Biomedical subjects

Alessandra Russo

Publications and source records attributed to Alessandra Russo.

23 records · Page 2Linked to original sources

PubMed2002

Improved antioxidant effect of idebenone-loaded polyethyl-2-cyanoacrylate nanocapsules tested on human fibroblasts.

PURPOSE: The protective antioxidant role of idebenone both as free drug and drug-loaded Tween 80-coated polyethyl-2-cyanoacrylate (PECA) nanocapsules is reported. The relationship between oxidative damage and apoptotic or nonapoptotic cell death is evaluated in vitro. METHODS: Idebenone-loaded nanocapsules were prepared with the interfacial polymerization method in the presence of Tween 80. Human nonimmortalized fibroblasts. under different stress conditions, either 0.5 mM diethylmaleate (DEM) for 60 min or 0.1 mM H2O2 for 30 min, were used as the experimental in vitro model. The production of reactive oxygen species, the cell viability, and the nuclear DNA damage were evaluated. The presence of apoptotic damage was evaluated both by the determination of caspase-3-like protein activity and by Promega's fluorescent apoptotic detection system. RESULTS: DEM and H2O2 affected the cultured cells in different ways. DEM induced a moderate cellular insult, which was efficaciously antagonized by idebenone-loaded PECA nanocapsules. H2O2 elicited severe damage to nuclear DNA, which was reduced by idebenoneloaded PECA nanocapsules. The free drug was less effective than idebenone-loaded nanocapsules. CONCLUSIONS: The findings reported here demonstrate that an improved antioxidant effect was obtained with a low idebenone concentration (0.5 microM) when the drug was entrapped within Tween 80-coated PECA nanocapsules.

Antioxidants↗

PubMed2002

Prediction of facial nerve outcome using electromyographic responses in acoustic neuroma surgery.

OBJECTIVE: To determine whether early and late postoperative facial nerve function can be predicted on the basis of electromyographic responses in acoustic neuroma surgery. SETTING: Prospective blinded study. DESIGN: Tertiary referral center. PATIENTS AND METHODS: Burst and train electromyographic responses were recorded intraoperatively during the last step of vestibular schwannoma removal. The responses were classified and compared with early and late postoperative facial function in 49 patients who underwent enlarged translabyrinthine acoustic neuroma surgery. RESULTS: In the early postoperative period, 20 of 22 patients with an irritable pattern and 10 of 13 patients with an ordinary pattern had Grade III or better facial nerve function, whereas all 3 patients with a stray pattern and 9 of 11 patients with a silent pattern had Grade V or VI. In the late postoperative period, on the other hand, Grade III or better facial nerve function was achieved in 37 of 38 patients with an irritable, stray, or ordinary pattern, but the facial nerve function remained at Grade V or VI in 2 patients with the silent pattern. CONCLUSION: Patients with mechanically evoked facial electromyographic responses to the last step of tumor dissection may not experience severe facial nerve dysfunction or show a remarkable improvement. However, patients with silent electromyographic responses during this step tend to experience severe facial nerve dysfunction early in the postoperative course, and some patients may not show any functional improvement.

Adult↗

PubMed2002

Treatment of residual vestibular schwannoma.

OBJECTIVE: To evaluate the results of the surgical removal of residual vestibular schwannomas and compare them with results obtained from the first operation. STUDY DESIGN: Retrospective case review. SETTING: Tertiary otologic and skull base referral center. PATIENTS Twenty-three patients with residual vestibular schwannoma from a total of 637 patients who underwent surgery during the same time (April 1987 to April 2001). Only 1 patient had previously been treated in the same center. All but 1 patient had previously undergone at least 1 retrosigmoid approach. The majority of patients experienced an extensive list of complications and additional treatments after the first operation. Only 2 patients experienced some measurable hearing preoperatively. Previous hospitalization averaged 34.9 days, with a minimum of 5 and a maximum of 150 days. INTERVENTIONS: 16 patients were treated through an enlarged translabyrinthine approach and 7 through a modified transcochlear approach. MAIN OUTCOME MEASURES: Total tumor removal, postoperative complications, hospital stay. RESULTS: All but 2 patients underwent a total removal. Complications recorded were 1 temporary hemiparesis and aphasia, 1 subcutaneous abdominal hematoma, and 2 transitory VIth cranial nerve palsies. No additional treatment was required. The postoperative hospital stays ranged from 3 to 22 days, with a mean of 6.9. CONCLUSIONS: Patients with vestibular schwannoma should be treated by an experienced team in a referral center to reduce postoperative morbidity and decrease the need to resort to only partial removal. Planned subtotal removal should be reserved for a few selected cases. The retrosigmoid approach is considered to have the highest risk that tumor remnants will unintentionally be left. In surgery of a residual vestibular schwannoma that has previously been treated through the retrosigmoid approach, the translabyrinthine approach offers some advantages with respect to performing another retrosigmoid procedure. In the presence of long-lasting facial palsy, the modified transcochlear approach represents the safest and most viable option available.

Adult↗

PubMedDate not supplied

Venlafaxine-induced urinary incontinence resolved after switching to sertraline.

The authors report a case of urinary incontinence (UI) that occurred in a woman after administration of venlafaxine. UI resolved after discontinuation of the drug and did not reappear after switching to sertraline therapy. A 56-year-old white woman with a diagnosis of reactive depression developed severe UI after a 30 days' treatment with venlafaxine 75 mg/day. Symptoms resolved without consequence 48 hours after discontinuation of venlafaxine. The patient was then treated with sertraline without experiencing any incontinence episodes. Urinary incontinence is an important medical condition with clinical and social implications. Further studies need to be carried out to clarify the pharmacologic differences between dual and selective 5-HT and norepinephrine reuptake inhibitors on lower urinary tract function.

Cyclohexanols↗

PubMedDate not supplied

Involvement of HSP70 in resveratrol-induced apoptosis of human prostate cancer.

BACKGROUND: 70 KDa heat shock proteins (HSPs70), either as a constitutive or inducible form, are expressed at very high levels in malignant human tumors of various origin. In different cell types, they are known to play an antiapoptotic role. Resveratrol (3,5,4'-trihydroxy-trans-stilbene), a polyphenol present in red wine, grapes and other dietary and medicinal plants, has been shown to be active in inhibiting multistage carcinogenesis, inducing apoptotic cell death. MATERIALS AND METHODS: With the present study, a possible relationship between HSP70 expression and cell death elicited by resveratrol in DU-145 cells, which mimic the late hormone-refractory stages of prostate carcinoma, was investigated. To this end, we treated DU-145 with different concentrations. (50, 100 and 200 microM) of resveratrol and cell viability, by tetrazolium salts assay (MTT) and membrane breakdown, by lactic dehydrogenase (LDH) release, were measured. The possible induction of oxidative stress was evidenced both by performing a fluorescent analysis of intracellular reactive oxygen species (ROS) production, or evaluating the amount of nitrite/nitrate (NO) in culture medium. In addition, the expression of HSP70 level, evaluated by immunoblotting, was examined and compared with caspase-3 activity (fluorimetrically measured) and DNA damage, determined by Single Cell Gel Electrophoresis or COMET assay. RESULTS: Our data clearly indicate that the addition of resveratrol to DU-145 reduces cell viability and increases membrane breakdown, in a dose-dependent way, without interfering with ROS production or NO synthesis, unless 200 microM resveratrol was added. Furthermore, at low concentration (50-100 microM) resveratrol is able to raise HSP70 levels but, at high concentration (200 microM), the measured levels of protective HSP70 were unmodified with respect to that of the control values. CONCLUSION: Our results confirm the ability of resveratrol to suppress the proliferation of human prostate cancer cells with a typical apoptotic feature, interfering with the expression of HSPs70.

Antineoplastic Agents, Phytogenic↗