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Biomedical subjects

V Nicolas

Publications and source records attributed to V Nicolas.

At least 55 records · Page 3Linked to original sources
PubMed1997

Antiproliferative effect of Pygeum africanum extract on rat prostatic fibroblasts.

The effect of a Pygeum africanum extract (Tadenan) (Pa), used in the treatment of micturition disorders associated with BPH, has been examined on the proliferation of rat prostatic stromal cells stimulated by different growth factors. EGF, bFGF, and IGF-I but not KGF are mitogenic for prostatic fibroblasts in culture. Pygeum africanum inhibits both basal and stimulated growth with IC50 values of 4.5, 7.7 and 12.6 micrograms./ml. for EGF, IGF-I and bFGF, respectively, compared to 14.4 micrograms./ml. for untreated cells, the inhibition being stronger towards EGF. Pygeum africanum inhibited the proliferation induced by TPA or PDBu in a concentration-dependent manner with IC50 values of 12.4 and 8.1 micrograms./ml. respectively. The antiproliferative effects of Pa were not ascribed to cytotoxicity. These results show that Pygeum africanum is a potent inhibitor of rat prostatic fibroblast proliferation in response to direct activators of protein kinase C, the defined growth factors bFGF, EGF and IGF-I, and the complex mixture of mitogens in serum depending on the concentration used. PKC activation appears to be an important growth factor-mediated signal transduction for this agent. These data suggest that therapeutic effect of Pygeum africanum may be due at least in part to the inhibition of growth factors responsible for the prostatic overgrowth in man.

Animals↗
PubMed1996

[Comparison of CT arterioportography and spiral CT arterioportography in malignant lesions of the liver].

PURPOSE: To determine the value of spiral CT during arterial portography (SCTAP) in detecting and localising focal liver lesions we compared the SCTAP findings to those gained by conventional CT during arterial portography (CTAP). MATERIAL AND METHODS: We evaluated a total of CT scans of 128 patients with 162 malignant lesions of the liver. 45 patients underwent SCTAP and 83 patients CTAP. Results of radiological studies were compared with surgical and pathological findings. RESULTS: The overall sensitivity of SCTAP was 93% with a sensitivity of 80% for lesions of less than 1 cm diameter. For CTAP the overall sensitivity was 88%, but the sensitivity for lesions smaller than 1 cm was only 53%. Although with SCTAP examination of hepatic vasculature and liver parenchyma was continuous, we found no advantage in the localisation of lesions to the liver segments compared to CTAP, and the sensitivity of localisation did not correlate with the size of lesions. CONCLUSION: In our study SCTAP turned out to be a reliable radiological method in the preoperative detection of focal liver lesions, with a high overall sensitivity. SCTAP showed improved sensitivity in the detection of small malignant lesions (< 1 cm) in comparison to CTAP.

Adult↗
PubMed1996

Acute pulmonary embolism: value of transthoracic and transesophageal echocardiography in comparison with helical CT.

OBJECTIVE: The goal of this study was to prospectively compare the accuracy of transthoracic and transesophageal B-mode and Doppler echocardiography with helical CT for detecting acute pulmonary embolism. SUBJECTS AND METHODS: Thirty-five consecutive patients underwent transthoracic and transesophageal echocardiography and contrast-enhanced helical CT. Echocardiographic examinations were analyzed for indirect criteria, including increased main pulmonary artery diameter, tricuspid regurgitation, and dilatation of the right ventricular cavity, as well as for direct thrombus visualization. Sensitivity, specificity, and negative and positive predictive values were calculated. RESULTS: Pulmonary embolism was revealed by helical CT in 22 of 35 patients; in 11 of these 22 cases, central pulmonary embolism was seen. Transthoracic and transesophageal B-mode echocardiography failed to reveal pulmonary embolism in nine patients, two of whom had central pulmonary embolism. The sensitivity and specificity of the combination of both echocardiographic investigations were 59% and 77% respectively (82% and 92% for central pulmonary embolism). In three patients, pulmonary embolism was diagnosed by direct clot detection with transesophageal echocardiography. In two patients, only the indirect parameters indicated pulmonary embolism. Overall indirect echocardiographic parameters were characterized by a low sensitivity that ranged from 50% for tricuspid regurgitation to 21% for main pulmonary artery diameter. CONCLUSION: In comparison with helical CT, transthoracic and transesophageal echocardiography had limited accuracy for detecting pulmonary embolism.

Acute Disease↗
PubMed1995

Paradoxical effects of phosphate to directly regulate the level of skeletal alkaline phosphatase activity in human osteosarcoma (SaOS-2) cells and inversely regulate the level of skeletal alkaline phosphatase mRNA.

Recent studies indicate that the amount of alkaline phosphatase (ALP) activity in human osteoblast-line cells is proportional to the concentration of phosphate in the culture medium. The current studies were intended to extend those observations and to determine whether the effects of phosphate (and phosphate esters and analogs) to alter the cellular level of ALP activity, in human osteosarcoma SaOS-2 cells, reflected regulation at the level of transcription. Consistent with previous findings, we found direct, time- and dose-dependent correlations between the concentration of phosphate and the amount of ALP activity/mg cell protein (P < 0.05). Surprisingly, we also found a negative correlation between the phosphate concentration in the medium and the level of skeletal ALP mRNA (e.g., r = -0.98, P < 0.01 at 24 hours). As the highest cellular levels of skeletal ALP activity were associated with the lowest levels of ALP mRNA, these data indicated that the phosphate-dependent increase in ALP activity was not mediated by an increase in transcription and, conversely, that the effect of phosphate withdrawal to decrease ALP activity was not mediated by a decrease in transcription.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1995

An age-related decrease in the concentration of insulin-like growth factor binding protein-5 in human cortical bone.

The skeletal contents of insulin-like growth factor-2 (IGF-II), insulin-like growth factor binding protein-5 (IGFBP-5), and insulin-like growth factor binding protein-3 (IGFBP-3) were determined in duplicate samples of human femoral cortical bone obtained from 64 subjects (44 males and 20 females) between the ages of 20 and 64 years. The results of these quantitative measurements revealed an age-related decrease in the femoral cortical content of IGFBP-5 (r = -0.272, P = 0.031) in the total population. Although the femoral cortical content of IGF-II did not show a similar decrease with age, it could be correlated to the femoral cortical content of IGFBP-5 (r = 0.442, P < 0.001). In contrast, the femoral cortical content of IGFBP-3 did not decrease with age and could not be correlated to the femoral cortical contents of either IGFBP-5 or IGF-II. Comparisons of these results with previous measurements of insulin-like growth factor-1 (IGF-I) and transforming growth factor-beta (TGF-beta), in extracts of the same bones, showed significant cross-correlations between the femoral cortical contents of each of these growth factors and the femoral cortical contents of IGFBP-5 (r = 0.625 for IGF-I versus IGFBP-5, r = 0.554 for TGF-beta versus IGFBP-5, P < 0.001 for each) but not IGFBP-3.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Calcitonin acutely increases tyrosyl-phosphorylation of proteins in human osteosarcoma (SaOS-2) cells.

In order to test the hypothesis that salmon calcitonin has direct effects to modulate tyrosyl-protein phosphorylation in human osteosarcoma cells, SaOS-2 cells (with very high steady-state levels of skeletal alkaline phosphatase) were exposed to calcitonin, in duplicate serum-free cultures, at concentrations ranging from 10(-13) to 10(-9) mol/liter, for 0-60 minutes at 37 degrees C. Phospho-tyrosyl proteins were identified by autoradiography of Western blots after incubation with 125I-labeled antiphosphotyrosine antibodies (or with unlabeled antibodies and 125I-labeled protein A) and quantitated by laser densitometry. The results of these studies revealed (1) time-dependent effects of salmon calcitonin (sCt) (at 3 x 10(-12) mol/liter) to increase the level of tyrosylphosphorylation of at least six proteins, with apparent molecular weights of 20, 25, 27, 41, 48, and 135 kD (P < 0.05 for each); and (2) dose-dependent effects of sCt (during 15 minutes of exposure) to increase the level of tyrosyl-phosphorylation of at least 10 proteins with apparent molecular weights of 19, 20, 27, 35, 41, 102, 135, 195, 220, and 244 kD (P < 0.05 for each). A supplementary study of calcitonin effects on tyrosyl-protein phosphorylation in a subpopulation of SaOS-2 cells with very low steady-state levels of skeletal alkaline activity revealed similar responses--time and dose-dependent increases in the tyrosyl-phosphorylation of at least seven proteins with apparent molecular weights of 44, 48, 57, 62, 101, 244, and 280 kD (P < 0.05 for each).(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1995

[Phlebography of the upper extremity. I. The technic and findings in 230 studies].

We report on 230 phlebographic examinations in the shoulder arm region which were performed by conventional X-ray technique and/or digital subtraction angiography (DSA). The detailed method of examination as well as anatomical variants of the vessels are explained. The group of patients was analysed concerning its composition and was subdivided with regard to clinically relevant diagnoses. Contrary to statements in the literature, the number of pathological findings in men or women were equal. The main age was between 40 and 50 years. The brachial vein was found to be doubled so often that this might be accepted as a normal situation. Phlebographic examinations were performed in the right arm twice as often as in the left one. 172 primary examinations, more than 60% showed a pathological result.

Adolescent↗
PubMed1995

[De Anquin disease or spinous engagement syndrome].

We report on a rare disorder called de Anquin's disease or spinous engagement or impingement syndrome. Low back pain in this specific syndrome probably combined with sciatica is caused by a hypertrophic spinous process in combination with a spina bifida occulta of an underlying vertebra which leads to compression of the neural structures beneath. Mostly the enlarged spinous process is seen at the level L5 and the spina bifida occulta at the level S1. Between 1981 and 1993 six patients were treated surgically after long-lasting periods of conservative therapy by resection of the hypertrophic spinous process combined with revision of the nerve roots and division of adhaesions. All patients had been reexamined clinically and radiologically. Up to now three of six patients are free of all symptoms, pain diminished in two others. The back pain situation is unchanged in only one patient.

Adult↗
PubMed1995

[Magnetic resonance tomography diagnosis of plexiform fibrohistiocytic tumor].

A case report on a 30-year old female patient who underwent resection of a haemangiopericytoma followed by radiation therapy in 1988 is presented. 6 months ago a space-occupying lesion was detected within the radiation field, which was classified as a plexiform fibrohistiocytic tumour (PFT). On MRI PFT showed the similar signal intensities as the muscles in T1, as well as T2-weighted images. After gadolinium-DTPA no enhancement within the tumour could be measured. Based on its exclusively dermal and subcutaneous location, and its signal behaviour uncommon for a malignant soft tissue mass, PFT must be included in differential diagnosis in any examining for local tumour recurrence.

Adult↗
PubMed1995

[POEMS syndrome].

The POEMS-syndrome is a very rare disorder, of which not much more than 100 cases are known worldwide, mostly in Japan. The following case report depicts the typical radiological changes to the skeletal system and inner organs.

Biopsy↗
PubMed1994

[Imaging of alloplastic ligament implant. An in vivo and in vitro study exemplified by Kevlar].

Neither native X-ray nor CT or NMR allow to evaluate intraarticular implantation results of Kevlar -49 directly. In animal trials, the course of an artificial ligament may only be presumed from connective tissue ingrowth. Although soft tissue structure appears much better in NMR than in CT, direct proof of ligament continuity is still impossible. As soon as the connective tissue becomes continuous, it appears clearly and allows indirect evaluation of the prosthesis, as integrity can be judged by its shape like in natural cruciate ligament. Anatomic preparations show that connective tissue fills up the small space between the two cords of a Kevlar -49 two bundle prosthesis eight weeks after implantation, so that imaging systems show only one intraarticular bundle.

Animals↗
PubMed1994

[Primary diagnosis and follow-up in acute pulmonary embolism: comparison of digital subtraction angiography and spiral CT].

The aim of this prospective study was to evaluate Spiral CT in the primary diagnosis of acute pulmonary emboli and for follow-up after thrombolytic treatment. Digital subtraction angiography of the lung was used as the reference method. 38 patients were subjected to both procedures. 79% of Spiral CT and 63% of DSA examinations were optimal. The two methods agreed in the diagnosis of thrombo-embolism in 30 patients and excluded it in eight patients. Spiral CT verified thrombi in a total of 213 cases; of these 23 were in a main pulmonary artery (11%), 88 in lobar arteries (41%), and 102 in segmental arteries (48%). DSA demonstrated 180 thrombi. 17% of the adherent and partially occlusive thrombi were not shown. 38 pulmonary infarcts were found in 18 patients. In 15 patients resolution of thrombi following thrombolytic treatment was shown by Spiral CT. Spiral CT is an excellent alternative to DSA and its use in the diagnosis of pulmonary emboli is entirely appropriate.

Acute Disease↗
PubMed1994

[MR tomography in prostatic carcinoma: comparison of conventional and endorectal MRT].

In a prospective study an attempt was made to determine the value of conventional MRI (354 patients) and MRI using the endorectal surface coil (ESC) (36 patients) in the preoperative staging of prostatic carcinoma. Local preoperative staging with conventional MRI was correct in 83.9% and 88.9% with ESC-MRI. Compared to conventional MRI, ESC-MRI was better in the delineation of the prostatic capsule and early detection of infiltration into the neurovascular bundle. Lymph node staging with MRI showed a sensitivity of 54.4% in detecting pelvic lymph node metastasis. MRI is as limited as CT in assessing pelvic lymph node metastasis.

Evaluation Studies as Topic↗
PubMed1994

[MRT diagnosis of recurrence of gynecologic tumors].

Because of the differences in the signals from recurrent tumours and fibrosis during MRT, this method is highly suitable for differentiating between recurrent gynaecological tumours and scar formation. The value of MRT in investigating suspected recurrences was studied in 27 patients aged between 34 and 83 years. It was possible to distinguish between recurrent tumour with its high intensity signal from low signal fibrosis, using T2-weighted spin echo sequences in all cases. By means of multiplanar reconstruction and because of its high soft tissue contrast it was possible to determine the extent of tumour growth and differentiate it from surrounding tissues. With a sensitivity of 90%, specificity of 100% and accuracy of 92%, MRT is superior to all other imaging methods, including CT, in the diagnosis of tumour recurrence.

Adult↗
PubMed1994

Age-related decreases in insulin-like growth factor-I and transforming growth factor-beta in femoral cortical bone from both men and women: implications for bone loss with aging.

We determined the skeletal content of insulin-like growth factor-I (IGF-I) and transforming growth factor-beta (TGF beta) in human bone as a function of age, using 66 samples of femoral cortical bone obtained from 46 men and 20 women between the ages of 20-64 yr. We found a linear decline in the skeletal content of IGF-I (nanograms per mg protein) with donor age (r = -0.43; P < 0.001) in the total population. The skeletal content of TGF beta also decreased with age (i.e. 1/TGF beta vs. age; r = 0.28; P < 0.02) for the total population. We did not observe any difference in the skeletal growth factor content between male and female donors. IGF-I content, when analyzed by decade divisions of age, showed a reduction between the 20- to 29-yr-old and the 50- to 59-yr-old subjects (P < 0.02). The loss rate of IGF-I was 1.56 ng/mg protein.yr, corresponding to a net loss of 60% of skeletal IGF-I between the ages of 20-60 yr. The loss rate of TGF beta was 0.03 ng/mg protein.yr, corresponding to a net loss of 25% of the skeletal TGF beta between the ages of 20-60 yr.

Adult↗