Structural and Functional Alterations at Pre-Epileptic Stage Are Closely Associated with Epileptogenesis in Pilocarpine-induced Epilepsy Model

Pilocarpine-induced rat epilepsy model is an established animal model that mimics medial temporal lobe epilepsy in humans. The purpose of this study was to investigate neuroimaging abnormalities in various stages of epileptogenesis and to correlate them with seizure severity in pilocarpine-induced rat epilepsy model. Fifty male Sprague-Dawley rats were subject to continuous video and electroencephalographic monitoring after inducing status epilepticus (SE) and seizure severity was estimated by frequency and total durations of class 3 to 5 spontaneous recurrent seizures (SRS) by modified Racine's classification. The 7.0 Tesla magnetic resonance imaging (MRI) with high resolution flurodeoxyglucose positron emission tomography (FDG-PET) was performed at 3 hours, 1, 3, 7 days and 4 weeks after the initial insult. The initial SRS was observed 9.7±1.3 days after the pilocarpine injection. MRI revealed an abnormal T2 signal change with swelling in both hippocampi and amygdala in acute (day 1 after injection) and latent phases (days 3 and 7), in association with PET hypometabolism in these areas. Interestingly, the mean frequency of class 3 to 5 SRS was positively correlated with abnormal T2 signals in hippocampal area at 3 days. SRS duration became longer with more decreased glucose metabolism in both hippocampi and amygdala at 7 days after pilocarpine injection. This study indicates that development and severity of SRS at chronic phase could be closely related with structural and functional changes in hippocampus during the latent period, a pre-epileptic stage.

Technique failure in Korean incident peritoneal dialysis patients: a national population-based study

BACKGROUND: Technique failure is an important issue for peritoneal dialysis (PD) patients. In this study, we aimed to analyze technique failure rate in detail and to determine the predictors for technique failure in Korea. METHODS: We identified all patients who had started dialysis between January 1, 2005, and December 31, 2008, in Korea, using the Korean Health Insurance Review and Assessment Service database. A total of 7,614 PD patients were included, and the median follow-up was 24.9 months. RESULTS: The crude incidence rates of technique failure in PD patients were 54.1 per 1,000 patient-years. The cumulative 1-, 2-, and 3-year technique failure rates of PD patients were 4.9%, 10.3%, and 15.6%, respectively. However, those technique failure rates by Kaplan–Meier analysis were overestimated compared with the values by competing risks analysis, and the differences increased with the follow-up period. In multivariate analyses, diabetes mellitus and Medical Aid as a crude reflection of low socioeconomic status were independent risk factors in both the Cox proportional hazard model and Fine and Gray subdistribution model. In addition, cancer was independently associated with a lower risk of technique failure in the Fine and Gray model. CONCLUSION: Technique failure was a major concern in patients initiating PD in Korea, especially in diabetic patients and Medical Aid beneficiaries. The results of our study offer a basis for risk stratification for technique failure.

Improving Survival Rate of Korean Patients Initiating Dialysis

PURPOSE: The aim of this study was to investigate whether the survival rate among Korean dialysis patients changed during the period between 2005 and 2008 in Korea. MATERIALS AND METHODS: A total of 32357 patients who began dialysis between January 1, 2005 and December 31, 2008 were eligible for analysis. Baseline demographics, comorbidities, and mortality data were obtained from the database of the Health Insurance Review & Assessment Service. RESULTS: Kaplan-Meier curves according to the year of dialysis initiation showed that the survival rate was significantly different (log-rank test, p=0.005), most notably among peritoneal dialysis (PD) patients (p<0.001), although not among hemodialysis (HD) patients (p=0.497). In multivariate analysis, however, patients initiating either HD or PD in 2008 also had a significantly lower risk of mortality compared to those who began dialysis in 2005. Subgroup survival analysis among patients initiating dialysis in 2008 revealed that the survival rate of PD patients was significantly higher than that of HD patients (p=0.001), and the survival benefit of PD over HD remained in non-diabetic patients aged less than 65 years after adjustment of covariates. CONCLUSION: Survival of Korean patients initiating dialysis from 2005 to 2008 has improved over time, particularly in PD patients. In addition, survival rates among patients initiating dialysis in 2008 were different according to patients' age and diabetes, thus we need to consider these factors when dialysis modality should be chosen.

Excess mortality among patients on dialysis: Comparison with the general population in Korea

BACKGROUND: Although patients with end-stage renal disease (ESRD) experience excess mortality compared with the general population, the standardized mortality ratio (SMR) for Korean patients on dialysis has not yet been investigated. In this study, we evaluated the SMR among all Korean ESRD patients on maintenance ialysis in 2009 and 2010, and compared it according to age categories, sex, and dialysis modality. METHODS: We used data from all patients on maintenance dialysis between January 1, 2009 and December 31, 2010 in Korea using the database of the Korean Health Insurance Review and Assessment Service, and the SMR was determined by calculating of the ratio between the number of actual deaths and expected deaths. RESULTS: A total of 45,568 patients in 2009 and 48,170 patients in 2010 were included in the analysis. The overall age- and sex-adjusted SMR was 10.3 [95% confidence interval (CI), 10.0-10.6] in 2009 and 10.9 (95% CI, 10.7-11.2) in 2010. The SMR for females was much higher than for males. The SMR gradually decreased with increasing age groups. The overall SMR for maintenance hemodialysis patients was lower than that of peritoneal dialysis patients. CONCLUSION: The SMR among Korean ESRD patients is likely to be higher than in other countries. Further evaluation is needed to attempt to improve the outcomes.

Incidence and Epidemiological Characteristics of 2009 Pandemic Influenza A (H1N1) Among School-Based Populations in Korea / 감염과화학요법

BACKGROUND: During the 2009 influenza pandemic in Korea, school-age children were mostly attacked by the novel influenza A virus (H1N1). Nevertheless, there is limited information on the cumulative incidence of the 2009 influenza pandemic among school populations. The aim of this study was to estimate the incidence of 2009 H1N1 influenza and influenza-like illness (ILI), and characterize the epidemiology among school-based populations in Korea. MATERIALS AND METHODS: This study analyzed the data collected by the daily school influenza reporting system for laboratory-confirmed influenza (H1N1 2009 pdm) and ILI in elementary, middle and high schools in Korea during the period, July 1 to December 20, 2009. RESULTS: Between July 1 and December 20, 2009, a total of 525,668 cases of H1N1 2009 pdm were reported from the schools analyzed. The cumulative incidence of H1N1 2009 pdm was highest in elementary school children between 8 and 13 years of age (11,058 per 100,000 population), followed by middle school students between 14 and 16 years of age (10,080 per 100,000), and high school students between 17 and 19 years of age (8,886 per 100,000). With the alignment of the epidemic curves by the three levels of school education, the age group-specific differences in the timing of the infection became apparent. The infections peaked 1 week earlier in both middle and high school students (November 3, 2009) than in elementary school children (November 10, 2009). The infections occurred an average of 7.3 [95% confidence interval(CI): 7.2-7.4] and 3.4 (95% CI: 3.3-3.5) days earlier in the middle and high school students, respectively, than elementary school children (P<0.001). The overall trend of the epidemic waves from the school reporting system data was similar to that of the national surveillance date from the Korea Centers for Disease Control and Prevention. CONCLUSIONS: This study suggests that during the 2009 pandemic, one student in every 10 was infected with H1N1 2009 pdm, which is double that estimated from the national surveillance data. In addition, middle and high school students were important drivers of H1N1 2009 pdm transmission in 2009. During the 2009 influenza pandemic, the daily school reporting system provided valuable information for estimating the incidence as well as the epidemiological characteristics in school-based populations.

Genomic Alterations Detected in Colon Cancer Cell Lines by Using Array-Comparative Genomic Hybridization / 대한해부학회지

Cancer development is accompanied by genetic events like losses, gains and amplification of certain chromosome regions or alterations of chromatin structure. Array-based CGH (Array-CGH) is a highly comprehensive, sensitive and fast technique to allow investigation of general changes in target oncogenes and tumor suppressor genes. Recently, the prevalence of colon cancer is rapidly increasing in Korea and now it is the fourth leading cause of cancer death. So, the purpose of this study is to examine genomic alterations in colon cancer cell lines and to search novel genes which might be related to the development of colon cancer. In this study, genomic alterations are analyzed by using array-CGH in three colon cell lines from Korean, SNU-81, SNU-407 and SNU-1047. We observed numerous chromosomal imbalances from all cell lines. The common chromosomal gains were observed in 1p36.33, 1q22, 1q32.1, 2q35, 8p12, 8q22.3, 14q32.33, 16p13.3, and 16q24. Common chromosomal losses were found in 4q22.1, 9q13, 14q21.1, 14q32.33, 20p12.1, Xq21.1, and Yq11.223. Gains of 1p, 2q, 8p, and 8q or losses of 4q, 14q and 20p are already known to be associated with the colon cancer development. For gene alterations, we could see gains of some genes such as ELF3 and AAMP, which were already reported to be associated with colon cancer. Also, we could find some gene alterations which were known to be associated with other cancer types. These genes were GON4L, RNPEP, TMBIM1, TIMM17A, GPBAR1, PPP1R13B and SOX8. Besides, we found alterations of new genes such as PKND and LEPROTL1. The association of these genes with colon cancer is first demonstrated here. These genes may be the novel candidate genes functioning in the development of colon cancer. In conclusion, array-CGH demonstrated the complexity of genetic aberrations in several colon cell lines. These data about the patterns of genomic alterations could be a basic step for understanding more detailed genetic events in the carcinogenesis and also provide information about possible target genes for diagnosis and treatment in colon cancer.

Analysis of Genomic Alterations in Retinoblastoma Cell Lines by Array-CGH / 대한해부학회지

Retinoblastoma is the most common intraocular malignancy in young children, arising in approximately 1 per 20,000 live births. Although it is established that the functional loss of both alleles of the RB1 gene is a prerequisite for the development of retinoblastoma, little is known about the genetic events that are required for tumor progression. To screen the genomic aberrations, two retinoblastoma cell lines, Y-79 and WERI-Rb-1, were analysed by using array-CGH. As a result, gains of AHRR, EXOC3, CEP72, TRIP13, TERT, SEMA5A, TAS2R1, MARCH6, CTNND2, CDH12, NHLRC1, TPMT, AOF1, FANCC, NCBP1, XPA, TGFBR1, BAAT, MRPL50, ZNF189, ALDOB, ABCA1, FCMD, TAL2, ZNF462, COL27A1, ORM1, ORM2, AKNA, ASTN2, TRIM32, GSN, STOM, LHX2, PBX3, ABL1, FIBCD1, WNK4, CCDC56, CNT1, BECN1, PSME3, AOC2, LOXHD1, ST8SIA5, SMAD2, KIAA0427, COL18A1, COL6A2, FTCD and LSS were found in both cell lines. Lost clones detected in both cell lines were RB1, ZDHHC3, EXOSC7, CLEC3B, CACNA2D3, DEFB106A, FAM90A6P, FAM90A7, ZMYND11, LARP5, GTPBP4, IDI2, IDI1, KLF6, AKR1CL2, FBXO18, IL15RA, IL2RA, TAF3, GATA3, CUGBP2, DHTKD1, SEC61A2, NUDT5, ITGA8, PTER, C1QL3, RSU1, DNMT2, PTPLA, PLXDC2, NEBL, MLLT10, DNAJC1, PIP5K2A, PRTFDC1, NRP1, PARD3, MGMT, RFP2OS, RFP2, KCNRG, IGHV, CDH19, TXNDC10 and RTTN. Through this study, it is confirmed that many genomic aberrations are involved in the development and progression of retinoblastoma. Genomic profiling of retinoblastoma cell lines by array-CGH revealed numerous imbalanced regions and novel candidate genes. These data provide a basis for more detailed molecular characterization and testing their pathologic roles of these candidates.

Spatial and Temporal Patterns of SPARC and VEGF Immunoreactivities in the Rabbit Retina in Early Postnatal Life / 대한해부학회지

Tissue-derived angiogenic factors are thought to play an important role in angiogenesis. Among these, SPARC and VEGF are known to be involved in physiologic and pathologic angiogenesis. However, the expression of these factors in the rabbit retina, especially in the early postnatal period, remains unclear. To determine whether these factors contribute to retinal angiogenesis in the rabbit retina, expression of SPARC and VEGF was studied by immunohistochemistry at postnatal (P) days 0, 7, 14, and 28. (1) SPARC immunoreactivity was observed in the nerve fiber layer of the medullary ray and the pigment epithelium at all ages. In whole mount preparations, SPARC immunoreactivity was noted in many astrocytes surrounding nerve fibers or blood vessels in the medullary ray. (2) VEGF immunoreactivity of variable intensity was found in ganglion cells, vascular endothelial cells, and some astrocytes. VEGF immunoreactivity was detected from P0, was maintained until P14, and was markedly lower at P28. The spatial pattern of SPARC expression suggests that SPARC functions as a crucial regulator that determines the selective location of the retinal angiogenic process. The temporal pattern of VEGF expression suggests that VEGF is a major angiogenic factor involved in rabbit retinal angiogenesis.

Morphological Study of the Nerve Regeneration in Relation to the Laryngeal Functional Recovery after Recurrent Laryngeal Nerve Injury in Rat / 대한해부학회지

Recovery from the laryngeal dysfunction caused by the recurrent laryngeal nerve (RLN) injury is not common. Recently, we have found that PEMS treatment improved the functional recovery rate and shortened the recovery time after RLN transection and reanastomosis in rat. In this study, we compared the morphology of RLN stumps according to their laryngeal functional status to investigate 1) the nerve morphology associated with functional recovery and 2) the possible underlying mechanism of persistent laryngeal dysfunction after RLN injury. We transected left RLN and then performed primary neurorrhaphy in Sprague-Dawley rats (n = 36). They were randomly divided into PEMS and control groups. 19 animals (10 PEMS group, 7 control group and 2 normal control animals) survived until the end of the experiment were included in the morphological analysis. Both the proximal and distal segments of reanastomosed RLN were obtained and the ultrastructural study was done using transmission electron microscope. There is no prominent morphological difference between the PEMS and control groups. In the functional recovery group, the findings suggestive of nerve regeneration were prominent both in the proximal and distal segments. Many regenerating axons were also observed in the proximal segments of RLNs in non-recovery group. But findings such as degenerating axons, infiltration of macrophage and inflammatory cells, increased collagen fibrils were frequently observed in this group. Even in the distal segments of functional non-recovery group, prominent regenerative findings were observed in 9 out of 10 (4 out of 5 PEMS and all control group animals) samples. We could not find any regenerating findings in one case of the PEMS group. Through the above results, failure of the nerve regeneration is unlikely the main cause of functional non-recovery after RLN injury in rat. Possible other causes such as synkinesis or definite but inadequate nerve regeneration should be considered and needs further investigation.

Ectopic Tyrosine Hydroxylase-immunoreactive Neurons in the 6-OHDA-lesioned Striatum in Neonatal Rat / 대한해부학회지

Tyrosine hydroxylase-immunoreactive (TH-IR) neurons are known to exist in the substantia nigra pars compacta (SNpc), but not in the striatum in normal rats. In this study, injection of 6-OHDA into the 7 or 14 day neonatal rat striatum resulted in the appearance of ectopic TH-IR neurons in striatum. TH-IR cells were observed as early as postlesion day 3 and confirmed as neurons by TH/NeuN double immunohistochemistry. One or two neurons were found in most striatal sections at post-lesion day 4 where they were preferentially located in the ventro-lateral striatum, striatopallidal junction and globus pallidus. A small portion of these neurons persisted at least until post-lesion day 56, the oldest age studied. TH-IR neurons were found bilaterally in 6-OHDA-lesioned animals, but never in normal or vehicle-injected controls. To determine if these neurons resulted from stem cells, bromodeoxyuridine (BrdU) was injected daily for the first five days to label dividing cells. There was no co-localization of TH and BrdU immunoreactivity, excluding the possibility of stem cells as the source of these neurons. Although the TH-IR neurons were not numerous, their appearance following injury to the nigrostriatal system suggests that there is a capacity in neonatal brain to compensate for this lesion by upregulating dopaminergic phenotypic characters in pre-existing cells. The mechanism underlying this interesting phenotypic plasticity is unknown, but may be relevant to developing novel therapies for Parkinson's disease through stimulation of the brain's own potential for repair.

Effects of Folate Supplementation on Cerebral Nuclear Factor-kappa B (NF-kappaB) and Endothelial Nitric Oxide Synthase Activities in Experimental Hyperhomocysteinemia / 대한해부학회지

Homocysteine is a significant but modifiable risk factor for vascular diseases, including stroke. While several pathological processes may be involved, homocysteine can cause significant endothelial impairment and compromise vascular nitric oxide (NO) bioactivity. Endothelial dysfunction can be characterized not only by impaired vasoreactivity with decreased availability of NO but also abnormal inflammatory cell-endothelial interactions and increased expression of cell adhesion molecules. Nuclear factor-kappa B (NF-kappaB) is a transcriptional factor which plays a coordinating role in inflammation and cellular proliferation and may be involved in early atherosclerosis. Experimentally, we investigated the effects of folate supplementation on endothelial nitric oxide synthase (eNOS) activity in the hyperhomocysteinemic rat brain and related the changes of eNOS activity to the expression of NF-kappaB. Animals were raised on an experimental diet containing 0.3% homocystine for 4 weeks or on a 0.3% homocystine diet for 2 weeks with or without folate supplementation (8 mg/kg diet). The cerebrovascular endothelial nitric oxide synthase (eNOS) activity was investigated by the immunohistochemical method. Cerebral contents of eNOS and NF-kappaB were also evaluated with the western blot analysis. At 4 wks, diet- induced hyperhomocysteinemia up to 4-fold (control: 6.5+/-0.4 micromol/L, homocystine: 26.2+/-2.5 micromol/L), and a reduction in the expression of cerebral eNOS with a concomitant increase in NF-kappaB. Dietary folate supplementation caused a significant decrease in plasma homocysteine levels with a concomitant increase in hyperhomocysyeinemia-induced reduction of the cerebral eNOS and decrease in hyperhomocysyeinemia-induced NF-kappaB expression.

Morphological Changes of Astrocytes and Muller Cells in the Neonatal Rat Model of Retinopathy of Prematurity / 대한해부학회지

OBJECTIVES: Retinopathy of prematurity (ROP) is one of the major cause of vision loss among children. Recently, the prevalence of ROP is markedly increasing as the survival rate of very-low-birth-weight premature infants has been improved. It is widely accepted that retinal hypoxia results in the release of factors influencing new blood vessel growth. But, it is little known about the morphological changes of retinal astrocytes and Muller cells in the ROP model. So, we planned to investigate the morphological changes of those retinal glial cells induced by alternating hyperoxic and hypoxic injury in ROP. METHODS: Newborn rats (postnatal day 6) were exposed to two different oxygen concentrations alternating every 24 hours until postnatal day 14. Used oxygen concentrations were 10~15% for hypoxic episode and 55~80% for hyperoxic episode. Afterthen, they were returned to room air. A group of animal served as a room air control. Retinal vascularity was assessed by ADPase reaction and morphology of retinal glial cells was observed using transmisson electron microscope. RESULTS: Preretinal neovascular tufts were observed in 2 out of 12 animals of group III (75/10%) and 4 out of 12 animals of group IV (80/10%), respectively. There was no remarkable structural change of astrocytes. But we could observe some morphological changes of Muller cells. Retraction of the radial processes of Muller cells and breaking of basal lamina were noted at the site of preretinal neovascularization. Decrease in the space occupied by the cytoplasmic processes of Muller cells was observed in the inner nuclear layer of group IV retinae. Infiltration of microglia or macrophage into the vitreo-retinal interface and the site of extravasation was noted. Findings suggestive of neuronal cell death were also observed especially in the inner nuclear layer. CONCLUSIONS: Morphological change of Muller cells and resultant loss of integrity of internal limiting membrane seemed to be the most important step for preretinal neovascularization. But, no structural changes of astrocytes were noted.

The Effects of Pulsed Electromagnetic Stimulation on Functional Recovery Following Laryngeal Reinnervation in the Rat / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Ideal treatment for vocal cord paralysis is to restore normal movement of the vocal cord and to bring back the natural voice. Pulsed electromagnetic stimulation (PEMS)has been known to bring early nerve regeneration as well as better functional recovery. The purpose of this investigation is to learn the effect of PEMS on regeneration of the recurrent laryngeal nerve. MATERIALS AND METHOD: Using 36 healthy male Sprague-Dawley rats, we made transections on their left recurrent laryngeal nerves and performed primary anastomosis under the operating microscope. Rats were divided into an experimental group and a control group, each having 18 rats by random sampling. For the experimental group, PEMS was carried out three hours a day and five days a week for twelve weeks. For the control group, PEMS was not given while other conditions were kept the same as in the experimental group. The extent of functional recovery was observed for each group by performing videostroboscopic examination once every week. After twelve weeks, a test for the functional recovery was performed electrophysiologically through laryngeal electromyography during respiration. RESULTS: After the twelve-week experiment, 14 out of 18 rats survived in the group which received PEMS while 8 out of 18 rats stayed alive in the control group. Ten rats (71%)in the PEMS performed group and 3 rats (38%)in the control group showed recovery of vocal cord movement, but it did not reveal any significant difference statistically. However, the time it took for functional recovery was 3.93+/-0.27 weeks and 7.87+/-0.85 weeks for the PEMS performed group and the control group, respectively. And the difference was statistically significant. CONCLUSION: This investigation confirmed the efficacy of PEMS on the early functional recovery in rats with surgically transected and reanastomosed recurrent laryngeal nerve. Further studies to understand the mechanism of action of these effects as well as the local stimulation rather than the total body stimulation seem to be necessary.

Synaptic Morphology of the Mouse Striatal Cholinergic Neurons in the Early Postnatal Life / 대한해부학회지

The cholinergic neurons in the striatal complex are the major interneurons that integrate the informations incoming to and outflowing from the striatum. The shape of synapses may change even after birth and the synaptic morphology reflects the functional state of synapse. However, it is not well known about the synaptic morphology of the mouse striatal cholinergic neurons in their early postnatal life. Thus, we investigated the synaptic morphology of the mouse striatal cholinergic neurons in their early postnatal life by the electron microscopy combined with immunohis-tochemistry. In addition, we investigated the trends of change in synaptic morphology and whether the difference between two compartments exists or not. Experimental animals which are ICR mice, were divided into 5 groups according to their postnatal age: 3-day, 1-week, 2-week, 4-week, and 6-week. Pre-embedding immunohisto-chemistry was done with anti-choline acetyl transferase antibody. The results were as follows. 1. In synapses that immunoreactive terminals constitute the presynaptic components, most of synapses are symmetric type in all age groups (p<0.05). Most of synapses in the dorsal striatum are symmetric form from 1-week of postnatal age, but it is not prominent in the ventral striatum until 2-week of postnatal age. 2. In synapses that immunoreactive terminals constitute the postsynaptic components, both symmetric and asymmetric synapses are noted in similar proportions (p<0.05). There are no difference in the synaptic morphology between dorsal and ventral striatum. 3. No specific findings are observed in synaptic curve according to the postnatal age or compartment. In conclusion, the synaptic morphology of mouse striatal cholinergic neurons is similar to mature pattern from 2-week of postnatal age. And it is thought that period between birth and 2-week of postnatal age is the critical period for synaptogenesis. The synaptic curve does not reflect the degree of synaptic maturity. Further investigations will be required to generalize the synaptic curve as a marker for synaptic maturity.

VEGF and SPARC Immunoreactivities in the Rat Retina / 대한해부학회지

Normal angiogenesis is very important in the embryonic period and even in the postnatal period. If the vascularization is inadequate or excessive, several pathologic conditions may develop. Angiogenesis is well controlled and there are several angiogenic factors. Vascular endothelial growth factor (VEGF) has been identiified as an endothelial cell specific mitogen with potent angiogenic properties. Recently, a matricellular protein known as SPARC (secreted protein, acidic and rich in cysteine) is also proposed as one of new angiogenic factors. So, I planned to investigate the expression pattern of these two factors in the rat retina and to correlate their expression pattern with intraretinal vascularization. I used Sprague-Dawley rat as the experimental animals and divided them into 7 groups according to their postnatal age: 0-day, 3-day, 7-day, 14-day, 21-day, 28-day and adult. Immunohistochemistry was done. The results were as follows. 1. No SPARC immunoreactivity is observed in neural retina until postnatal day 7. At that time, weak immunore-activity is noted and it is gradually increased. The most intense immunoreactivity is noted at postnatal day 21 and 28. SPARC immunoreactivity is restricted in the nerve fiber layer and especially prominent around the blood vessels. Although SPARC immunoreactivity is much weaker than that of GFAP, the expression patterns of both factors are similar to each other. But, no SPARC immunoreactivity is observed in the adult retina. 2. Weak VEGF immunoreactivity is observed in the nerve fiber layer, ganglion cell layer and inner portion of inner nuclear layer even at postnatal day 0. After postnatal day 14, VEGF immunoreactivity is dramatically decreased in the nerve fiber layer, but it still remained in the ganglion cell layer and inner portion of inner nuclear layer. Although immunoreactivity is most intense at postnatal day 14 and 21, VEGF immunoreactivity is still observed in the ganglion cells at postnatal day 28 and adult. The spatial and temporal patterns of VEGF expression suggest that VEGF may function as a direct angiogenic factor in the retinal angiogenesis of rat. In the contrary, SPARC immunoreactivity is observed transiently in some period. So, SPARC is seemed to be a regulator that is involved only in limited steps of the retinal angiogenesis.

The effects of capsaicin on the neurosecretory cells of the paraventricular and supraoptic nucei in the adult rat / 대한해부학회지

Capsaicin, the pungent algesic substance of the red pepper is known to be a neurotoxic substance, interrupting the pain conducting pathway. To investigate the effects on the adult animals, immunohistochemical staining have been done after capsaicin treatment. Capsaicin 50 mg/kg was injected subcutaneously to the adult rats and after 1 week, 1 month and 2 months later, the morphometric change of vasopressin & oxytocin-secreting cells in supraoptic and paraventricular nuclei of the hypothalamic area were investigated. The count of vasopressin- and oxytocin-immunoreactive cells in supraoptic & paraventricular nuclei were decreasing from 1 month after capsaicin treatment and these decreasing was continued until 2 months. The area of neurons in the supraoptic & paraventricular nuclei were measured and they diminished in the all kinds of neurons. With the above results, capsaicin treatment in adult rats had no effects in central nervous system neurotransmitters, however, some part of the hypothalamus where blood brain barrier was not formed were affected. Therefore central nervous system could be affected by capsaicin depending upon the location.

Migration of Normal Corneal Epithelial Cells in Rats / 대한해부학회지

In the stratified squamous epithelium, most of basal cells in the entire epithelium function as stem cells. But many researchers report that stem cells in the corneal epithelium are located exclusively in the limbus. We planned to investigate the morphological characteristics of migrating corneal epithelial cells by the electron microscopy. Sprague-Dawley rats at fullterm, postnatal day 5, 10, 15, and adult were used as experimental animals. The results are as follows. 1. Stratification of the corneal epithelium : The number of layers in the corneal epithelium was dramatically increased in the period between postnatal day 10 and 15. 2. Migration of the corneal epithelial cells : In the groups of postnatal day 10 and adult, wide intercellular spaces were noted. Especially in the adult, the limbal side of basal cells was being lifted from the Bowman's membrane and centripetal polarity of them are noted. According to the above results, the wide intercellular spaces at postnatal day 10 seems to be resulted from the migration of corneal epithelial cells for epithelial stratification. The centripetal polarity of limbal basal cells in adult rat suggests that only the limbal basal cells may function as stem cells in that period.

Distribution of the Mouse Striatal Cholinergic Neurons in Their Early Postnatal Period / 대한해부학회지

The category of striatal complex contains caudate nucleus, putamen, nucleus accumbens septi, and olfactory tubercle. The striatal complex is composed of two compartments, dorsal and ventral striatum. In the striatum, cholinergic neuron is known as one of the most important intrinsic neurons, but there were little morphological reports about the early postnatal expression of mouse striatal cholinergic neurons. So, we planned to investigate the distribution of mouse striatal cholinergic neurons in their early postnatal period by the immunohistochemistry. We used ICR mouse as the experimental animals and divided them into 5 groups according to their postnatal age : 3-day, 1-week, 2-week, 4-week, and 6-week. Immunohistochemistry was done with anti-choline acetyl transferase antibody (chemicon). The results were as follow. 1 The striatal cholinergic neurons are already detected in the 3-day group, but the intensity was weak and the expression rate was extremely low. In the caudoputamen, the cholinergic expression rate was increased significantly between 3-day and 2-week. And in the nucleus accumbens septi, it was increased significantly between 1-week and 2-week. 2. The cholinergic expression rates of the adult mouse striatum were similar in both compartments. But, the difference of maturational time was noted. In the dorsal striatum, the cholinergic expression rate was increased significantly in the first postnatal week, but in the ventral striatum, it was approached to the adult level only after second postnatal week. In conclusion, the cholinergic expression rate in the mouse striatum was significantly increased after birth. And it was approached nearly to the adult level after 2-week of postnatal age. But, according to the compartments or rostrocaudal subdivisions, the difference of maturational time was noted.

Effect of Perinatal Asphyxia and Gentamicin on Urinary B2-microglobulin Concentration and Renal Function in Fullterm Neonates

Perinatal asphyxia can cause ischemic injury to immature kidney of neonates. Proximal renal tubule is the most sensitive area, showing various manifestations ranging from mild reversible injury to irreversible tubular necrosis. Aminoglycosides can be nephrotoxic in therapeutic range in immature or damaged kidney. Thess are the very important factors to be taken into corsideration on fluid therapy and nephrotoxic drugs in neonates. The purpose of this study is to detect renal dysfunction resulting from asphyxia and gentamicin treatment. The results were as follows; 1) Urinary 2-microglobulin concentration was significantly higher in neonatal asphyxia group irrespective of meconium stain (p0.05). The group with neonatal asphyxia and meconium stain (Ib) received gentamicin for 7 days. Their urinary 2-microglobulin concentration dropped on 4 the day and increased again on 7 th day (p0.05). 2) No differences were shown in serum creatinine, serum sodium level and urinary creatinine concentrations between each group (p>0.05). 3) No differences were shown in creatinine clearance between each group (p>0.05).Fractional excretion of urinary sodium (FENa) was significantly higher on lst day in group, I, but no differences were shown afterwards (p>0.05). 4) There is no relationship between urinary 2-microglobulin concentration and serum creatinine level, creatinine clearance of FENa. 5) No differences were shown in incidence of renal dysfunction between each group. In conclusion, acute tubular injury by perinatal asphyxia recovered soon after birth. But nephrotoxic gentamicin worsened the recovering tubular injury. In case of mild fetal hypoxia without neonatal asphyxia, proximal tubular injury was not significant.

Adult respiratory distress syndrome in infancy

No abstract available.