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Biomedical subjects

T Tervo

Publications and source records attributed to T Tervo.

At least 91 records · Page 5Linked to original sources
PubMed1990

Plasmin and epidermal growth factor in the tear fluid of contact-lens wearers: effect of wearing different types of contact lenses and association with clinical findings.

The concentrations of plasmin and epidermal growth factor were determined in tear fluid (TF) samples from wearers of different types of contact lenses (CLs) during and after cessation of CL wear (CLW). TF samples of 50 healthy eyes served as controls. The plasmin concentrations in the control group (0.4 +/- 0.1 microgram/ml; mean +/- SEM) were significantly lower (p less than 0.001) than in the group of soft CL (SCL) wearers during CLW (1.2 +/- 0.2 microgram/ml). Cessation of CLW led to a decrease in TF plasmin concentrations from 1.2 +/- 0.2 to 0.6 +/- 0.1 micrograms/ml in the group of SCL wearers (p less than 0.001), from 1.5 +/- 1.1 to 0.3 +/- 0.2 micrograms/ml in the group of extended-wear SCL wearers (p greater than 0.05) and from 0.4 +/- 0.3 to 0.0 +/- 0.0 microgram/ml in the group of gas-permeable CL wearers (p greater than 0.05). After CLW cessation, TF plasmin levels of CL wearers did not differ from those of controls. The occurrence of plasmin in TF was associated with a higher degree of corneal neovascularization and with the presence of limbal injection. The concentrations of epidermal growth factor in TF were not significantly altered by the discontinuation of CLW.

Conjunctiva↗
PubMed1989

Epidermal growth factor is a constant component of normal human tear fluid.

Epidermal growth factor (EGF) is a mitogenic polypeptide, which was first isolated from mouse submaxillary gland. Since EGF also stimulates the growth of corneal epithelial cells and only preliminary data exist on its presence in tear fluid, we studied the occurrence of human EGF (hEGF) in the tear fluid of 36 healthy persons (31 women and 5 men from 20 to 59 years of age; 60 eyes). hEGF, as measured by an immunofluorometric assay, was present in all tear fluid samples investigated. Its concentration varied from 200 to 2860 pg/ml (median, 705 pg/ml). The tear fluid hEGF concentrations differed less between the eyes of one individual than between individuals. The total amount of hEGF released to the tear fluid increased with fluid flow, but the higher the flow was, the lower the concentration of hEGF. We could not find any evidence of sex dependency in the hEGF concentrations. In demonstrating that hEGF is a normal component of human tear fluid, the results of this study suggest that hEGF may be important for conjunctival and corneal epithelial integrity.

Adult↗
PubMed1989

Contact lens wear is associated with the appearance of plasmin in the tear fluid--preliminary results.

We determined biochemically the plasmin concentration in tear fluid from 50 externally healthy eyes and from 49 eyes during contact lens (CL) wear. After cessation of CL wear, samples were collected again from 41 of the 49 eyes. Plasmin was detected more frequently (P less than 0.0001) in the CL-wearing group (75.5%) than in the control group (20%). After the cessation of CL wear (3-21 days), the frequency of plasmin detection in tear fluid decreased significantly (P less than 0.0006) but was still higher (39%) than in the control group. We conclude that the occurrence of plasmin in tear fluid is correlated with CL wear. The proteolytic activity of plasmin may contribute to the development of corneal epithelial pathology associated with CL wear.

Contact Lenses↗
PubMed1989

Plasminogen activator and its inhibitor in the experimental corneal wound.

Anterior keratectomy was performed to 10 eyes of 8 adult rabbits. The animals were killed 3-24 hr after wound closure. The corneas were excised and subjected to histochemical demonstration of urokinase-type plasminogen activator (u-PA), tissue-type PA (t-PA) and plasminogen activator inhibitor [PAI-1) using commercial antibodies. A strong immunoreaction for u-PA, a weaker reaction for PAI-1 and a very weak t-PA-like immunoreaction appeared in the anterior stroma of the wounded area. None of the antisera used showed any immunostaining in the cornea outside the wound. The role of the plasminogen activator-plasmin system in the healing of the corneal wound is discussed.

Animals↗
PubMed1989

Demonstration of tenascin-like immunoreactivity in rabbit corneal wounds.

Tenascin, a novel extracellular matrix protein, was demonstrated immunohistochemically in rabbit corneas that had healed after anterior keratectomy. Tenascin-like immunofluorescence (T-LI) appeared in the corneal stroma at the wound area only. The wound edge showed the most intense specific fluorescence. The corneal epithelium, in general, displayed a moderate T-LI. Wounding did not induce any change in epithelial T-LI or T-LI located in the stroma outside the wound.

Animals↗
PubMed1989

Plasmin and plasminogen activator activities in tear fluid during corneal wound healing after anterior keratectomy.

Plasmin can degrade fibronectin and laminin, two important components of the extracellular matrix facilitating cell sliding and healing following a wound. In this study we investigated the relationship between the tear fluid level of plasmin and plasminogen activator and the healing of a corneal wound. Anterior keratectomy (AKE) was performed for seven rabbits (11 eyes). Eight eyes were rewounded after re-epithelialization. Tear fluid samples were collected with capillaries before wounding and during wound healing. Plasmin and plasminogen activator (PA) activities were determined using radial caseinolysis procedures. After AKE the plasmin concentrations increased rapidly, from a mean (+/- SEM) of 3.9 +/- 0.9 micrograms/ml to a mean of 37.9 +/- 7.8 micrograms/ml (p less than 0.01), and decreased during wound healing. Rewounding also resulted in an increase in plasmin concentration in the tear fluid (from a mean of 2.9 +/- 0.6 micrograms/ml to a mean of 5.0 +/- 1.1 micrograms/ml; p greater than 0.05). The PA activity showed an inverse trend as it decreased after AKE from a mean of 2.0 +/- 0.6 IU/ml to a mean of 0.3 +/- 0.1 IU/ml (p less than 0.001). During wound healing and re-epithelialization, the PA activity increased again, to 2.1 +/- 0.3 IU/ml (p less than 0.001). Abrasion of the newly grown epithelium in eight eyes caused a second elevation of PA activity which was not significant. This study demonstrates a close association between the healing of corneal wounds and changes in the plasmin and PA activities in tear fluid. Determination of the activity of these enzymes may therefore be useful for monitoring corneal wound healing.

Animals↗
PubMed1989

[Acute keratitis and contamination of contact lens care systems with Bacillus cereus].

Two patients, both contact lens wearers, were treated for acute keratitis in both eyes. Routine microbiologic tests done for all four eyes confirmed merely the presence of Staphylococcus epidermidis in the conjunctival flora; neither fungi nor any viruses were detected on the patients' corneas. However, the contact lens soaking solutions were contaminated with a large number of microorganisms, including above all--or solely--Bacillus cereus. Two of the contact lenses used were also colonized by fungi of the genus Rhodotorula, Cryptococcus albicans and Wangiella dermatidis. The acute inflammation was treated quickly and effectively in all cases by specific antimicrobial therapy. Bacterial contamination of lens care systems is well known as a potential cause of keratitis in contact lens wearers. Although the clinical importance of Bacillus cereus in ocular surface pathology is still unknown, the cases reported here indicate that this microorganism may be of pathological significance in lens care systems. The authors therefore recommend including the lens care systems in routine bacteriologic tests in all cases of corneal infection where the patient wears contact lenses.

Acute Disease↗
PubMed1989

[Cluster headache].

Explore the source record for details and available documents.

Cluster Headache↗
PubMed1988

Elevation of tear fluid plasmin in corneal disease.

Plasmin concentration was determined in tear fluid from 76 eyes showing corneal epithelial disorders, such as corneal ulcers and erosions due to trauma or contact lens wear. Nearly 70% of the eyes with corneal disease had plasmin in their tear fluid, whereas plasmin was present in only 20% of the eyes in a control group of 50 eyes. Re-examination of the plasmin positive control eyes revealed conjunctival bacterial growth or mild subclinical viral infection in most cases. We conclude that plasmin is released into the tear fluid in the presence of corneal or conjunctival lesions or infections, suggesting a pathogenic role of plasmin in these disorders. The significance of the occurrence of plasmin in tear fluid during corneal wound healing is discussed.

Adult↗
PubMed1988

Use of soft contact lenses for the study of external ocular microbiology.

In the diagnosis of corneal ulcers, bacterial cultures from scrapings, investigations on viral and fungal growth, as well as staining of smears from the lesion often lead to the correct diagnosis. We report four cases of corneal ulcer where all the methods mentioned failed to reveal the causative microorganism. After the patients had received various medical treatments without any clinical improvement, soft therapeutic contact lenses were fitted, worn overnight, and removed the next morning with sterile forceps. The contact lenses were cultured in blood and Mac Leod agars. Growth of various bacteria was then detected. The infection subsided after the antibiotic treatment was changed according to the bacterial resistance. We conclude that, in selected cases, soft contact lenses may be used for microbiological studies.

Adult↗
PubMed1987

CSF protein and cellular profiles in various stages of HIV infection related to neurological manifestations.

CSF protein and cellular profiles were studied in 28 HIV-infected patients. Twenty of them had neurological complaints, but only 6 patients had objective neurological deficits such as dementia, ocular motility disorders or polyneuropathy. The serum/CSF HIV antibody ratio was on average lowest in acquired immunodeficiency syndrome (AIDS) (4 patients) and highest or almost normal in lymphadenopathy syndrome (LAS) (11) and asymptomatic seropositivity (ASX) (7), while it varied between these extremes in AIDS-related complex (ARC) (6). However, low values of the ratio were also found in the HIV-infected patients free of neurological symptoms and even in one ASX patient. The CSF IgG index was elevated in all these 4 general stages of HIV infection without any significant differences between them. The CSF/serum albumin ratio was slightly increased in patients with neurological deficits, but this ratio showed no association with any other clinical factor analysed. CSF leucocytes were increased in the early stages of the disease, but later the cellular reaction subsided. HIV was isolated from post mortem brain tissue of two AIDS patients and from the CSF of one of them. The results suggest increased intrathecal virus-specific IgG synthesis, not only in patients with neurological deficits and at advanced stages of infection, but also in neurologically symptom-free subjects and at early infection. The lack of correlation between the increased virus-specific IgG synthesis within the CNS and the presence of neurological symptoms suggests that neurologically "silent" areas of brain white matter are often affected in HIV infection.

AIDS-Related Complex↗
PubMed1987

Tarsorraphy in the treatment of persistent corneal lesions.

Altogether 38 tarsorraphies were carried out to 19 patients with corneal epithelial defects resistant to conventional therapy. The main operative indications were lagothalmos, dry eyes and inadequate blinking (6 patients). Corneal ulcer was detected in 17 eyes, six of which perforated. All patients had been treated from one week to 16 months (mean 3.5 months) without healing. Retarsorraphy was needed in 6 eyes. In perforations tarsorraphy was combined to tissue adhesive (3 eyes) or to therapeutic contact lens (4 eyes) or to conjunctival flap (2 eyes). The corneal epithelium healed in all except 2 cases (one perforation, one ulcer that is slowly improving). Five of the 6 perforations could also be cured without grafting. One eye of a severely debilitated patient was treated with a Gundersen's conjunctival flap and total tarsorraphy, but remained hazy. We consider, that tarsorraphy is valuable in treating corneal lesions due to lagophthalmos, dry eyes or disturbed lid function. It can also be used in threatening of manifest corneal perforation, if combined with the use of tissue adhesive or therapeutic contact lens.

Adolescent↗
PubMed1987

Cortisone, heparin and argon laser in the treatment of corneal neovascularization.

Chemical burns and contact lenses can induce corneal neovascularization. The pathogenic mechanisms of angiogenesis are not well understood. A heparin-cortisone combination has been shown to inhibit traumatic angiogenesis and argon laser photocoagulation has been useful in the treatment of corneal graft neovascularization. We describe three patients treated for corneal neovascularization with these methods. Tear fluid plasmin levels were also monitored. The corneal neovascularization was caused by contact lens use in two patients, and by a severe chemical burn in one patient. Subconjunctival cortisone injections proved to be efficient in the treatment of the contact lens induced corneal neovascularization. Corneal argon laser photocoagulation seemed to have an additional effect. The role of topical heparin remained unclear. The tear fluid plasmin levels were not significantly elevated.

Adolescent↗
PubMed1987

Plasmin in tear fluid of patients with corneal ulcers: basis for new therapy.

In a patient with chronic corneal ulcer, resistant to conventional therapy, analysis of tear fluid revealed a high plasmin activity which could be inhibited by aprotinin, an inhibitor of serine proteinases. Therapy with topical aprotinin resulted in rapid epithelialization. After this initial patient, within a period of four months tear fluid specimens of altogether 48 patients with corneal lesions were analyzed, and 32 were found to be positive for proteolytic activity. Of these 18 were treated with topical aprotinin which rapidly promoted corneal epithelial healing. Six of these patients had been treated with conventional therapy for 3-10 weeks but proved to be completely therapy-resistant. Our observations on three successfully treated patients with chemical burns of the cornea indicated appearance of plasmin in tear fluid after a few days correlating with cessation of epithelialization. In all patients, in which tear fluid plasmin activity was followed, the activity disappeared during aprotinin therapy correlating with corneal re-epithelialization. In some patients with low proteolytic activity aprotinin was combined with fibronectin with a beneficial therapeutic effect. No proteolytic activity was found in the tear fluid of control individuals. These preliminary data indicate that in patients with treatment-resistant corneal lesions inhibition of proteolytic activity can assist in epithelial healing. Such an inhibition is likely to be a prerequisite for the proteinase-sensitive cell adhesion proteins such as fibronectin to promote epithelialization.

Administration, Topical↗
PubMed1987

Updating of methods for prevention of HIV transmission during ophthalmological procedures.

The presence of HIV (human immunodeficiency virus) particles in the tear fluid, on the conjunctival surface or in the contact lenses of patients with chronic HIV infection has made it necessary to establish better for guide-lines for decontamination of instruments during ophthalmological procedures. The methods are now at the stage of evolution. The present paper describes the disinfection procedures used in the Helsinki University Eye Hospital and updates the present decontamination protocols.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Conjunctival nerve pathology in multiple endocrine neoplasia. A case report.

A 31-year-old male with typical clinical features of multiple endocrine neoplasia type 2b (MEN 2b) was subjected to conjunctival biopsy. The patient had previously been operated for pheochromocytoma and medullary carcinoma of the thyroid. He came for ophthalmologic consultation because of redness and irritation of the eye due to dry eye syndrome. The conjunctival biopsy taken from his left eye revealed not only an increase in the number of conjunctival nerves but also an increase of their axons. The ultrastructure of the nerves was mostly normal, but the perineurium was often incomplete, and the interaxonal space appeared to be enlarged. Immunohistochemically, SP-, neurofilament- and, unexpectedly, leucine-enkephalin-positive nerve fibres were demonstrated in the conjunctival stroma. The rat is the only species in which enkephalin-like immunoreactivity has been described in the anterior segment of the eye. Thus, the presence of enkephalin-positive nerves in the conjunctiva of our MEN 2b patient may reflect a profound neural alteration.

Adult↗
PubMed1987

Long-term neural regeneration in the rabbit following 180 degrees limbal incision.

Penetrating 180 degrees superior limbal incisions were made on the right eye of four adult New Zealand albino rabbits. The contralateral eye served as control. Corneal touch thresholds (CTT) for the central, superior and inferior cornea (2-3 mm from limbus) were determined 3, 9, 15, 24 and 30 months after surgery. In all animals, the CTT was significantly elevated in the superior region of the cornea throughout the measurement period. CTT was elevated in the central and inferior cornea 3 months following surgery and was not affected in the inferior cornea on all other occasions. The animals were then sacrificed and the corneas subjected to histochemical demonstration of acetylcholinesterase corneal nerves. All rabbits showed a reduction in the number of histochemically detectable stromal nerve trunks in the operated region. These stromal nerve trunks showed regenerative changes including abnormally curved course and a subnormal number of axons within a nerve trunk. Epithelial nerve fiber defects included absence or distorted architecture of the basal epithelial plexus and intra-epithelial terminals. These results indicate that although extensive stromal reinnervation had occurred, the extent and quality of stromal nerves was inadequate to restore a normal epithelial plexus and corneal sensitivity.

Animals↗