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Biomedical subjects

C Levy

Publications and source records attributed to C Levy.

At least 73 records · Page 4Linked to original sources
PubMed1994

[Imaging of cerebral thrombophlebitis].

Because of the polymorphic nature of the clinical presentations observed, the diagnosis of cerebral vein thrombosis (CVT) is often difficult and based on the findings of various imaging techniques. Routine CT scan constitutes a guiding examination allowing exclusion of other diseases responsible for the clinical symptoms and signs. MRI, a noninvasive technique allowing analysis of perfusion and thrombosis would appear to be the first-line examination for diagnosis as well as follow-up. The development of MR angiography techniques now allows confirmation of the diagnosis of dural sinus occlusion. However, certain false-negatives may be observed with MRI, especially in the case of cortical vein thrombosis. When doubt persists concerning the diagnosis, cerebral angiography remains the reference examination.

Cerebral Angiography↗
PubMed1993

Endocarditis caused by Rochalimaea henselae.

A case of community-acquired, culture-negative, infective endocarditis was diagnosed in a 57-year-old construction worker. Small, pleomorphic gram-negative rods were seen in Brown-Hopps tissue gram stains and Warthin-Starry silver stains. The organism was identified as Rochalimaea henselae by polymerase chain reaction amplification and sequencing of the 16S rDNA gene sequence. This is the first report of infective endocarditis caused by R henselae.

Community-Acquired Infections↗
PubMed1993

Cerebral infarction due to painless thoracic aortic and common carotid artery dissections.

BACKGROUND: Aortic arch dissection is usually lethal unless emergency surgery is performed. The dissection rarely may have a benign outcome or may occur without pain and be revealed by cerebral infarction. It is then likely to be seen primarily by a neurologist. In such cases, the value of new noninvasive diagnostic testing has not been reported. CASE DESCRIPTION: A 51-year-old man had a sudden left-sided hemiplegia due to hemorrhagic capsular and caudate infarcts on the right side. Cervical ultrasound examination with color flow imaging showed a bilateral common carotid artery dissection extending up to the bifurcation. Transesophageal echocardiography showed an aortic arch dissection, involving the innominate and left common carotid artery origins, which was confirmed by magnetic resonance imaging and aortography. The patient spontaneously fully recovered and is still alive 24 months after the stroke onset. CONCLUSIONS: This case emphasizes the usefulness of new noninvasive techniques such as transesophageal echocardiography and color-coded Doppler echocardiography in the diagnosis and follow-up of painless dissection of aortic and common carotid arteries. This cause of stroke may be underestimated.

Aortic Dissection↗
PubMed1993

An experience of the use of radioactive plaques after failure of external beam radiation in the treatment of retinoblastoma.

The authors have reviewed the results of radioactive plaques in recurrent retinoblastoma after external beam radiation in 34 eyes. They give their results on ocular conservation and on the visual outcome and compare these results with other series previously published. They think radioactive plaques are an alternative to enucleation in recurrent retinoblastoma after external beam.

Brachytherapy↗
PubMed1993

[Pulmonary artery pseudoaneurysm caused by a Swan-Ganz catheter and treated by embolization].

The frequency of life-threatening complications induced by Swan-Ganz catheter is estimated at 2% to 17%. Pseudoaneurysm formation secondary to traumatic injury of the pulmonary artery is rare (0.66% to 2%), but carries a high risk of hemorrhagie. Recognition of possible lesions should be based on clinical data and predisposing factors. Diagnostic and therapeutic investigations should be rapidly performed. Embolization is the best treatment giving very good results. Should acute hemorrhage occur in the operating room, emergency vascular occlusion can be carried out by the use of the Swan-Ganz catheter.

Aged↗
PubMed1993

Adaptive modeling in a mammalian skeletal model system.

Juvenile BALB/c mice were used as a model system to test the effects of various loading and exercise regimens on the growth and development of femora. Six treatments and three controls were used to document changes in geometric, mechanical, and material properties of the femora associated with strength. In each age-matched experiment, body weight and the strength, length, anterior and posterior diameters, cross-sectional area, moments of inertia in the anteroposterior and lateromedial directions, cortical wall thickness, and mineral content of the femora were assessed and found to vary significantly among treatment groups. An adaptive interpretation of these data was provided by calculating Pearson correlation coefficients between moment at failure (one measure of strength) and each geometric, mechanical and material property of the femora that contributes to strength. We make the assumption that at the termination of the experiment the greater the coordination between changes in strength and changes in the parameters that contribute to strength (the greater the number of correlations), the more adaptively modeled the femora are. Adaptive modeling here refers to the manner in which the femora grow and develop (adapt) under a given treatment regimen. Absolute strength of whole femora was reflected by our measure of adaptive modeling in all groups with one exception. In each experiment, the voluntary exercise controls were the most adaptively modeled. The least adaptively modeled groups also showed a general retardation of growth. It appears that juvenile mouse femora demonstrate a wide range of responses to different conditions of loading and exercise and that some of these changes are likely permanent. Moreover, at least two major variables--1) mechanical loading and 2) glucocorticoid mediated psychological stress--appear to contribute to the differences seen between the treatment groups.

Adaptation, Physiological↗
PubMed1992

[Discordant heart xenografts. Experimental study in pigs conditioned by total lymphoid irradiation and cyclosporine A].

The use of discordant xenografts may solve some of donor shortage problems. The beneficial effects of treatment with total lymphoid irradiation (TLI) and classical drugs on this discordant model of transplantation rejection was evaluated. Twenty-four lamb hearts were transplanted heterotopically in the abdomen of 24 pigs. Group I received no treatment (control). Group II received continuous intravenous medical treatment cyclosporin A (CyA) (5 mg/kg) and azathioprine (3 mg/kg) 3 days prior to transplantation. Group III received the same medical treatment and simultaneously 12 grays of irradiation in 5 equal fractions with a high rate (100 cGy/min) or a low rate (1.6 cGy/min) prior to transplantation. Group IV also received 12 grays in 5 fractions at a high rate followed by the medical treatment started 5 days after TLI and continued until the day of transplantation. Antibody and serum cyclosporine levels were monitored. Histology specimen were analyzed at the end of the experiment. Mean GST (graft survival time) in group I and II was 140 +/- 35 min and 117 +/- 27.4 min respectively. The histological features of these hearts suggested acute humoral rejection (hemorrhage, thrombosis, and edema) without cellular infiltration. In group III, one heart functioned 4.5 days with pathological features of cellular rejection and a second animal died at 6 hours with a functioning graft with no evidence of an acute rejection. Both had been treated with the low rate TLI protocol (1.6 cGy/min). The mean GST in this group was 1080 +/- 794 min. In Group IV, one graft functioned for 6.5 days and another for 3.25 days. Mean GST was significantly increased in this group to 4800 +/- 2647 min (p < 0.05). A cellular infiltration was seen in this two grafts. The remaining graft was rejected in 6 hours with histological lesions typical of acute humoral rejection. Antibodies levels at the time of transplantation were lowest (40%) in group IV and in the low rate irradiation group. The ability of TLI to induce tolerance and to prolong survival in a discordant xenograft model depends upon cumulative dose, rate of irradiation, delay between TLI and graft placement, and combined treatment with immunosuppressive drugs. A high rate of TLI and graft placement is delayed. Low rates of irradiation may be beneficial when there is a very short period between treatment and transplantation. These findings highlight the potential usefulness of TLI in combination with immunosuppressive drug therapy when antibody-mediated rejection occurs, such as with xenograft and in sensitized patient.

Animals↗
PubMed1992

Occurrence of Ixodes pacificus (Parasitiformes: Ixodidae) in Arizona.

Adults and immatures of Ixodes pacificus Cooley & Kohls were collected by flagging vegetation and from lizards during a 3-mo period in the Hualapai Mountain Park, Mohave County, AZ, in 1991. Collections were made at altitudes > or = 2,134 m. Two of 48 gut-salivary gland extracts of adult ticks were positive by IFA using a monoclonal antibody (H5332) specific to Borrelia burgdorferi. These are the first records of I. pacificus and of spirochetes tentatively identified as B. burgdorferi in Arizona.

Animals↗
PubMed1992

[Unusual localization of an olfactory esthesioneuroma].

Olfactory neuroblastoma, a nerve tumour arising in the olfactory mucosa, is a relatively easy diagnosis in the case of a mass centered around the cribriform plate. It is more difficult to diagnose in its exceptional ectopic forms (maxillary sinus) in the absence of any cytological and histochemical arguments (fibrils, olfactory rosettes). Its local malignancy is variable with a 42% 5-year survival for stage C and metastases in 30% of cases (principally cervical nodes, bone and liver). The role of imaging is to define the criteria of a mass syndrome and to perform the preoperative staging in a case of apparently simple sinus obstruction.

Brain Neoplasms↗
PubMed1992

[Preoperative embolization of cervical bone metastasis with radio-controlled direct puncture].

Surgery of vertebral hypervascular metastasis can take advantage of preoperative embolization to make the surgical procedure easier to perform. Usually, embolizations are executed by vascular tract. We report a case of one cervical metastasis located in C4 for which embolization was executed with direct puncture of the vertebra. This method has the advantage to be feasible whatever tumoral vascularization, and more particularly in case of departure of radiculo-medullary artery or any other cephalic vessel from the tumoral site.

Biopsy, Needle↗
PubMed1992

[Gardner syndrome: possibility of early detection of carriers by examination of the ocular fundus?].

Through indirect ophthalmoscopic examination it was possible to analyse three families originated from the same Swiss alpine valley (Poschiavo) and carrying Gardner syndrome (SdG) to check if their members with SdG were presenting hypertrophic changes of the retinal epithelium which is supposed to be an early symptom of that syndrome. This lesion was found to be present only in two out of 11 patients (18%) with at least one symptom of SdG. Because of its lacking sensitivity, ophthalmoscopic examination is not able to substitute colonoscopy as a valid screening method to find out which members of a SdG-family are at risk to develop colonic poliposis and cancer.

Chromosome Aberrations↗
PubMed1991

Stage I-II squamous cell carcinoma of the oral cavity treated by iridium-192: is elective neck dissection indicated?

This is a retrospective analysis of 233 evaluable patients with stage I-II squamous cell carcinoma of the oral cavity treated by definitive branchytherapy. Minimum follow-up is 3 years. Treatment of neck was chosen by a multidisciplinary team, according to age, medical status and availability for regular follow-up. One hundred and ten patients (47%) underwent elective neck dissection (END); 28 (25%) had positive nodes and received neck irradiation post-operatively. One hundred and twenty three patients (53%) were regularly followed up only, with therapeutic neck dissection (TND) reserved for cases of node relapses. In the END group, there were 19 neck relapses (17%): 12/60 (20%) in patients with mobile tongue carcinoma and 7/50 (14%) in patients with floor of the mouth carcinoma. Salvage treatment was successful in 9/19 (47%) cases. In the TND group, there were 21 neck relapses (17%): 16/82 (20%) in patients with mobile tongue carcinoma and 5/41 (10%) in patients with floor of the mouth carcinoma. Salvage treatment was successful in 13/21 (62%) cases. Ten-year survival is 37% for the END group and 31% for the TND group. Tumour stage and infiltration into underlying tissues increased the probability of neck relapse and death. Furthermore, a multivariate analysis showed that patients treated in the TND group had a higher probability of death than patients treated in the END group (p less than 0.04).

Adult↗