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Biomedical subjects

S Osterlin

Publications and source records attributed to S Osterlin.

At least 19 recordsLinked to original sources
PubMed1994

Glucose concentration in the vitreous of nondiabetic and diabetic human eyes.

Glycation (nonenzymatic glucosylation) of collagen may play a role in the primary pathology of the vitreous in diabetes. The extent of glycation is determined by the glucose concentration in the tissue. In this study glucose concentration was assayed in blood and vitreous samples obtained from three patient groups undergoing vitrectomy: nondiabetic patients (ND), diabetic patients with insulin-dependent diabetes mellitus (IDDM) and diabetic patients with non-insulin-dependent diabetes mellitus (NIDDM). In the ND group the glucose concentration in the vitreous (3.5 +/- 1.8 mM/l) was always lower than in the blood (9.1 +/- 3.5 mM/l). In the diabetic groups the vitreous glucose concentration was, with a few exceptions, generally lower than the blood glucose concentration. The vitreous glucose concentration in these groups was generally higher (IDDM 9.4 +/- 3.3 mM/l, NIDDM 7.2 +/- 3.9 mM/l) than in the ND group, and in 15 specimens exceeded 11 mM/l, a level increasing the probability of collagen glycation in the vitreous of diabetic patients.

Blood Glucose↗
PubMed1994

Pilocarpine-induced lysosomal enzyme secretion, from bovine trabecular meshwork cells.

It has long been held that pilocarpine-induced ciliary muscle contraction causes a mechanical change in the configuration of the trabecular meshwork, thereby increasing its fluid conductance. Though the results of many studies are consistent with this theory, other findings suggest a direct action of pilocarpine on the meshwork. We used cultured bovine trabecular meshwork (BTM) cells to study the cell biological effects of pilocarpine, chemically a weak base, and demonstrated increased vacuolization of the BTM cells after incubation with pilocarpine, reflecting a trapping of the protonated base inside the lysosomes. We also showed that pilocarpine enhanced the release of lysosomal hydrolases into the medium. We hypothesize that this is clinically relevant and that the pilocarpine-induced release of hydrolases modifies the extracellular matrix of the trabecular meshwork, thereby increasing its fluid conductance.

Animals↗
PubMed1994

Diabetes mellitus but not impaired glucose tolerance is associated with dysfunction in peripheral nerves.

To clarify whether long-term impaired glucose tolerance (IGT) is associated with dysfunction of peripheral and autonomic nerves, age-matched men with IGT and diabetes mellitus were followed prospectively for 12-15 years, when peripheral and autonomic nerve function was assessed. The patients comprised four subgroups: (1) 51 IGT subjects (duration of IGT at least 12-15 years); (2) 35 diabetic patients, with IGT 12-15 years ago, who later developed diabetes; (3) 34 diabetic patients, duration of diabetes at least 12-15 years; and (4) 62 age-matched non-diabetic control subjects. Mean age of the whole study population was 61 +/- 2 years (mean +/- SD), not different in the four groups. Peripheral nerve function tests included nerve conduction velocities, amplitudes, distal latencies, F-reflexes, and sensory perception thresholds for heat, cold, and vibration. Autonomic nerve function tests included the heart rate reaction during deep breathing (expiration to inspiration ratio) and to tilt (acceleration and brake indices). Despite 12-15 years of IGT, peripheral nerve function did not differ between IGT and control subjects, whereas autonomic nerve function deviated; an abnormal expiration to inspiration ratio (a sign of vagal nerve dysfunction) was significantly more common (15/51 versus 5/62; p < 0.01) in IGT than in control subjects. Diabetic patients (groups 2 and 3) showed lower conduction velocities (in general 2-4 m s-1 lower) than IGT and control subjects in all tested nerves. In conclusion, diabetes but not IGT, is associated with peripheral nerve dysfunction.

Age Factors↗
PubMed1990

Autonomic neuropathy in non-insulin dependent (type II) diabetes mellitus. Possible influence of obesity.

To assess the prevalence of autonomic neuropathy (AN) in non-insulin dependent diabetes mellitus (NIDDM) and its relationships with other diabetic complications, duration of diabetes, and obesity, we evaluated 51 NIDDM patients (age 41-59 years, mean 49 years, duration of diabetes 0-15 years, mean 6.9 years). AN tests included a deep breathing test (E/I ratio) and an orthostatic tilt table test (acceleration and brake (25 of 51, 49%) and the most frequent disturbance was an impaired E/I ratio (18 of 25; 72%). There were no obvious correlations between AN indices and the duration of diabetes, symptoms of AN, peripheral neuropathy or retinopathy. However, an influence of obesity on AN was suggested. Patients with AN showed a significantly higher BMI than patients without AN (31.0 +/- 0.9 vs. 27.5 +/- 0.8; P less than 0.01).

Adult↗
PubMed1987

Autonomic neuropathy in type I diabetes: influence of duration and other diabetic complications.

To evaluate the influence of duration on the development of autonomic neuropathy (AN) a group of type I diabetic patients (n = 58) who had been diagnosed between the ages of 15 and 25 years was investigated. The duration of diabetes varied from 2 months to 30 years (mean 13 years). AN tests included a deep breathing test (E/I ratio) and an orthostatic test on tilt table (acceleration and brake indices) and the results were corrected for age. A clear correlation between AN test and duration of diabetes was shown only for the E/I ratio (r = -0.44, p less than 0.001). On the other hand, deteriorations in the brake index were unrelated to the duration of diabetes and occurred early; 35% of the patients with a duration of 10 years or less showed an abnormal brake index. Autonomic test deviations were related to other diabetic complications. The E/I ratio and the acceleration index were especially low in patients with retinopathy as well as in patients with symptoms of AN if combined with peripheral neuropathy (PN). The brake index was low in patients with symptoms of AN independent of PN.

Adolescent↗
PubMed1985

Posterior vitreous detachment. A combined clinical and physiochemical study.

Sixty-one postmortem eyes were examined with clinical methods (slit lamp) and later sectioned for measurement of the liquid and gel vitreous. The amount of liquid vitreous was found to be progressively greater with increasing posterior vitreous detachment (PVD), and it was concluded that slit-lamp examination is a reliable method of evaluating the rheological state of the vitreous in the living eye. The total content of sodium hyaluronate (NaHA) in the vitreous was measured. Eyes proven to have no PVD had a higher concentration of NaHA than eyes with total PVD. Also, females had a lower concentration than males. There was no significant difference in NaHA concentration between the gel and liquid vitreous. The role played by different structural elements for the stability of the vitreous gel is discussed.

Aged↗
PubMed1981

Retinal vessels in the ora region. Possible role in the vitreo-retinal pathology in aphakia.

During intracapsular lens extraction the extreme retinal periphery is subjected to zonula-mediated traction and possible damage to the retinal vessels. The vascular pattern at the ora serrata was studied with special reference to the frequency and distribution of vessels positioned adjacent to the ora structures. The possible role of leakage from such vessels in vitreo-retinal pathology of the aphakic eye is discussed.

Aphakia, Postcataract↗
PubMed1977

On the molecular biology of the vitreous in the aphakic eye.

The vitreous of aphakic and phakic eyes was assayed for hyaluronic acid. Intracapsular cataract extraction was regularly followed by decreased hyaluronic acid concentration and studies on the distribution of hyaluronic acid within the vitreous cavity showed that removal of the lens facilitates diffusion of hyaluronic acid into the anterior chamber. Based on these studies certain postoperative features of the aphakic eye are discussed. The instability of the vitreous gel, as reflected by rupture of the anterior vitreous face and an increased incidence of vitreous detachment supports the hypothesis of hyaluronic acid as a stabilizer of the gel. The decreased adhesion of the neural retina in the aphakic eye might be caused by the loss of hyaluronic acid. Normally the high concentration of hyaluronic acid adjacent to the retina contributes to the resistance of bulk flow of fluid into the subretinal space making it possible for the active transport system of the pigment epithelium to maintain a pressure drop across the neural retina. It is anticipated that saccades create currents in the fluid vitreous close to the eye wall after vitreous detachment. Model experiments showed that these currents were greatly enhanced, when the concentration of hyaluronic acid was lowered.

Aged↗
PubMed1977

Preludes to retinal detachment in the aphakic eye.

The author reviews the characteristic differences in primary rhegmatogenous retina detachment occurring in phakic eyes and in aphakic eyes. The preoperative findings in aphakic detachment are explained on the basis of two factors: surgical trauma during cataract extraction and postoperative changes in the macromolecular compostion of the vitreous.

Cataract Extraction↗
PubMed1976

Hydrodynamic events in the vitreous space accompanying eye movements. Significance for the pathogenesis of retinal detachment.

The powers elicited in the vitreous body by eye movements have hardly been subjected to examinations, and the same goes for currents in the vitreous. Model experiments have demonstrated that intra-ocular currents are not elicited by translatory, but so much more by rotatory movements. Furthermore, it is demonstrated that a thin perforated membrane fitted on the inside of the wall of a glass cylinder filled with water, will detach, with rotatory movements. Even minimal rotational movements cause a flow through the hole. It is discussed whether these findings apply to the eye in vivo.

Adult↗
PubMed1976

Cathepsin D activity in bovine articular cartilage, synovial membrane and fluid: degradation of cartilage proteoglycans from same joint.

Cathepsin D type proteases were extracted from articular cartilage, synovial membrane, and synovial fluid from normal, adult bovine knee joints. A sensitive enzyme assay made it possible to measure protease activity in the different tissues from individual joints. Highest activity was found in the synovial membrane, while cell free synovial fluids contained comparatively low activity. The degrading effect on articular cartilage proteoglycans (PGC and PGS), isolated from the same joints, was demonstrated by gelfiltration on Sepharose columns and by viscometry. Gelfiltration profiles of incubation mixtures indicated a proteolytic effect on PGC and on PGS), at pH 3.5, in concentrations of enzyme and proteoglycans found in cartilage tissue. No effect at neutral pH was obtained despite a 100-fold increase of enzyme concentration. These findings were supported by viscometry data. The degrading effect of enzymes from all sources was completely inhibited by pepstatin.

Animals↗
PubMed1975

The fibrinolytic system in patients with diabetes mellitus with special reference to diabetic retinopathy.

The fibrinolytic system has been studied in 168 patients with diabetes mellitus (DM) and compared to that of a group of 153 sex- and age-matched control subjects. The following determination were made: spontaneous fibrinolytic activity of the blood; fibrinolytic response to standardized venous stasis (stimulated fibrinolytic activity, "fibrinolytic capacity"); histochemical determination of fibrinolytic activators in the walls of superficial veins collected by biopsy. Diabetic patients were found as a group to have an impaired fibrinolytic system with the above fibrinolytic parameters decreased to various degrees in comparison with those of the controls. Less clear differences were observed between patients with and without ophthalmoscopically visible diabetic changes of the retina. However, patients with beginning angiopathy were found to have a significantly higher amount of fibrinolytic activators in their vessel walls than patients with more advanced retinopathy and without ophthalmoscopically detectable retinopathy. Furthermore, unlike patients without retinopathy, patients with retinopathy increased less or did not increase at all their spontaneous and stimulated fibrinolytic activity along the duration of the disease. The defective fibrinolytic system of diabetic patients may contribute to the occurrence of the vascular complications frequently seen in this disease. In the diabetic group, those patients who develop retinopathy show an impaired fibrinolytic defense with the duration of the disease.

Adolescent↗