Comparison between Placement of an Amniotic Membrane Contact Lens and Temporary Amniotic Membrane Transplantation

Purpose@#We compared the clinical utilities of an amniotic contact lens and temporary amniotic membrane transplantation in patients with persistent corneal epithelial defects. @*Methods@#Patients diagnosed with persistent corneal epithelial defects from November 2019 to July 2022 were randomly assigned to either lens placement for 2 weeks or temporary transplantation for 1 week, and the outcomes were retrospectively analyzed. The best-corrected visual acuity, corneal sensation, tear film break-up time, and corneal opacity were measured before and after the interventions. The treatment success rates, recurrences, and other complications were analyzed during the follow-up period. @*Results@#We placed lenses in 32 patients (32 eyes) and 20 patients (20 eyes) underwent transplantation. In both groups, significant differences in best-corrected visual acuity, corneal sensation, tear film break-up time, and corneal opacity were apparent after intervention vs. before. None of the parameters showed any significant differences in terms of their rates of change. @*Conclusions@#In patients with persistent corneal epithelial defects, amniotic contact lens placement is an effective outpatient procedure and is not inferior to temporary amniotic membrane transplantation.

Clinical Benefits of Amniotic Membrane Contact Lens

Purpose@#To investigate the clinical efficacy of MS-Amnion amniotic membrane contact lenses. @*Methods@#MS-Amnion amniotic membrane contact lenses were placed for 1 week in patients with severe superficial punctate keratitis or corneal epithelial defects that did not respond to medical treatment. Eighteen eyes followed-up for ≥3 months were evaluated in terms of the best-corrected visual acuity, tear break-up time, and corneal sensation and opacity before and after application of the MS-Amnion amniotic membrane contact lens. The success and recurrence rates, and complications during follow-up, were recorded. @*Results@#Out of 18 eyes, 15 (83.3%) healed within 2 weeks without any treatment other than the amniotic membrane; three eyes (16.7%) were unresponsive, and thus underwent temporary amniotic membrane transplantation. Recurrence developed in three eyes (20%). The amniotic membrane contact lens dropped out in five eyes (27.8%) and folded over in two (11.1%). The mean best-corrected visual acuity improved from 0.89 to 0.27 logarithm of the minimal angle of resolution after 3 months, while the mean corneal opacity decreased from 0.38 to 0.11 after 3 months; the changes were statistically significant. The tear break-up time and corneal sensation also improved, but they were not statistically significant. We encountered no significant complications. @*Conclusions@#The MS-Amnion amniotic membrane contact lenses can heal the amniotic membrane and do not require suturing when applied in the outpatient clinic. This may be beneficial for patients with intractable ocular surface disorders.

A Study of Otologic Symptoms and Prognosis in Patients With Ramsay Hunt Syndrome and Bell’s Palsy / 대한이비인후과학회지

Background and Objectives@#Although several studies have compared the characteristics of Ramsay Hunt syndrome (RHS) with Bell’s palsy (BP), the differences in comorbid symptoms and prognosis according to symptoms have not been determined. This study therefore evaluated the differences in otologic symptoms and prognosis between patients with these two conditions.Subjects and Method The medical records of 118 patients with RHS and 215 patients with BP were retrospectively reviewed. Factors compared in these two groups included otologic symptoms, general health condition, electroneurography (ENoG) and House-Brackmann grades. @*Results@#Age, sex, body mass index, lipid profiles, ENoG, rate of diabetes, and side of palsy did not differ significantly between patients with RHS and BP (p>0.05). The rates of hearing disturbance, tinnitus, vertigo, and postauricular pain were significantly higher in RHS (p0.05). Additionally, in patients with facial paralysis, diabetes was associated with hearing disturbance and vertigo symptoms and dyslipidemia was associated with postauricular pain (p<0.05 each). @*Conclusion@#Otologic symptoms were more common in RHS than in BP. However, the prognosis of RHS and BP were not related to otologic symptoms. In patients with facial palsy hearing disturbance and vertigo were associated with diabetes and hypertension. Also, dyslipidemia was associated with post auricular pain.

Protective Role of Transduced Tat-Thioredoxin1 (Trx1) against Oxidative Stress-Induced Neuronal Cell Death via ASK1-MAPK Signal Pathway

Oxidative stress plays a crucial role in the development of neuronal disorders including brain ischemic injury. Thioredoxin 1 (Trx1), a 12 kDa oxidoreductase, has anti-oxidant and anti-apoptotic functions in various cells. It has been highly implicated in brain ischemic injury. However, the protective mechanism of Trx1 against hippocampal neuronal cell death is not identified yet. Using a cell permeable Tat-Trx1 protein, protective mechanism of Trx1 against hydrogen peroxide-induced cell death was examined using HT-22 cells and an ischemic animal model. Transduced Tat-Trx1 markedly inhibited intracellular ROS levels, DNA fragmentation, and cell death in H 2O 2-treatment HT-22 cells. Tat-Trx1 also significantly inhibited phosphorylation of ASK1 and MAPKs in signaling pathways of HT-22 cells. In addition, Tat-Trx1 regulated expression levels of Akt, NF-κB, and apoptosis related proteins. In an ischemia animal model, Tat-Trx1 markedly protected hippocampal neuronal cell death and reduced astrocytes and microglia activation. These findings indicate that transduced Tat-Trx1 might be a potential therapeutic agent for treating ischemic injury.

Cerebral Coenurosis of a Long-Tailed Goral, Naemorhedus caudatus, in Korea

We intended to describe a case of cerebral coenurosis in a long-tailed goral, Naemorhedus caudatus, from Hwacheon-gun, Gangwon-do (Province), in the Korea. The goral, a 10-year-old male, was suffering from neurological symptoms, such as turning the circle to one side without lifting the head straight, and died at 30 days after admission to the wildlife medical rescue center in Chuncheon-si, Gangwon-do. A fluid-filled cyst was detected in the left cerebral hemisphere by computed tomography and magnetic resonance imaging. The cyst removed from the deceased goral was transparent, about 3×3 cm in size, contained a clear fluid and approximately 320 protoscolices invaginating from the internal germinal layer. The protoscolex had 4 suckers and a rostellum with 28 hooklets arranged in 2 rows. By the present study, a case of cerebral coenurosis was first confirmed in a long-tailed goral, N. caudatus, from Gangwon-do, in Korea. The residents frequently exposed in the sylvatic environment should be careful the accidental infections of zoonotic metacestode of Taenia multiceps, Coenurus cerebralis, in Korea.

Nasal Septal Deviation and Incidental Paranasal Sinus Opacification: A Role of Computed Tomography

Background and Objectives@#The purpose of this study was to investigate the prevalence of incidental paranasal sinus (PNS) opacification in nasal septal deviation (NSD) using computed tomography (CT) and to identify contributing factors.Subjects and Method: We analyzed 216 patients who underwent septoplasty for the correction of NSD and who underwent preoperative PNS CT. We assessed the prevalence of incidental PNS opacification in these patients and determined the type of NSD according to Mladina classification. We also evaluated whether the direction of NSD affected the presence of PNS opacification on CT, and whether the presence of PNS opacification was associated with other rhinologic symptoms. @*Results@#Of 216 patients with NSD, 86 showed opacified PNS on CT. According to Mladina classification, NSD patients were classified as type I (24.1%), type II (36.1%), type III (20.8%), type IV (5.6%), type V (9.7%), type VI (2.3%), or type VII (1.4%). Patients with type II NSD showed a significantly higher incidence of PNS opacification compared with other types of NSD (p=0.001). However, the direction of NSD did not significantly influence the presence of incidental PNS opacification. Furthermore, regardless of the presence of PNS opacification, there was no significant difference in rhinologic symptoms such as olfactory dysfunction, among others. @*Conclusion@#We found that incidental PNS opacification on CT was common in NSD patients, especially in patients with type II NSD. Thus, we suggest that CT evaluation of patients with NSD may be helpful for assessing comorbid PNS pathologies as well as objectively identifying nasal septal deformities.

Protective Role of Transduced Tat-Thioredoxin1 (Trx1) against Oxidative Stress-Induced Neuronal Cell Death via ASK1-MAPK Signal Pathway

Oxidative stress plays a crucial role in the development of neuronal disorders including brain ischemic injury. Thioredoxin 1 (Trx1), a 12 kDa oxidoreductase, has anti-oxidant and anti-apoptotic functions in various cells. It has been highly implicated in brain ischemic injury. However, the protective mechanism of Trx1 against hippocampal neuronal cell death is not identified yet. Using a cell permeable Tat-Trx1 protein, protective mechanism of Trx1 against hydrogen peroxide-induced cell death was examined using HT-22 cells and an ischemic animal model. Transduced Tat-Trx1 markedly inhibited intracellular ROS levels, DNA fragmentation, and cell death in H 2O 2-treatment HT-22 cells. Tat-Trx1 also significantly inhibited phosphorylation of ASK1 and MAPKs in signaling pathways of HT-22 cells. In addition, Tat-Trx1 regulated expression levels of Akt, NF-κB, and apoptosis related proteins. In an ischemia animal model, Tat-Trx1 markedly protected hippocampal neuronal cell death and reduced astrocytes and microglia activation. These findings indicate that transduced Tat-Trx1 might be a potential therapeutic agent for treating ischemic injury.

Transduced Tat-aldose Reductase Protects Hippocampal Neuronal Cells against Oxidative Stress-induced Damage

Aldose reductase (AR) protein, a member of the NADPH-dependent aldo-keto reductase family, reduces a wide range of aldehydes and enhances cell survival by inhibition of oxidative stress. Oxidative stress is known as one of the major pathological factor in ischemia. Since the precise function of AR protein in ischemic injury is fully unclear, we examined the function of AR protein in hippocampal neuronal (HT-22) cells and in an animal model of ischemia in this study. Cell permeable Tat-AR protein was produced by fusion of protein transduction domain in Tat for delivery into the cells. Tat-AR protein transduced into HT-22 cells and significantly inhibited cell death and regulated the mitogen-activate protein kinases (MAPKs), Bcl-2, Bax, and Caspase-3 under oxidative stress condition. In an ischemic animal model, Tat-AR protein transduced into the brain tissues through the blood-brain barrier (BBB) and drastically decreased neuronal cell death in hippocampal CA1 region. These results indicate that transduced Tat-AR protein has protective effects against oxidative stress-induced neuronal cell death in vitro and in vivo, suggesting that Tat-AR protein could be used as potential therapeutic agent in ischemic injury.

BCR-ABL₁ transcripts (MR(4.5)) at post-transplant 3 months as an early predictor for long-term outcomes in chronic myeloid leukemia

BACKGROUND/AIMS: The aim of this study was to identify the role of BCR-ABL1 transcript level as a predictor for post-transplant relapse and outcome in patients who underwent allogeneic stem cell transplantation (SCT) for chronic phase (CP) chronic myeloid leukemia (CML). METHODS: Of 101 patients receiving allograft in CML CP, 85 had available quantitative reverse transcriptase polymerase chain reaction data at post-transplant 3 months. These patients were divided into two groups according to molecular response (MR(4.5)), defined as a BCR-ABL₁ transcript level ≤ 0.0032% on the international scale, at 3 months based on receiver operating characteristic curve analysis of relapse. RESULTS: The 4-year overall survival and event-free survival (EFS) were 80.6% and 57.3%, respectively, and the cumulative incidence of relapse at 4 years was 29.6% after a median follow-up of 126.4 months. We performed multivariate analyses including potential variables to evaluate the early predictive role of MR(4.5) at 3 months and found that MR(4.5) at 3 months was associated with a higher EFS (p = 0.028) and showed a trend for a lower relapse rate (p = 0.089). CONCLUSIONS: our results imply that frequent molecular monitoring and immune suppressive therapy modulation are required for patients without reduction of BCR-ABL1 transcripts to this level after SCT.

Erratum: In Vitro Evaluation of Allergen Potencies of Commercial House Dust Mite Sublingual Immunotherapy Reagents

Corrections for Table. 1 in page 125 are needed. We apologize for any inconvenience that this may have caused.

Establishment of a mouse model of 70% lethal dose by total-body irradiation / 한국실험동물학회지

Whereas increasing concerns about radiation exposure to nuclear disasters or side effects of anticancer radiotherapy, relatively little research for radiation damages or remedy has been done. The purpose of this study was to establish level of LD70/30 (a lethal dose for 70% of mice within 30 days) by total-body γ irradiation (TBI) in a mouse model. For this purpose, at first, 8-week-old male ICR and C57BL/6N mice from A and B companies were received high dose (10, 11, 12 Gy) TBI. After irradiation, the body weight and survival rate were monitored for 30 days consecutively. In next experiment, 5-week-old male ICR and C57BL/6N mice from B company were received same dose irradiation. Results showed that survival rate and body weight change rate in inbred C57BL/6N mice were similar between A and B company. In ICR mice, however, survival rate and body weight change rate were completely different among the companies. Significant difference of survival rate both ICR and C57BL6N mice was not observed in between 5-week-old and 8-week-old groups receiving 10 or 12 Gy TBI. Our results indicate that the strain and age of mice, and even purchasing company (especially outbred), should be matched over experimental groups in TBI experiment. Based on our results, 8-week-old male ICR mice from B company subjected to 12 Gy of TBI showed LD70/30 and suitable as a mouse model for further development of new drug using the ideal total-body irradiation model.

Outbreaks of Middle East Respiratory Syndrome in Two Hospitals Initiated by a Single Patient in Daejeon, South Korea

BACKGROUND: A Middle East Respiratory Syndrome coronavirus (MERS-CoV) outbreak in South Korea in 2015 started by a single imported case and was amplified by intra- and inter-hospital transmission. We describe two hospital outbreaks of MERS-CoV infection in Daejeon caused by a single patient who was infected by the first Korean case of MERS. MATERIALS AND METHODS: Demographic and clinical information involving MERS cases in the Daejeon cluster were retrospectively collected and potential contacts and exposures were assessed. The incubation periods and serial intervals were estimated. Viral RNAs were extracted from respiratory tract samples obtained from the index case, four secondary cases and one tertiary case from each hospital. The partial S2 domain of the MERS-CoV spike was sequenced. RESULTS: In Daejeon, a MERS patient (the index case) was hospitalized at Hospital A in the first week of illness and was transferred to Hospital B because of pneumonia progression in the second week of illness, where he received a bronchoscopic examination and nebulizer therapy. A total of 23 secondary cases (10 in Hospital A and 13 in Hospital B) were detected among patients and caregivers who stayed on the same ward with the index case. There were no secondary cases among healthcare workers. Among close hospital contacts, the secondary attack rate was 15.8% (12/76) in Hospital A and 14.3% (10/70) in Hospital B. However, considering the exposure duration, the incidence rate was higher in Hospital B (7.7/100 exposure-days) than Hospital A (3.4/100 exposure-days). In Hospital B, the median incubation period was shorter (4.6 days vs. 10.8 days), the median time to pneumonia development was faster (3 days vs. 6 days) and mortality was higher (70% vs. 30.8%) than in Hospital A. MERS-CoV isolates from 11 cases formed a single monophyletic clade, with the closest similarity to strains from Riyadh. CONCLUSION: Exposure to the MERS case in the late stage (2nd week) of diseases appeared to increase the risk of transmission and was associated with shorter incubation periods and rapid disease progression among those infected. Early detection and isolation of cases is critical in preventing the spread of MERS in the hospital and decreasing the disease severity among those infected.

Standardization of Weed Pollen Extracts, Japanese Hop and Mugwort, in Korea

PURPOSE: Japanese hop (Humulus spp.) and mugwort (Artemisia spp.) are notable causes of autumn pollinosis in East Asia. However, Japanese hop and mugwort pollen extracts, which are widely used for the diagnosis, have not been standardized. This study was performed to standardize Japanese hop and mugwort pollen extracts. MATERIALS AND METHODS: Allergen extracts were prepared in a standardized way using locally collected Humulus japonicus and purchased Artemisia vulgaris pollens. The immunoglobulin E (IgE) reactivities of prepared extracts were compared with commercial extracts via IgE immunoblotting and inhibition analyses. Intradermal skin tests were performed to determine the bioequivalent allergy unit (BAU). RESULTS: The IgE reactive components of the extracts via IgE immunoblotting were similar to those of commercial extracts. A 11-kDa allergen showed the strongest IgE reactivity in Japanese hop, as did a 28-kDa allergen in mugwort pollen extracts. Allergenic potencies of the investigatory Japanese hop and mugwort extracts were essentially indistinguishable from the commercial ones. Sums of erythema of 50 mm by the intradermal skin test (SigmaED50) were calculated to be 14.4th and 13.6th three-fold dilutions for Japanese hop and mugwort extracts, respectively. Therefore, the allergenic activity of the prepared extracts was 90827.4 BAU/mg for Japanese hop and 34412 BAU/mg for mugwort. CONCLUSION: We produced Japanese hop and mugwort pollen extracts using a standardized method. Standardized Japanese hop and mugwort pollen extracts will facilitate the production of improved diagnostic and immunotherapeutic reagents.

Optimal scan delay depending on contrast material injection duration in abdominal multi-phase computed tomography of pancreas and liver in normal Beagle dogs

This study was conducted to establish the values for optimal fixed scan delays and diagnostic scan delays associated with the bolus-tracking technique using various contrast material injection durations in canine abdominal multi-phase computed tomography (CT). This study consisted of two experiments employing the crossover method. In experiment 1, three dynamic scans at the porta hepatis were performed using 5, 10 and 15 sec injection durations. In experiment 2, two CT scans consisting of five multi-phase series with different scan delays of 5 sec intervals for bolus-tracking were performed using 5, 10 and 15 sec injection duration. Mean arrival times to aortic enhancement peak (12.0, 15.6, and 18.6 sec for 5, 10, and 15 sec, respectively) and pancreatic parenchymal peak (17.8, 25.1, and 29.5 sec) differed among injection durations. The maximum mean attenuation values of aortas and pancreases were shown at the scan section with 0 and 5, 0 and 10 and 5 and 10 sec diagnostic scan delays during each injection duration, respectively. The optimal scan delays of the arterial and pancreatic parenchymal phase in multi-phase CT scan using fixed scan delay or bolus-tracking should be determined with consideration of the injection duration.

Immunomodulatory Roles of PE/PPE Proteins and Their Implications in Genomic Features of Mycobacterium tuberculosis

Tuberculosis, caused by Mycobacterium tuberculosis (Mtb), remains a notorious cause of human death worldwide. A deeper understanding of the proline-glutamate (PE) and proline-proline-glutamate (PPE) families, which compromise 10% of the coding regions in the Mtb genome, has uncovered their unique roles in host-pathogen interactions. Further, comparative genomic analysis of different Mtb strains has proposed that Mtb has acquired diverse gene sets that play immunomodulatory roles in host-pathogen interactions. This review delineates the various immunomodulatory roles of PE/PPE antigens and discusses their implications in the development of the improved diagnostic tools and vaccines.

Reversible Pulmonary Arterial Hypertension Associated with Dasatinib for Chronic Myeloid Leukemia / Journal of the Korean Cancer Association, 대한암학회지

We describe two cases of pulmonary arterial hypertension (PAH) that occurred under dasatinib treatment and were resolved after dasatinib discontinuation. Two patients with chronic phase chronic myeloid leukemia (CML) were switched to dasatinib therapy because of hematological progress while receiving imatinib. These patients had New York Heart Association (NYHA) functional class II dyspnea with elevated right ventricular systolic pressure (RVSP), which progressed under dasatinib treatment. After dasatinib treatment was discontinued, subjective symptoms were improved to NYHA functional class I and the follow-up transthoracic Doppler echocardiography showed improved RVSP. Treatment with an alternate tyrosine kinase inhibitor was initiated and had been continued without development of dyspnea or elevation of RVSP. This report suggests that dasatinib can cause the reversible PAH, therefore, routine cardiopulmonary evaluation before and during treatment with dasatinib may be needed in CML patients with clinical manifestations.

In Vitro Evaluation of Allergen Potencies of Commercial House Dust Mite Sublingual Immunotherapy Reagents

PURPOSE: The clinical efficacy of allergen-immunotherapy is known to be dose dependent. However, optimal maintenance dosage has not yet been determined for sublingual immunotherapy (SLIT). Furthermore, since companies adopt their own units for expression of allergenicity, the allergen concentrations of individual reagents cannot be compared easily. We sought to measure and compare the allergenicities of 3 commercially available house dust mite (HDM) SLIT regents and a subcutaneous immunotherapy reagent. METHODS: We measured the HDM allergenic potency of the maintenance dosages of three SLIT reagents: Staloral(R) (300 index of reactivity [IR] /mL, recommended maintenance dosage [MD]: 120 IR), SLITone(R) (1,000 standard therapeutic unit [STU]/mL, recommended MD: 200 STU), Wolwopharma(R) (100 microg/mL, recommended MD: 20 microg), and subcutaneous immunotherapy regents of Hollister-Stier (10,000 allergy unit [AU] /mL). The allergenic potency was assessed by measuring the total protein concentrations, mite group 1 and 2 allergens using 2-site ELISA, and an inhibition test against IgE specific to Dermatophagoides farinae and Dermatophagoides pteronyssinus. RESULTS: The protein content of the Wolwopharma(R) reagent was 1.5-261.4 times higher than that of the other 2 SLIT reagents. The concentration of group 1 major allergens in Staloral(R) (132.03 microg/mL) was 33- to 44.5-fold higher than in SLITone(R) (4.00 microg/mL) and Wolwopharma(R) (2.97 microg/mL). The concentration of group 2 major allergen was also 8.9- to 10.5-fold higher in Staloral(R) (15.7 microg/mL) than in SLITone(R) (1.8 microg/mL) or Wolwopharma(R) (1.5 microg/mL). An ELISA inhibition study against HDM-specific IgE showed that the allergen potency of Staloral(R) reagent is 8.5-fold and 21-fold higher than that of SLITone(R) or Wolwopharma(R), respectively. The differences between the maintenance dosages are further exaggerated by the differences in the recommended volumes of SLIT reagents. CONCLUSIONS: The allergen potencies of commercially available HDM SLIT reagents are markedly different. Consensus regarding the optimal allergen concentration for SLIT reagents used to treat HDM respiratory allergies is needed.

The Relationship between Uric Acid and Homocysteine Levels based on Alcohol-related Facial Flushing

BACKGROUND: This study aimed to determine the correlation between blood uric acid and homocysteine levels, based on alcohol-related facial flushing. METHODS: Among male adults who visited a health examination center of a university hospital located in Daejeon, Korea, for a personal health examination from March 2013 to February 2014, 702 subjects were analyzed including 401 subjects without alcohol-related facial flushing and 301 with facial flushing. Pearson's correlation and stepwise multivariate linear regression analyses were performed between the log homocysteine levels and other variables including uric acid. RESULTS: Uric acid showed a significant positive correlation with log homocysteine (gamma=0.166, P=0.001) (beta=0.176; P=0.001) in the non-flushing group. In contrast, none of the variables showed any significant correlations with log homocysteine in the flushing group. CONCLUSIONS: Alcohol users not exhibiting alcohol-related facial flushing showed a positive correlation between uric acid and homocysteine levels, whereas those without facial flushing showed no such correlation.

Oenanthe javanica extract increases immunoreactivities of antioxidant enzymes in the rat kidney / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Oenanthe javanica is an aquatic perennial herb originated from East Asia. Nowadays, the effects of Oenanthe javanica have been proven in various disease models. Studies regarding the antioxidant effect of Oenanthe javanica in the kidney are still unclear.</p><p><b>METHODS</b>This study was therefore performed to investigate the effect of the Oenanthe javanica extract (OJE) in the rat kidney using immunohistochemistry for antioxidant enzymes, copper, zinc-superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), catalase (CAT) and glutathione peroxidase (GPx). Sprague-Dawley rats were randomly assigned to three groups: (1) normal diet fed-group (normal-group), (2) diet containing ascorbic acid (AA)-fed group (AA-group) as a positive control, (3) diet containing OJE-fed group (OJE-group). AA and OJE were supplied during 28 days.</p><p><b>RESULTS</b>The side-effects were not observed in all the groups. Immunoreactivities of SOD1, SOD2, CAT and GPx were easily detected in the distal tubules of the kidney, and their immunoreactivities in the AA-and OJE-groups were increased to about 1.4-1.5 times and 2 times, respectively, compared with those in the normal-group.</p><p><b>CONCLUSION</b>OJE significantly increased expressions of SOD1 & 2, CAT and GPx immunoreactivities in the distal tubules of the rat kidney, and this finding suggests that significant enhancements of endogenous enzymatic antioxidants by OJE treatment may be a legitimate strategy for decreasing oxidative stresses in the kidney.</p>

The Timing of Surgical Ligation for Patent Ductus Arteriosus Is Associated with Neonatal Morbidity in Extremely Preterm Infants Born at 23-25 Weeks of Gestation

The purpose of this study was to evaluate prognostic factors associated with surgical ligation for patent ductus arteriosus (PDA) in extremely preterm infants born at the limits of viability. Ninety infants who were born at 23-25 weeks of gestation and who received surgical ligation were included and their cases were retrospectively reviewed. Infants were classified into two different groups: survivors with no major morbidity (N), and non-survivors or survivors with any major morbidity (M). Clinical characteristics were compared between the groups. Possible prognostic factors were derived from this comparison and further tested by logistic regression analysis. The mean gestational age and the mean birth weight of M were significantly lower than those of N. Notably, the mean postnatal age at time of ligation in N was significantly later than that of the other group (17+/-12 vs 11+/-8 days in N and M, respectively). An adjusted analysis showed that delayed ligation (>2 weeks) was uniquely associated with a significantly decreased risk for mortality or composite morbidity after surgical ligation (OR, 0.105; 95% CI, 0.012-0.928). In conclusion, delayed surgical ligation for PDA (>2 weeks) is associated with decreased mortality or morbidities in extremely preterm infants born at 23-25 weeks of gestation.