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Biomedical subjects

I Immonen

Publications and source records attributed to I Immonen.

66 records · Page 4Linked to original sources

Concentration of angiotensin-converting enzyme in tears of patients with sarcoidosis.

The concentration of angiotensin-converting enzyme (ACE) was studied in 39 patients with sarcoidosis, 6 of whom had active uveitis, 7 patients with non-sarcoid uveitis and 36 healthy controls. ACE concentration in tears was also compared with total protein concentration in tears in order to exclude the effect of varying dilution of tears at sampling. Mean tear ACE concentration and ACE/protein ratio were higher in patients with sarcoidosis than in controls. There were no significant differences in tear ACE concentration or ACE/protein ratio between sarcoidosis patients with uveitis and those with no eye involvement. Tear ACE concentration and ACE/protein ratio did not correlate significantly with serum ACE concentration. It is concluded that the mean concentration of tear ACE and ACE/protein ratio are elevated in sarcoidosis, but that this elevation is independent of any eye involvement.

Adult↗

T lymphocyte activation state in the minor salivary glands of patients with Sjögren's syndrome.

Local lymphoplasmacytoid infiltration of the diseased exocrine glands is a cardinal sign of Sjögren's syndrome (SS). The state of T lymphocyte activation present in these local infiltrations was studied by three different techniques: determination of interleukin 2 (IL2) receptor (Tac) on cell surface membrane; autoradiography combined with immunoperoxidase staining of T cell epitopes; and electron microscopic analysis of the lymphoblast subclasses. Although 64 (SEM 4)% of the local inflammatory cells expressed Ia antigen, only 4 (SEM 1)% of them displayed the T cell activation antigen Tac. Autoradiography-immunoperoxidase double labelling showed that less than 1% of all T cells in situ were [3H]thymidine incorporating blasts. This finding suggests that although T lymphocyte is the dominant cell in situ, only a few of these cells have passed the G0/G1 interphase, and even fewer have been pushed to the S phase of the cell cycle by IL2. Transmission electron microscopy showed that few T blasts were present, even though there were many plasma cells. This result further confirms the impression that only a minor T cell subpopulation in situ is blast transformed despite the fact that many of the local T lymphocytes in the diseased salivary glands in SS are Ia positive.

Adult↗

Angiotensin-converting enzyme in sarcoid and chalazion granulomas of the conjunctiva.

Angiotensin-converting enzyme (ACE) was studied immunohistochemically in conjunctival biopsies from 6 patients with systemic sarcoidosis, 4 patients with posterior non-sarcoid uveitis and in specimens from 4 patients with chalazion of the eyelid. Specimens with sarcoid granulomas showed intense ACE-positive immunoreactivity in epitheloid cells of the granuloma, whereas chalazion granulomas did not contain ACE-immunoreactivity. There was no difference in staining patterns between specimens without granulomas. Thus immunohistochemical staining for ACE may be of help in differentiating conjunctival granulomatous tissue of a chalazion from sarcoid granuloma.

Conjunctival Diseases↗

Marathon run: effects on plasma renin activity, renin substrate, angiotensin converting enzyme, and cortisol.

Altogether 33 Finnish amateur runners were studied before and after a non-competitive Marathon run over the classical itinerary in Athens in 1976 (n = 8), 1977 (n = 14) and 1978 (n = 11). Plasma renin activity (PRA) rose 3-fold in all runs, whereas plasma renin substrate (RS) concentration did not change significantly. Serum angiotensin converting enzyme (ACE) activity was not changed. Serum cortisol concentration was increased 2-3 fold. The unchanged plasma RS concentration, in spite of increasing PRA, indicates that plasma RS is kept within normal limits during prolonged strenuous physical exercise. One contributing mechanism may be stimulation of RS biosynthesis by cortisol. Low PRA levels in two old runners, 65 and 83 years old, may indicate a decreased ability to respond with renin release to the stimuli of physical exercise.

Adult↗

Plasma renin substrate in the prediction of pregnancy outcome in threatened abortion.

Concentrations of plasma renin substrate, serum oestradiol-17 beta, human chorionic gonadotrophin, sex-hormone binding globulin and plasma renin activity were measured in 77 samples from 74 patients with uterine bleeding during the first and second trimesters of pregnancy and in a control group of 29 normal pregnant women (51 samples). Mean concentrations of these substances were lower than control values in patients with an abnormal outcome of pregnancy. In patients with a normal outcome after uterine bleeding, concentrations were mostly within the control range. Serum oestradiol-17 beta concentration was superior to the other variables in predicting fetal outcome in the whole group. In patients with a live fetus at the time of blood sampling but who subsequently aborted, serum oestradiol-17 beta concentration was mostly normal, whereas plasma renin substrate was decreased. Our results suggest that plasma renin substrate may provide additional prognostic information to that given by serum oestradiol-17 beta measurement or ultrasonography in threatened abortion.

Abortion, Threatened↗

Plasma renin substrate and oestrogens in normal pregnancy.

Relationship between concentrations of serum oestrogens, plasma renin substrate and plasma renin activity were studied in six women throughout pregnancy. There was a significant positive correlation between serum oestradiol-17 beta and plasma renin substrate concentrations (r=0.60). Serum oestriol concentrations also correlated significantly with plasma renin substrate concentrations (r = 0.68). Correlation coefficients calculated separately for each subject throughout pregnancy were higher than those for the whole group. Also, there was much individual variation in dose-response of serum oestrogens to plasma renin substrate concentrations. There was no significant correlation between serum oestrogens and plasma renin activity. Our results support the view that oestrogens cause the increase in plasma renin substrate concentration during pregnancy, and emphasize the individual variation in response of renin substrate concentration to serum level of oestrogens.

Estradiol↗

Reduction of plasma renin substrate after parturition; role of renin.

Plasma renin substrate concentration, renin activity, serum sex hormone binding globulin and total protein concentration were measured sequentially in 10 women after elective caesarean section. Plasma renin substrate concentration decreased from 5406 +/- 000 micrograms AI/l (mean +/- SD) at term to 2369 +/- 726 micrograms AI/l 6 days post partum. Plasma renin activity decreased from 6.2 +/- 3.3 micrograms AI/l/h at term to 4.2 +/- 4.0 micrograms AI/l/h 6 days after delivery. Serum sex hormone binding globulin decreased more slowly than plasma renin substrate concentration. Clearance of plasma renin substrate based on plasma renin activity was calculated. This consumption by renin could explain only 12% of the decrement in plasma renin substrate concentration at the steepest part of the plasma renin substrate disappearance curve. It is concluded that metabolic clearance of plasma renin substrate may be much greater than that calculated from plasma renin activity.

Angiotensinogen↗

Bilateral oophorectomy and plasma renin substrate concentration.

Plasma renin substrate concentration was studied in 11 premenopausal women subjected to bilateral oophorectomy and hysterectomy. Preoperative plasma renin substrate concentration was 1573 +/- 477 ng angiotensin I/ml (mean +/- SD). Plasma renin substrate concentration did not change significantly after operation (1632 +/- 459 ng angiotensin I/ml) or after 3 months of postoperative estradiol valerate treatment (2 mg/day) (1762 +2- 467 ng angiotensin I/ml). It is concluded that non-pregnant levels of endogenous estrogens are of no significance in the regulation of plasma renin substrate.

Angiotensinogen↗

Age dependence of human plasma renin substrate.

Renin substrate (angiotensinogen) was measured with an assay employing exhaustive incubation of plasma with purified human kidney renin and radioimmunoassay of the angiotensin I (AI) generated. Plasma renin substrate concentration was higher at the age of 3 days (females: 2028 +/- 551, males: 1951 +/- 565 micrograms AI/l, mean +/- SD) than in age group 0-15 years (females: 1513 +/- 555, males: 1263 +/- 392 micrograms AI/l). Plasma renin substrate concentration at the age over 15 years (females: 1780 +/- 464, males 1752 +/- 321 micrograms AI/l) was higher than in children 0-15 years. Expectedly, high concentrations of plasma renin substrate were found in pregnant women at term (4127 +/- 1961 micrograms AI/l).

Adolescent↗

Grading choroidal neovascular membrane regression after strontium plaque radiotherapy; masked subjective evaluation vs planimetry.

PURPOSE: To analyze angiographic changes in choroidal neovascular membranes (CNVM) after strontium-plaque (90Sr) irradiation for exudative age-related macular degeneration (AMD) using masked measurement of the CNVM areas and a masked subjective comparison of CNVM size and leakage. METHODS: We studied the baseline, 3, 6, and 12-month angiograms of 19 eyes treated with 90Sr-plaque irradiation for exudative AMD. The area of CNVM-related hyperfluorescence was measured quantitatively, and the angiograms were subjectively evaluated by a masked grader. RESULTS: In 7 of the 19 eyes the CNVM-related hyperfluorescence was too scattered to be analyzed by planimetry but masked subjective grading correlated with the clinical response to irradiation. In the remaining 12 eyes, the CNVM decreased in size in 67% of the eyes and showed leakage in 67%. Planimetry and subjective assessment of the size and leakage of the CNVMs similarly reflected the regression after irradiation. CONCLUSIONS: CNVM size and leakage frequently diminish after 90Sr-plaque irradiation. Quantitative measurement of the CNVM areas, or a grading system based on masked subjective assessment, give similar results for evaluating these changes. Masked subjective grading can be used even in cases where the CNVM is too scattered to be outlined for planimetry.

Aged↗

Visual outcome of eyes with malignant melanoma of the uvea after ruthenium plaque radiotherapy.

BACKGROUND AND OBJECTIVE: To analyze the overall visual outcome in 100 consecutive eyes with malignant uveal melanoma irradiated with ruthenium-106 plaques between 1981 and 1991. PATIENTS AND METHODS: The follow-up ranged from 4 months to 10.1 years (median 3.0 years). Scattergrams of equal follow-up periods, life-table survival analysis, and Cox's proportional hazards analysis were used to analyze visual outcome. RESULTS: VA increased for some time in 14 eyes. By 3 years, VA of at least 20/70, 20/200, counting fingers, and light perception were retained in 27%, 41%, 67% and 82% of eyes, respectively. Macular pathology cause loss of reading vision; neovascular glaucoma or enucleation caused loss of light perception. In univariate analysis, large tumor size (height > 5 mm or TNM class T3) predicted visual loss of all VA levels. For the loss of light perception, the tumor's largest basal diameter > 15 mm reached significance. In Cox's multivariate analysis tumor height > 5 mm was the only significant independent risk indicator for loss of VA levels 20/70 and 20/200. For the level CF, largest basal tumor diameter also reached significance, but location of the tumor within 1 disc diameter of the optic disc, either alone or in addition to the fovea, had the greatest risk ratio (6.3, 95% CI 4.1-9.8). For losing light perception, large TNM size (T3) was the strongest risk indicator (risk ratio 10.0; 95% CI 4.5-22.5), followed by proximity of the tumor to the optic disc (risk ratio 4.3, 95% CI 2.4-7.8). CONCLUSION: Ruthenium brachytherapy may retain vision in an eye with a malignant melanoma of the uvea for a considerable period of time. The data presented are useful in patient counseling and allow comparison to subsequent series.

Adult↗