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Biomedical subjects

V Rusu

Publications and source records attributed to V Rusu.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

[Moiré effect. Application in medicine and dental technology].

Moiré effect is an optical phenomenon that occurs when two similar arrays of alternately opaque and transparent lines or dots are superimposed upon each other. Superimposition of two such similar, but slightly different, line arrays causes interference between the arrays; the interference results in the formation of moiré fringes. There is a definite relationship between the pitches of the two arrays and the spacing of the fringes. Therefore, given the pitch of one of the arrays and the distance between the moiré fringes, the pitch of the other array can be calculated. The moiré effect can be used to determine the development of cutaneous tumors in a very short time-frame and to assess the measurement of dental eruption within 20 minutes. The 3-D facial, palatal and dental morphology can thus be evaluated very accurately. The CAD/CAM dental technology is actually possible due to the moiré effect.

Dental Arch↗
PubMedDate not supplied

[18F FDG PET- applications in oncology].

The greatest branch of evolution in Nuclear Medicine that appear in the last period of time, also in medical practice, is scintigraphy with 18F FDG-PET. At the beginning, the images with 18F FDG were used especially in the study of functional cerebral metabolism. Now, new data show that the method presents en major role in cancer diagnosis, localize the tumour and metastasis, and monitoring the treatment in oncology because of the peculiars changes in glucose metabolism of the cancer cells. In this two parts of reference synthesis our goal was to present the following subjects: I) first part include the particularities of glucose metabolism of tumour cells, functionality and components of PET, radiopharmaceutical used in PET, the synthesis of 18F FDG, the clinical procedure and the detection of unknown cancers; II) the second part is about the mains types of tumours identified with 18F FDG-PET (lung, breast, lymphoma, melanoma, colorectal cancer and others). The clinical cases that illustrate the applications are investigated at CERMEP, Lyon, France.

Fluorodeoxyglucose F18↗
PubMedDate not supplied

[Assessment of Tc-99m MIBI uptake mechanism in Mycobacterium tuberculosis and normal cells (fibroblasts and myocytes) cultures].

One of the factors which can explain the scintigraphic Tc-99m MIBI positives images in pulmonary tuberculosis could be the Mycobacterium tuberculosis radiotracer uptake; this can be investigated in vitro, on cell culture, in comparison with normal cell types known to have high (myocites) or low (fibroblasts) uptake. Mycobacterium tuberculosis cultures were realised on Löwenstein Jensen medium, by standard methodology. Myocites and fibroblasts cultures were realized from neonatal rat hearts. Monolayer cells culture were incubated with a same 1.85 kBq/?l Tc-99m MIBI concentration, at 37 degrees C for 15, 60 and 90 minutes. The kinetic was stopped by rapidly washing the cells, with a 4 degrees C physiological saline solution and than scrapped cells were counted for the uptaken radioactivity. The results show that radiotracer cellular uptake (reported at the protein concentration) in myocites was maximum at 60 minutes. Cellular uptake in fibroblasts was very low at all the intervals. In Mycobacterium tuberculosis a peak was observed after 15 minutes, the uptake being similar to that of 60 minutes incubated myocites, considered 100%. After 90 minutes the Mycobacterium tuberculosis uptake was smaller than the 15 minutes value (65.82%). In conclusion, Mycobacterium tuberculosis in vitro uptake results could explain the more positives scintigraphic images in BK positive patients obtain at 15 minutes, in comparison with the delayed images.

Animals↗
PubMedDate not supplied

[18F FDG PET-Applications in Oncology].

In the first part our intention was, essentially, to present the particularities of glucose tumoral cells metabolism, PET components, the synthesis of 18F FDG and the detection of unknown cancers. This second part makes reference about mainly types of tumors who benefit by FDG-PET indications. Clinical PET has a rapid growth because of its use in cancer diagnosis and management. According with published studies all over the world, the sensibility and specificity of FDG-PET, noninvasive method, is higher than that of the conventional methods like CT, IRM, ultrasonography. PET is en excellent detection method of most of common cancer types and depends not on the histological neoplasm type; the more aggressive is the tumor, more it will uptake the radiotracer. The cost is significant, so the indications must be very precise: evaluating the malignity of solitary pulmonary nodules, evaluating the recurrences of melanoma, colon cancer diagnosis, differentiation between recurrent brain tumor and radiation injury, differential diagnosis of the benign lymph and malign lymph nodes, staging of Hodgkin's and non-Hodgkin's lymphoma, evaluation the response to therapy. Because the PET images are difficult to interpret, appears the necessity of correlation with anatomic images: this was the fusion images beginnings (the PET and CT images combination); now the physiologic information has precise anatomic localization. The growing of this method is very probably, both using 18F FDG -thanks to its highly favorable physical characteristics- and other new radiopharmaceuticals. The clinical cases that illustrate the applications are investigated at CERMEP, Lyon, France.

Diagnosis, Differential↗
PubMedDate not supplied

[Multiple perfusion defects detected by scintigraphy].

Pulmonary embolism is a cause of death and the most common pathological condition involving the lungs of hospitalized patients. Early detection can rise prognosis of survival. In this case presented below, a patient suspected of pulmonary embolism was sent to our department, for assessing the lung perfusion, performing the pulmonary perfusion scintigram with 99mTc-MAA for establishing a diagnosis. Lung imaging is a noninvasive technique without patient discomfort that objectively can depict the distribution of the radiopharmaceutical throughout the lungs. We conclude that multiple non segmental defects with no radiological abnormalities state that the probability of pulmonary embolism is lower than 20%.

Female↗
PubMedDate not supplied

Image processing in myocardial SPECT acquisition.

Image processing for the imagistic medicine domain nuclear medicine have long time being realised through specifical protocols which rarely allowed the intervention of other informatical modalities. Processing depends first of all on the acquisition type. This paper presents the steps of one of the most complex image processing protocols, in the case of myocardial SPECT acquisition (Single Photon Emission Computed Tomography).

Heart↗
PubMedDate not supplied

Cancer evolution assessment using artificial neural networks.

Artificial Neural Networks have demonstrated good utility to establish disease prognostic, if there are correctly trained. Our aim was to realize Artificial Neural Networks in different cancer types, to evaluate time survival. For the beginning this was applied for breast cancer. The conclusion is that the homogeneity of data entrance sets, the number, and their coding in relation with their importance for cancer prognostic are decisive for the results of the trained ANN. These results can be useful in the physician clinical decision.

Adult↗
PubMedDate not supplied

[A retrospective study of bone metastases distribution on 420 whole body scans].

UNLABELLED: 420 patients with cancer of breast, prostate, lung and colon were investigated through 99mTc Methylene-diphosphonate whole body scintigraphy. The presence of pathologic radiotracer uptake was qualitatively and quantitatively analyzed in order to establish the metastases distribution. Patient selection was realized over 2455 whole body scintigraphies effectuated between 1998 and 2001 in our Nuclear Medicine Service. All selected cases were metastases with known origin primary cancer. RESULTS: Using the Qui-square Test we have compared the frequency of nine well delimited skeleton regions involved like metastatic site in the different cancer types. We have found a significant statistic difference of the range of frequency only between breast and prostate cancers as well as between pulmonary and prostate cancers. The mean number of the metastatic involved skeletal regions was significantly greater in breast and prostate cancers in comparison with lung and colon cancers (p < 0.0001). The higher metastases site frequency was the rachis, than the pelvis, the ribs and the sternum. The skull metastases localization is more frequent in breast cancer in comparison with all other cancers (7.67% versus less than 4% in other cancer types). The pelvis was more involved for the metastatic process in prostate neoplasm. On the other hand, the highest mean anatomic sites number per patient was found in breast cancer (5.7) and prostate cancer (4.8) related to colon (3.3) and lung (3.0) cancers. CONCLUSIONS: Even some particularities were evident, in our study, between the metastases distribution in these four cancer types, the data are not sufficient to sustain the existence of a characteristic pattern related to the primary cancer origin. Metastases localization could be, however, related to the metastazation mechanism.

Algorithms↗
PubMedDate not supplied

[Correlation in imaging techniques for the early detection of bone metastases in a case of breast cancer].

The presented case is part of a pilot study performed in the Biophysics and Nuclear Medicine Service from the Tenon Hospital (Paris), chief Department Prof. J.N. Talbot. A 46 years patient, with mastectomy for a left breast cancer in 1999, followed by radiotherapy, is detected, in January 2004, through CT scan, with a tumoral mass at the left thoracic base. To confirm the rib osteolysis hypothesis a standard Rx was done; the result was the detection of a pathologic IX left rib fracture and a lacuna site on the L1 vertebra. The following bone scintigraphy make evidence of two hot spots (rib and vertebra) and also of a new pathologic site on the sternum. An 18FFDG PET image detects, despite the three known sites, another one on the left iliac bone crest. In conclusion, an extensive scintigraphic examination, including PET, is necessary to optimize the osteofil cancer metastases detection.

Bone Neoplasms↗
PubMedDate not supplied

[Role of radioisotopic investigations in breast cancer diagnosis and follow-up].

Breast cancer represents the disease with the highest incidence in the female population. In the last years there was observed, in western countries, an increase of morbidity by breast tumors and in the same time, a decrease of mortality in direct relation with an earlier diagnosis. Until the spread at distance, breast cancer it's a loco-regional disease that can be curable by surgical treatment and adjuvant therapy, like chemotherapy or radiotherapy. The principal goal is to diagnose it before distal metastases appear, most frequently bone metastasis. Certain role has nuclear medicine in the diagnosis and prognosis of breast cancer because it's more sensitive and gives functional imaging. The aim of this study is to answer the question: what technique, in what indication. The detection of sentinel lymph node has now a clear place in the algorithm, the scintimammography test is important, especially for prediction of tumor resistance to chemotherapy. The bone scintigraphy (which explores the entire body in one time)is generally used in the detection of bony metastases and FDG tomoscintigraphy for the evaluation of local and distal recurrences, or response to chemotherapy. The measure of the isotopic ejection fraction, actually considered the gold standard, is very useful and also very easy to perform, in patients who will receive chemotherapy.

Bone Neoplasms↗
PubMedDate not supplied

[Simulation models of the processes of the interface in dental structures].

The occlusal forces have an effect on the dental structure in the longitudinal axis of the tooth, on the one hand, but, on the other hand, in the horizontal plane, they are conducted through interdental contact points. In this paper we try to simulate the stress and the deformations determined by different forces in different directions, over the dental interfaces. We have used the method of finite elements and Fastflo domain for the mathematical calculations of probability. Our conclusions are that the changes in the deformation field appear only for those materials that comply with the rate of elasticity changes in the condition where delta = E1/E2 < 20.

Algorithms↗
PubMedDate not supplied

[Experimental data about microhardness of some alloys used in metal-ceramic technology].

The measurements of micro-hardness was achieved with a view to studying the influence of chemical composition and fabrication with a view to obtain metal-ceramic dental restorations. The materials used were specimens of metal alloys (Remanium Cs) and specimens of metal alloys-ceramics (Remanium-Biodent ceramic) prepared through polish, lustre and acid attack; the PMT3 machine for microhardness measurements; a 50 grams weight and a length of loading 15 sec. The results of determinations are prove the technological process for cover metal structure of Remanium Cs with ceramics influence significantly the microhardness of metal ingot and Remanium further polish (with and without oxidation).

Algorithms↗
PubMedDate not supplied

[Radioisotopes for the evaluation of pulmonary capillary permeability in ARDS].

The dysfunction of pulmonary capillary represents the marker of Acute Respiratory Distress Syndrome (ARDS). Each current mean of investigation in ARDS (radiography, CT, ultrasonography, double dilution technique, electric impedance, bronchoscopy) has its downfalls and has not succeeded in becoming a gold standard in evaluation of this pathology. The development of any treatment is hampered by the lack of a rapid and objective method of evaluation of the progress of the disease. The radioisotopic evaluation of pulmonary capillary permeability realizes a picture of a physiologic process blood-interstitial exchange at pulmonary level. The most recent studies appear to suggest that this method of investigation can objectively evaluate and be a predictive parameter for ARDS evolution. We will present the principle of the radio-isotopic method and some of its current clinical applications.

Capillary Permeability↗
PubMedDate not supplied

[Metabolic and cardiovascular changes in experimental diabetes, stress and orchiectomy].

When Aloran (Al) was administered to normal or orchiectomized animals, the adult ones proved to be more sensitive, most normal animals (77.7%) developing a DAla and the remainder (22.3%) a DAlc, while of the orchiectomized animals 66.6 developed a DAlc and 33.4% presented a decreased glucose tolerance. 33.4% of the young normal developed a DAla and 66.7% a DAlc, while of the young orchiectomized ones 33.4% presented a DAlc and 66.7% a STG. No matter of age, orchiectomy induced an increased resistance to the various action of Al. Glycemia and lipid fractions, especially LT and TG were significantly elevated in the normal animals with DAla and in the young orchiectomized animals with DAlc. Insulinemia was elevated in most young animals, except for the orchiectomized ones with DAlc, in which it decreased. Serum cholesterol was the most markedly elevated in the adult animals belonging to the group ACTH + D2 + Al, form DAlc. Histopathologically, in this last group degenerative lesions and microcalcifications in aorta and interstitial infiltrate and homogenization of myocardial fibres in the myocardium were found.

Adrenocorticotropic Hormone↗