Expression and function of the insulin receptor in normal and osteoarthritic human chondrocytes: modulation of anabolic gene expression, glucose transport and GLUT-1 content by insulin.

OBJECTIVE: Chondrocytes respond to insulin, but the presence and role of the specific high affinity insulin receptor (InsR) has never been demonstrated. This study determined whether human chondrocytes express the InsR and compared its abundance and function in normal and osteoarthritis (OA) human chondrocytes. DESIGN: Cartilage sections were immunostained for detection of the InsR. Non-proliferating chondrocyte cultures from normal and OA human cartilage were treated with 1nM or 10nM insulin for various periods. InsR, insulin-like growth factor receptor (IGFR), aggrecan and collagen II mRNA levels were assessed by real time RT-PCR. InsR, glucose transporter (GLUT)-1, phospho-InsRbeta and phospho-Akt were evaluated by western blot and immunofluorescence. Glucose transport was measured as the uptake of [3H]-2-Deoxy-d-Glucose (2-DG). RESULTS: Chondrocytes staining positively for the InsR were scattered throughout the articular cartilage. The mRNA and protein levels of the InsR in OA chondrocytes were approximately 33% and 45%, respectively, of those found in normal chondrocytes. Insulin induced the phosphorylation of the InsRbeta subunit. Akt phosphorylation and 2-DG uptake increased more intensely in normal than OA chondrocytes. Collagen II mRNA expression increased similarly in normal and OA chondrocytes while aggrecan expression remained unchanged. The Phosphoinositol-3 Kinase (PI3K)/Akt pathway was required for both basal and insulin-induced collagen II expression. CONCLUSIONS: Human chondrocytes express functional InsR that respond to physiologic insulin concentrations. The InsR seems to be more abundant in normal than in OA chondrocytes, but these still respond to physiologic insulin concentrations, although some responses are impaired while others appear fully activated. Understanding the mechanisms that regulate the expression and function of the InsR in normal and OA chondrocytes can disclose new targets for the development of innovative therapies for OA.

Tracking chemical interactions of folic acid on gold surface by SERS spectroscopy.

Surface-enhanced Raman scattering (SERS) spectroscopy was used in the investigation of the adsorption of folic acid (FA) on the surface of gold nanoparticles (AuNPs) in the absence and presence of surface modifiers hydrochloride acid (HCl) and 1-mercaptoethanol (ME). The proposal for the chemical interactions of FA with the metallic surface was based on vibrational assignment supported by Density Functional Theory (DFT) calculations. In the absence of surface modifiers, FA interacts with the gold surface through the pteridine moiety in a tilted geometry. In the presence of ME, the molecule of FA is anchored through hydrogen bonds with the surface modifier. The presence of HCl induced ion-pair interactions involving chloride ions, adsorbed on gold surfaces, and both the nitrogen N1 of the pteridine ring and the γ-carboxylic acid of the glutamic acid moiety. In this condition, keto-enol equilibrium can be evidenced by a remarkable enhancement of marker bands in the SERS spectra.

Impact of congenital calcitonin deficiency due to dysgenetic hypothyroidism on bone mineral density.

The objective of the present study was to determine the effect of chronic calcitonin deficiency on bone mass development. The results of 11 patients with thyroid dysgenesis (TD) were compared to those of 17 normal individuals (C) and of 9 patients with other forms of hypothyroidism (OH): 4 with hypothyroidism due to inborn errors of thyroid hormone synthesis and 5 with Hashimoto's thyroiditis. The subjects received an intravenous calcium stimulus and blood was collected for the determination of ionized calcium (Ca2+), calcitonin, and intact parathyroid hormone. Bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry. After calcium administration the levels of Ca2+ in the two groups of hypothyroidism were significantly higher than in the normal control group (10 min after starting calcium infusion: C=1.29 +/- 0.08 vs TD=1.34 +/- 0.03 vs OH=1.34 +/- 0.02 mmol/l; P<0.05), and only the TD group showed no calcitonin response (5 min after starting calcium infusion: C = 27.9 5.8 vs TD = 6.6 0.3 vs OH = 43.0 13.4 ng/l). BMD values did not differ significantly between groups (L2-L4: C=1.116 +/- 0.02 vs TD=1.109 +/- 0.03 vs OH=1.050 +/- 0.04 g/cm2). These results indicate that early deficiency of calcitonin secretion has no detrimental effect on bone mass development. Furthermore, the increased calcitonin secretion observed in patients with inborn errors of thyroid hormone biosynthesis does not confer any advantage in terms of BMD.

Sequential versus alternating regimens in the treatment of advanced breast cancer. Argentine Breast Cancer Cooperative Group.

With the object of proving whether sequential or alternate forms of chemotherapy would be advantageous one over the other in treating advanced breast cancer and with the purpose of evaluating two different anthracyclines at equimolecular doses in the above-mentioned alternating regimens, 250 patients who had received no prior chemo- or hormonotherapy were entered in a prospective randomized trial. Group A was administered 4-epiadriamycin and cyclophosphamide for 8 courses, followed by 6 cycles of CMF, and medroxyprogesterone acetate (MPA) from the beginning of therapy until progression. In group B, adriamycin + cyclophosphamide were alternated with CMF every two courses until 14 cycles were completed. Group C received 4'-epiadriamycin + cyclophosphamide alternated with CMF for 14 courses. In groups B and C, MPA was administered as in group A. Two hundred and twenty-four patients were evaluated. CR + PR were observed in 55.8% of group A, 43.4% of group B, and 46.4% of group C. Median duration of responses was 16 months (m) in group A, 13 m in group B and 20 m in group C, and median survival (CR + PR) was 16.5 m in group A, 16 m in group B and 24 m in group C. There were no statistically significant differences among the three groups in terms of response rate, duration of response and survival; furthermore, toxicity was moderate in all groups. At equimolecular doses there were no differences between adriamycin and epirubicin in the alternating schedules.

Identification of the sentinel lymph node stained with blue dye in breast cancer patients.

PURPOSE: This study aimed to evaluate the reproducibility of sentinel lymphadenectomy in breast cancer patients (T1N0M0 and T2N0M0) and its possibility of predicting the total axillary behavior. METHODS: A total of 25 patients were evaluated, all presenting palpable mammary nodes between 1.5 and 5 cm (T1 and T2), with clinically negative axillary lymph nodes (N0). After an incisional biopsy of the tumor and histopathological confirmation of invasive breast carcinoma, a study of the sentinel lymph node took place with a peritumoral injection of 4 ml of blue dye at 2.5%. After waiting for 15 to 20 minutes, a search for the blue stained lymphatic vase in the axillary fat was carried out, which would lead to the sentinel lymph node, stained or not. At that point, a mastectomy (20 patients) or a quadrantectomy (5 patients) was performed, both with axillary lymphadenectomy at grades 1, 2 and 3. The sentinel lymph nodes and the material from the axillary dissection were sent separately for an anatomicopathological test in paraffin. RESULTS: The lymph nodes were identified in 19 patients, which represented a 76% detection rate. There was a concordance between the sentinel lymphadenectomy and the standard axillary dissection in 68.4% of the patients. The false-positive and the false-negative rates observed were 10% and 55.5%, respectively. A higher detection rate was found in tumors larger than 2 cm and situated in external quadrants. CONCLUSIONS: Sentinel lymphadenectomy identified the sentinel lymph node in the majority of the patients in this study, although the high rate of false-negatives observed prevented an accurate staging.

Impact of congenital calcitonin deficiency due to dysgenetic hypothyroidism on bone mineral density

The objective of the present study was to determine the effect of chronic calcitonin deficiency on bone mass development. The results of 11 patients with thyroid dysgenesis (TD) were compared to those of 17 normal individuals (C) and of 9 patients with other forms of hypothyroidism (OH): 4 with hypothyroidism due to inborn errors of thyroid hormone synthesis and 5 with Hashimoto's thyroiditis. The subjects received an intravenous calcium stimulus and blood was collected for the determination of ionized calcium (Ca2+), calcitonin, and intact parathyroid hormone. Bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry. After calcium administration the levels of Ca2+ in the two groups of hypothyroidism were significantly higher than in the normal control group (10 min after starting calcium infusion: C = 1.29 ± 0.08 vs TD = 1.34 ± 0.03 vs OH = 1.34 ± 0.02 mmol/l; P < 0.05), and only the TD group showed no calcitonin response (5 min after starting calcium infusion: C = 27.9 ± 5.8 vs TD = 6.6 ± 0.3 vs OH = 43.0 ± 13.4 ng/l). BMD values did not differ significantly between groups (L2-L4: C = 1.116 ± 0.02 vs TD = 1.109 ± 0.03 vs OH = 1.050 ± 0.04 g/cm²). These results indicate that early deficiency of calcitonin secretion has no detrimental effect on bone mass development. Furthermore, the increased calcitonin secretion observed in patients with inborn errors of thyroid hormone biosynthesis does not confer any advantage in terms of BMD.

Creatinuria: un indicador nutricional / Creatininuria: a nutritional index

Se estudiaron los índices de creatinina-peso y de creatinina-talla en 125 adolescentes de uno y otro sexos comprendidos entre las edades de 13 y 17 años. La determinación de la creatinina en la orina se llevó a efecto por el método del picrato. Se plantea que los valores medios de excreción en la orina son significativamente mayores en el sexo masculino. Se discute su utilidad como medio de apoyo en la evaluación del estado nutricional del individuo y se sugiere su ampliación a otros grupos etarios y actividades diferentes