[Acute progressive primary chronic osteomyelitis in the mandibular bone in childhood - A case report].

Inflammation of bone is caused either by bacterial infection or occasionally by physical stimulus. Primary chronic osteomyelitis of mandibular bone is a chronic inflammation of an unknown cause. Pain, swelling, limited mouth opening, regional lymphadenopathy and hypaesthesia are clinical symptoms at initial presentation.

A novel three-dimensional bone chip organ culture.

Objectives: The objective of this study was to develop a 3D bone chip organ culture model. We aimed to collect in vitro evidence of the ability of vital bone chips to promote new bone formation.

Materials And Methods: We developed a 3D in vitro hypoxic bone chip organ culture model.

Comparison of choroidal and optic nerve head blood flow regulation during changes in ocular perfusion pressure.

Purpose: We compared the response of choroidal and optic nerve head blood flow (ChBF, ONHBF) in response to an increase in ocular perfusion pressure (OPP) during isometric exercise and during a decrease in OPP during an artificial increase in intraocular pressure (IOP).

Methods: We included 96 healthy subjects in our study. In 48 subjects OPP was increased by 6 minutes of squatting, and either ONHBF (n = 24) or ChBF (n = 24) was measured continuously.

Effect of nifedipine on choroidal blood flow regulation during isometric exercise.

Purpose: To determine whether nifedipine, an L-type calcium channel blocker, alters choroidal blood flow (ChBF) regulation during isometric exercise in healthy subjects.

Methods: The study was carried out in a randomized, placebo-controlled, double-masked, two-way crossover design. Fifteen healthy male subjects were randomly assigned to receive either placebo or nifedipine on two different study days.

Retinal blood flow in type 1 diabetic patients with no or mild diabetic retinopathy during euglycemic clamp.

Objective: To compare total retinal blood flow in diabetic patients with no or mild nonproliferative diabetic retinopathy and healthy control subjects and to investigate in patients whether there is a difference between retinal blood flow before morning insulin and under normoglycemic conditions using a glucose clamp.

Research Design And Methods: Twenty patients with type 1 diabetes with no or mild diabetic retinopathy were included in this open parallel-group study, and 20 healthy age- and sex-matched subjects were included as control subjects. Retinal blood flow was assessed by combining velocity measurements using laser Doppler velocimetry and diameter measurements using a commercially available dynamic vessel analyzer.

Effects of antioxidants (AREDS medication) on ocular blood flow and endothelial function in an endotoxin-induced model of oxidative stress in humans.

Purpose: The Age-Related Eye Disease Study (AREDS) has shown that supplementation of antioxidants slows the progression of age-related macular degeneration (AMD). The mechanism underlying this therapeutic effect may be related to a reduction of reactive oxygen species (ROS). The authors have recently introduced a model showing that the response of retinal blood flow (RBF) to hyperoxia is diminished by administration of lipopolysaccharide (LPS).

Ocular haemodynamic changes after single treatment with photodynamic therapy assessed with non-invasive techniques.

Purpose: To investigate in patients with neovascular age-related macular degeneration (ARMD) the changes in ocular perfusion caused by single treatment with photodynamic therapy (PDT) by different non-invasive methods; to evaluate correlations between relative changes of ocular haemodynamic parameters after PDT among each other and compared to morphological parameters; and to assess this in relation to early changes of visual acuity.

Study Population: 17 consecutive patients with subfoveal choroidal neovascularization (CNV) caused by ARMD scheduled for PDT without previous PDT treatment (four patients with predominantly classic CNV and 13 patients with occult CNV).

Observation Procedures: best-corrected visual acuity (before PDT, 6 and 8 weeks after PDT), fundus photography, fluorescein angiography, haemodynamic measurements with laser Doppler flowmetry (LDF), laser interferometry and ocular blood flow (OBF) tonometry (baseline and 1, 2, 6 and 8 weeks after treatment).

Role of NO in the control of choroidal blood flow during a decrease in ocular perfusion pressure.

Purpose: The study was conducted to investigate whether the L-arginine/nitric oxide system plays a role in choroidal blood flow (ChBF) regulation during a decrease in ocular perfusion pressure (OPP).

Methods: Experiments were performed on 3 days in a randomized double-masked, placebo-controlled, three-way crossover design. On different study days, subjects received intravenous infusions of N(G)-monomethyl-L-arginine (L-NMMA), phenylephrine, or placebo.

Twelve-hour reproducibility of retinal and optic nerve blood flow parameters in healthy individuals.

Purpose: The aim of the present study was to investigate the reproducibility and potential diurnal variation of optic nerve head and retinal blood flow parameters in healthy individuals over a period of 12 hr.

Methods: We measured optic nerve head and retinal blood flow parameters in 16 healthy male non-smoking individuals at five time-points during the day (08:00, 11:00, 14:00, 17:00 and 20:00 hr). Outcome parameters were perimacular white blood cell flux (as assessed with the blue field entoptic technique), blood velocities in retinal veins (as assessed with bi-directional laser Doppler velocimetry), retinal arterial and venous diameters (as assessed with the retinal vessel analyser), optic nerve head blood flow, volume and velocity (as assessed with single point and scanning laser Doppler flowmetry) and blood velocities in the central retinal artery (as assessed with colour Doppler imaging).

Reactivity of retinal blood flow to 100% oxygen breathing after lipopolysaccharide administration in healthy subjects.

Administration of low doses of Escherichia coli endotoxin (LPS) to humans enables the study of inflammatory mechanisms. The purpose of the present study was to investigate the retinal vascular reactivity after LPS infusion. In a randomized placebo-controlled cross-over study, 18 healthy male volunteers received 20 IU/kg LPS or placebo as an intravenous bolus infusion.

Multifocal electroretinographical changes in monkeys with experimental ocular hypertension: a longitudinal study.

Purpose: To study the time course of changes in the multifocal electroretinograms (mfERG) in monkeys with experimental ocular hypertension (OHT).

Methods: The mfERGs were recorded in 12 eyes out of 6 monkeys. Two baseline measurements were used to quantify the reproducibility, the inter-ocular and the inter-individual variability of the ERG signals.

Regulation of choroidal blood flow during combined changes in intraocular pressure and arterial blood pressure.

Purpose: To test the hypothesis that human choroidal blood flow (ChBF) may depend, not only on ocular perfusion pressure (OPP), but also on absolute mean arterial pressure (MAP) and intraocular pressure (IOP).

Methods: There were two study days in an open design. On the first day, OPP was varied by elevating IOP during a squatting-induced increase in MAP (28 subjects).

Choroidal microcirculation in patients with rotary cardiac assist device.

Background: In recent years, fully implanted rotary blood pumps have been used for long-term cardiac assist in patients with end-stage heart failure. With these pumps, the pulsatility of arterial blood flow and arterial pressure pulse is considerably reduced. Effects on end-organ perfusion, particularly microcirculation, have been assessed.

C-peptide does not affect ocular blood flow in patients with type 1 diabetes.

Objective: The aim of the present study was to investigate the effect of intravenous C-peptide infusion on ocular blood flow in patients with type 1 diabetes under euglycemic conditions.

Research Design And Methods: The study was performed in a randomized, placebo-controlled, double-masked, two-way, crossover design in 10 type 1 diabetic patients. C-peptide was intravenously administered at two different dosages (dosage 1: 25 pmol .

Influence of infusion volume on the ocular hemodynamic effects of peribulbar anesthesia.

Purpose: To test the hypothesis that ocular blood-flow response to peribulbar anesthesia can be reduced by using a smaller volume of anesthetic mixture.

Setting: Departments of Ophthalmology and Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.

Methods: Twenty patients scheduled for bilateral age-related cataract surgery were enrolled in a prospective randomized balanced observer-masked crossover study.

Choroidal hemodynamic changes during isometric exercise in patients with inactive central serous chorioretinopathy.

Purpose: Imaging studies suggest that the choroidal vasculature may be altered in central serous chorioretinopathy. Little is known, however, about the regulation of ocular blood flow in patients with central serous chorioretinopathy (CSC). The hypothesis for the present study was that choroidal blood flow changes during an increase in ocular perfusion pressure induced by isometric exercise may be altered in CSC.

Comparison of the autoregulatory mechanisms between middle cerebral artery and ophthalmic artery after thigh cuff deflation in healthy subjects.

Purpose: To compare dynamic autoregulation in the middle cerebral artery (MCA) and the ophthalmic artery (OA) after a step decrease in systemic blood pressure.

Methods: Eighteen healthy male young subjects were studied. Ultrasound parameters and systemic blood pressures were recorded in each subject before, during, and after a step decrease in blood pressure.

Influence of exercise induced hyperlactatemia on retinal blood flow during normo- and hyperglycemia.

Purpose: Short term hyperglycemia has previously been shown to induce a blood flow increase in the retina. The mechanism behind this effect is poorly understood. We set out to investigate whether exercise-induced hyperlactatemia may alter the response of retinal blood flow to hyperglycemia.

Specific endothelin ET(A) receptor antagonism does not modulate insulin-induced hemodynamic effects in the human kidney, eye, or forearm.

There is evidence that hyperinsulinemia may stimulate endothelin-1 (ET-1) generation or release, which may affect diabetic vascular complications. BQ-123, a specific ET(A) receptor antagonist, was used to investigate if insulin-induced vascular effects are influenced by an acute ET-1 release. Two randomized, placebo-controlled, double-blind, cross-over studies were performed.

Topical fundus pulsation measurement in patients with active central serous chorioretinopathy.

Objective: To determine regional pulsatile choroidal blood flow using laser interferometry in patients with active central serous chorioretinopathy (CSC).

Method: The study compared an equally sized age-, sex-, and refractive error-matched control group of healthy volunteers obtained from the Department of Clinical Pharmacology with 18 consecutive patients who had newly diagnosed active, unilateral CSC obtained from the University of Vienna Eye Clinic, Vienna, Austria.

Main Outcome Measures: Regional fundus pulsation amplitude as assessed using laser interferometry.

Effects of adenosine on intraocular pressure, optic nerve head blood flow, and choroidal blood flow in healthy humans.

Purpose: There is evidence from a variety of animal studies that the adenosine system plays a role in the control of intraocular pressure (IOP) and ocular blood flow. However, human data on the effect of adenosine on IOP and choroidal and optic nerve blood flow are not available.

Methods: The effect of stepwise increases in doses of adenosine (10, 20, and 40 micro g/kg per minute, 30 minutes per infusion step) on optic nerve head blood flow, choroidal blood flow, and IOP was determined in a placebo-controlled double-masked clinical trial in 12 healthy male volunteers.

Calculation of the diameter of the central retinal artery from noninvasive measurements in humans.

Purpose: The aim of the present study was to calculate the diameter of the central retinal artery from results as obtained with non-invasive techniques in healthy young subjects.

Methods: Twenty-four healthy male subjects participated in this study. Total retinal blood flow was calculated from combined bi-directional laser Doppler velocimetry and measurement of retinal venous diameters using the Zeiss retinal vessel analyzer.

Nitric oxide regulates retinal vascular tone in humans.

The purpose of the present study was to investigate the contribution of basal nitric oxide (NO) on retinal vascular tone in humans. In addition, we set out to elucidate the role of NO in flicker-induced retinal vasodilation in humans. Twelve healthy young subjects were studied in a three-way crossover design.