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Biomedical subjects

V Sollazzo

Publications and source records attributed to V Sollazzo.

10 recordsLinked to original sources
PubMed2002

Modulation of gene expression in human osteoblasts by targeting a distal promoter region of human estrogen receptor-alpha gene.

Estrogen receptor (ER) alpha is expressed during osteoblast differentiation; however, both its functional role in bone metabolism and its involvement in osteoporotic pathogenesis caused by estrogen deficiency are not well understood. Loss of ER alpha gene expression could be one of the mechanisms leading to osteoporosis. Therefore, we investigated a possible modulation of ER alpha gene expression in a human osteoblastic cell line and in four primary osteoblast cultures by using a decoy strategy. Double stranded DNA molecules, mimicking a regulatory region of the ER alpha gene promoter (DNA-102) and acting as a 'silencer' in breast cancer cells, were introduced into osteoblasts as 'decoy' cis-elements to bind and functionally inactivate a putative negative transcription factor, and thus to induce ER alpha gene expression. We found that the DNA-102 molecule was able to specifically bind osteoblast nuclear proteins. Before decoy treatment, absence or variable low levels of ER alpha RNAs in the different cultures were detected. When the cells were transfected with the DNA-102 decoy, an increase in expression of ER alpha and osteoblastic markers, such as osteopontin, was observed, indicating a more differentiated osteoblastic phenotype both in the cell line and in primary cultures. These results showed that the DNA-102 sequence competes with endogenous specific negative transcription factors that may be critical for a decrease in or lack of ER alpha gene transcription. Therefore, osteoblastic transfection with the DNA-102 decoy molecule may be considered a tempting model in a putative therapeutic approach for those pathologies, such as osteoporosis, in which the decrease or loss of ER alpha expression plays a critical role in bone function.

Biomarkers↗
PubMed2001

Effects of pulsed electromagnetic fields on human articular chondrocyte proliferation.

Low-energy, low-frequency pulsed electromagnetic fields (PEMFs) can induce cell proliferation in several cell culture models. In this work we analysed the proliferative response of human articular chondrocytes, cultured in medium containing 10% FBS, following prolonged exposure to PEMFs (75 Hz, 2.3 mT), currently used in the treatment of some orthopaedic pathologies. In particular, we investigated the dependence of the proliferative effects on the cell density, the availability of growth factors and the exposure lengths. We observed that PEMFs can induce cell proliferation of low density chondrocyte cultures for a long time (6 days), when fresh serum is added again in the culture medium. In the same conditions, in high density cultures, the PEMF-induced increase in cell proliferation was observed only in the first three days of exposure. The data presented in this study show that the availability of growth factors and the environmental constrictions strongly condition the cellular proliferative response to PEMFs.

Aged↗
PubMed2000

A two-locus model for non-syndromic congenital dysplasia of the hip (CDH).

Complex segregation analysis was conducted in a sample of 171 pedigrees collected through probands affected by non-syndromic dysplasia of the hip (CDH) treated in Ferrara's CDH Centre in the period 1991-6. The analysis favoured a two-locus model, in which the accepted segregation model at the major locus was compatible with recessive transmission, with a gene frequency of the deleterious allele of around 0.20. For the other locus, among the Mendelian hypotheses tested, the recessive model turned out to be the most parsimonious. When ultrasonographic level was examined as an indication of severity, a significant improvement in the fit of the model was observed, giving clear evidence that information on the severity of CDH is important for a better definition of the hereditary transmission model.

Child↗
PubMed1999

Correlation between pulsed electromagnetic fields exposure time and cell proliferation increase in human osteosarcoma cell lines and human normal osteoblast cells in vitro.

We have exposed cultured bone cells to a pulsed electromagnetic field (PEMF) for different times to find the minimal exposure time necessary to stimulate an increase of DNA synthesis. We used two different human osteosarcoma cell lines, TE-85 and MG-63, and human normal osteoblast cell (NHOC) obtained from surgical bone specimens. The cells were placed in multiwell plates and set in a tissue culture incubator between a pair of Helmoltz coils powered by a pulse generator (1.3-ms pulse, repeated at 75 Hz) for different periods of time. [3H]Thymidine incorporation was used to evaluate cell proliferation. The two osteosarcoma cell lines increase their thymidine incorporation when exposed to a PEMF for at least 30 min, both in a medium containing 10% fetal calf serum and in a serum-free medium. NHOC are known to increase their cell proliferation when exposed to PEMF but only if cultured in the presence of 10% fetal calf serum. In this experimental condition, three of the four cell lineages studied required at least 9 h of PEMF exposure to increase their DNA synthesis, whereas one cell lineage increased its cell proliferation after 6 h of PEMF exposure. Our observations confirm the hypothesis that the proliferative responses of NHOC and human osteosarcoma cell lines to PEMF exposure are quite different. Moreover, NHOC required minimal exposure times to PEMF to increase their cell proliferation, similar to that needed to stimulate bone formation in vivo.

Adult↗
PubMed1999

Effects of pulsed electromagnetic fields on human chondrocytes: an in vitro study.

(3)H-thymidine incorporation was studied in cultured human nasal and articular chondrocytes exposed to low-energy, low-frequency pulsed electromagnetic fields (PEMFs) (75 Hz, 2.3 mT). The reverse transcriptase polymerase chain reaction (RT-PCR) analysis shows that human secondary chondrocytes derived from both nasal and articular cartilage express collagen type II mRNA, which is a specific marker of the chondrocyte phenotype. In a preliminary series of experiments, cells were exposed to PEMF for different time periods ranging from 6 to 30 hours (time-course), in medium supplemented with 10% or 0.5% fetal calf serum (FCS) and in serum-free medium. The ratios between the (3)H-thymidine incorporation in PEMFs and control cultures show an increase of the cell proliferation in cultures exposed to PEMFs when serum is present in the culture medium, whereas no effect was observed in serum-free conditions. The increase in DNA synthesis, induced by PEMFs, was then evaluated only at the times of maximum induction and the results were analyzed by the three-factor analysis of variance (ANOVA). The data presented in this study show that even if (3)H-thymidine incorporation is higher in nasal than in articular chondrocytes, PEMF induce an increase in the proliferation of both cell types. Moreover, the concentration of FCS in the culture medium greatly influences the proliferative response of human chondrocytes to the PEMF exposure. Though normal human osteoblast cells increase their proliferation when exposed to PEMFs if only 10% FCS is present in the medium, human chondrocytes are able to increase their cell proliferation when exposed to PEMFs in the presence of both 0.5% and 10% of FCS in the medium. The results obtained may help to explain the basic mechanisms of PEMF stimulation of fracture healing.

Adolescent↗
PubMed1997

Responses of human MG-63 osteosarcoma cell line and human osteoblast-like cells to pulsed electromagnetic fields.

We have studied the effects of low-energy, low-frequency pulsed electromagnetic fields (PEMF) on cell proliferation, in both human osteoblast-like cells obtained from bone specimens and in human MG-63 osteosarcoma cell line. Assessment of osteoblastic phenotype was performed both by immunolabeling with antiosteonectin antibody and by verifying the presence of parathyroid hormone receptors. The cells were placed in multiwell plates and set in a tissue culture incubator between a pair of Helmholtz coils powered by a pulse generator (1.3 ms, 75 Hz) for different periods of time. [3H]Thymidine incorporation was used to evaluate cell proliferation. Since it had previously been observed that the osteoblast proliferative response to PEMF exposure may also be conditioned by the presence of serum in the medium, experiments were carried out at different serum concentrations. [3H]Thymidine incorporation increases in osteoblast-like cells, when they are exposed to PEMF in the presence of 10% fetal calf serum (FCS). The greatest effect is observed after 24 hours of PEMF exposure. No effects on cell proliferation are observed when osteoblast-like cells are exposed to PEMF in the presence of 0.5% FCS or in a serum-free medium. On the other hand, PEMF-exposed MG-63 cells show increased cell proliferation either at 10% FCS, 0.5% FCS and in serum-free medium. Nevertheless, the maximum effect of PEMF exposure on MG-63 cell proliferation depends on the percentage of FCS in the medium. The higher the FCS concentration, the faster the proliferative response to PEMF exposure. Our results show that, although MG-63 cells display some similarity with human bone cells, their responses to PEMF's exposure are quite different from that observed in normal human bone cells.

Adult↗
PubMed1990

[Forme fruste of Gorlin's syndrome with a left ventricular neoplasm].

We report on a 25-year-old man, referred for atypical chest pain and negative T waves in leads V5-V6. A cardiac tumor, localized in the posterolateral left ventricular wall was diagnosed in this patient by nuclear techniques and bidimensional echocardiography. A complex form of pluridistrectual dysmorphic disorder (hypertelorism, prognathism, frontal bossing, multiple cysts of the mandible, calcification in falx cerebri, etc) was also present, suggesting a limited form of Gorlin's syndrome (nevoid basal cell carcinoma syndrome).

Adult↗
PubMedDate not supplied

Total hip arthroplasty in octogenarians: our experience.

The progressive aging of the population, a phenomenon that is common to all Western societies, means an increase in the number of patients aged over 80 years requiring total hip replacement. It is the purpose of this study to report our experience in the use of total hip replacement for the treatment of patients aged over 80 years. The study is retrospective, and it was conducted on a group of 27 patients, for a total of 33 hips. An analysis of the results led us to conclude that there are no differences in indications for total hip replacement in patients aged over 80 years as compared to younger subjects. Nonetheless, it is important to carefully evaluate the general conditions of these patients, prior to surgery, because failure may have dramatic consequences.

Age Factors↗
PubMedDate not supplied

Total hip arthroplasty using femoral head shelf autografts in dysplastic hips. Our experience.

The present work deals with a series of 28 patients (a total of 31 hips) suffering from coxarthrosis in dysplasia of the hip. All patients had undergone arthroplasty where an autograft of cortico-cancellous bone was taken from the head of the patientís femur. In 21 of these hips the prosthetic components were not cemented while the other 10 cases were. The patients (average age 57 years 5 months) underwent radiography and were clinically evaluated using the Harris Hip Score. The average follow-up was 6 years and 7 months. In the 10 hips which had been cemented, the average pre-operative Harris Hip Score was 46.9 points (range 24-85) while it was 80.5 upon check-up (range 50-98). In the 21 hips which were not cemented the average pre-operative Harris Hip Score was 44.3 points (range 21-62) while, at the time of check-up it was 90.8 (range 60-100). Only in 3 cases (9.67%) did the cotyloid portion require reoperation because of mobilization. In all cases (100%) the graft integrated perfectly with the host bone. The present study provides encouraging data regarding the use of autografts of cortico-cancellous bone taken from the head of the femur during hip replacement in patients with coxarthrosis in dysplasia of the hip. No differences were seen between the cemented and non cemented prostheses.

Acetabulum↗