Expression of AT1 and AT2 angiotensin receptors in astrocytomas is associated with poor prognosis

Astrocytomas develop intense vascular proliferation, essential for tumour growth and invasiveness. Angiotensin II (ANGII) was initially described as a vasoconstrictor; recent studies have shown its participation in cellular proliferation, vascularisation, and apoptosis. We conducted a prospective study to evaluate the expression of ANGII receptors – AT1 and AT2 – and their relationship with prognosis. We studied 133 tumours from patients with diagnosis of astrocytoma who underwent surgery from 1997 to 2002. AT1 and AT2 were expressed in 52 and 44% of the tumours, respectively, when determined by both reverse transcriptase–polymerase chain reaction and immunohistochemistry. Ten per cent of low-grade astrocytomas were positive for AT1, whereas grade III and IV astrocytomas were positive in 67% (P<0.001). AT2 receptors were positive in 17% of low-grade astrocytomas and in 53% of high-grade astrocytomas (P=0.01). AT1-positive tumours showed higher cellular proliferation and vascular density. Patients with AT1-positive tumours had a lower survival rate than those with AT1-negative (P<0.001). No association to survival was found for AT2 in the multivariate analysis. Expression of AT1 and AT2 is associated with high grade of malignancy, increased cellular proliferation, and angiogenesis, and is thus related to poor prognosis. These findings suggest that ANGII receptors might be potential therapeutic targets for high-grade astrocytomas

Mother-fetus transference of lead and cadmium in rats, involvement of metallothionein

This study was designed to assess the effect of Cadmium (Cd) and lead (Pb) exposure during pregnancy in rats and their correlation with metallothionein (MT). Rats were exposed to either 10 ppm Cd or 300 ppm Pb through drinking water during pregnancy. Both metals were measured in placenta, fetus brain and fetal and maternal blood. MT was quantified in placenta and fetus brain and it was also observed in placenta by immunohistochemical technique. Offspring weight was found to be significantly lower for the Cd exposure group than for the control group. A Cd increase in the placenta of the exposed group was accompanied by MT induction; these effects were related to a limited accumulation of Cd in fetus brain. In contrast, dam Pb exposure caused an accumulation of Pb in the fetus brain and induced damage to placenta. The results account for differences in the transference of these metals during pregnancy that could be related to their toxicity

Angiogenesis and expression of estrogen and progesterone receptors as predictive factors of recurrence in meningiomas: A long-term prospective study

e13013 Background: Meningioma is a bening tumor, with a high rate of recurrence after surgery (80%); the most important relapse predictive factor is the extent of surgical resection; other potentially predictive factors have been studied with poor results. Angiogenesis has an important role in growth and spread of neoplasic cells; previous studies have shown a high incidence of cyclin E (CE), estrogen, and progesterone receptors (ER, PR) in meningiomas. The aim of this prospective study was to evaluate the prognostic significance of clinical-pathological factors (CPF), vascular density index (VDI), cell proliferation index (CPI), CE, ER, and PR tissue expression in meningioma recurrence of patients submitted to surgical resection. Methods: From January 1995 to December 2000, we enrolled 42 patients with histopathological diagnosis of meningioma and treated only with surgical resection. Tumor VDI, CPI, CE, ER, and PR tissue expression were evaluated by immunohistochemistry in patients with or without recurrence. CPF, VDI, CPI, and expression of CE, ER, and PR were associated with recurrence. Results: Complete surgical resection was achieved in 32.5% of patients. Minimal follow-up was 6 years. Recurrence of meningioma was found in 17 patients (40%). Mean time of recurrence was 32 + 8 months. Tissue expression was positive for CE, ER, and PR in 90.9%, 27.6%, and in 64% of patients, respectively. VDI was &gt;8 (40X in 10 fields) in 52.6% of patients and CPI was &gt;600 (40X in 10 fields) in 54.2% of patients. Significant recurrence-associated factors were extent of resection (RR = 2.4, 95% CI 1.7–2.9, p = 0.03) and VDI &gt;8 (RR = 1.7, 95% CI 1.003–2.9, p = 0.001). CPI, CE, ER, and PR expressions were not statistically significant (p = 0.83, p = 0.16, p = 0.46, and p = 0.74, respectively). Conclusions: Patients with partially resected meningioma and high VDI have an increased recurrence risk and could benefit of additional therapeutic measures. No significant financial relationships to disclose. </jats:p

Mechanical performance and in vivo tests of an acrylic bone cement filled with bioactive Sepia officinalis cuttlebone

To promote osteointegration, bioactive cuttlebone particles containing collagen were used to fill an acrylic cement, varying filler concentration (0-50 wt%). Cuttlebone was characterized by X-ray diffraction, plasma atomic emission and FT-IR. Mechanical properties of the filled cement were determined following ASTM procedures, included stress-strain, compression, bending, and fracture toughness tests. For in vivo tests, three groups of seven adult healthy rabbits were prepared to make an implant in the parietal bone of each one. For such groups (I-III), the amount of filler in the cement was 0, 10 and 30 wt%, respectively. Mechanical results for the composites complied with norm requirements. However, as mechanical performance for composite with 50 wt% of filler decreased significantly, for the in vivo tests, such composite was excluded. In vivo tests showed that three implants of group I were loosely attached to the parietal bone, whereas all the implants made with cement containing cuttlebone particles (groups II and III) were firmly attached to the parietal bone, indicating osteointegration. These results clearly show the potential of this type of bioactive filler to be used for medical applications. © 2010 VSP