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Biomedical subjects

A Margulis

Publications and source records attributed to A Margulis.

At least 19 recordsLinked to original sources
PubMed2006

[Ankle chondrocytes are more resistant to Interleukin-1 than chondrocytes derived from the knee].

BACKGROUND: The incidence of degenerative changes and osteoarthritis is lower in the ankle than in the knee joints. This cannot be explained exclusively with differences in anatomy and biomechanical properties of these two synovial joints. Previous studies have indicated distinct differences in the biochemical composition of the extracellular matrix of articular cartilage from knee and ankle joints. The aim of this study was to identify potential metabolic differences between knee and ankle joint chondrocytes using isolated cells to distinguish the secondary effects of the resident extracellular matrix from the primary matrix-independent effects of cellular differentiation. METHOD: Isolated knee and ankle chondrocytes from the same human donor were cultured in alginate beads and subsequently exposed to a three-day pulse of the catabolic cytokine interleukin-1 (IL-1) as a model of an inflammatory episode. The metabolism of proteoglycans (PG's) was analyzed as expressed changes in 35S-sulfate incorporation into glycosaminoglycans (GAG's). RESULTS: The presence of IL-1 induced an inhibition of PG synthesis in knee and ankle articular chondrocytes. The 50% inhibitory concentration (IC50) of IL-1 was about 5 times lower for knee than for ankle chondrocytes. CONCLUSION: Ankle chondrocytes are more resistant to IL-1 induced inhibition of PG synthesis than chondrocytes from the knee.

Adult↗
PubMed2006

[Clinical and genetic study in 22 patients with basal cell nevus syndrome].

BACKGROUND: Nevoid basal cell carcinoma syndrome is an autosomal dominant disorder characterized by developmental abnormalities and cancer predisposition. The PTCH 1 gene, the human homolog of the Drosophila segment polarity gene patched, has been shown to be involved in the development of nevoid basal cell carcinoma syndrome. PTCH 1 is mapped to chromosome 9q22.3. The aim of the present study was to report on clinical and genetic characteristics in patients followed for nevoid basal cell carcinoma syndrome and to compare them to the data in the literature. PATIENTS AND METHODS: Screening for PTCH 1 mutations was done in 22 patients followed between 1981 and 2003 for clinical suspicion of nevoid basal cell carcinoma syndrome. Clinical and radiological data were reviewed retrospectively from records. Genetic analysis was performed using blood samples after patient informed consent was obtained. When possible, DNA was also analyzed from the parents of patients in whom PTCH 1 mutations were found. RESULTS: All patients had developed basal cell carcinomas: 45% palmar and plantar pitting, 62% jaw cysts and 66% calcification of falx cerebri. Medulloblastomas and meningiomas were the most common associated tumors. PTCH 1 mutations were identified in 13 patients: 6 familial cases, 3 sporadic cases and for 4 patients, it was not possible to conclude. Nine different new germ-line mutations were identified. DISCUSSION: Genetic analysis allows molecular confirmation of diagnosis in about half of all patients. Early diagnosis is essential for detection of clinical and radiological manifestations in young patients and for provision of advice concerning protection of the skin from the sunlight.

Adolescent↗
PubMed2006

Microcystic adnexal carcinoma: report of seven cases including one with lung metastasis.

BACKGROUND: Microcystic adnexal carcinoma (MAC) is a rare cutaneous neoplasm, with a high rate of local recurrences. OBJECTIVE: A series of MAC was analyzed and compared to previously published cases. METHODS: Seven cases of MAC were identified in the register of the institution. Medical and pathological records were reviewed. RESULTS: The primary MAC were located on the face in all patients, and 85% were initially misdiagnosed. The mean follow-up duration was 108 months. The recurrence rate was high: 4 patients developed recurrences. In 3 patients, the course of the disease was severe: one of them developed pathologically proven lung metastasis. CONCLUSION: The present study and review of the literature confirm the clinically aggressive evolution of MAC and its rare ability to give rise to metastasis. Long-term clinical follow-ups with imaging investigations are mandatory.

Adult↗
PubMed2003

[Significance of sentinel lymph node biopsy in Merkel cell carcinoma. Analysis of 11 cases].

BACKGROUND: Merkel cell carcinoma is an aggressive cutaneous neoplasm with a high propensity for nodal metastases. Regional lymph node involvement develops in 45 to 65 p. 100 of patients. We evaluated in Merkel cell carcinoma the use of sentinel lymph node biopsy which allows the identification of occult nodal metastases. PATIENTS AND METHODS: Eleven patients diagnosed with Merkel cell carcinoma without clinical nodal involvement underwent pre-operative lymphoscintigraphy followed by sentinel lymphadenectomy with histologic analysis. Identification of microscopic nodal metastases led to complete lymph node dissection and adjuvant radiation therapy to the lymph node basin. RESULTS: The sentinel lymph node was successfully identified in 9 patients. Two patients demonstrated metastatic disease in their sentinel lymph nodes. At subsequent complete node dissection, one of two patients had an additional metastatic lymph node. None of the eleven patients experienced recurrent disease at a follow-up varying from 1 to 42 months. One patient with a negative sentinel lymph node experienced lymphoedema. COMMENTS: Our results are consistent with the 14 published studies which totalled 93 patients with Merkel cell carcinoma and identified 29 patients (30 p. 100) with nodal involvement. Metastatic disease was identified only after immunohistochemical analysis in 20 p. 100 of these patients (n=6). Lymph node involvement appears to be a bad prognostic factor with 29.6 p. 100 of disease recurrence, as opposed to 3 p. 100 in patients with an uninvolved sentinel lymph node. Although the prognostic significance of this technique seems interesting, there is no optimal therapeutic approach to sentinel lymph node involvement.

Adult↗
PubMed2002

Diffraction-enhanced X-ray imaging of articular cartilage.

OBJECTIVE: To introduce a novel X-ray technology, diffraction-enhanced X-ray imaging (DEI), in its early stages of development, for the imaging of articular cartilage. DESIGN: Disarticulated and/or intact human knee and talocrural joints displaying both undegenerated and degenerated articular cartilage were imaged with DEI. A series of three silicon crystals were used to produce a highly collimated monochromatic X-ray beam to achieve scatter-rejection at the microradian level. The third crystal (analyser) was set at different angles resulting in images displaying different characteristics. Once the diffraction enhanced (DE) images were obtained, they were compared to gross and histological examination. RESULTS: Articular cartilage in both disarticulated and intact joints could be visualized through DEI. For each specimen, DE images were reflective of their gross and histological appearance. For each different angle of the analyser crystal, there was a slight difference in appearance in the specimen image, with certain characteristics changing in their contrast intensity as the analyser angle changed. CONCLUSIONS: DEI is capable of imaging articular cartilage in disarticulated, as well as in intact joints. Gross cartilage defects, even at early stages of development, can be visualized due to a combination of high spatial resolution and detection of X-ray refraction, extinction and absorption patterns. Furthermore, DE images displaying contrast heterogeneities indicative of cartilage degeneration correspond to the degeneration detected by gross and histological examination.

Adult↗
PubMed2002

[Delayed cerebral radionecrosis following radiation therapy of cutaneous squamous cell carcinomas of the head].

INTRODUCTION: Three cases of cerebral radionecrosis occurring after radiation therapy for squamous cell carcinomas of the scalp are reported. This rare and poorly documented complication of radiotherapy is discussed. CASE REPORTS: Three patients presenting with squamous cell carcinomas of the scalp were treated with surgery and radiotherapy for recurrent or incomplete resection of squamous cell carcinomas of the head. X-ray doses range were 50 to 60 Grays in 22 to 24 fractions. Cerebral radionecrotic lesions were diagnosed 6 months to 14 years after irradiation, and were inconstantly associated with clinical symptoms. The patients were treated with systemic steroids, which were of limited efficacy in one of our patients. DISCUSSION: Little is known of cerebral radionecrosis following radiotherapy. This may be related to their rare occurrence and/or to the difficulties in establishing diagnosis. The delay of occurrence after radiotherapy can vary between a few months and several years, and the lesions are directly correlated with the doses and the fractionning of the X-rays. Intracerebral localization of the tumour is the main differential diagnosis. Localized and cystic forms of cerebral radionecrosis can be treated by surgery. Treatment otherwise relies on systemic steroids.

Aged↗
PubMed2001

Indium-111 octreotide scintigraphy of Merkel cell carcinomas and their metastases.

BACKGROUND: Somatostatin receptor scintigraphy (SRS) may be of interest for staging Merkel Cell Carcinoma (MCC). This study was undertaken to evaluate the sensitivity and specificity of SRS and to determine its role compared to conventional investigations. PATIENTS AND METHODS: From 1993 to December 2000, 20 patients (10 females and 10 males, aged from 38 to 88, mean 66 years) were included prospectively. At the time of SRS: 12 patients had been diagnosed as having stage I disease, 6 stage II and 4 stage III. Two patients had two SRS studies during the course of their disease. SRS was performed with Indium-111 pentetreotide (Octreoscan), a radiolabelled somatostatin analogue. Patients were treated according to the clinical stage. A regular follow-up was scheduled every three months. RESULTS: SRS depicted stage I and II MCC tumour sites with an overall sensitivity of 78% (95% confidence interval (CI): 40%-97%) and a specificity of 96% (81%-100%). The histopathological diagnosis was used as the gold standard. Sites visualised by SRS were compared to those detected with conventional modalities and to follow-up data for all stages: SRS visualised four out of five primary tumour sites, six out of eight lymph node sites, no skin metastases (14 sites in 2 patients), two out of three thoracic metastases and zero out of two hepatic metastases. SRS did not influence treatment decision-making in any of the cases. CONCLUSIONS: Although SRS seems highly specific in MCC and could be of help in difficult cases, it cannot be recommended for routine evaluation.

Adult↗
PubMed2000

Rate of deactivation of nitric oxide-stimulated soluble guanylate cyclase: influence of nitric oxide scavengers and calcium.

Soluble guanylate cyclase (sGC) is highly activated by nitric oxide (NO) and is the known mediator of the effects of NO on a variety of physiological processes. The rates at which sGC is activated and deactivated are therefore of wide interest since they determine the duration of a tissue's response to NO. The effect of NO on smooth muscle dissipates in 1-2 min, suggesting that both activation and deactivation are fast. In vitro measurements show that the activation of sGC occurs in less than a second, while the deactivation takes several hours at 20 degrees C. However, recent reports indicate that Mg-GTP, oxyhemoglobin, and reducing and oxidizing agents could deactivate the cyclase in several seconds to minutes, though the effectiveness of each of these agents is in dispute. We investigated the lifetime of NO-sGC in the cytosol of retina by monitoring its enzymatic activity at 20 degrees C. Our results show that Mg-GTP, the substrate of NO-sGC, has no influence on the deactivation. Similarly, reducing agents glutathione and dithiothreitol shortened the half-life of NO-sGC only by about 30%. The greatest effect on the deactivation was caused by scavengers of NO: oxyhemoglobin reduced the half-life of NO-sGC from 106 min to 18 s; another NO scavenger, 2-(4-carboxyphenyl)-4,4,5, 5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO), reduced it to 42 s (20 degrees C). Similarly rapid deactivation was observed with the enzyme from bovine lung, immunoprecipitated enzyme from bovine retina, and heme-deficient enzyme from bovine retina reconstituted with heme. On the other hand, YC-1, an activator of sGC, stabilized the activated enzyme, preventing NO dissociation, as was evident from the inability of oxyhemoglobin or CPTIO to deactivate NO-sGC. Calcium, which is known to inhibit NO-sGC, also inhibited the effects of oxyhemoglobin and CPTIO, slowing down the deactivation of the enzyme. Lithium, which is also known to inhibit NO-sGC, had no effect on the deactivation rate of the enzyme. These results, taken together, suggest that two factors with major impact on the lifetime of NO-sGC are the proximity to NO scavengers and the calcium concentration in the cell.

Animals↗
PubMed2000

Evaluation of cosmetic results of a randomized trial comparing surgery and radiotherapy in the treatment of basal cell carcinoma of the face.

Basal cell carcinoma is the most frequent cutaneous carcinoma, and it is characterized by its local spreading and an exceptional tendency to metastasize. Radical excision or destruction ensures the highest chance of cure. The most frequent site of this tumor is the face, where radical excision is limited by the proximity of essential anatomic structures. The main difficulty is to avoid mutilation and to provide good cosmetic results despite the vicinity of the eyes, the nose, and the mouth. Surgery and radiotherapy are known to provide similar chances of cure, but results concerning cosmetic sequelae are controversial, depending sometimes on the specialty of the physician in charge of the treatment. A randomized trial was performed at the Gustave-Roussy Institute to compare basal cell carcinomas of the face treated either by surgery or by radiotherapy. In summary, a significant advantage was observed in favor of surgery, as has been published elsewhere. Looking at the details of the cosmetic results, we analyzed the specific methodology of the cosmetic evaluation set up to eradicate the usual bias owing to subjective judgments. We looked also to the evolution of the cosmetic results with time. A panel of five judges performed repeated evaluations during the follow-up, and standardized photographs were taken at each visit and rated later by three nonmedical judges. In total, 174 patients were treated by surgery and 173 by radiotherapy; the choice of the treatment was allocated by randomization. Postoperative complications were higher in the radiotherapy group. The final cosmetic results after 4 years of follow-up were rated significantly better with surgery than with radiotherapy (good in 87 percent versus 69 percent according to the patient, 79 percent versus 40 percent according to the dermatologist, and respectively for each of the observers). Evolution of the ratings during the follow-up demonstrated an improvement of the cosmesis after surgery and stable or deteriorated results after radiotherapy. The same trend was observed regardless of the site of the tumor on the face, except for the nose, where the difference--still in favor of the surgery--was not significant. Concordance of all assessments in our study was the main guarantee of reliability of our methodology for cosmetic evaluation.

Adult↗
PubMed2000

[Cerebral magnetic resonance imaging (MRI) in the diagnosis of leptomeningeal carcinomatosis in melanoma patients].

OBJECTIVE: Meningeal involvement is frequent in metastatic melanoma, approximately 30% in autopsy series. Functional signs may be misleading and the neurological examination may be normal. Certain diagnosis requires identification of tumor cells in the cerebrospinal fluid. CSF cytology is however sometimes negative and magnetic resonance imaging (MRI) with gadolinium injection may provide the diagnosis. The aim of this retrospective study was to assess the role of imaging in the diagnosis of leptomeningeal carcinomatosis. PATIENTS AND METHODS: The diagnosis of leptomeningeal carcinomatosis was made in 8 patients between 1992 and 1998. All had signs of neurological function impairment, but the neurology examination was abnormal in only 2. RESULTS: Cytology examination of the cerebrospinal fluid provided the diagnosis of leptomeningeal carcinomatosis in 5 patients. One out of 5 brain CT scans were positive, showing meningeal enhancement confirmed by brain MRI. The spinal tap was not contributive in 2 cases and was not done in 1. In these three cases, the brain CT did not provide any diagnostic element while the brain MRI with gadolinium injection confirmed the diagnosis of leptomeningeal carcinomatosis. DISCUSSION: Forty-one percent of patients with autopsy proven leptomeningeal carcinomatosis have a normal ante mortem spinal tap. Brain MRI with gadolinium injection has better sensitivity than brain CT scan. All patients with nonspecific neurological signs and a normal spinal tap should be explored with a brain MRI.

Adolescent↗
PubMed1999

Antisense inhibition of hyaluronan synthase-2 in human articular chondrocytes inhibits proteoglycan retention and matrix assembly.

In order to define the role of cell-associated hyaluronan in cartilage matrix retention, human articular chondrocytes as well as cartilage slices were treated with phosphorothioate oligonucleotides comprised of sequence antisense to the mRNA of human HA synthase-2 (HAS-2). As a prerequisite for these studies, it was necessary to determine which HA synthase (HAS), of three separate human genes capable of synthesizing HA, designated HAS-1, HAS-2, or HAS-3, is primarily responsible for HA synthesis in human articular chondrocytes. The copy number of each HAS mRNA expressed in cultured human articular chondrocytes was determined using quantitative (competitive) reverse transcription-polymerase chain reaction (RT-PCR). Only HAS-2 and HAS-3 mRNA expression was detected. The level of HAS-2 mRNA expression was 40-fold higher than that of HAS-3. Cultures of human articular chondrocytes and cartilage tissue slices were then transfected with HAS-2-specific antisense oligonucleotides. This treatment resulted in time-dependent inhibition of HAS-2 mRNA expression, as measured by quantitative RT-PCR, and a significant loss of cell-associated HA staining. Sense and reverse HAS-2 oligonucleotides showed no effect. The consequences of reduced HA levels (due to HAS-2 antisense inhibition) were a decrease in the diameter of the cell-associated matrix and a decreased capacity to retain newly synthesized proteoglycan. These results suggest that HA synthesized by HAS-2 plays a crucial role in matrix assembly and retention by human articular chondrocytes.

Base Sequence↗
PubMed1999

[Plagiocephaly in children: etiology, differential diagnosis and helmet treatment].

Plagiocephaly in a head-and-neck irradiated rat model or rhomboid-shaped head, occurs in at least 1 in 300 live births. In most cases such asymmetry is not caused by synostosis of the unilateral coronal or lambdoid sutures, but is rather a deformity produced by intrauterine and/or postnatal deformational forces. Categorization and diagnosis of plagiocephaly as synostotic or deformational is reliably made by physical examination and computerized tomography. Its differential diagnosis is extremely important because prompt surgical correction is usually indicated for the synostotic type. In contrast, infants with deformational frontal or occipital plagiocephaly generally respond to helmet treatment. 10 infants with significant deformational plagiocephaly were treated with individual plastic helmets during the past 2 years and 4 other infants with plagiocephaly are currently being treated. In each instance, cranial asymmetry dramatically improved as the brain grew and the head filled out the helmet. There were no significant complications. Awareness of deformational plagiocephaly allows more accurate diagnosis and appropriate treatment, avoiding unnecessary surgical intervention in patients with positional molding.

Head Protective Devices↗
PubMed1999

Prognostic value of high-frequency sonography and color Doppler sonography for the preoperative assessment of melanomas.

OBJECTIVE: The purposes of this study were to determine the efficacy of high-frequency sonography for the preoperative assessment of melanomas and to determine the prognostic value of tumor vascularity measured by color Doppler sonography. SUBJECTS AND METHODS: Twenty-seven patients with melanomas were prospectively examined using high-frequency sonography before they underwent surgery. For each tumor, morphologic evaluation (20-MHz probe), including the measurement of maximum tumor thickness, and color Doppler sonography analysis (13-MHz probe), including the measurement of intratumor vascularity, were performed. Diagnosis was confirmed by histologic findings, tumor thickness was measured using the Breslow index, and vascularity was assessed by immunochemical findings. RESULTS: Each of the 27 melanomas was depicted on high-frequency sonography as a homogeneous hypoechoic structure with well-defined margins. Tumor thickness was measured using high-frequency sonography as ranging from 0.3 to 8.0 mm, whereas it was measured using the Breslow index as ranging from 0.26 to 8.0 mm. Sonography measurements and Breslow index values were strongly correlated (r > .95). In the cases in which the Breslow index value exceeded 1 mm (n = 11), surgical reexcision was necessary but could have been avoided if surgery had been planned on the basis of high-frequency sonography measurements. Intratumor vessels were depicted on color Doppler sonography (n = 10). Color Doppler sonography data and histologic findings were significantly correlated. CONCLUSION: High-frequency sonography is a simple, reliable, noninvasive, and accurate method for the preoperative measurement of melanoma thickness. In fact, surgical planning could be adapted according to this measurement. The prognostic value of vascularization evaluated with color Doppler sonography is comparable with that determined by the Breslow index.

Aged↗
PubMed1999

[Primary cutaneous leiomyosarcoma: 32 cases].

BACKGROUND: Superficial leiomyosarcomas are rare tumors, which may be confined to the dermis or extend to subcutaneous tissues. PATIENTS AND METHODS: We report the results of a retrospective study of 32 patients treated for leiomyosarcomas through a twenty-two year period (from 1975 to 1997). RESULTS: Mean age was 45 years, with 50 p. 100 of patients less than 35 years of age. Forty seven percent of the tumors were located on the lower limbs and mean diameter was 2.8 cm. Three clinical types have been isolated: nodule beneath normal epidermis (50 p. 100), purple nodule ulcerated or not (28 p. 100), swelling tumor (22 p. 100). Sixteen percent were intradermal, whereas sixty nine percent involved subcutaneous tissues. With regard to tumor grade, 37 p. 100 of tumors were grade I, 44 p. 100 of tumors were grade II, and 19 p. 100 were grade III. Immunohistochemical staining showed positive reactions for all tumors with anti-vimentin and anti-alpha smooth muscle actin. Main treatment was complete surgical excision. Follow-up informations were available for all patients and 75 p. 100 of them had a follow up period longer than a year. Five patients with leiomyosarcomas involving the subcutis developed local recurrences, and two of them died of the disease. DISCUSSION: Leiomyosarcomas can occur at any age without predominant sex-ratio. Main prognostic factors are tumor size, distal location, depth of tumor invasion and pathological grade. Immunohistological staining with anti-alpha smooth muscle actin is more sensitive and specific than with anti-desmin or anti-HHF 35. Main treatment is surgical excision with wide margins.

Actins↗