media after betaAP treatment with a time-course overlapping to contents of the intracellular protein. Contribution of TRAIL to betaAP neurotoxicity is demonstrated by data showing that TRAIL-neutralizing monoclonal antibody protects neuronal SH-SY5Y cells from betaAP neurotoxicity. Moreover, exposure of neuronal SH-SY5Y cells to TRAIL leads to cell death, indicating that this substance per se is endowed with neurotoxic properties. We also found that, similarly to betaAP and TRAIL, activation of the death-domain adaptor protein FADD results in neuronal cell death. Lack of FADD function, by overexpression of its dominant negative, rescued cells from either TRAIL- or betaAP-induced neurotoxicity, supporting the hypothesis that these three molecules share common intracellular pathways. Finally, we found that betaAP strongly activated caspase-8, and the cell-permeable, selective caspase-8 inhibitor z-IETD-FMK prevents both betaAP- and TRAIL-induced neurotoxicity. In view of TRAIL's potency in inducing neuronal death, and its role as mediator of betaAP, it is plausible to hypothesize that TRAIL can be regarded as a molecule that provides substantial contribution to betaAP-dependent cell death, which takes part in the progression of the neurodegenerative process and related chronic inflammatory response.

Adaptor Proteins, Signal Transducing↗
PubMed2003

Results of double-blind placebo-controlled challenge with nickel salts in patients affected by recurrent aphthous stomatitis.

BACKGROUND: The aetiology of recurrent aphthous stomatitis (RAS) has so far not been completely clarified. Recently, several studies reported that patients affected by cutaneous diseases (i.e. dermatitis, eczema and urticaria) with positive patch test to nickel have a positive oral nickel challenge. OBJECTIVE: A retrospective data analysis of patch test and oral nickel challenge in 380 patients (204 women and 176 men) affected by RAS was performed. PATIENTS AND METHODS: We examined 380 consecutive patients affected by RAS during the period 1990-1999. In 28/380 patients the appearance of their oral symptoms coincided with the fitting of orthodontic appliance, while 352/380 reported that their oral symptoms worsened after the fitting of orthodontic appliance. All patients were studied with the series (European standard series and series for dental materials) for patch tests. RESULTS: Seventy out of 380 patients (18.4%) presented a contact sensitization to nickel sulphate (positive patch test). In all of these, the orthodontic appliance was replaced with one made of nickel-free materials. All patients were re-examined by the dentist 6 months after the removal of the orthodontic appliance. The symptoms had completely remitted in 28/70 patients, partially had improved in 31/70 patients and had remained unchanged in 11/70 patients. In all patients (n = 70) with a positive patch test to nickel we performed an oral double-blind placebo-controlled challenge (DBPC) test with nickel sulphate. The DBPC was positive in 32/70 patients, 21 of whom had partially improved and 11 had not, even after the replacement of the orthodontic appliance with material not containing nickel. None of the 28 patients in complete remission showed an adverse reaction to oral nickel challenge. CONCLUSION: The results of this study demonstrate that, in some patients with a positive patch test to nickel sulphate, the perpetuation of RAS can be related to a hypersensitivity to ingested nickel salts, independently of local contact to nickel.

Adult↗
PubMed2001

Divergent effects of corticotropin releasing hormone on endothelial cell nitric oxide synthase are associated with different expression of CRH type 1 and 2 receptors.

1. Endothelium is a target for an array of factors involved in inflammation. Endothelial cells express receptors for CRH, a neuropeptide produced during inflammation. We report both the concentration-dependent inhibitory effect of CRH upon cytokine-stimulated nitrite release by H5V murine endothelioma cells, and its stimulatory one in HUVEC cells. 2. Western blot analysis showed that CRH inhibits cytokine-stimulated iNOS protein in H5V cells, and, instead, potentiated it in HUVEC cells. 3. H5V cells expressed both CRH receptors (CRH-R1 and R2) mRNAs, whereas HUVEC cells expressed the CRH-R2 mRNA solely. 4. CRH increased medium nitrites and iNOS protein expression in H5V cells pretreated with the selective CRH-R1 antagonist CP 154,526. However, the selective CRH-R2 antagonist anti-Svg-30 failed to produce similar effects. In fact, anti-Svg-30 inhibited CRH-induced increase of nitrite release and iNOS expression in HUVEC cells. 5. Our results confirm the activating role of CRH on endothelial cells, although it suggests its possible inhibitory role in the late phase of the inflammatory response. NO-mediated effects of CRH on endothelial cells could be exploited in therapeutic strategies related to inflammatory and/or degenerative diseases.

Animals↗
PubMed2000

Incidence of sensitivity to Anisakis simplex in a risk population of fishermen/fishmongers.

BACKGROUND: Anisakis simplex, a fish and cephalopodes parasite, can cause either gastrointestinal symptoms or allergic reactions in humans on eating/handling contaminated fish. OBJECTIVE: The aim of our study was to determine the capacity of Anisakis simplex to induce specific IgE production and allergic reactions following eating and handling fish in a population at risk. METHODS: We determined the levels of total IgE, specific IgE, and eosinophil count in 28 fishermen/fishmongers (group A) and 15 healthy donors (group B). A skin prick test (SPT) with extracts from Anisakis and the most common species of fish in our country, were also carried out. RESULTS: Specific IgE to Anisakis were found in 14 subjects of group A (13 of them had a positive SPT to the same extract) and none of group B (only one subject had a positive SPT). The SPT with fish extracts was positive in 4 patients of group A but in none of group B. Subjects in group A with specific IgE to Anisakis showed higher total IgE levels and eosinophil counts compared with either other individuals of the same group or to those of group B. CONCLUSIONS: These results indicate that fishermen/fishmongers are a population at risk for Anisakis simplex sensitization and suggest that this kind of sensitization should also be investigated not only in subjects like fishermen/fishmongers who live in countries where fish is likely to be contaminated with Anisakis simplex parasites, but also in those who handle fish for other reasons.

Adolescent↗
PubMed2000

[Treatment of inguinal hernia. Case reports].

BACKGROUND: The aim of this study was to evaluate the extent to which inguinal hernia surgery has changed over the past few years. As confirmed by the bibliography, the authors draw attention to the fact that the use of more resistant and well tolerated heterologous graft materials has led to the rapid spread of "tension-free" techniques which have now replaced conventional methods with good long-term results. The development of these techniques has been flanked by the growing use of day hospitals, leading to a marked reduction in hospitalization costs. METHODS: The authors describe the series of hernia operations performed by a day hospital linked to a general surgery ward over the past six years. The series refers to the 1st division of general surgery at Ospedale Nuovo Martini in Turin and covers the period from January 1993 to July 1998 with a total of 1387 patients. RESULTS: Over this short period, the percentage of inguinal hernia operations in inpatients fell from 92.9 to 22.4% while those undergoing surgery in the day hospital rose from 7.1 to 77.6%. This was flanked by a move away from conventional plastic surgery (Bassini, Shouldice) in favour of Lichtenstein's technique which was used in over 76% of monolateral hernia and over 55% of bilateral cases. Local anesthesia induced by the surgeon was used in the majority of cases (98%). Mersilene prostheses were initially used but were soon replaced by prolene grafts, both of which were well tolerated in over 84% of cases. Short-term antibiotic prophylaxis was administered in all cases, whereas the use of postoperative painkillers was limited to minor analgesics. CONCLUSIONS: The surgical treatment of inguinal hernia has changed drastically over a relatively short period with regard to both operating techniques, as is shown by the widespread use of prostheses, and the indications for day hospital surgery which have gradually increased owing to the reliability and tolerability of hernia mesh and the use of local anesthesia.

Adolescent↗
PubMed2000

[Elective and emergency minimally invasive surgery in pleural diseases].

In the last years the video-assisted thoracic surgery (V.A.T.S.) assumed an important order for the diagnosis and treatment of the pleural disease. In this particular field, the procedure allows obtaining almost the same outcomes of traditional surgery and is very safety. V.A.T.S. reduces hospital time and trauma with a fast return to the working life. The Authors describe their experience and outline the diagnostic and therapeutic indications for the treatment of choice and emergency.

Elective Surgical Procedures↗
PubMed1999

A clinicopathologic study of scarring alopecia due to lichen planus: comparison with scarring alopecia in discoid lupus erythematosus and pseudopelade.

The clinicohistologic findings in 68 patients with lichen planus scarring alopecia (LP) were compared with those of 25 patients with discoid lupus erythematosus of the scalp (DLE) and 25 with pseudopelade (PP). The combination of diffuse scaling, erythema, telangiectases, and mottled hyperpigmentation within areas of scarring alopecia was a distinctive feature of DLE, whereas the clinical picture of PP was indistinguishable from that seen in 29 patients with LP. In most patients with LP, the histologic changes involved only the follicles and the perifollicular dermis. Less frequently, the inflammatory process extended to the epidermis and the papillary dermis. In all cases, histopathologic features allowed LP to be distinguished from DLE regardless of the stage of the disease. The finding of a bandlike fibrotic thickening of the papillary dermis accompanied by fibrotic tracts at sites of destroyed follicles appeared to be a hallmark of "burnt out" lesions of LP. This histologic clue may be helpful in achieving a specific diagnosis of LP in cases that fulfill the clinical criteria for PP.

Adult↗
PubMed1999

Distraction osteogenesis to achieve mandibular vertical bone regeneration: a case report.

In this case report a surgical technique for vertical ridge augmentation is presented. The procedure, performed in a 30-year-old woman with an atrophied alveolar ridge in the anterior portion of the mandible, is based on the biologic concept of osteogenesis distraction previously introduced in orthopedic and maxillofacial surgery. After elevation of a full-thickness flap a horizontal osteotomy was performed 7 to 8 mm from the top of the ridge. Two vertical osteotomies were prepared with drills of increasing diameter (2, 2.8, and 3.25 mm), tapping was performed for the first 5 to 6 mm, and two distractor base plugs were placed at the base of the osteotomies with a repositioning tool. An intraosseous distraction implant was then inserted and 2 inward vertical cuts were made in the bone to allow proper distraction to take place. Correct functioning of the device was checked by distracting the bone fragment 1 mm using the axial distraction screw. A latency distraction healing screw was inserted in each of the distraction implants and the area was left to heal for 5 days. Once primary healing had occurred, the distraction of the newly formed bone callus was activated each day for 10 days (1 mm per day). At the end of the distraction period a final distraction screw was left in place and a final healing screw was inserted. During this time there were no complications and the patient on no occasion complained of discomfort. The distractor device was removed 30 days later, leaving the base plugs in place. One month later a vertical augmentation of 7 mm had been achieved; the base plugs were removed, 3 intraosseous implants were inserted, and a biopsy of the newly formed tissue was obtained. Histologic evaluation of the biopsy specimen showed woven bone formation approximately 75 days after the initial procedure.

Adult↗
PubMed1999

[TB-test in the diagnosis of "closed" tuberculosis of the urinary tract. Preliminary study].

BACKGROUND: Tuberculosis (TBC) is a disease that is found throughout the world with a particularly high incidence in under developed countries. Genitourinary tuberculosis has been reported in 8-10% of all cases in developed countries and in 20% in Third World countries. This study aimed to describe a method of diagnosis applicable to so-called "closed" forms of tuberculosis affecting the urinary tract, namely those with negative results for KB bacteriological and culture assay, but in which suspected diagnosis based on clinical grounds and diagnostic procedures call for further analysis; these forms account for 10% of the total cases. METHODS: A prospective study was carried out in order to tritade the antigenic fraction A60 of the group of thermostable macromolecular antigens (TMA); the latter belong to the pool of liposoluble antigens forming the cell wall and represent the main component of tuberculin and purified protein derivative (PPD). The identification and assay of antigen A60, which can stimulate both the antibody and cell-mediated response, was performed using the ELISA method in order to identify IgG and IgM specific antibodies (TB-test). Twenty-nine patients were selected (11 males, 18 females) with a clinical history of recurrent symptomatic manifestations of upper and lower urinary tract infections resistant to common antibiotic treatment. Urinary tests showed that 96.5% of patients presented an acid urinary pH associated with pyuria, and the urographic imaging revealed calico/pyelic lesions of the excretory tracts. RESULTS: Seven patients (24%) showed a form of urinary TBC of an areactive type (AA) or with intermediate reactivity (RI.AI); six patients (20.64%) showed reactive TBC or in the process of resolution; fifteen patients (51.6%) were negative to the TB-test, and after one year's follow-up still showed no positivity to assays for Koch's bacillus. CONCLUSIONS: The authors affirm that the TB-test, a rapid and relatively inexpensive diagnostic method, is a valid aid for the diagnosis of "closed" forms of urinary tract TBC.

Adult↗
PubMed1998

Localized ridge augmentation with chin grafts and resorbable pins: case reports.

Six block grafts harvested from the mandibular symphysis were used to augment partially atrophied ridges. Three maxillary defects and three mandibular defects were treated in five patients. Autologous bone grafts from the chin were stabilized in the recipient sites with resorbable pins and no membranes were used over the grafts. Healing proceeded without complications. At 3 to 4 months the external cortical surface of the grafts progressively resorbed and the profiles of the pins protruded from underneath the buccal tissue that covered the augmented areas. However, the pins never perforated the tissue and they were resorbed macroscopically within 4 to 6 months. At 6 months the areas treated showed successful ridge augmentation and when exposed for stage 2 surgery, remnants of the pin holes on the external surface of the repaired defects were detected. Radiographic evaluation of the block grafts was performed at 3 and 6 months and histologic specimens were obtained at 6 months; the specimens demonstrated incomplete pin resorption and encapsulation. A severe foreign-body reaction was detected in one case. The presence of an acellular bone matrix in certain sections and a normal bone pattern with a cellular component in others was a consistant finding. ITI endosseous Implants were placed with excellent primary stability in all treated cases.

Absorbable Implants↗