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Biomedical subjects

A Fryczkowski

Publications and source records attributed to A Fryczkowski.

At least 19 recordsLinked to original sources
PubMed1994

Rate of antigen entry into the circulation in experimental versus naturally occurring immune complex glomerulonephritis.

This study tested the hypothesis that the rate of antigen entry into the circulation in systemic lupus erythematosus (SLE), a naturally occurring immune complex glomerulonephritis (IC-GN), is slow compared with that of traditional experimental models of IC-GN, in which the antigen is delivered rapidly as a daily iv bolus. This hypothesis was tested by comparing rates of decline of the third component of complement (C3) and of circulating neutrophils (PMN) in SLE patients with active disease with those of cynomolgus monkeys (CYN) undergoing induction of experimental IC-GN by means of a daily bolus infusion of antigen. It has previously been shown that, as antigen enters the circulation and forms circulating IC, C3 levels and circulating PMN decline acutely. Thus, acute changes in these parameters can be surrogates for the rate of antigen entry into the circulation. In the CYN undergoing induction of IC-GN (N = 11), infusion of the antigen (bovine gamma-globulin) over 10 min resulted in acute declines in C3 levels (25 +/- 6.6%; P = 0.0018 and PMN counts (59 +/- 9%; P < 0.0002). In addition, the CYN experienced the onset of acute respiratory distress and hypotension. By contrast, in patients with active SLE (N = 9), C3 and white blood cell counts measured at 24-h intervals did not change significantly, and episodes of acute hypotension or respiratory distress were not observed. In the CYN, the onset of visible vasculitic lesions in the omentum were also documented within minutes of the infusion of bovine gamma-globulin. The rapidity of onset of these vascular lesions suggests that the tempo at which lesions develop in experimental models of IC disease is faster than that of naturally occurring IC diseases. It was concluded that, in naturally occurring IC diseases, antigen probably enters the circulation slowly over prolonged periods of time, rather than as large boluses over short periods of time, as in traditional experimental models of IC-GN. Thus, models of IC-GN involving a daily bolus infusion of antigen may not be clinically relevant, particularly when IC clearing mechanisms are tested, because the efficiency of these mechanisms may be markedly influenced by the rate at which IC form in the circulation.

Animals↗
PubMed1990

Hibiclens keratopathy. A clinicopathologic case report.

A 39-year-old woman developed a painful, red eye immediately following oral surgery associated with preoperative preparation of her face with the antiseptic, Hibiclens. Epithelial and stromal edema was observed 2 weeks after surgery and progressed to diffuse bullous keratopathy. This led to penetrating keratoplasty 10 months later. Light and electron microscopic findings of the cornea included epithelial edema with bullous changes, marked loss of keratocytes, a thickened Descemet's membrane, and an attenuated, disrupted endothelial cell layer. These findings demonstrate the corneal damage that may occur following ocular exposure to Hibiclens.

Adult↗
PubMed1989

Dose-dependent effects of epidermal growth factor on corneal wound healing.

The dose-dependent effect of epidermal growth factor (EGF) on the development of wound tensile strength following full-thickness corneal wounds was evaluated in 60 adult rabbits. One eye from each rabbit received a single 7-mm long corneal incision. After injury each rabbit was treated three times daily for 5 or 10 days with either EGF at 0.001 mg/ml (10 eyes), 0.01 mg/ml (10 eyes), 0.1 mg/ml (10 eyes), 1.0 mg/ml (15 eyes), or vehicle (15 eyes). The tensile strength of the wound was evaluated using a 5-mm wide strip of cornea mounted on a tensiometer. We found that EGF at 0.1 mg/ml and at 0.01 mg/ml increased wound strength by 100% at 5 days and by 60% at 10 days (P less than 0.05 and P less than 0.05). However, EGF at 0.001 mg/ml and 1.0 mg/ml appeared to have no effect on wound strength. Histologic examination of full-thickness wounds in a separate series showed an increase in wound fibroblastic response and a diminished fibrin clot at 5 days in rabbits treated with 0.1 mg/ml and 0.01 mg/ml. We conclude that EGF enhances the wound strength of full-thickness corneal wounds in a dose-dependent manner which may be explained in part by an increased fibroblastic response. Concentrations of EGF greater or less than an optimal dose may be less effective in enhancing corneal wound strength.

Administration, Topical↗
PubMed1983

Refractive corneal surgery: the use of implantable alloplastic lens material.

A basic problem encountered in all forms of lamellar refractive surgery has been the predictability of the optical corrections. Corneal tissue used in refractive surgery behaves in a variable fashion because its shape is determined in vivo by the process of healing and graft repopulation. Therefore no preoperative measure of the ultimate power of the lathed corneal lens can be made. Another drawback is the limited supply of donor corneal tissue. In an effort to overcome these problems, we have used alloplastic materials in conjunction with lamellar refractive surgery to improve the predictability of the result. The use of this material would also allow accurate preoperative determination of lens power. Intralamellar implants appeared to heal quite rapidly after surgery. Their optical clarity was excellent and the corneal surface appeared stable. Further research into long-term stability and predictability are currently underway.

Animals↗
PubMed1982

Functional importance of central retinal artery anastomoses in the anterior part of the optic nerve.

A three-dimensional study showed the existence of three vascular networks in the optic nerve: a peripheral, a periaxial and an axial one. The axial network, which was seen in 30% of the specimens, was formed by ramifying collateral branches from the pia mater of the optic nerve, but in the anterior part of the optic nerve there was an axial system which entirely depended on branches of the central retinal artery. This artery had important anastomoses with branches originating from the pia mater of the optic nerve and other collateral branches originating from the ophthalmic artery and its branches (the ciliary system).

Adolescent↗
PubMed1978

The blood supply of the optic nerve.

The central retinal artery gives, throughout its length, branches, which, in 85% of the cases, supply the anterior segment of the optic nerve. These branches anastomose with collateral branches of the ophthalmic artery, vessels of the pia mater and recurrent branches of the Zinn-Haller circle. The contribute to form the peripheral, periaxial and axial vascular meshwork of the optic nerve. In this series no specific artery of the optic nerve was found, but in 45% of the cases there was an axial vascular meshwork.

Adult↗
PubMed1977

Microcirculation of the anterior part of the optic nerve.

In 85% of the cases the central retinal artery gives off branches for the blood supply of the optic nerve. In this series of 35 optic nerves no central optic nerve artery was found, but frequently and axial vascular system, formed by branches of the central retinal artery was observed. In the region of the lamina cribrosa the central retinal artery gives no important branches.

Adult↗
PubMed1976

[Internal carotid artery occlusion - clinical-morphological correlations].

An attempt has been made by the authors to find correlations between the collateral circulation and clinical condition in thirty-three patients suffering from occlusions of the internal and common carotid arteries. It has been found that the course of disease will be less severe when a collateral circulation is developed; also, this results in late consequences being much less severe in character. The age and general condition of the patient were found to be of major importance to the course of disease. Patients of advanced age usually do not show any appreciable improvement even in those cases where a collateral circulation has developed. Anatomical examinations showed that there existed a large number of collateral circulations between the external carotid artery and the branches of the ophthalmic artery. Playing the most important role among these branches of the external carotid artery are the maxillary and facial arteries. This has also been confirmed by the results of angiographic examinations made in vivo. Also described in this paper are rare cases of development of collateral circulations which were reported in the literature and which may be considered as contributing to the compensation of conditions characterized by the occlusion of the internal carotid artery.

Adolescent↗