Biomedical subjects

Cristina Stan

Publications and source records attributed to Cristina Stan.

9 recordsLinked to original sources

PubMed2006

[Hyperpneumatization of sphenoid sinus--a possible etiology of posterior optic neuropathy].

We take in debate a rare cause of compressive retrobulbar optic neuropathy. We present three patients with bilateral retrobulbar optic neuropathy in which these could not be found any other cause, but the hyperpneumatization of sphenoid sinus. We emphasize the role of cranial computer tomography in the diagnosis of this disease and the necessity to keep in mind this possible etiology of posterior optic neuropathy.

Adrenal Cortex Hormones↗

PubMed2006

[Choroidal hemangioma and epiretinal membrane].

Choroidal hemangiomas are benign vascular hamartomas developed from birth, but undetected until the 4th and 5th decade. They have been seldom described in association with epiretinal membranes. Here we present a patient with associated pathology choroidal hemangioma with atypical fluorescein angiography pattern, undetected on ocular echography hence the difficulties in establishing a positive diagnosis and epiretinal membrane observed both clinically and on fluorescein angiography. Visual acuity is impaired by cystoid macular edema, with a complicated pathogenetic mechanism.

Choroid Neoplasms↗

PubMed2005

[Bilateral malignant glaucoma--case report].

Patient hospitalized for angle closure glaucoma in right eye underwent trabeculectomies in both eyes. In the right eye, six months after surgery, he presented intraocular hypertension, shallow anterior chamber and cataract, considered to be intumescent cataract. The left eye (operated six months after the right eye) showed same signs two weeks after surgery. Diagnosis was malignant glaucoma in spite of missing of ultrasound signs- pooling of aqueous in vitreous body. Note the relapse episodes of intraocular hypertension, shallow anterior chamber in left eye, with complete resolution after cicloplegics-mydratics drops only.

Adult↗

PubMed2005

[Posterior scleritis--diagnostic difficulties--a case report].

We present a patient with pain and trouble vision in her right eye, we want to show how difficult it is to diagnose a posterior scleritis before any complication might occur. Diagnosis was established by ocular ultrasound. Treatment included steroids for several months.

Adrenal Cortex Hormones↗

PubMed2004

Dynamic control by sinusoidal perturbation and by Gaussian noise of a system of two nonlinear oscillators: computation and experimental results.

In this paper we report numerical and experimental studies of the dynamic control of the inter-anode plasma of a double electrical discharge and of a system of two coupled nonlinear oscillators modeling this plasma. We compare the transition between chaotic dynamics and periodic dynamics induced by a sinusoidal perturbation and by small-dispersion Gaussian noise. Besides considerable differences between the effect of the two types of perturbation we also find important similarities. For small amplitude, both the sinusoidal and the white noise perturbations can induce the system to change from chaotic to regular dynamics. In the case of sinusoidal perturbation, the transition time from the chaotic to regular state has a definite duration that depends on the values of the perturbation parameters. The suppression of the perturbation has no influence on the state - the system remains in the same regular state. Subsequent reinstatement of the same type of perturbation with the same amplitude does not change the periodic state of the system but, for considerably higher amplitude, the system is switched back to its chaotic state. For moderate-amplitude sinusoidal perturbation, intermittent transitions between the chaotic and regular states is observed. Most of these predictions of the model have been observed experimentally in a system of two coupled electrical discharges. Our results suggest practical methods that can be used for controlling the discharge plasma dynamics.

Journal Article↗

PubMed2002

Control of chaos by random noise in a system of two coupled perturbed van der Pol oscillators modeling an electrical discharge plasma.

The control of chaos in nonlinear systems by different methods is still a high interest topic particularly when this is achieved by random noise as in this work. The change of chaotic dynamics into periodic dynamics induced by random noise in a system of two coupled perturbed van der Pol oscillators and comparison with the experimentally observed behavior of a double discharge plasma that it models is presented. Methods specific to nonlinear analysis such as phase portraits, Lyapunov exponents, and Fourier spectra are used to demonstrate the changeover from chaotic to regular dynamics induced by random noise. A phase diagram determines the range of noise parameters corresponding to the lowest orders of an observed bifurcation sequence of 3 x 2(n) type and particulars of the transitions are presented.

Journal Article↗

PubMed2002

[Orbital teratoma- tooth in the orbit. Case report].

A case with orbital dermoid adherent to a tooth in the frontal bone is discussed. The X-ray exam showed dental abnormalities in the same patient. Because of the presence of true bone we considered the correct diagnosis is orbital teratoma.

Adult↗

PubMed2002

[Trigeminal neuropathy, diagnostic and treatment problems].

AIM OF THE STUDY: Clinical evaluation of patients with the diagnosis of Sturge-Weber syndrome (encephalotrigeminal angiomathosis) for establishing an accurate diagnosis and therapy. MATERIAL AND METHOD: The paper presents 5 cases of encephalotrigeminal angiomathosis (4 of them associating glaucoma) admitted in our clinic in the last 5 years, pointing out the peculiarities concerning the clinical, diagnostic, therapeutically aspects and outcome. RESULTS: The analysis of our cases showed that glaucoma does not correlate with the extension of skin lesion (nevus flammeus). The outcome of glaucoma's therapy is dictated by the adjustment of the therapy to the type of glaucoma. CONCLUSION: Glaucoma associated with the Sturge-Weber syndrome has always proved to be a therapeutic challenge and remains one of the causes of increased intraocular pressure, difficult to control. The management of glaucoma in Sturge-Weber syndrome includes surgical and drug therapy. These patients need long-term follow-up from the clinical and imagistic point of vue.

Adolescent↗

PubMed2002

[Is atropine efficient in para-bulbar injections?].

Supposing the fact that atropine has antispastic effect on blood vessels, we studied the variation of blood flow in ophthalmic artery, central retinal artery and ciliary arteries, by Doppler ultrasound. We used 1 ml Atropine 1@1000 in parabulbar administration to 17 eyes with neuro-retinal diseases and the arterial flow was registered for 3 times: before the injection, at 15 and respective 30 minutes after administration. The results were processed using t-Student method. The atropine effect seemed to be more intensive 30 minutes after administration on central retinal artery.

Atropine↗