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Biomedical subjects

M A Rosa

Publications and source records attributed to M A Rosa.

At least 19 recordsLinked to original sources
PubMed2007

Methotrexate-added acrylic cement: biological and physical properties.

BACKGROUND: Previous reports have demonstrated the suitability of adding different chemotherapeutic drugs to acrylic cement for the treatment of bone metastases. The best results so far have been obtained with methotrexate (MTX) for which diffusion from the implanted cement has been demonstrated both in vitro and in vivo. In this study the suitability of adding MTX to acrylic cement as local adjuvant chemotherapy was investigated. METHODS: Using an in vitro model of human breast cancer cells we demonstrated that the drug is eluted in an active form able to exert a cytotoxic effect over a long period of time. The use of different concentrations of drug on the kinetic of elution and on the mechanical properties of cement was also evaluated. RESULTS: The results obtained suggest that the release of MTX is higher at the beginning and progressively decreases over time being affected by the concentration of drug used. Our results also demonstrated that the addition and the subsequent elution of MTX does not alter the compressive properties of the cement. CONCLUSION: These findings confirm the suitability of MTX-supplemented cement and support its use as an effective aid for the management of bone metastases requiring surgical curettage and acrylic cement implantation for structural support.

Antineoplastic Agents↗
PubMed2004

Application of ozonation process in industrial wastewaters: textile, kraft E1 and whey effluents.

A large variety of organic and inorganic compounds can be found in wastewater from industrial processes. In this work, Advanced Oxidative Processes (AOPs) have been applied for the control of water pollution and the ozonation of different effluents was investigated. Wastewater from textile, kraft E1 and cheese manufacturing processes were chosen as examples of industrial effluents. The efficiency of substrate mineralization has been comparatively analyzed by the decrease in total organic carbon (TOC), color, and toxicity. The results revealed that the ozonation process can be a method for decolorization of effluent, but it is not effective for TOC reduction. The whey effluent was the most recalcitrant wastewater for ozone treatment which produced no TOC removal.

Industrial Waste↗
PubMed2003

Acrylic cement added with antiblastics in the treatment of bone metastases. Ultrastructural and in vitro analysis.

An increased long-term survival of patients with alignant tumours also increases the possibility of the development of skeletal metastases and pathological fractures. The management of bone metastases includes the removal of gross disease and the administration of local adjuvants. We have investigated the possibility of adding antiblastic drugs to acrylic cement. Cylinders of acrylic cement were manufactured containing three different antiblastic drugs, methotrexate, cisplatin and doxorubicin. We performed in vitro analysis on MCF-7 human breast cancer cells in order to evaluate the biological effect of the mixtures and surface analysis of the acrylic cement-cisplatin cylinders using energy-dispersive x-ray analysis (EDAX). All drugs were released in an active form from the cement. Each drug had a different effect on cell viability. Doxorubicin had the greatest effect on breast cancer cells. Surface analysis showed that antiblastic drugs were present in the form of granules. These results confirm the potential of antiblastic-loaded cement as a possible adjuvant in the local treatment of bone metastases. Further studies should be undertaken to determine whether the release of antiblastic drugs from cement is elution or if they are only released from the surface.

Antineoplastic Agents↗
PubMed2001

Rapidly progressive antineutrophil cytoplasm antibodies associated with pulmonary-renal syndrome in a 10-year-old girl.

CONTEXT: The term pulmonary-renal syndrome has been used frequently to describe the clinical manifestations of a great number of diseases in which pulmonary hemorrhage and glomerulonephritis coexist. The classic example of this type of vasculitis is Goodpasturés syndrome, a term used to describe the association of pulmonary hemorrhage, glomerulonephritis and the presence of circulating antiglomerular basement membrane antibodies (anti-GBM). Among the several types of systemic vasculitides that can present clinical manifestations of the pulmonary-renal syndrome, we focus the discussion on two types more frequently associated with antineutrophil cytoplasm antibodies (ANCA), microscopic polyangiitis and Wegener's granulomatosis, concerning a 10 year old girl with clinical signs and symptoms of pulmonary-renal syndrome, with positive ANCA and rapidly progressive evolution. CASE REPORT: We describe the case of a 10-year-old girl referred to our hospital for evaluation of profound anemia detected in a primary health center. Five days before entry she had experienced malaise, pallor and began to cough up blood-tinged sputum that was at first attributed to dental bleeding. She was admitted to the infirmary with hemoglobin = 4 mg/dL, hematocrit = 14 %, platelets = 260,000, white blood cells = 8300, 74 % segmented, 4 % eosinophils, 19 % lymphocytes and 3 % monocytes. Radiographs of the chest revealed bilateral diffuse interstitial alveolar infiltrates. There was progressive worsening of cough and respiratory distress during the admission day, when she began to cough up large quantities of blood and hematuria was noted. There was rapid and progressive loss of renal function and massive lung hemorrhage. The antineutrophil cytoplasm antibody (ANCA) test with antigen specificity for myeloperoxidase (anti-MPO) was positive and the circulating anti-GBM showed an indeterminate result.

Anti-Glomerular Basement Membrane Disease↗
PubMed2000

Proliferating cell nuclear antigen labelling index in localised pigmented villo-nodular synovitis and its relationship to the size of nodules.

Proliferating cell nuclear antigen (PCNA) is one of the cell cycle-related proteins directly involved in DNA synthesis. It is a marker of cellular proliferation and has been shown to correlate with ploidy and proliferative activity of cells. Its expression has been used to estimate the growth fraction of human cancer and its prognostic value. Pigmented villo-nodular synovitis (PVNS) is characterised by a nodular lesion in the paratendinous synovial tissue or, less frequently, in a joint. Whether PVNS is a neoplastic or inflammatory lesion remains controversial. We have studied immunohistochemical PCNA expression with pc10 monoclonal antibody in 16 paraffin sections, in 16 cases of localised PVNS, or giant cell tumour of tendon sheath. We have found significant correlation between the size of the lesions and PCNA-LI (labelling index).

Adolescent↗
PubMed1999

Oxidizing side of the cyanobacterial photosystem I. Evidence for interaction between the electron donor proteins and a luminal surface helix of the PsaB subunit.

Photosystem I (PSI) interacts with plastocyanin or cytochrome c6 on the luminal side. To identify sites of interaction between plastocyanin/cytochrome c6 and the PSI core, site-directed mutations were generated in the luminal J loop of the PsaB protein from Synechocystis sp. PCC 6803. The eight mutant strains differed in their photoautotrophic growth. Western blotting with subunit-specific antibodies indicated that the mutations affected the PSI level in the thylakoid membranes. PSI proteins could not be detected in the S600R/G601C/N602I, N609K/S610C/T611I, and M614I/G615C/W616A mutant membranes. The other mutant strains contained different levels of PSI proteins. Among the mutant strains that contained PSI proteins, the H595C/L596I, Q627H/L628C/I629S, and N638C/N639S mutants showed similar levels of PSI-mediated electron transfer activity when either cytochrome c6 or an artificial electron donor was used. In contrast, cytochrome c6 could not function as an electron donor to the W622C/A623R mutant, even though the PSI activity mediated by an artificial electron donor was detected in this mutant. Thus, the W622C/A623R mutation affected the interaction of the PSI complex with cytochrome c6. Biotin-maleimide modification of the mutant PSI complexes indicated that His-595, Trp-622, Leu-628, Tyr-632, and Asn-638 in wild-type PsaB may be exposed on the surface of the PSI complex. The results presented here demonstrate the role of an extramembrane loop of a PSI core protein in the interaction with soluble electron donor proteins.

Cyanobacteria↗
PubMed1999

Bilateral acetabular fracture without trauma.

In the absence of trauma fracture of the acetabulum is an extremely rare injury. We describe a 70 year old man who spontaneously developed fractures in both acetabulae due to bony insufficiency. It was successfully treated by bilateral total hip replacement.

Acetabulum↗
PubMed1993

Scanning electron microscopy study of articular cartilage in the evolution of hip arthritis.

The authors report the results of scanning electron microscopy examination of samples of articular surface taken from 15 arthritic femoral heads removed during hip replacement. The specimens were collected from areas of the femoral head where different degrees of degenerative changes were identified, and processed with the normal techniques for scanning electron microscopy. A definition was made of the mechanisms leading to articular cartilage wear, the most obvious sign of cartilage degeneration. The earlier stages were characterized by the appearance of clefts in the surface layer, which merged and formed scales that flaked off, giving rise to superficial abrasions. The evolution of the degenerative process led to a deepening of the clefts, reaching the intermediate and deep layers and creating further scales of cartilage tissue, oblique or perpendicular to the surface. The elimination of these formations causes more or less marked wear that can extend down to the subchondral bone (ulcers and ground surfaces). As well as information on the condition of the articular surfaces, scanning electron microscopy may also provide details on the morphology and structure of the chondrocytes and the fibrillar network in the sagittal sections, showing the regressive phenomena associated with arthritis.

Aged↗
PubMed1992

Neopterin in tuberculous and neoplastic pleural fluids.

Neopterin is derived from guanosine-triphosphate, produced by stimulated macrophages under the influence of gamma interferon of lymphocyte origin. It has been suggested as an excellent marker for activation of the monocyte/macrophage axis in some clinical situations. We evaluated its concentration in the pleural effusions of 25 individuals (10 tuberculous and 15 neoplastic) as well as in the blood of 22 of them (8 tuberculous and 14 neoplastic), comparing these levels with those of a control group in 99 normal individuals. The concentration of neopterin was determined by radioimmunologic assay. This showed a significant increase (p less than 0.001) of neopterin levels in the tuberculous pleural fluid, compared to the neoplastic group (42 +/- 23/17 +/- 9 nmol/L). In the blood, values were nearly identical to the pleural fluid (41.3 +/- 25/15.8 +/- 6.9 nmol/L), although with significant differences between them and in relation to the control group (p less than 0.001), which had a normal serum value (5.11 +/- 1.92 nmol/L). We emphasize the influence of the neopterin levels in the pleural fluid on the diagnosis of causes of pleurisy and its importance as a marker of immunologic cellular activity.

Aged↗
PubMed1991

[Familial metaphyseal dysplasia: incidental detection of an osteochondroma].

The authors take advantage of an incidental observation of osteochondroma in a patient affected by familial metaphyseal dysplasia to look further into the study of this congenital osteopathy. Examination of the family medical background brings to light the blood-relation of the patient's parents and the presence of the same clinical and radiological features in the patient's sister. Particular attention is given to histological and ultrastructural study of the removed bone tissue.

Adult↗
PubMed1989

[Review of 115 cases of osteoid osteoma].

115 cases of osteoid osteoma treated over more than 18 years is reported. In 1 case the nidus was manifested in 2 different sites after 14 years. The following is emphasized: the terminology for osteoid osteoma should be changed in reference to osteoblastoma; osteoid osteoma and osteoblastoma constitute different aspects of the same neoplasia; the number of observations of osteoid osteoma increases as there is greater knowledge on the varieties of the tumor; treatment, which is exclusively surgical, may be limited to excision of the nidus, in order to guarantee the best healing possible. Resection should be limited to observations where the nidus is masked by osteosclerosis.

Adolescent↗
PubMed1989

[Solitary metastasis of the appendicular bones: role of orthopedic surgery].

The authors report their experience in the treatment of solitary metastasis of the appendicular skeletal system with reference to a group of 59 cases treated. The importance of orthopaedic surgery, involving medical oncology, radiotherapy and physiotherapy is emphasised. The surgical methods used to obtain stable synthesis and facilitate assistance to the patients are discussed. In circumscribed lesions the use of cryotherapy with azote fluid may be useful, and in some cases skeletal reconstruction with autoplastic bone transplant is indicated.

Adult↗
PubMed1989

[Multiple exostoses disease (observations in 21 reported cases)].

With reference to 21 cases the authors describe the clinical, radiological and anatomo-pathological findings of multiple exostoses disease. The indications for the surgical treatment are discussed; they are, however, the same to the solitary osteochondroma.

Adolescent↗
PubMed1987

Circumscribed spontaneous heterotopic ossification in the soft tissues simulating sarcoma.

Eight cases are described of circumscribed heterotopic ossification in the soft tissues characterised by spontaneous onset, no history of trauma, and rapid course which have frequently led to a mistaken preoperative diagnosis of highly malignant tumour. The terminology differentiates it from myositis ossificans, which is a different entity. The authors emphasize the need for accurate evaluation of all the clinical and radiographic data in order to avoid an erroneous diagnosis of extraosseous osteogenic sarcoma or parosteal osteogenic sarcoma. In this regard, both radiography and histological examination demonstrate the so-called zoning pattern, namely a radiolucent central zone corresponding to the more immature area and consisting of fibrous tissue with active histiofibroblastic proliferations and a radiopaque peripheral area, where ossification is more mature the closer it gets to the periphery. Histological specimens obtained exclusively from the central area may lead even the most expert pathologists to a diagnosis of fibrosarcoma or osteogenic sarcoma. Finally, the pathogenetic aspects of the anomaly are discussed, as well as those concerned with the differential diagnosis from other types of heterotopic ossification.

Adolescent↗