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Biomedical subjects

O Simell

Publications and source records attributed to O Simell.

At least 73 records · Page 4Linked to original sources

Low-saturated fat, low-cholesterol diet in 3-year-old children: effect on intake and composition of trans fatty acids and other fatty acids in serum phospholipid fraction-The STRIP study. Special Turku coronary Risk factor Intervention Project for children.

OBJECTIVE: We evaluated whether replacing a proportion of saturated fat with vegetable oils in the diet of young children increases trans fatty acid intake. STUDY DESIGN: Dietary counseling aimed to reach a dietary fat ratio of unsaturated to saturated fat of 2:1 within a total fat intake of 30% to 35% of energy (E%). Four-day food records of 813 3-year-old children were analyzed, and serum phospholipid fatty acid compositions of 25 randomly selected intervention children and 17 control children were analyzed. RESULTS: trans fatty acid intake of the intervention and control children was small (0.8 E% and 0.6 E%, respectively; P <.001). The relative content of serum phospholipid trans 18:1 was closely similar in intervention and control children (1.0% and 0.9% of all fatty acids, respectively). Trans fatty acid intake and serum trans 18:1 correlated poorly with children's serum cholesterol and HDL cholesterol concentrations and inversely with serum phospholipid arachidonic to linoleic acid ratio (r = -0.373). CONCLUSIONS: Trans fatty acid intake of children in Finland is minimal. Dietary intervention replacing saturated with unsaturated fatty acids is safe because it does not increase trans fatty acid intake or the relative content of trans fatty acids in the serum phospholipid fraction.

Arachidonic Acid↗

Effect of lysine infusion on urea cycle in lysinuric protein intolerance.

Poor intestinal absorption and excessive renal loss of dibasic amino acids result in low plasma concentrations in patients with lysinuric protein intolerance (LPI). Arginine and ornithine deficiency impair the function of the urea cycle and cause hyperammonemia after protein intake, while chronic lysine deficiency may cause growth failure and lead to reduced bone density in such patients. Since high lysine concentrations inhibit several enzymes of the urea cycle in the liver, lysine supplementation may induce hyperammonemia in LPI. We thus studied how LPI patients tolerate high plasma lysine by intravenous (IV) infusion of 3.3 mmol/kg lysine hydrochloride over 90 minutes in 6 adult patients and 4 healthy controls. The plasma lysine concentration (mean +/- SD, range) peaked in the patients (9,114 +/- 1,864, 7,156 to 12,044 micromol/L) and controls (10,185 +/- 2,253, 7,714to 13,122 micromol/L) at 90 minutes. Urinary lysine excretion peaked in the second 2-hour urine collection in the patients (4,582 +/- 1,276, 3,018 to 6,315 micromol/m2 body surface area per hour) and in the first 2-hour collection in the controls (5,373 +/- 1,766, 3,551 to 7,286 micromol/m2/h). Two patients had mild nausea but no hyperammonemia and one patient had moderate hyperammonemia (peak, 112 micromol/L) at the end of the infusion. Orotic acid excretion increased in 2 subjects with a peak excretion rate of 33 and 251 micromol/m2/h in the third 2-hour collection after starting the load. All other subjects remained asymptomatic and showed no change in plasma ammonia or urinary orotic acid excretion. We thus conclude that an acute increase in plasma lysine caused minimal clinical or biochemical untoward effects in patients with LPI. Moderate increases in plasma lysine after low-dose oral supplementation with lysine or well-absorbed lysine derivatives are probably well tolerated in LPI.

Adult↗

Intercellular adhesion molecule-1 (ICAM-1) K469E polymorphism: no association with type 1 diabetes among Finns.

The intercellular adhesion molecule-1 (ICAM-1) has an important role in the process of lymphocyte migration and activation, and is supposed to be involved in the pathogenesis of type 1 diabetes. We studied A/G (K469E) polymorphism of the ICAM-1 gene in 218 type 1 diabetes patients and 212 controls from Finland and found no association. We then studied transmission of the ICAM-1 alleles in 102 Finnish families using a transmission disequilibrium test (TDT). Alleles A and G were transmitted to the affected offspring in 50% each. Stratification by the HLA-DQB1-DQA1 genotypes, sex and age at onset did not reveal association. Our data demonstrate that in the Finnish population K469E polymorphism of the ICAM-1 gene is not associated with type 1 diabetes.

Adolescent↗

Geographical differences within Finland in the frequency of HLA-DQ genotypes associated with type 1 diabetes susceptibility. The Childhood Diabetes in Finland Study Group.

Geographical variations in the HLA-DQ genotypes associated with risk for type 1 diabetes were evaluated in Finland. Samples of 280 diabetic children diagnosed in Turku (south-west of the country) and 405 in Oulu (north of the country) were studied as well as a series of 14 096 and 10 016 newborns collected from the same hospitals. There were no major differences in the risk or protection conferred by various HLA-DQB1 genotypes between south-western and northern parts of the country when genotypes of children with type 1 diabetes from these two centres were compared with those of newborns, representing the background populations. However, the distribution of various genotypes was different, both in diabetic children and in newborns, when compared between the two regions (P < 0.0001, chi2 test). These differences reflected the allele frequencies in newborn cohorts in which HLA-DQB1*02 and DQB1*0301 were found more often in Turku and DQB1*0302 more often in Oulu (P < 0.0001 for all differences). Similar types of differences were detected when children who were diagnosed as having diabetes during the national 'Childhood Diabetes in Finland' (DiMe) study between the years 1986-1989 were compared according to their residence. The observed differences in genotype and allele frequencies demonstrate the heterogeneity for HLA alleles even in a population that is generally regarded as highly homogeneous. These differences also affect the sensitivity and efficiency of the screening programme used for identifying infants with genetic susceptibility to IDDM in the ongoing Finnish Diabetes Prediction and Prevention Study.

Adolescent↗

Fatty acid composition of serum cholesterol esters as a reflector of low-saturated-fat, low-cholesterol diet in young children: the STRIP project. The Special Turku coronary Risk factor Intervention Project.

STRIP (the Special Turku coronary Risk factor Intervention Project) is an ongoing intervention trial which aims at a permanent reduction in the intake of saturated fat and cholesterol starting in childhood. A total of 75 intervention and 63 control children was studied consecutively at the ages of 7 and 13 mo, and 2, 3 and 5 y to evaluate the influence of such intervention on serum cholesterol ester (CE) fatty acid composition, a widely used biomarker of fatty acid intake. Analysis of 4-d food records showed that total intake of fat and of saturated fat increased with age in both groups of children but was constantly lower in intervention than in control children, e.g. at the age of 5 y the mean intakes of total fat and of saturated fatty acids were 31.1 E% and 33.9 E% and 12.1 E% and 14.6 E% in intervention and control children, respectively (p = 0.009 and 0.0001, respectively). Serum CE fatty acid compositions did not differ between the 2 groups at any age; the mean proportion of CE linoleic acid was 52.4% and 52.0% in 5-y-old intervention and control children, respectively. Correlation analysis showed, however, that the percentage of linoleic acid and of polyunsaturated fatty acids in CE reflected well the respective dietary intakes (r = 0.36; p = 0.0001 for both coefficients). In conclusion, CE fatty acid composition did not differ between the intervention and control groups, whereas CE linoleic and total polyunsaturated fatty acids reflected well the differences in their intakes at the individual level.

Child, Preschool↗

Sodium intake of 1 to 5-year-old children: the STRIP project. The Special Turku Coronary Risk Factor Intervention Project.

The aim of this study is to examine sodium intake and dietary sodium sources of 1-5-y-old children in a prospective, randomized long-term coronary heart disease prevention trial, focused on dietary fat modification. Counselling included no advice about reducing salt in the children's diets. Food consumption of 100 intervention children and 100 control children was recorded for 3 consecutive days at the age of 13 mo and for 4 consecutive days at the ages of 3 and 5 y. Sodium intakes were calculated using the Micro Nutrica program. Children's mean daily sodium (NaCl) consumption (intervention and control children combined) was 1600+/-527 mg (4.0+/-1.3 g), 1900+/-504 mg (4.8+/-1.3 g) and 2200+/-531 mg (5.5+/-1.3 g) at the ages of 13 mo and 3 and 5 y, respectively. The intervention children consumed as much or slightly more sodium than the control children at all ages studied. Half the sodium consumption was derived from added salt in commercially prepared or homemade foods. Milk, meat products, bread and cereals were other important sodium sources. In conclusion, nutrition counselling in the Special Turku Coronary Risk Factor Intervention Project (STRIP) trial, with its main focus on the quality of fat in child nutrition, has had minimal influence on children's sodium intake. To avoid excessive sodium intake in children, dietary counselling should include information about salt use, and food manufacturers should be encouraged to provide more low-sodium products.

Child, Preschool↗

Special Turku Coronary Risk Factor Intervention Project for Babies (STRIP).

BACKGROUND: Introducing nutritional and lifestyle principles to children in late infancy may permanently improve their adherence to a low-saturated fat, low-cholesterol diet, thus reducing of coronary risk factors, but worries about possible effects on growth and development have hampered such an approach. OBJECTIVE: The Special Turku Coronary Risk Factor Intervention Project for Babies (STRIP) aimed to decrease exposure to known environmental atherosclerosis risk factors in children 7-36 mo of age. DESIGN: Repeated, individualized counseling aimed at promoting a fat intake of 30% of energy and a 1:1:1 ratio of saturated to monounsaturated to polyunsaturated fat intake was provided (n = 540 intervention children; 284 boys). Nutrition was discussed superficially with the families of the control children (n = 522; 266 boys) and food intake was recorded at 3-6-mo intervals by use of 3-4-d food diaries. Serum lipids were measured at 6-12-mo intervals and growth was monitored regularly. RESULTS: Fat intake of the intervention (control) children provided 29.5% (29.4%) of energy at the age of 8 mo, 26.6% (28.5%) of energy at 13 mo, 30.5% (33.5%) of energy at 24 mo, and 31. 5% (33.5%) of energy at 36 mo. The intervention children consistently consumed less saturated fat than did the control children (P: <0.0001). Recommended intakes of other nutrients (except vitamin D and occasionally iron) were reached irrespective of the amount and type of dietary fat. Serum cholesterol, non-HDL cholesterol, and HDL-cholesterol concentrations were 3-6% lower in the intervention children than in the control children. The intervention had no effect on height, weight, or head circumference gain. Fat intake did not predict children's growth patterns. CONCLUSION: Repeated, individualized counseling in early childhood aimed at reducing consumption of saturated fat and cholesterol was effective and feasible and did not restrict growth in circumstances in which children were regularly monitored.

Child Development↗

Cytokine balance and lipid antigen presentation in the NOD mouse pancreas during development of insulitis.

The role of cytokine balance and lipid antigen presentation in the development of diabetes was studied using immunohistochemistry of cytokines in the pancreas of non-obese diabetic mice (NOD) and BALB/c mice at various ages. In both the NOD and BALB/c mice, interleukin 10 (IL-10) was expressed in the islets. IL-10 was also present in the epithelial cells of the exocrine tissue in both strains. In the NOD mice, IL-10 disappeared from both the islets and the exocrine tissue at 16 weeks of age. At this age, IL-10 was still present in the islets and exocrine tissue of the BALB/c pancreata. IL-10 was not present in the pancreata of diabetic NOD mice. IL-6 first appeared in the pancreas at 10 weeks of age and disappeared at the age of 16 weeks in both NOD and BALB/c mice. It was present in the endothelial cells. Neither the pancreata of normal BALB/c mice nor NOD mice at 2-16 weeks of age contained tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), IL-4, or IL-12. At 8 weeks of age, a few IL-2+ cells were found in the pancreas of one of three NOD mice. CD1d was already present in both strains at 2 weeks of age but disappeared from the NOD mice at 16 weeks of age. CD1d localized to walls of tubular structures probably representing collecting tubules. These results suggest that in the NOD mice the disappearance of the T(H0), T(H1), and T(H2) responses inhibiting IL-10 from the islets at the age of 16 weeks may trigger the final stage of the immune response leading to overt diabetes. The simultaneous disappearance of CD1d suggests that activation of immune responses against lipid antigens does not play a role in this stage of the disease.

Aging↗

The role of lipid antigen presentation, cytokine balance, and major histocompatibility complex in a novel murine model of adoptive transfer of insulitis.

After adoptive transfer of insulitis from nonobese diabetic (NOD) mice, leukocytes accumulate in the pancreas of SCID/SCID and NOD/SCID mice. These cells express classical antigen-presenting molecules and costimulators of T-cell activation and adhesion molecules involved in homing. The aim of the present study was to study the expression of cytokines involved in regulation of the T(H1)/T(H2) balance by these cells, the role of lipid antigen presentation in the local immune system activation in the pancreas during onset of insulitis, and the role of major histocompatibility complex in this process. Splenocytes from NOD and BALB/c mice were injected intraperitoneally to SCID/SCID and NOD/SCID mice. Sections from the pancreata of these injected mice were stained for cytokines (tumor necrosis factor alpha [TNF-alpha], interferon gamma [IFN-gamma], CD1d, interleukin 2 [IL-2], IL-4, IL-6, IL-10, and IL-12). Some SCID/SCID and NOD/SCID mice injected with NOD splenocytes developed a severe disease. IL-10 was expressed in almost all the animals: in exocrine pancreas, large groups of infiltrating lymphocytes, endothelia of blood vessels, pancreatic islets, and interstitial tissue. CD1d was found in most of the mice: in the endothelia of collecting ducts and blood vessels of the pancreas, lymphocytic infiltrates, interstitial tissue, septae, islets, and a pancreatic lymph node. TNF-alpha was expressed notably more often in the pancreata of NOD/SCID than SCID/SCID mice. It was found between pancreatic lobules, in the epithelia of collecting ducts, endothelia of blood vessels, islets, capillaries, infiltrates, and septae. IL-6 was expressed more in the SCID/SCID than in the NOD/SCID mice. It was seen in infiltrates, walls of blood vessels, around islets, and in connective tissue. IFN-gamma was found only in the pancreata of SCID/SCID and NOD/SCID mice injected with NOD splenocytes. The expression of IL-2 and IL-12 was very scarce. IL-4 was not expressed at all. The present study clearly shows that antigen presentation has a role in the development of autoimmune diseases after adoptive transfer of splenocytes from diseased mice to intact ones and that IL-10 may have a central role in the control of the disease process.

Adoptive Transfer↗

Leucine 7 to proline 7 polymorphism in the preproneuropeptide Y is associated with birth weight and serum triglyceride concentration in preschool aged children.

The Leu7Pro gene variant of the signal peptide part of neuropeptide Y (NPY), has been shown to affect cholesterol metabolism in obese adults. This study investigates whether the Leu7Pro polymorphism in the prepro-NPY has an impact on serum lipid concentrations in preschool-aged children at 5 and 7 yr of age. As birth weight may influence future lipid values, we also investigated whether Leu7Pro polymorphism is associated with birth weight. The study comprised 688 children participating in the Special Turku Coronary Risk Factor Intervention Project. Fasting lipid concentrations were determined first at the age of 5 yr and again at the age of 7 yr. The Leu7Pro polymorphism was not associated with serum total or low density lipoprotein cholesterol values in boys or in girls. However, Pro7 substitution in prepro-NPY was constantly associated with 14-17% higher mean serum triglyceride values in the boys at the ages of 5 and 7 yr (P = 0.023). In addition, boys with the Pro7 substitution had, on the average, a 193-g higher birth weight than boys homozygous for Leu7 (P = 0.03). The Leu7Pro polymorphism may thus be linked with serum triglyceride concentrations, but not with serum cholesterol concentrations, in gender-specific manner in preschoolers.

Birth Weight↗

Non-class II HLA gene associated with type 1 diabetes maps to the 240-kb region near HLA-B.

Several studies provide evidence that in addition to the DQ-DR genes, HLA contains another uncharacterized gene or genes associated with type 1 diabetes. Our aim was to investigate the effect of this gene independently of the DQ-DR genes and to localize it with a matched case-control study. More than 1,400 patients and 30,000 control individuals from Finland were studied. They were first genotyped for the selected alleles of the HLA-DQB1, -DQA1, and -DRB1 genes. For the DR3/4(0404) genotype, 75 patients and 181 control subjects were stratified, and 241 patients and 354 controls were stratified for the DR3/4(0401) genotype. Ten microsatellite markers in the HLA class III and I regions (D6S273, TNFa, C12A, STR MICA, MIB, C125, C143, C245, C3211, and MOGc) and selected alleles of the HLA-A and HLA-B genes were studied. In the DR3/4(0404)-stratified group, we found that markers located between C12A and C143 near the HLA-B gene confer a strong additional diabetes association. This was confirmed by the population differentiation test in both DR3/4(0404)- and DR3/4(0401)-stratified groups. Our data indicate that an additional gene associated with type 1 diabetes is located in the 240-kb region near HLA-B. We excluded STR MICA polymorphism as a mutation responsible for diabetes association.

Adolescent↗

T-cell responses to enterovirus antigens in children with type 1 diabetes.

Enterovirus infections, implicated in the pathogenesis of type 1 diabetes in a number of studies, may precipitate the symptoms of clinical diabetes and play a role in the initiation of the beta-cell damaging process. The aim of this study was to evaluate whether cellular immune responses to enterovirus antigens are abnormal in children with type 1 diabetes. Lymphocyte proliferation responses to enterovirus antigens were analyzed in 41 children with new-onset type 1 diabetes, 23 children with type 1 diabetes for 4-72 months, and healthy control children in subgroups matched for HLA-DQB1 risk alleles, sex, and age. Children with diabetes for 4-72 months more often had T-cell responses to the Coxsackievirus B4-infected cell lysate antigen than children with new-onset diabetes (P < 0.01) or control children (P < 0.01). Responses to recombinant nonstructural protein 2C of Coxsackievirus B4 were also more frequent in children with type 1 diabetes for 4-72 months when compared with control subjects (P = 0.03), whereas the responses to purified Coxsackievirus B4 and recombinant VP0 protein, which did not contain nonstructural proteins, did not differ. These data suggest that T-cell responses to Coxsackievirus B4 proteins and particularly to the antigens containing the nonstructural proteins of the virus are increased in children with type 1 diabetes after the onset of the disease. However, in children with new-onset diabetes, responses were normal or even decreased. This phenomenon was specific for enteroviruses and could be caused by trapping of enterovirus-specific T-cells in the pancreas.

Age of Onset↗

Enterovirus infection as a risk factor for beta-cell autoimmunity in a prospectively observed birth cohort: the Finnish Diabetes Prediction and Prevention Study.

Previous studies suggest that enterovirus infections may initiate and accelerate beta-cell damage years before the clinical manifestation of type 1 diabetes. We have now analyzed the role of enterovirus infections in the initiation of autoimmunity in children who have tested positive for diabetes-associated autoantibodies in a prospective study starting at birth (the Finnish Diabetes Prediction and Prevention Study). The frequency of enterovirus infections was studied using both serology and testing for the presence of enterovirus RNA in the sera of 21 children who developed and retained autoantibodies and in 104 control subjects chosen from the same study cohort and matched for the time of birth, sex, and HLA alleles determining genetic diabetes susceptibility. Sample intervals were taken as basic units of follow-up, to which the observed number of infections was adjusted. Enterovirus infections were detected in 26% of sample intervals in the case subjects and in 18% of the sample intervals in the control children (P = 0.03). A temporal relationship between enterovirus infections and the induction of autoimmunity was found; enterovirus infections were detected in 57% of the case subjects during a 6-month follow-up period preceding the first appearance of autoantibodies compared with 31% of the matched control children in the same age-group (odds ratio 3.7, 95% CI 1.2-11.4). The frequency of adenovirus infections did not differ between the patient and control groups. Our data imply that enterovirus infections are associated with the development of beta-cell autoimmunity and provide evidence for the role of enteroviruses in the initiation of beta-cell destruction.

Alleles↗

Apoptosis in the pattern formation of the ventricular wall during mouse heart organogenesis.

Apoptosis is an important mechanism in organogenesis, but its role in heart development has been poorly characterized. We have here studied apoptosis in the developing ventricular wall of mouse embryonic heart. Developing mice hearts on days 11 to 16 of gestation were studied using in situ end-labeling of degraded DNA (TUNEL), immunocytochemistry of regulatory genes Bcl-2 and Bax, and light and electron microscopy. TUNEL end-labeled apoptotic cells were found in the ventricular wall on days 11 to 16 of gestation. The proportions of apoptotic cells of all cells in the ventricular wall differed between the trabecular and compact regions (P = 0.003) and between the days of gestation (P = 0.0001), the calculated apoptotic index was greater in the compact region at all ages except day 14. Ultrastructural analysis showed typical apoptotic shrinkage, chromatin degradation, and apoptotic bodies in several myoblastic and myocardial endothelial cells which were also positive by DNA end-labeling. Immunocytochemical reaction for the apoptosis checkpoint proteins in the ventricular wall showed clearly more Bcl-2 positive cells than Bax positive cells. The numerical densities of all cells in the compact and trabecular regions remained always higher in the compact region (P = 0.04) despite the fact that apoptosis was present in both areas at the same time. In conclusion, apoptosis takes place in the developing myocardial muscle as well as the myocardial endothelium during ventricular morphogenesis on days 11 through 16 and decreases clearly on day 16. We suggest that apoptosis and its regulatory factors are closely involved in the morphogenesis of the ventricular wall of the mammalian heart.

Animals↗

Reduced brain creatine in gyrate atrophy of the choroid and retina with hyperornithinemia.

OBJECTIVE: To analyze in vivo brain creatine (Cr) content in gyrate atrophy of the choroid and retina with hyperornithinemia (GA). BACKGROUND: GA is caused by inherited deficiency of ornithine-delta-aminotransferase activity. Patients lose their vision by middle age and develop selective atrophy of type II skeletal muscle fibers. As demonstrated by MRS, the patients' skeletal muscles have diminished stores of high-energy Cr phosphate. Minor structural and electrophysiologic abnormalities in the brain of these patients also imply that the CNS may be affected. METHODS: The authors acquired proton MR spectra of the basal ganglia of 22 healthy control subjects and 20 GA patients. Nine patients received supplementary Cr or its precursors, and one child was on an arginine-restricted diet to normalize plasma ornithine concentration. The ratios of N-acetylaspartate (NAA) to Cr, NAA to choline (Cho), and Cho to Cr, and the ratios of NAA, Cho, and Cr to tissue water were calculated. RESULTS: NAA/Cr (Cho/Cr) in the untreated and treated patients and control subjects were (mean +/- SD) 3.3+/-0.4, 2.0+/-0.4, and 1.5+/-0.7 (1.9+/-0.3, 1.3+/-0.4, and 0.9+/-0.2), indicating that Cr content in untreated GA patients was proportionally and markedly diminished, and partially corrected by therapy (p < 0.0001). NAA/Cho was similar in all three groups. Cr/water in the untreated patients was only 46%, and increased to 75% of the control ratios in the treated patients (p < 0.0001). CONCLUSIONS: Hyperornithinemia-associated Cr deficiency in GA also affects the CNS, further supporting the possibility that Cr deficiency also has a pathogenetic role in the retina. The deficiency was partially corrected by Cr supplementation and an arginine-restricted diet.

Adolescent↗

Central nervous system involvement in gyrate atrophy of the choroid and retina with hyperornithinaemia.

In gyrate atrophy of the choroid and retina with hyperornithinaemia (GA), a genetically determined deficiency of ornithine delta-aminotransferase activity leads to high ornithine concentrations in body fluids. GA is characterized by centripetally progressing retinal and choroidal destruction and selective atrophy with tubular aggregates in type II skeletal muscle fibres. These findings have been suggested to be mediated by hyperornithinaemia-induced deficiency of high-energy creatine phosphate. As abnormal brain magnetic resonance images and electroencephalograms are found in another disorder of creatine metabolism, guanidinoacetate methyltransferase deficiency, we investigated the central nervous system involvement in GA, which seems to be associated with a milder degree of phosphocreatine deficiency. We compared 23 untreated GA patients with age-matched healthy controls, and with 9 patients who had received creatine or creatine precursor supplementation daily for several years. The mean age of the patients (32 +/- 18 years) was similar to that of the controls (36 +/- 22 years). The MRI or EEG findings of the patients on creatine supplementation did not differ from those of the untreated group. Brain MRI revealed degenerative lesions in the white matter in 50% of the GA patients, and 70% of the patients had premature atrophic changes, with a striking increase in the number of Virchow's spaces. Of the patients whose EEG was recorded, 58% had abnormal slow background activity, focal lesions or high-amplitude beta rhythm (> 50 microV). The EEG findings were not associated with the MRI changes or with the age or the sex of the patients. Early degenerative and atrophic brain changes and abnormal EEG are thus features of GA, in addition to the well-characterized eye and muscle manifestations.

Adolescent↗