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Biomedical subjects

E Nagel

Publications and source records attributed to E Nagel.

131 records · Page 8Linked to original sources

Retinal vessel reaction to short-term IOP elevation in ocular hypertensive and glaucoma patients.

PURPOSE: Regulation of ocular blood flow might be impaired in glaucoma patients. We compared the reaction of retinal vessels to a short-term increase of intraocular pressure (IOP), using a retinal vessel analyzer (RVA), in normal volunteers, ocular hypertensive patients (OH) and primary open angle glaucoma patients (POAG). METHODS: Ten healthy subjects (56+/-8 years, IOP 13.7+/-1.6 mmHg), 10 OH patients (55+/-12 years, IOD 23.4+/-4.1 mmHg) and 11 POAG patients (60+/-11 years, IOP 23.3+/-1.95 mmHg) were evaluated. Arterial and venous retinal vessel diameter was measured continuously before, during and after raising IOP to suprasystolic values by the suction cup method, described as ocular oscillo-dynamography. RESULTS: The change in vessel diameter after the IOP rise differed in its temporal sequence and in absolute values depending on the group examined. In the retinal branch veins the reduction of vessel diameter during the IOP rise was significantly different in POAG (0%+/-6.7) and volunteers (-6.7%+/-8.5; p = 0.06) and in POAG and OH (-6.7%+/-7.0; p = 0.04). At 70-130 sec after IOP increase a dilatation occurred, again differing significantly in POAG (+5.8%+/-3.9) and volunteers (+9.7%+/-4.3; p = 0.03). Systemic blood pressure did not show any significant differences between groups or during the course of the examination. DISCUSSION: At short-term rise in IOP leads to less retinal vessel reaction in POAG patients than in volunteers and OH. This might be due to impaired autoregulation to ocular perfusion changes in POAG patients.

Blood Flow Velocity↗

Blood pressure effects on retinal vessel diameter and flicker response: a 1.5-year follow-up.

PURPOSE: The study examined the influence of individual blood pressure changes overtime on retinal vessel diameter and the latter's response to flicker light. METHODS: The diameter of a retinal arterial and venous segment was measured continuously on-line with a Dynamic Vessel Analyzer in 20 patients twice (mean interval between examinations of 24 months). Eleven patients had no cardiovascular disease. Nine patients had arterial hypertension and were untreated at the time of the first measurement; at the time of the second measurement they were undergoing various antihypertensive therapies. Each test consisted of a 50-s baseline plus three 20-s periods of flicker stimulation followed by an 80-s period of observation. During the examinations the blood pressure was measured at 1-minute intervals. RESULTS: In the hypertension group changes in the mean arterial blood pressure (MAP) correlated significantly with changes in the arterial baseline diameter (y = -0.1 - 0.37x, r =0.74, p (increase) <0.03). A comparison of the two measurements showed no such relationship in the group of cardiovascularly healthy subjects. The venous baseline and the arterial and venous flicker response did not change significantly in either group between the two measurements and showed no relationship to blood pressure changes. CONCLUSIONS: In hypertensive subjects, long-term therapy-related changes in blood pressure induced a change in the arterial baseline by approximately +3.7 microm/-10 mmHg MAP. An influence of lowering MAP to the arterial flicker response could not be detected.

Antihypertensive Agents↗

DNA aneuploidy by flow cytometry is an independent prognostic factor in squamous cell carcinoma of the oral cavity.

BACKGROUND: The clinical significance of flow cytometric DNA content in head and neck squamous cell carcinoma is still controversial. PATIENTS AND METHODS: We prospectively investigated the prognostic importance of tumor size (T), lymph node involvement at presentation (N), degree of histologic differentiation (G) and DNA ploidy (DNA) in 429 surgically treated patients with primary oral squamous cell carcinoma using multivariate statistics. RESULTS: T, G and DNA were independent predictors of metastasis to the neck. N and DNA were independent prognostic factors of loco-regional recurrence development. N and T were prognostic of overall survival. N and DNA were predictive of recurrence-free survival. For the neck negative group, DNA remained as the only predictor of overall and relapse-free survival. CONCLUSION: DNA flow cytometry adds significant prognostic information beyond that provided by established prognostic factors.

Analysis of Variance↗