Electrophysiological changes in optic neuropathy of streptozotocin induced diabetic rats.

UNLABELLED: The visually evoked potentials are electrical signals generated by the occipital cortex due to electrical stimulus. The clinical importance of VEP is to diagnose the functional changes of the optic nerve in different diseases such as diabetic mellitus. Our study sought latency of VEP changes depending on glycemic value and duration of diabetes in Wistar rats. METHODS: this study evaluated the VEP of 25 rats in three groups: control group, diabetic group 1 with glycemic values between 200-400mg/dl and diabetic group 2 with glycemic values between 400 and 600mg/dl. These rats from diabetic group 2 were followed for 4 months and the ones in control group and diabetic group 1 for 5 months. RESULTS: the latency of VEP shows slight changes without any statistical significance in the control group. In diabetic group 1 and 2 similar changes occurred, with statistical significance and the amplitude of the changes was proportional with the glycemic value. The rats had a rapid increase of VEP latency after the induction of diabetes and returned to a normal range in the first month. After a time, when the latencies of VEP were in normal range, a new growth appeared faster and larger as the glycemic values were higher. CONCLUSION: diabetes brings changes to the visual signal transmission and to the central processing, this being revealed by the examination of the visually evoked potential. Increased VEP latency is statistically correlated with the changes that occur at the level of the values of glucose in blood. A rapid growth in blood sugar lowers the visual signal transmission. This change is temporary despite the persistence of elevated blood glucose values, probably by adjusting to the new condition. However, maintaining high glycemic values remotely produces a progressive increase of the delay of the visual signal. This progressive increase is faster as blood glucose levels are higher.

Analysis of the visual evoked potential in anesthesia with sevoflurane and chloral hydrate : (Variability of amplitudes, latencies and morphology of VEP with the depth of anesthesia).

UNLABELLED: The visually evoked potential (VEP) is an electrical signal generated by the occipital cortex in response to light stimulation of the retina. The clinical importance of the VEP consists in the diagnosis of optic nerve diseases and others ocular diseases. For experimental studies of VEP in experimental animals anesthesia is frequently required. Our study sought VEP changes depending on the type and depth of anesthesia. METHODS: this study evaluated VEPs in 20 Wistar rats under two anesthetics. Ten rats were anesthetized with sevoflurane and ten rats with chloral hydrate. RESULTS: The amplitudes, latencies and morphology of the VEP varied with the depth of anesthesia. The latency of VEP increases with the depth of anesthesia and the amplitude of the waves becomes more positive once the anesthesia decreases under sevoflurane and more negative under chloral hydrate. The variability of VEP was different under the two anesthetics with greater peak latencies under sevoflurane than under chloral hydrate at the same depth of anesthesia. IN CONCLUSION: it is important to know the influence of the anesthetic and the depth of anesthesia over VEPS, because they may constitute a confounding factor in studying VEP in different diseases of optic nerve or eyeball.

Videocapsule endoscopy and single balloon enteroscopy: novel diagnostic techniques in small bowel pathology.

Videocapsule endoscopic (VCE) exploration represents a major breakthrough in non-invasive imagistic, especially of the small bowel. Our study group consisted of 29 initial subjects admitted in the 1st Internal Medicine and Gastroenterology Clinic at the Emergency County Hospital of Craiova between June 2008 and March 2009. We have excluded a number of eight subjects from the VCE-group, as their pathology represented an absolute contraindication for capsule ingestion. The remaining 21 patients (11 men - 52.38% vs. 10 women - 47.61%) underwent videocapsule diagnostic investigation followed by single balloon enteroscopy with biopsy or surgical removal, where case. Large resection cups were histologically prepared in the Pathology Department of the Emergency County Hospital of Craiova. We performed a statistical analysis of the data using Fisher's Exact Test, which is applicable to small numbered lots. In five cases (23.80%) VCE investigation did not reveal any abnormalities. Five (23.80%) cases had non-tumoral pathology, all of them being inflammatory lesions. We found tumoral lesions in 11 (52.38%) cases: five (23.80%) benign and six (28.57%) malign. We found that inflammatory lesions predominantly affected subjects in the 15-30 and 30-45 years intervals (p=0.00103), whereas tumoral lesions are positively correlated with old age, predominantly affecting the 45-60 and above 60-year-old groups (p=0.00216). VCE combined with SBE open new frontiers for small bowel exploration. Histology remains the single most accurate test for establishing the nature of a lesion.