Quantification of ocular surface microcirculation by computer assisted video microscopy and diffuse reflectance spectroscopy.

In piglets we tested the applicability of digital video microscopy and diffuse reflectance spectroscopy for non-invasive assessments of limbal and bulbar conjunctival microcirculation. A priori we postulated that the metabolic rate is higher in limbal as compared to bulbar conjunctiva, and that this difference is reflected in microvascular structure or function between the two locations. Two study sites, Oslo University Hospital (OUH), Norway and Cleveland Clinic (CC), USA, used the same video microscopy and spectroscopy techniques to record limbal and bulbar microcirculation in sleeping piglets.

Acute skin trauma induces hyperemia, but superficial papillary nutritive perfusion remains unchanged.

Objectives: Superficial skin papillary capillaries with blood supply from a superficial vascular plexus and regulated by local metabolic needs supply oxygen and nutrients for epithelial cell proliferation. A deep vascular plexus regulated by autonomous nerves serves body thermoregulation. In healthy volunteers, we assessed circulatory effects of a standardized skin trauma by CAVM, DRS, and LDPM to assess the measuring depth of the three techniques and to describe the acute trauma effects on nutritive and thermoregulatory perfusion.

Effect of Surgical Technique on Corneal Implant Performance.

Purpose: Our aim was to determine the effect of a surgical technique on biomaterial implant performance, specifically graft retention.

Methods: Twelve mini pigs were implanted with cell-free, 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS) cross-linked recombinant human collagen type III (RHCIII) hydrogels as substitutes for donor corneal allografts using overlying sutures with or without human amniotic membrane (HAM) versus interrupted sutures with HAM. The effects of the retention method were compared as well as the effects of collagen concentration (13.

Skin microvascular morphology and hemodynamics during treatment with veno-arterial extra-corporeal membrane oxygenation.

Objectives: To explore the potentials of microcirculatory assessments for predicting outcome of patients treated with extra corporeal membrane oxygenation for cardiogenic shock.

Methods: Eight patients with acute cardiogenic shock treated with ECMO and eight healthy controls were examined with skin vital microscopy and laser Doppler perfusion measurements.

Results: Three patients died on ECMO (group 1).

Alpha-smooth muscle actin expression in rat and mouse mesenteric wounds after transforming growth factor-beta1 treatment.

Rat mesenteric perforations heal by contraction within 5 to 7 days, whereas mouse mesenteric perforations seldom close within 3 weeks unless stimulated by transforming growth factor-beta1. In this article, we quantified the expression of alpha-smooth muscle actin by quantitative-reverse transcription-polymerase chain reaction and the orientation of actin filaments at the wound margin by Fourier transformation image analysis after treatment with transforming growth factor-beta1. The expression of transforming growth factor-beta1 and its type II receptor was also assessed.

A note on the compartmental analysis and related issues in laser Doppler flowmetry.

Compartmental analysis (CA) in laser Doppler flowmetry (LDF) means deciphering the nutritional and thermoregulating flows from the measured perfusion flux. Based on the new theories proposed in [1] and [2], the CA is formulated here as an optimal approximation without directly involving the geometric information of the vessel network. It is seen that this approximation approach could also solve the biological zero (BZ) problem simultaneously, therefore, it actually provides a systematic solution to the BZ problem without estimating the BZ flux experimentally.

A mathematical analysis on the biological zero problem in laser Doppler flowmetry.

The biological zero (BZ) problem is a critical issue inherent in laser Doppler flowmetry (LDF). It causes confusion when measuring low tissue blood flows. Many experimental studies have been done on the question of whether the BZ flux should be subtracted from the normally measured flux in various situations.

Actin fiber orientation in connective tissue contraction: a quantitative study with the perforated rat mesentery model.

Numerous fibroblasts with long cytoplasmic protrusions containing F-actin appear during closure by contraction of rat mesenteric perforations. These protrusions are predominantly arranged parallel to the wound margin. In the present study, the spatial and temporal organization of such protrusions was quantitated during normal and retarded healing in zinc-deficient animals.