PURPOSE: This study was performed to describe the ultrastructure of stromal nerve fibers in central, mid-peripheral, and peripheral parts of the human cornea by flat serial corneal section. METHODS: Seven samples from fresh normal cornea, derived from eyes with retinoblastoma and eyes from eye bank, were processed for transmission electron microscopic examinations. Flat serial sections reaching from mid-epithelium to the anterior stroma were observed. RESULTS: The myelinated and unmyelinated nerve fibers are alternately arranged and run parallel to the stromal collagen fibers at the periphery of the cornea. The main difference between the limbal and the central cornea is the presence of myelinated nerve fibers in the anterior peripheral stroma. The diameter of the unmyelinated nerve fiber measures between 0.25 and 0.63 micrometer in size. The corneal nerve fibers contain vesicles, mitochondria, and glycogen particles. The peripheral nerve fibers contain both clear and dense vesicles. The nerve fiber is separated by an interval of 0.3 micrometer from the cytoplasmic wall of keratocyte at the center of the cornea. CONCLUSIONS: The majority of the corneal nerve fibers can be classified as C-fibers due to their size. The presence of both clear and dense vesicles within the cytoplasm of the periphery of the cornea suggest that a small portion in the peripheral corneal nerve may be originated from the sympathetic nervous system. A close vicinity between the nerve fibers and keratocyte supports that nerve fibers might modulate the release of growth factors in the regulation of stromal and epithelial metabolism.
Collagen ; Cornea ; Cytoplasm ; Eye Banks ; Glycogen ; Humans ; Intercellular Signaling Peptides and Proteins ; Metabolism ; Mitochondria ; Myelin Sheath ; Nerve Fibers ; Nerve Fibers, Myelinated ; Nerve Fibers, Unmyelinated ; Peripheral Nerves ; Retinoblastoma ; Sympathetic Nervous System

OBJECTIVE: To set up the methodology for PCR analysis of XbaI/intron 22 polymorphism of the factor VIII gene, and to identify the usefulness of XbaI/intron 22 polymorphism analysis for carrier detection and prenatal diagnosis of hemophilia A in the Korean population. DESIGN: A laboratory analysis. MATERIALS AND METHODS: A XbaI/intron 22 polymorphism of the factor VIII gene was analyzed in 56 unrelated Korean mothers of patients with severe hemophilia A, using polymerase chain reaction. RESULTS: Analysis of XbaI/intron 22 polymorphisms of the factor VIII gene were feasible by PCR method. The expected heterozygosity rates of XbaI/intron 22 polymorphism of the factor VIII gene were 44.8%. Analysis of XbaI/intron 22 polymorphism revealed heterozygous patterns in 22 (39.3%) of 56 mothers studied. Using linkage analysis with XbaI/intron 22 polymorphism, we have attempted one case of carrier detection and two cases of prenatal diagnosis in two families of patients with severe hemophilia A. CONCLUSION: These results suggest that PCR analysis of the XbaI/intron 22 polymorphism within the factor VIII gene is very useful in the carrier detection and prenatal diagnosis of hemophilia A in the Korean population.
Diagnosis* ; DNA* ; Factor VIII ; Hemophilia A* ; Humans ; Molecular Biology* ; Mothers ; Polymerase Chain Reaction* ; Prenatal Diagnosis

BACKGROUND: Diamond Blackfan anemia (DBA), characterized by impaired red cell production, is a rare condition that is usually symptomatic in early infancy. The purpose of this study was to assess nationwide experiences of DBA encountered over a period of 20 years. METHODS: The medical records of 56 patients diagnosed with DBA were retrospectively reviewed from November 1984 to July 2010. Fifteen institutions, including 13 university hospitals, participated in this study. RESULTS: The male-to-female ratio of patients with DBA was 1.67:1. The median age of diagnosis was 4 months, and 74.1% were diagnosed before 1 year of age. From 2000 to 2009, annual incidence was 6.6 cases per million. Excluding growth retardation, 38.2% showed congenital defects: thumb deformities, ptosis, coarctation of aorta, ventricular septal defect, strabismus, etc. The mean hemoglobin concentration was 5.1+/-1.9 g/dL, mean corpuscular volume was 93.4+/-11.6 fL, and mean number of reticulocytes was 19,700/mm3. The mean cellularity of bone marrow was 75%, with myeloid:erythroid ratio of 20.4:1. After remission, 48.9% of patients did not need further steroids. Five patients with DBA who received hematopoietic transplantation have survived. Cancer developed in 2 cases (3.6%). CONCLUSION: The incidence of DBA is similar to data already published, but our study had a male predilection. Although all patients responded to initial treatment with steroids, about half needed further steroids after remission. It is necessary to collect further data, including information regarding management pathways, from nationwide DBA registries, along with data on molecular analyses.
Anemia ; Anemia, Diamond-Blackfan ; Aortic Coarctation ; Bone Marrow ; Congenital Abnormalities ; Diamond ; Erythrocyte Indices ; Heart Septal Defects, Ventricular ; Hemoglobins ; Hospitals, University ; Humans ; Incidence ; Korea ; Male ; Medical Records ; Registries ; Reticulocytes ; Retrospective Studies ; Steroids ; Strabismus ; Thumb ; Transplants